auto import from //depot/cupcake/@135843

61 files changed, 0 insertions, 20531 deletions

diff --git a/concurrent/src/main/java/java/util/concurrent/AbstractExecutorService.java b/concurrent/src/main/java/java/util/concurrent/AbstractExecutorService.java
deleted file mode 100644
index ed4ce4f..0000000
--- a/concurrent/src/main/java/java/util/concurrent/AbstractExecutorService.java
+++ /dev/null
@@ -1,223 +0,0 @@
-/*
- * Written by Doug Lea with assistance from members of JCP JSR-166
- * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
- */
-
-package java.util.concurrent;
-
-import java.util.*;
-
-/**
- * Provides default implementation of {@link ExecutorService}
- * execution methods. This class implements the <tt>submit</tt>,
- * <tt>invokeAny</tt> and <tt>invokeAll</tt> methods using the default
- * {@link FutureTask} class provided in this package.  For example,
- * the implementation of <tt>submit(Runnable)</tt> creates an
- * associated <tt>FutureTask</tt> that is executed and
- * returned. Subclasses overriding these methods to use different
- * {@link Future} implementations should do so consistently for each
- * of these methods.
- *
- * @since 1.5
- * @author Doug Lea
- */
-public abstract class AbstractExecutorService implements ExecutorService {
-
-    public Future<?> submit(Runnable task) {
-        if (task == null) throw new NullPointerException();
-        FutureTask<Object> ftask = new FutureTask<Object>(task, null);
-        execute(ftask);
-        return ftask;
-    }
-
-    public <T> Future<T> submit(Runnable task, T result) {
-        if (task == null) throw new NullPointerException();
-        FutureTask<T> ftask = new FutureTask<T>(task, result);
-        execute(ftask);
-        return ftask;
-    }
-
-    public <T> Future<T> submit(Callable<T> task) {
-        if (task == null) throw new NullPointerException();
-        FutureTask<T> ftask = new FutureTask<T>(task);
-        execute(ftask);
-        return ftask;
-    }
-
-    /**
-     * the main mechanics of invokeAny.
-     */
-    private <T> T doInvokeAny(Collection<Callable<T>> tasks,
-                            boolean timed, long nanos)
-        throws InterruptedException, ExecutionException, TimeoutException {
-        if (tasks == null)
-            throw new NullPointerException();
-        int ntasks = tasks.size();
-        if (ntasks == 0)
-            throw new IllegalArgumentException();
-        List<Future<T>> futures= new ArrayList<Future<T>>(ntasks);
-        ExecutorCompletionService<T> ecs = 
-            new ExecutorCompletionService<T>(this);
-
-        // For efficiency, especially in executors with limited
-        // parallelism, check to see if previously submitted tasks are
-        // done before submitting more of them. This interleaving
-        // plus the exception mechanics account for messiness of main
-        // loop.
-
-        try {
-            // Record exceptions so that if we fail to obtain any
-            // result, we can throw the last exception we got.
-            ExecutionException ee = null;
-            long lastTime = (timed)? System.nanoTime() : 0;
-            Iterator<Callable<T>> it = tasks.iterator();
-
-            // Start one task for sure; the rest incrementally
-            futures.add(ecs.submit(it.next()));
-            --ntasks;
-            int active = 1;
-
-            for (;;) {
-                Future<T> f = ecs.poll(); 
-                if (f == null) {
-                    if (ntasks > 0) {
-                        --ntasks;
-                        futures.add(ecs.submit(it.next()));
-                        ++active;
-                    }
-                    else if (active == 0) 
-                        break;
-                    else if (timed) {
-                        f = ecs.poll(nanos, TimeUnit.NANOSECONDS);
-                        if (f == null)
-                            throw new TimeoutException();
-                        long now = System.nanoTime();
-                        nanos -= now - lastTime;
-                        lastTime = now;
-                    }
-                    else 
-                        f = ecs.take();
-                }
-                if (f != null) {
-                    --active;
-                    try {
-                        return f.get();
-                    } catch(InterruptedException ie) {
-                        throw ie;
-                    } catch(ExecutionException eex) {
-                        ee = eex;
-                    } catch(RuntimeException rex) {
-                        ee = new ExecutionException(rex);
-                    }
-                }
-            }    
-
-            if (ee == null)
-                ee = new ExecutionException();
-            throw ee;
-
-        } finally {
-            for (Future<T> f : futures) 
-                f.cancel(true);
-        }
-    }
-
-    public <T> T invokeAny(Collection<Callable<T>> tasks)
-        throws InterruptedException, ExecutionException {
-        try {
-            return doInvokeAny(tasks, false, 0);
-        } catch (TimeoutException cannotHappen) {
-            assert false;
-            return null;
-        }
-    }
-
-    public <T> T invokeAny(Collection<Callable<T>> tasks, 
-                           long timeout, TimeUnit unit) 
-        throws InterruptedException, ExecutionException, TimeoutException {
-        return doInvokeAny(tasks, true, unit.toNanos(timeout));
-    }
-
-    public <T> List<Future<T>> invokeAll(Collection<Callable<T>> tasks)
-        throws InterruptedException {
-        if (tasks == null)
-            throw new NullPointerException();
-        List<Future<T>> futures = new ArrayList<Future<T>>(tasks.size());
-        boolean done = false;
-        try {
-            for (Callable<T> t : tasks) {
-                FutureTask<T> f = new FutureTask<T>(t);
-                futures.add(f);
-                execute(f);
-            }
-            for (Future<T> f : futures) {
-                if (!f.isDone()) {
-                    try { 
-                        f.get(); 
-                    } catch(CancellationException ignore) {
-                    } catch(ExecutionException ignore) {
-                    }
-                }
-            }
-            done = true;
-            return futures;
-        } finally {
-            if (!done)
-                for (Future<T> f : futures) 
-                    f.cancel(true);
-        }
-    }
-
-    public <T> List<Future<T>> invokeAll(Collection<Callable<T>> tasks, 
-                                         long timeout, TimeUnit unit) 
-        throws InterruptedException {
-        if (tasks == null || unit == null)
-            throw new NullPointerException();
-        long nanos = unit.toNanos(timeout);
-        List<Future<T>> futures = new ArrayList<Future<T>>(tasks.size());
-        boolean done = false;
-        try {
-            for (Callable<T> t : tasks) 
-                futures.add(new FutureTask<T>(t));
-
-            long lastTime = System.nanoTime();
-
-            // Interleave time checks and calls to execute in case
-            // executor doesn't have any/much parallelism.
-            Iterator<Future<T>> it = futures.iterator();
-            while (it.hasNext()) {
-                execute((Runnable)(it.next()));
-                long now = System.nanoTime();
-                nanos -= now - lastTime;
-                lastTime = now;
-                if (nanos <= 0)
-                    return futures; 
-            }
-
-            for (Future<T> f : futures) {
-                if (!f.isDone()) {
-                    if (nanos <= 0) 
-                        return futures; 
-                    try { 
-                        f.get(nanos, TimeUnit.NANOSECONDS); 
-                    } catch(CancellationException ignore) {
-                    } catch(ExecutionException ignore) {
-                    } catch(TimeoutException toe) {
-                        return futures;
-                    }
-                    long now = System.nanoTime();
-                    nanos -= now - lastTime;
-                    lastTime = now;
-                }
-            }
-            done = true;
-            return futures;
-        } finally {
-            if (!done)
-                for (Future<T> f : futures) 
-                    f.cancel(true);
-        }
-    }
-
-}
diff --git a/concurrent/src/main/java/java/util/concurrent/ArrayBlockingQueue.java b/concurrent/src/main/java/java/util/concurrent/ArrayBlockingQueue.java
deleted file mode 100644
index 43b9fd0..0000000
--- a/concurrent/src/main/java/java/util/concurrent/ArrayBlockingQueue.java
+++ /dev/null
@@ -1,687 +0,0 @@
-/*
- * Written by Doug Lea with assistance from members of JCP JSR-166
- * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
- */
-
-package java.util.concurrent;
-import java.util.concurrent.locks.*;
-import java.util.*;
-
-// BEGIN android-note
-// removed link to collections framework docs
-// END android-note
-
-/**
- * A bounded {@linkplain BlockingQueue blocking queue} backed by an
- * array.  This queue orders elements FIFO (first-in-first-out).  The
- * <em>head</em> of the queue is that element that has been on the
- * queue the longest time.  The <em>tail</em> of the queue is that
- * element that has been on the queue the shortest time. New elements
- * are inserted at the tail of the queue, and the queue retrieval
- * operations obtain elements at the head of the queue.
- *
- * <p>This is a classic &quot;bounded buffer&quot;, in which a
- * fixed-sized array holds elements inserted by producers and
- * extracted by consumers.  Once created, the capacity cannot be
- * increased.  Attempts to offer an element to a full queue will
- * result in the offer operation blocking; attempts to retrieve an
- * element from an empty queue will similarly block.
- *
- * <p> This class supports an optional fairness policy for ordering
- * waiting producer and consumer threads.  By default, this ordering
- * is not guaranteed. However, a queue constructed with fairness set
- * to <tt>true</tt> grants threads access in FIFO order. Fairness
- * generally decreases throughput but reduces variability and avoids
- * starvation.
- *
- * <p>This class implements all of the <em>optional</em> methods
- * of the {@link Collection} and {@link Iterator} interfaces.
- *
- * @since 1.5
- * @author Doug Lea
- * @param <E> the type of elements held in this collection
- */
-public class ArrayBlockingQueue<E> extends AbstractQueue<E>
-        implements BlockingQueue<E>, java.io.Serializable {
-
-    /**
-     * Serialization ID. This class relies on default serialization
-     * even for the items array, which is default-serialized, even if
-     * it is empty. Otherwise it could not be declared final, which is
-     * necessary here.
-     */
-    private static final long serialVersionUID = -817911632652898426L;
-
-    /** The queued items  */
-    private final E[] items;
-    /** items index for next take, poll or remove */
-    private transient int takeIndex;
-    /** items index for next put, offer, or add. */
-    private transient int putIndex;
-    /** Number of items in the queue */
-    private int count;
-
-    /*
-     * Concurrency control uses the classic two-condition algorithm
-     * found in any textbook.
-     */
-
-    /** Main lock guarding all access */
-    private final ReentrantLock lock;
-    /** Condition for waiting takes */
-    private final Condition notEmpty;
-    /** Condition for waiting puts */
-    private final Condition notFull;
-
-    // Internal helper methods
-
-    /**
-     * Circularly increment i.
-     */
-    final int inc(int i) {
-        return (++i == items.length)? 0 : i;
-    }
-
-    /**
-     * Insert element at current put position, advance, and signal.
-     * Call only when holding lock.
-     */
-    private void insert(E x) {
-        items[putIndex] = x;
-        putIndex = inc(putIndex);
-        ++count;
-        notEmpty.signal();
-    }
-
-    /**
-     * Extract element at current take position, advance, and signal.
-     * Call only when holding lock.
-     */
-    private E extract() {
-        final E[] items = this.items;
-        E x = items[takeIndex];
-        items[takeIndex] = null;
-        takeIndex = inc(takeIndex);
-        --count;
-        notFull.signal();
-        return x;
-    }
-
-    /**
-     * Utility for remove and iterator.remove: Delete item at position i.
-     * Call only when holding lock.
-     */
-    void removeAt(int i) {
-        final E[] items = this.items;
-        // if removing front item, just advance
-        if (i == takeIndex) {
-            items[takeIndex] = null;
-            takeIndex = inc(takeIndex);
-        } else {
-            // slide over all others up through putIndex.
-            for (;;) {
-                int nexti = inc(i);
-                if (nexti != putIndex) {
-                    items[i] = items[nexti];
-                    i = nexti;
-                } else {
-                    items[i] = null;
-                    putIndex = i;
-                    break;
-                }
-            }
-        }
-        --count;
-        notFull.signal();
-    }
-
-    /**
-     * Creates an <tt>ArrayBlockingQueue</tt> with the given (fixed)
-     * capacity and default access policy.
-     * @param capacity the capacity of this queue
-     * @throws IllegalArgumentException if <tt>capacity</tt> is less than 1
-     */
-    public ArrayBlockingQueue(int capacity) {
-        this(capacity, false);
-    }
-
-    /**
-     * Creates an <tt>ArrayBlockingQueue</tt> with the given (fixed)
-     * capacity and the specified access policy.
-     * @param capacity the capacity of this queue
-     * @param fair if <tt>true</tt> then queue accesses for threads blocked
-     * on insertion or removal, are processed in FIFO order; if <tt>false</tt>
-     * the access order is unspecified.
-     * @throws IllegalArgumentException if <tt>capacity</tt> is less than 1
-     */
-    public ArrayBlockingQueue(int capacity, boolean fair) {
-        if (capacity <= 0)
-            throw new IllegalArgumentException();
-        this.items = (E[]) new Object[capacity];
-        lock = new ReentrantLock(fair);
-        notEmpty = lock.newCondition();
-        notFull =  lock.newCondition();
-    }
-
-    /**
-     * Creates an <tt>ArrayBlockingQueue</tt> with the given (fixed)
-     * capacity, the specified access policy and initially containing the
-     * elements of the given collection,
-     * added in traversal order of the collection's iterator.
-     * @param capacity the capacity of this queue
-     * @param fair if <tt>true</tt> then queue accesses for threads blocked
-     * on insertion or removal, are processed in FIFO order; if <tt>false</tt>
-     * the access order is unspecified.
-     * @param c the collection of elements to initially contain
-     * @throws IllegalArgumentException if <tt>capacity</tt> is less than
-     * <tt>c.size()</tt>, or less than 1.
-     * @throws NullPointerException if <tt>c</tt> or any element within it
-     * is <tt>null</tt>
-     */
-    public ArrayBlockingQueue(int capacity, boolean fair,
-                              Collection<? extends E> c) {
-        this(capacity, fair);
-        if (capacity < c.size())
-            throw new IllegalArgumentException();
-
-        for (Iterator<? extends E> it = c.iterator(); it.hasNext();)
-            add(it.next());
-    }
-
-    /**
-     * Inserts the specified element at the tail of this queue if possible,
-     * returning immediately if this queue is full.
-     *
-     * @param o the element to add.
-     * @return <tt>true</tt> if it was possible to add the element to
-     *         this queue, else <tt>false</tt>
-     * @throws NullPointerException if the specified element is <tt>null</tt>
-     */
-    public boolean offer(E o) {
-        if (o == null) throw new NullPointerException();
-        final ReentrantLock lock = this.lock;
-        lock.lock();
-        try {
-            if (count == items.length)
-                return false;
-            else {
-                insert(o);
-                return true;
-            }
-        } finally {
-            lock.unlock();
-        }
-    }
-
-    /**
-     * Inserts the specified element at the tail of this queue, waiting if
-     * necessary up to the specified wait time for space to become available.
-     * @param o the element to add
-     * @param timeout how long to wait before giving up, in units of
-     * <tt>unit</tt>
-     * @param unit a <tt>TimeUnit</tt> determining how to interpret the
-     * <tt>timeout</tt> parameter
-     * @return <tt>true</tt> if successful, or <tt>false</tt> if
-     * the specified waiting time elapses before space is available.
-     * @throws InterruptedException if interrupted while waiting.
-     * @throws NullPointerException if the specified element is <tt>null</tt>.
-     */
-    public boolean offer(E o, long timeout, TimeUnit unit)
-        throws InterruptedException {
-
-        if (o == null) throw new NullPointerException();
-        final ReentrantLock lock = this.lock;
-        lock.lockInterruptibly();
-        try {
-            long nanos = unit.toNanos(timeout);
-            for (;;) {
-                if (count != items.length) {
-                    insert(o);
-                    return true;
-                }
-                if (nanos <= 0)
-                    return false;
-                try {
-                    nanos = notFull.awaitNanos(nanos);
-                } catch (InterruptedException ie) {
-                    notFull.signal(); // propagate to non-interrupted thread
-                    throw ie;
-                }
-            }
-        } finally {
-            lock.unlock();
-        }
-    }
-
-
-    public E poll() {
-        final ReentrantLock lock = this.lock;
-        lock.lock();
-        try {
-            if (count == 0)
-                return null;
-            E x = extract();
-            return x;
-        } finally {
-            lock.unlock();
-        }
-    }
-
-    public E poll(long timeout, TimeUnit unit) throws InterruptedException {
-        final ReentrantLock lock = this.lock;
-        lock.lockInterruptibly();
-        try {
-            long nanos = unit.toNanos(timeout);
-            for (;;) {
-                if (count != 0) {
-                    E x = extract();
-                    return x;
-                }
-                if (nanos <= 0)
-                    return null;
-                try {
-                    nanos = notEmpty.awaitNanos(nanos);
-                } catch (InterruptedException ie) {
-                    notEmpty.signal(); // propagate to non-interrupted thread
-                    throw ie;
-                }
-
-            }
-        } finally {
-            lock.unlock();
-        }
-    }
-
-
-    public boolean remove(Object o) {
-        if (o == null) return false;
-        final E[] items = this.items;
-        final ReentrantLock lock = this.lock;
-        lock.lock();
-        try {
-            int i = takeIndex;
-            int k = 0;
-            for (;;) {
-                if (k++ >= count)
-                    return false;
-                if (o.equals(items[i])) {
-                    removeAt(i);
-                    return true;
-                }
-                i = inc(i);
-            }
-
-        } finally {
-            lock.unlock();
-        }
-    }
-
-    public E peek() {
-        final ReentrantLock lock = this.lock;
-        lock.lock();
-        try {
-            return (count == 0) ? null : items[takeIndex];
-        } finally {
-            lock.unlock();
-        }
-    }
-
-    public E take() throws InterruptedException {
-        final ReentrantLock lock = this.lock;
-        lock.lockInterruptibly();
-        try {
-            try {
-                while (count == 0)
-                    notEmpty.await();
-            } catch (InterruptedException ie) {
-                notEmpty.signal(); // propagate to non-interrupted thread
-                throw ie;
-            }
-            E x = extract();
-            return x;
-        } finally {
-            lock.unlock();
-        }
-    }
-
-    /**
-     * Adds the specified element to the tail of this queue, waiting if
-     * necessary for space to become available.
-     * @param o the element to add
-     * @throws InterruptedException if interrupted while waiting.
-     * @throws NullPointerException if the specified element is <tt>null</tt>.
-     */
-    public void put(E o) throws InterruptedException {
-        if (o == null) throw new NullPointerException();
-        final E[] items = this.items;
-        final ReentrantLock lock = this.lock;
-        lock.lockInterruptibly();
-        try {
-            try {
-                while (count == items.length)
-                    notFull.await();
-            } catch (InterruptedException ie) {
-                notFull.signal(); // propagate to non-interrupted thread
-                throw ie;
-            }
-            insert(o);
-        } finally {
-            lock.unlock();
-        }
-    }
-
-    // this doc comment is overridden to remove the reference to collections
-    // greater in size than Integer.MAX_VALUE
-    /**
-     * Returns the number of elements in this queue.
-     *
-     * @return  the number of elements in this queue.
-     */
-    public int size() {
-        final ReentrantLock lock = this.lock;
-        lock.lock();
-        try {
-            return count;
-        } finally {
-            lock.unlock();
-        }
-    }
-
-    // this doc comment is a modified copy of the inherited doc comment,
-    // without the reference to unlimited queues.
-    /**
-     * Returns the number of elements that this queue can ideally (in
-     * the absence of memory or resource constraints) accept without
-     * blocking. This is always equal to the initial capacity of this queue
-     * less the current <tt>size</tt> of this queue.
-     * <p>Note that you <em>cannot</em> always tell if
-     * an attempt to <tt>add</tt> an element will succeed by
-     * inspecting <tt>remainingCapacity</tt> because it may be the
-     * case that a waiting consumer is ready to <tt>take</tt> an
-     * element out of an otherwise full queue.
-     * 
-     * @return the remaining capacity
-     */
-    public int remainingCapacity() {
-        final ReentrantLock lock = this.lock;
-        lock.lock();
-        try {
-            return items.length - count;
-        } finally {
-            lock.unlock();
-        }
-    }
-
-
-    public boolean contains(Object o) {
-        if (o == null) return false;
-        final E[] items = this.items;
-        final ReentrantLock lock = this.lock;
-        lock.lock();
-        try {
-            int i = takeIndex;
-            int k = 0;
-            while (k++ < count) {
-                if (o.equals(items[i]))
-                    return true;
-                i = inc(i);
-            }
-            return false;
-        } finally {
-            lock.unlock();
-        }
-    }
-
-    public Object[] toArray() {
-        final E[] items = this.items;
-        final ReentrantLock lock = this.lock;
-        lock.lock();
-        try {
-            Object[] a = new Object[count];
-            int k = 0;
-            int i = takeIndex;
-            while (k < count) {
-                a[k++] = items[i];
-                i = inc(i);
-            }
-            return a;
-        } finally {
-            lock.unlock();
-        }
-    }
-
-    public <T> T[] toArray(T[] a) {
-        final E[] items = this.items;
-        final ReentrantLock lock = this.lock;
-        lock.lock();
-        try {
-            if (a.length < count)
-                a = (T[])java.lang.reflect.Array.newInstance(
-                    a.getClass().getComponentType(),
-                    count
-                    );
-
-            int k = 0;
-            int i = takeIndex;
-            while (k < count) {
-                a[k++] = (T)items[i];
-                i = inc(i);
-            }
-            if (a.length > count)
-                a[count] = null;
-            return a;
-        } finally {
-            lock.unlock();
-        }
-    }
-
-    public String toString() {
-        final ReentrantLock lock = this.lock;
-        lock.lock();
-        try {
-            return super.toString();
-        } finally {
-            lock.unlock();
-        }
-    }
-
-
-    public void clear() {
-        final E[] items = this.items;
-        final ReentrantLock lock = this.lock;
-        lock.lock();
-        try {
-            int i = takeIndex;
-            int k = count;
-            while (k-- > 0) {
-                items[i] = null;
-                i = inc(i);
-            }
-            count = 0;
-            putIndex = 0;
-            takeIndex = 0;
-            notFull.signalAll();
-        } finally {
-            lock.unlock();
-        }
-    }
-
-    public int drainTo(Collection<? super E> c) {
-        if (c == null)
-            throw new NullPointerException();
-        if (c == this)
-            throw new IllegalArgumentException();
-        final E[] items = this.items;
-        final ReentrantLock lock = this.lock;
-        lock.lock();
-        try {
-            int i = takeIndex;
-            int n = 0;
-            int max = count;
-            while (n < max) {
-                c.add(items[i]);
-                items[i] = null;
-                i = inc(i);
-                ++n;
-            }
-            if (n > 0) {
-                count = 0;
-                putIndex = 0;
-                takeIndex = 0;
-                notFull.signalAll();
-            }
-            return n;
-        } finally {
-            lock.unlock();
-        }
-    }
-
-
-    public int drainTo(Collection<? super E> c, int maxElements) {
-        if (c == null)
-            throw new NullPointerException();
-        if (c == this)
-            throw new IllegalArgumentException();
-        if (maxElements <= 0)
-            return 0;
-        final E[] items = this.items;
-        final ReentrantLock lock = this.lock;
-        lock.lock();
-        try {
-            int i = takeIndex;
-            int n = 0;
-            int sz = count;
-            int max = (maxElements < count)? maxElements : count;
-            while (n < max) {
-                c.add(items[i]);
-                items[i] = null;
-                i = inc(i);
-                ++n;
-            }
-            if (n > 0) {
-                count -= n;
-                takeIndex = i;
-                notFull.signalAll();
-            }
-            return n;
-        } finally {
-            lock.unlock();
-        }
-    }
-
-
-    /**
-     * Returns an iterator over the elements in this queue in proper sequence.
-     * The returned <tt>Iterator</tt> is a "weakly consistent" iterator that
-     * will never throw {@link java.util.ConcurrentModificationException},
-     * and guarantees to traverse elements as they existed upon
-     * construction of the iterator, and may (but is not guaranteed to)
-     * reflect any modifications subsequent to construction.
-     *
-     * @return an iterator over the elements in this queue in proper sequence.
-     */
-    public Iterator<E> iterator() {
-        final ReentrantLock lock = this.lock;
-        lock.lock();
-        try {
-            return new Itr();
-        } finally {
-            lock.unlock();
-        }
-    }
-
-    /**
-     * Iterator for ArrayBlockingQueue
-     */
-    private class Itr implements Iterator<E> {
-        /**
-         * Index of element to be returned by next,
-         * or a negative number if no such.
-         */
-        private int nextIndex;
-
-        /**
-         * nextItem holds on to item fields because once we claim
-         * that an element exists in hasNext(), we must return it in
-         * the following next() call even if it was in the process of
-         * being removed when hasNext() was called.
-         **/
-        private E nextItem;
-
-        /**
-         * Index of element returned by most recent call to next.
-         * Reset to -1 if this element is deleted by a call to remove.
-         */
-        private int lastRet;
-
-        Itr() {
-            lastRet = -1;
-            if (count == 0)
-                nextIndex = -1;
-            else {
-                nextIndex = takeIndex;
-                nextItem = items[takeIndex];
-            }
-        }
-
-        public boolean hasNext() {
-            /*
-             * No sync. We can return true by mistake here
-             * only if this iterator passed across threads,
-             * which we don't support anyway.
-             */
-            return nextIndex >= 0;
-        }
-
-        /**
-         * Check whether nextIndex is valid; if so setting nextItem.
-         * Stops iterator when either hits putIndex or sees null item.
-         */
-        private void checkNext() {
-            if (nextIndex == putIndex) {
-                nextIndex = -1;
-                nextItem = null;
-            } else {
-                nextItem = items[nextIndex];
-                if (nextItem == null)
-                    nextIndex = -1;
-            }
-        }
-
-        public E next() {
-            final ReentrantLock lock = ArrayBlockingQueue.this.lock;
-            lock.lock();
-            try {
-                if (nextIndex < 0)
-                    throw new NoSuchElementException();
-                lastRet = nextIndex;
-                E x = nextItem;
-                nextIndex = inc(nextIndex);
-                checkNext();
-                return x;
-            } finally {
-                lock.unlock();
-            }
-        }
-
-        public void remove() {
-            final ReentrantLock lock = ArrayBlockingQueue.this.lock;
-            lock.lock();
-            try {
-                int i = lastRet;
-                if (i == -1)
-                    throw new IllegalStateException();
-                lastRet = -1;
-
-                int ti = takeIndex;
-                removeAt(i);
-                // back up cursor (reset to front if was first element)
-                nextIndex = (i == ti) ? takeIndex : i;
-                checkNext();
-            } finally {
-                lock.unlock();
-            }
-        }
-    }
-}
diff --git a/concurrent/src/main/java/java/util/concurrent/BlockingQueue.java b/concurrent/src/main/java/java/util/concurrent/BlockingQueue.java
deleted file mode 100644
index ddb7d77..0000000
--- a/concurrent/src/main/java/java/util/concurrent/BlockingQueue.java
+++ /dev/null
@@ -1,227 +0,0 @@
-/*
- * Written by Doug Lea with assistance from members of JCP JSR-166
- * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
- */
-
-package java.util.concurrent;
-
-import java.util.Collection;
-import java.util.Queue;
-
-// BEGIN android-note
-// removed link to collections framework docs
-// END android-note
-
-/**
- * A {@link java.util.Queue} that additionally supports operations
- * that wait for the queue to become non-empty when retrieving an element,
- * and wait for space to become available in the queue when storing an 
- * element.
- *
- * <p>A <tt>BlockingQueue</tt> does not accept <tt>null</tt> elements.
- * Implementations throw <tt>NullPointerException</tt> on attempts
- * to <tt>add</tt>, <tt>put</tt> or <tt>offer</tt> a <tt>null</tt>.  A
- * <tt>null</tt> is used as a sentinel value to indicate failure of
- * <tt>poll</tt> operations.
- *
- * <p>A <tt>BlockingQueue</tt> may be capacity bounded. At any given
- * time it may have a <tt>remainingCapacity</tt> beyond which no
- * additional elements can be <tt>put</tt> without blocking.
- * A <tt>BlockingQueue</tt> without any intrinsic capacity constraints always
- * reports a remaining capacity of <tt>Integer.MAX_VALUE</tt>.
- *
- * <p> While <tt>BlockingQueue</tt> is designed to be used primarily
- * for producer-consumer queues, it additionally supports the {@link
- * java.util.Collection} interface.  So, for example, it is possible
- * to remove an arbitrary element from a queue using
- * <tt>remove(x)</tt>. However, such operations are in general
- * <em>not</em> performed very efficiently, and are intended for only
- * occasional use, such as when a queued message is cancelled.  Also,
- * the bulk Collection operations, most notably <tt>addAll</tt>, are
- * <em>not</em> necessarily performed atomically, so it is possible
- * for <tt>addAll(c)</tt> to fail (throwing an exception) after adding
- * only some of the elements in <tt>c</tt>.
- *
- * <p>A <tt>BlockingQueue</tt> does <em>not</em> intrinsically support
- * any kind of &quot;close&quot; or &quot;shutdown&quot; operation to
- * indicate that no more items will be added.  The needs and usage of
- * such features tend to be implementation-dependent. For example, a
- * common tactic is for producers to insert special
- * <em>end-of-stream</em> or <em>poison</em> objects, that are
- * interpreted accordingly when taken by consumers.
- *
- * <p>
- * Usage example, based on a typical producer-consumer scenario.
- * Note that a <tt>BlockingQueue</tt> can safely be used with multiple
- * producers and multiple consumers.
- * <pre>
- * class Producer implements Runnable {
- *   private final BlockingQueue queue;
- *   Producer(BlockingQueue q) { queue = q; }
- *   public void run() {
- *     try {
- *       while(true) { queue.put(produce()); }
- *     } catch (InterruptedException ex) { ... handle ...}
- *   }
- *   Object produce() { ... }
- * }
- *
- * class Consumer implements Runnable {
- *   private final BlockingQueue queue;
- *   Consumer(BlockingQueue q) { queue = q; }
- *   public void run() {
- *     try {
- *       while(true) { consume(queue.take()); }
- *     } catch (InterruptedException ex) { ... handle ...}
- *   }
- *   void consume(Object x) { ... }
- * }
- *
- * class Setup {
- *   void main() {
- *     BlockingQueue q = new SomeQueueImplementation();
- *     Producer p = new Producer(q);
- *     Consumer c1 = new Consumer(q);
- *     Consumer c2 = new Consumer(q);
- *     new Thread(p).start();
- *     new Thread(c1).start();
- *     new Thread(c2).start();
- *   }
- * }
- * </pre>
- *
- * @since 1.5
- * @author Doug Lea
- * @param <E> the type of elements held in this collection
- */
-public interface BlockingQueue<E> extends Queue<E> {
-
-    /**
-     * Inserts the specified element into this queue, if possible.  When
-     * using queues that may impose insertion restrictions (for
-     * example capacity bounds), method <tt>offer</tt> is generally
-     * preferable to method {@link Collection#add}, which can fail to
-     * insert an element only by throwing an exception.
-     *
-     * @param o the element to add.
-     * @return <tt>true</tt> if it was possible to add the element to
-     *         this queue, else <tt>false</tt>
-     * @throws NullPointerException if the specified element is <tt>null</tt>
-     */
-    boolean offer(E o);
-    
-    /**
-     * Inserts the specified element into this queue, waiting if necessary
-     * up to the specified wait time for space to become available.
-     * @param o the element to add
-     * @param timeout how long to wait before giving up, in units of
-     * <tt>unit</tt>
-     * @param unit a <tt>TimeUnit</tt> determining how to interpret the
-     * <tt>timeout</tt> parameter
-     * @return <tt>true</tt> if successful, or <tt>false</tt> if
-     * the specified waiting time elapses before space is available.
-     * @throws InterruptedException if interrupted while waiting.
-     * @throws NullPointerException if the specified element is <tt>null</tt>.
-     */
-    boolean offer(E o, long timeout, TimeUnit unit)
-        throws InterruptedException;
-
-    /**
-     * Retrieves and removes the head of this queue, waiting
-     * if necessary up to the specified wait time if no elements are
-     * present on this queue.
-     * @param timeout how long to wait before giving up, in units of
-     * <tt>unit</tt>
-     * @param unit a <tt>TimeUnit</tt> determining how to interpret the
-     * <tt>timeout</tt> parameter
-     * @return the head of this queue, or <tt>null</tt> if the
-     * specified waiting time elapses before an element is present.
-     * @throws InterruptedException if interrupted while waiting.
-     */
-    E poll(long timeout, TimeUnit unit)
-        throws InterruptedException;
-
-    /**
-     * Retrieves and removes the head of this queue, waiting
-     * if no elements are present on this queue.
-     * @return the head of this queue
-     * @throws InterruptedException if interrupted while waiting.
-     */
-    E take() throws InterruptedException;
-
-    /**
-     * Adds the specified element to this queue, waiting if necessary for
-     * space to become available.
-     * @param o the element to add
-     * @throws InterruptedException if interrupted while waiting.
-     * @throws NullPointerException if the specified element is <tt>null</tt>.
-     */
-    void put(E o) throws InterruptedException;
-
-    /**
-     * Returns the number of elements that this queue can ideally (in
-     * the absence of memory or resource constraints) accept without
-     * blocking, or <tt>Integer.MAX_VALUE</tt> if there is no
-     * intrinsic limit.
-     * <p>Note that you <em>cannot</em> always tell if
-     * an attempt to <tt>add</tt> an element will succeed by
-     * inspecting <tt>remainingCapacity</tt> because it may be the
-     * case that a waiting consumer is ready to <tt>take</tt> an
-     * element out of an otherwise full queue.
-     * @return the remaining capacity
-     */
-    int remainingCapacity();
-
-    /**
-     * Adds the specified element to this queue if it is possible to
-     * do so immediately, returning <tt>true</tt> upon success, else
-     * throwing an IllegalStateException.  
-     * @param o the element
-     * @return <tt>true</tt> (as per the general contract of
-     *         <tt>Collection.add</tt>).
-     *
-     * @throws NullPointerException if the specified element is <tt>null</tt>
-     * @throws IllegalStateException if element cannot be added
-     */
-    boolean add(E o);
-
-    /**
-     * Removes all available elements from this queue and adds them
-     * into the given collection.  This operation may be more
-     * efficient than repeatedly polling this queue.  A failure
-     * encountered while attempting to <tt>add</tt> elements to
-     * collection <tt>c</tt> may result in elements being in neither,
-     * either or both collections when the associated exception is
-     * thrown. Attempts to drain a queue to itself result in
-     * <tt>IllegalArgumentException</tt>. Further, the behavior of
-     * this operation is undefined if the specified collection is
-     * modified while the operation is in progress.
-     *
-     * @param c the collection to transfer elements into
-     * @return the number of elements transferred.
-     * @throws NullPointerException if c is null
-     * @throws IllegalArgumentException if c is this queue
-     * 
-     */
-    int drainTo(Collection<? super E> c);
-    
-    /**
-     * Removes at most the given number of available elements from
-     * this queue and adds them into the given collection.  A failure
-     * encountered while attempting to <tt>add</tt> elements to
-     * collection <tt>c</tt> may result in elements being in neither,
-     * either or both collections when the associated exception is
-     * thrown. Attempts to drain a queue to itself result in
-     * <tt>IllegalArgumentException</tt>. Further, the behavior of
-     * this operation is undefined if the specified collection is
-     * modified while the operation is in progress.
-     *
-     * @param c the collection to transfer elements into
-     * @param maxElements the maximum number of elements to transfer
-     * @return the number of elements transferred.
-     * @throws NullPointerException if c is null
-     * @throws IllegalArgumentException if c is this queue
-     */
-    int drainTo(Collection<? super E> c, int maxElements);
-}
diff --git a/concurrent/src/main/java/java/util/concurrent/BrokenBarrierException.java b/concurrent/src/main/java/java/util/concurrent/BrokenBarrierException.java
deleted file mode 100644
index 3f93fbb..0000000
--- a/concurrent/src/main/java/java/util/concurrent/BrokenBarrierException.java
+++ /dev/null
@@ -1,38 +0,0 @@
-/*
- * Written by Doug Lea with assistance from members of JCP JSR-166
- * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
- */
-
-package java.util.concurrent;
-
-/**
- * Exception thrown when a thread tries to wait upon a barrier that is
- * in a broken state, or which enters the broken state while the thread
- * is waiting.
- *
- * @see CyclicBarrier
- *
- * @since 1.5
- * @author Doug Lea
- *
- */
-public class BrokenBarrierException extends Exception {
-    private static final long serialVersionUID = 7117394618823254244L;
-
-    /**
-     * Constructs a <tt>BrokenBarrierException</tt> with no specified detail
-     * message.
-     */
-    public BrokenBarrierException() {}
-
-    /**
-     * Constructs a <tt>BrokenBarrierException</tt> with the specified
-     * detail message.
-     *
-     * @param message the detail message
-     */
-    public BrokenBarrierException(String message) {
-        super(message);
-    }
-}
diff --git a/concurrent/src/main/java/java/util/concurrent/Callable.java b/concurrent/src/main/java/java/util/concurrent/Callable.java
deleted file mode 100644
index abc4d04..0000000
--- a/concurrent/src/main/java/java/util/concurrent/Callable.java
+++ /dev/null
@@ -1,36 +0,0 @@
-/*
- * Written by Doug Lea with assistance from members of JCP JSR-166
- * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
- */
-
-package java.util.concurrent;
-
-/**
- * A task that returns a result and may throw an exception.
- * Implementors define a single method with no arguments called
- * <tt>call</tt>.
- *
- * <p>The <tt>Callable</tt> interface is similar to {@link
- * java.lang.Runnable}, in that both are designed for classes whose
- * instances are potentially executed by another thread.  A
- * <tt>Runnable</tt>, however, does not return a result and cannot
- * throw a checked exception.
- *
- * <p> The {@link Executors} class contains utility methods to
- * convert from other common forms to <tt>Callable</tt> classes.
- *
- * @see Executor
- * @since 1.5
- * @author Doug Lea
- * @param <V> the result type of method <tt>call</tt>
- */
-public interface Callable<V> {
-    /**
-     * Computes a result, or throws an exception if unable to do so.
-     *
-     * @return computed result
-     * @throws Exception if unable to compute a result
-     */
-    V call() throws Exception;
-}
diff --git a/concurrent/src/main/java/java/util/concurrent/CancellationException.java b/concurrent/src/main/java/java/util/concurrent/CancellationException.java
deleted file mode 100644
index 2c29544..0000000
--- a/concurrent/src/main/java/java/util/concurrent/CancellationException.java
+++ /dev/null
@@ -1,34 +0,0 @@
-/*
- * Written by Doug Lea with assistance from members of JCP JSR-166
- * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
- */
-
-package java.util.concurrent;
-
-/**
- * Exception indicating that the result of a value-producing task,
- * such as a {@link FutureTask}, cannot be retrieved because the task
- * was cancelled.
- *
- * @since 1.5
- * @author Doug Lea
- */
-public class CancellationException extends IllegalStateException {
-    private static final long serialVersionUID = -9202173006928992231L;
-
-    /**
-     * Constructs a <tt>CancellationException</tt> with no detail message.
-     */
-    public CancellationException() {}
-
-    /**
-     * Constructs a <tt>CancellationException</tt> with the specified detail
-     * message.
-     *
-     * @param message the detail message
-     */
-    public CancellationException(String message) {
-        super(message);
-    }
-}
diff --git a/concurrent/src/main/java/java/util/concurrent/CompletionService.java b/concurrent/src/main/java/java/util/concurrent/CompletionService.java
deleted file mode 100644
index e349e5f..0000000
--- a/concurrent/src/main/java/java/util/concurrent/CompletionService.java
+++ /dev/null
@@ -1,92 +0,0 @@
-/*
- * Written by Doug Lea with assistance from members of JCP JSR-166
- * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
- */
-
-package java.util.concurrent;
-
-/**
- * A service that decouples the production of new asynchronous tasks
- * from the consumption of the results of completed tasks.  Producers
- * <tt>submit</tt> tasks for execution. Consumers <tt>take</tt>
- * completed tasks and process their results in the order they
- * complete.  A <tt>CompletionService</tt> can for example be used to
- * manage asynchronous IO, in which tasks that perform reads are
- * submitted in one part of a program or system, and then acted upon
- * in a different part of the program when the reads complete,
- * possibly in a different order than they were requested.
-
- * <p>
- *
- * Typically, a <tt>CompletionService</tt> relies on a separate {@link
- * Executor} to actually execute the tasks, in which case the
- * <tt>CompletionService</tt> only manages an internal completion
- * queue. The {@link ExecutorCompletionService} class provides an
- * implementation of this approach.
- *
- */
-public interface CompletionService<V> {
-    /**
-     * Submits a value-returning task for execution and returns a Future
-     * representing the pending results of the task. Upon completion,
-     * this task may be taken or polled.
-     *
-     * @param task the task to submit
-     * @return a Future representing pending completion of the task
-     * @throws RejectedExecutionException if task cannot be scheduled
-     * for execution
-     * @throws NullPointerException if task null     
-     */
-    Future<V> submit(Callable<V> task);
-
-
-    /**
-     * Submits a Runnable task for execution and returns a Future 
-     * representing that task. Upon completion,
-     * this task may be taken or polled.
-     *
-     * @param task the task to submit
-     * @param result the result to return upon successful completion
-     * @return a Future representing pending completion of the task,
-     * and whose <tt>get()</tt> method will return the given result value 
-     * upon completion
-     * @throws RejectedExecutionException if task cannot be scheduled
-     * for execution
-     * @throws NullPointerException if task null     
-     */
-    Future<V> submit(Runnable task, V result);
-
-    /**
-     * Retrieves and removes the Future representing the next
-     * completed task, waiting if none are yet present.
-     * @return the Future representing the next completed task
-     * @throws InterruptedException if interrupted while waiting.
-     */
-    Future<V> take() throws InterruptedException;
-
-
-    /**
-     * Retrieves and removes the Future representing the next
-     * completed task or <tt>null</tt> if none are present.
-     *
-     * @return the Future representing the next completed task, or
-     * <tt>null</tt> if none are present.
-     */
-    Future<V> poll();
-
-    /**
-     * Retrieves and removes the Future representing the next
-     * completed task, waiting if necessary up to the specified wait
-     * time if none are yet present.
-     * @param timeout how long to wait before giving up, in units of
-     * <tt>unit</tt>
-     * @param unit a <tt>TimeUnit</tt> determining how to interpret the
-     * <tt>timeout</tt> parameter
-     * @return the Future representing the next completed task or
-     * <tt>null</tt> if the specified waiting time elapses before one
-     * is present.
-     * @throws InterruptedException if interrupted while waiting.
-     */
-    Future<V> poll(long timeout, TimeUnit unit) throws InterruptedException;
-}
diff --git a/concurrent/src/main/java/java/util/concurrent/ConcurrentHashMap.java b/concurrent/src/main/java/java/util/concurrent/ConcurrentHashMap.java
deleted file mode 100644
index f72c6fe..0000000
--- a/concurrent/src/main/java/java/util/concurrent/ConcurrentHashMap.java
+++ /dev/null
@@ -1,1353 +0,0 @@
-/*
- * Written by Doug Lea with assistance from members of JCP JSR-166
- * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
- */
-
-package java.util.concurrent;
-import java.util.concurrent.locks.*;
-import java.util.*;
-import java.io.Serializable;
-import java.io.IOException;
-import java.io.ObjectInputStream;
-import java.io.ObjectOutputStream;
-
-// BEGIN android-note
-// removed link to collections framework docs
-// removed cloneable interface from ConcurrentMap interface
-// END android-note
-
-/**
- * A hash table supporting full concurrency of retrievals and
- * adjustable expected concurrency for updates. This class obeys the
- * same functional specification as {@link java.util.Hashtable}, and
- * includes versions of methods corresponding to each method of
- * <tt>Hashtable</tt>. However, even though all operations are
- * thread-safe, retrieval operations do <em>not</em> entail locking,
- * and there is <em>not</em> any support for locking the entire table
- * in a way that prevents all access.  This class is fully
- * interoperable with <tt>Hashtable</tt> in programs that rely on its
- * thread safety but not on its synchronization details.
- *
- * <p> Retrieval operations (including <tt>get</tt>) generally do not
- * block, so may overlap with update operations (including
- * <tt>put</tt> and <tt>remove</tt>). Retrievals reflect the results
- * of the most recently <em>completed</em> update operations holding
- * upon their onset.  For aggregate operations such as <tt>putAll</tt>
- * and <tt>clear</tt>, concurrent retrievals may reflect insertion or
- * removal of only some entries.  Similarly, Iterators and
- * Enumerations return elements reflecting the state of the hash table
- * at some point at or since the creation of the iterator/enumeration.
- * They do <em>not</em> throw
- * {@link ConcurrentModificationException}.  However, iterators are
- * designed to be used by only one thread at a time.
- *
- * <p> The allowed concurrency among update operations is guided by
- * the optional <tt>concurrencyLevel</tt> constructor argument
- * (default 16), which is used as a hint for internal sizing.  The
- * table is internally partitioned to try to permit the indicated
- * number of concurrent updates without contention. Because placement
- * in hash tables is essentially random, the actual concurrency will
- * vary.  Ideally, you should choose a value to accommodate as many
- * threads as will ever concurrently modify the table. Using a
- * significantly higher value than you need can waste space and time,
- * and a significantly lower value can lead to thread contention. But
- * overestimates and underestimates within an order of magnitude do
- * not usually have much noticeable impact. A value of one is
- * appropriate when it is known that only one thread will modify
- * and all others will only read.
- *
- * <p>This class implements all of the <em>optional</em> methods
- * of the {@link Map} and {@link Iterator} interfaces.
- *
- * <p> Like {@link java.util.Hashtable} but unlike {@link
- * java.util.HashMap}, this class does NOT allow <tt>null</tt> to be
- * used as a key or value.
- *
- * @since 1.5
- * @author Doug Lea
- * @param <K> the type of keys maintained by this map
- * @param <V> the type of mapped values 
- */
-public class ConcurrentHashMap<K, V> extends AbstractMap<K, V>
-        implements ConcurrentMap<K, V>, Serializable {
-    private static final long serialVersionUID = 7249069246763182397L;
-
-    /*
-     * The basic strategy is to subdivide the table among Segments,
-     * each of which itself is a concurrently readable hash table.
-     */
-
-    /* ---------------- Constants -------------- */
-
-    /**
-     * The default initial number of table slots for this table.
-     * Used when not otherwise specified in constructor.
-     */
-    static int DEFAULT_INITIAL_CAPACITY = 16;
-
-    /**
-     * The maximum capacity, used if a higher value is implicitly
-     * specified by either of the constructors with arguments.  MUST
-     * be a power of two <= 1<<30 to ensure that entries are indexible
-     * using ints.
-     */
-    static final int MAXIMUM_CAPACITY = 1 << 30; 
-
-    /**
-     * The default load factor for this table.  Used when not
-     * otherwise specified in constructor.
-     */
-    static final float DEFAULT_LOAD_FACTOR = 0.75f;
-
-    /**
-     * The default number of concurrency control segments.
-     **/
-    static final int DEFAULT_SEGMENTS = 16;
-
-    /**
-     * The maximum number of segments to allow; used to bound
-     * constructor arguments.
-     */
-    static final int MAX_SEGMENTS = 1 << 16; // slightly conservative
-
-    /* ---------------- Fields -------------- */
-
-    /**
-     * Mask value for indexing into segments. The upper bits of a
-     * key's hash code are used to choose the segment.
-     **/
-    final int segmentMask;
-
-    /**
-     * Shift value for indexing within segments.
-     **/
-    final int segmentShift;
-
-    /**
-     * The segments, each of which is a specialized hash table
-     */
-    final Segment[] segments;
-
-    transient Set<K> keySet;
-    transient Set<Map.Entry<K,V>> entrySet;
-    transient Collection<V> values;
-
-    /* ---------------- Small Utilities -------------- */
-
-    /**
-     * Returns a hash code for non-null Object x.
-     * Uses the same hash code spreader as most other java.util hash tables.
-     * @param x the object serving as a key
-     * @return the hash code
-     */
-    static int hash(Object x) {
-        int h = x.hashCode();
-        h += ~(h << 9);
-        h ^=  (h >>> 14);
-        h +=  (h << 4);
-        h ^=  (h >>> 10);
-        return h;
-    }
-
-    /**
-     * Returns the segment that should be used for key with given hash
-     * @param hash the hash code for the key
-     * @return the segment
-     */
-    final Segment<K,V> segmentFor(int hash) {
-        return (Segment<K,V>) segments[(hash >>> segmentShift) & segmentMask];
-    }
-
-    /* ---------------- Inner Classes -------------- */
-
-    /**
-     * Segments are specialized versions of hash tables.  This
-     * subclasses from ReentrantLock opportunistically, just to
-     * simplify some locking and avoid separate construction.
-     **/
-    static final class Segment<K,V> extends ReentrantLock implements Serializable {
-        /*
-         * Segments maintain a table of entry lists that are ALWAYS
-         * kept in a consistent state, so can be read without locking.
-         * Next fields of nodes are immutable (final).  All list
-         * additions are performed at the front of each bin. This
-         * makes it easy to check changes, and also fast to traverse.
-         * When nodes would otherwise be changed, new nodes are
-         * created to replace them. This works well for hash tables
-         * since the bin lists tend to be short. (The average length
-         * is less than two for the default load factor threshold.)
-         *
-         * Read operations can thus proceed without locking, but rely
-         * on a memory barrier to ensure that completed write
-         * operations performed by other threads are
-         * noticed. Conveniently, the "count" field, tracking the
-         * number of elements, can also serve as the volatile variable
-         * providing proper read/write barriers. This is convenient
-         * because this field needs to be read in many read operations
-         * anyway. 
-         *
-         * Implementors note. The basic rules for all this are:
-         *
-         *   - All unsynchronized read operations must first read the
-         *     "count" field, and should not look at table entries if
-         *     it is 0.
-         *
-         *   - All synchronized write operations should write to
-         *     the "count" field after updating. The operations must not
-         *     take any action that could even momentarily cause
-         *     a concurrent read operation to see inconsistent
-         *     data. This is made easier by the nature of the read
-         *     operations in Map. For example, no operation
-         *     can reveal that the table has grown but the threshold
-         *     has not yet been updated, so there are no atomicity
-         *     requirements for this with respect to reads.
-         *
-         * As a guide, all critical volatile reads and writes are marked
-         * in code comments.
-         */
-
-        private static final long serialVersionUID = 2249069246763182397L;
-
-        /**
-         * The number of elements in this segment's region.
-         **/
-        transient volatile int count;
-
-        /**
-         * Number of updates; used for checking lack of modifications
-         * in bulk-read methods.
-         */
-        transient int modCount;
-
-        /**
-         * The table is rehashed when its size exceeds this threshold.
-         * (The value of this field is always (int)(capacity *
-         * loadFactor).)
-         */
-        transient int threshold;
-
-        /**
-         * The per-segment table
-         */
-        transient HashEntry[] table;
-
-        /**
-         * The load factor for the hash table.  Even though this value
-         * is same for all segments, it is replicated to avoid needing
-         * links to outer object.
-         * @serial
-         */
-        final float loadFactor;
-
-        Segment(int initialCapacity, float lf) {
-            loadFactor = lf;
-            setTable(new HashEntry[initialCapacity]);
-        }
-
-        /**
-         * Set table to new HashEntry array.
-         * Call only while holding lock or in constructor.
-         **/
-        void setTable(HashEntry[] newTable) {
-            table = newTable;
-            threshold = (int)(newTable.length * loadFactor);
-            count = count; // write-volatile
-        }
-
-        /* Specialized implementations of map methods */
-
-        V get(Object key, int hash) {
-            if (count != 0) { // read-volatile
-                HashEntry[] tab = table;
-                int index = hash & (tab.length - 1);
-                HashEntry<K,V> e = (HashEntry<K,V>) tab[index];
-                while (e != null) {
-                    if (e.hash == hash && key.equals(e.key))
-                        return e.value;
-                    e = e.next;
-                }
-            }
-            return null;
-        }
-
-        boolean containsKey(Object key, int hash) {
-            if (count != 0) { // read-volatile
-                HashEntry[] tab = table;
-                int index = hash & (tab.length - 1);
-                HashEntry<K,V> e = (HashEntry<K,V>) tab[index];
-                while (e != null) {
-                    if (e.hash == hash && key.equals(e.key))
-                        return true;
-                    e = e.next;
-                }
-            }
-            return false;
-        }
-
-        boolean containsValue(Object value) {
-            if (count != 0) { // read-volatile
-                HashEntry[] tab = table;
-                int len = tab.length;
-                for (int i = 0 ; i < len; i++)
-                    for (HashEntry<K,V> e = (HashEntry<K,V>)tab[i] ; e != null ; e = e.next)
-                        if (value.equals(e.value))
-                            return true;
-            }
-            return false;
-        }
-
-        boolean replace(K key, int hash, V oldValue, V newValue) {
-            lock();
-            try {
-                int c = count;
-                HashEntry[] tab = table;
-                int index = hash & (tab.length - 1);
-                HashEntry<K,V> first = (HashEntry<K,V>) tab[index];
-                HashEntry<K,V> e = first;
-                for (;;) {
-                    if (e == null)
-                        return false;
-                    if (e.hash == hash && key.equals(e.key))
-                        break;
-                    e = e.next;
-                }
-
-                V v = e.value;
-                if (v == null || !oldValue.equals(v))
-                    return false;
-
-                e.value = newValue;
-                count = c; // write-volatile
-                return true;
-                
-            } finally {
-                unlock();
-            }
-        }
-
-        V replace(K key, int hash, V newValue) {
-            lock();
-            try {
-                int c = count;
-                HashEntry[] tab = table;
-                int index = hash & (tab.length - 1);
-                HashEntry<K,V> first = (HashEntry<K,V>) tab[index];
-                HashEntry<K,V> e = first;
-                for (;;) {
-                    if (e == null)
-                        return null;
-                    if (e.hash == hash && key.equals(e.key))
-                        break;
-                    e = e.next;
-                }
-
-                V v = e.value;
-                e.value = newValue;
-                count = c; // write-volatile
-                return v;
-                
-            } finally {
-                unlock();
-            }
-        }
-
-
-        V put(K key, int hash, V value, boolean onlyIfAbsent) {
-            lock();
-            try {
-                int c = count;
-                HashEntry[] tab = table;
-                int index = hash & (tab.length - 1);
-                HashEntry<K,V> first = (HashEntry<K,V>) tab[index];
-
-                for (HashEntry<K,V> e = first; e != null; e = (HashEntry<K,V>) e.next) {
-                    if (e.hash == hash && key.equals(e.key)) {
-                        V oldValue = e.value;
-                        if (!onlyIfAbsent)
-                            e.value = value;
-                        ++modCount;
-                        count = c; // write-volatile
-                        return oldValue;
-                    }
-                }
-
-                tab[index] = new HashEntry<K,V>(hash, key, value, first);
-                ++modCount;
-                ++c;
-                count = c; // write-volatile
-                if (c > threshold)
-                    setTable(rehash(tab));
-                return null;
-            } finally {
-                unlock();
-            }
-        }
-
-        HashEntry[] rehash(HashEntry[] oldTable) {
-            int oldCapacity = oldTable.length;
-            if (oldCapacity >= MAXIMUM_CAPACITY)
-                return oldTable;
-
-            /*
-             * Reclassify nodes in each list to new Map.  Because we are
-             * using power-of-two expansion, the elements from each bin
-             * must either stay at same index, or move with a power of two
-             * offset. We eliminate unnecessary node creation by catching
-             * cases where old nodes can be reused because their next
-             * fields won't change. Statistically, at the default
-             * threshold, only about one-sixth of them need cloning when
-             * a table doubles. The nodes they replace will be garbage
-             * collectable as soon as they are no longer referenced by any
-             * reader thread that may be in the midst of traversing table
-             * right now.
-             */
-
-            HashEntry[] newTable = new HashEntry[oldCapacity << 1];
-            int sizeMask = newTable.length - 1;
-            for (int i = 0; i < oldCapacity ; i++) {
-                // We need to guarantee that any existing reads of old Map can
-                //  proceed. So we cannot yet null out each bin.
-                HashEntry<K,V> e = (HashEntry<K,V>)oldTable[i];
-
-                if (e != null) {
-                    HashEntry<K,V> next = e.next;
-                    int idx = e.hash & sizeMask;
-
-                    //  Single node on list
-                    if (next == null)
-                        newTable[idx] = e;
-
-                    else {
-                        // Reuse trailing consecutive sequence at same slot
-                        HashEntry<K,V> lastRun = e;
-                        int lastIdx = idx;
-                        for (HashEntry<K,V> last = next;
-                             last != null;
-                             last = last.next) {
-                            int k = last.hash & sizeMask;
-                            if (k != lastIdx) {
-                                lastIdx = k;
-                                lastRun = last;
-                            }
-                        }
-                        newTable[lastIdx] = lastRun;
-
-                        // Clone all remaining nodes
-                        for (HashEntry<K,V> p = e; p != lastRun; p = p.next) {
-                            int k = p.hash & sizeMask;
-                            newTable[k] = new HashEntry<K,V>(p.hash,
-                                                             p.key,
-                                                             p.value,
-                                                             (HashEntry<K,V>) newTable[k]);
-                        }
-                    }
-                }
-            }
-            return newTable;
-        }
-
-        /**
-         * Remove; match on key only if value null, else match both.
-         */
-        V remove(Object key, int hash, Object value) {
-            lock();
-            try {
-                int c = count;
-                HashEntry[] tab = table;
-                int index = hash & (tab.length - 1);
-                HashEntry<K,V> first = (HashEntry<K,V>)tab[index];
-
-                HashEntry<K,V> e = first;
-                for (;;) {
-                    if (e == null)
-                        return null;
-                    if (e.hash == hash && key.equals(e.key))
-                        break;
-                    e = e.next;
-                }
-
-                V oldValue = e.value;
-                if (value != null && !value.equals(oldValue))
-                    return null;
-
-                // All entries following removed node can stay in list, but
-                // all preceding ones need to be cloned.
-                HashEntry<K,V> newFirst = e.next;
-                for (HashEntry<K,V> p = first; p != e; p = p.next)
-                    newFirst = new HashEntry<K,V>(p.hash, p.key,
-                                                  p.value, newFirst);
-                tab[index] = newFirst;
-                ++modCount;
-                count = c-1; // write-volatile
-                return oldValue;
-            } finally {
-                unlock();
-            }
-        }
-
-        void clear() {
-            lock();
-            try {
-                HashEntry[] tab = table;
-                for (int i = 0; i < tab.length ; i++)
-                    tab[i] = null;
-                ++modCount;
-                count = 0; // write-volatile
-            } finally {
-                unlock();
-            }
-        }
-    }
-
-    /**
-     * ConcurrentHashMap list entry. Note that this is never exported
-     * out as a user-visible Map.Entry
-     */
-    static final class HashEntry<K,V> {
-        final K key;
-        V value;
-        final int hash;
-        final HashEntry<K,V> next;
-
-        HashEntry(int hash, K key, V value, HashEntry<K,V> next) {
-            this.value = value;
-            this.hash = hash;
-            this.key = key;
-            this.next = next;
-        }
-    }
-
-
-    /* ---------------- Public operations -------------- */
-
-    /**
-     * Creates a new, empty map with the specified initial
-     * capacity and the specified load factor.
-     *
-     * @param initialCapacity the initial capacity. The implementation
-     * performs internal sizing to accommodate this many elements.
-     * @param loadFactor  the load factor threshold, used to control resizing.
-     * @param concurrencyLevel the estimated number of concurrently
-     * updating threads. The implementation performs internal sizing
-     * to try to accommodate this many threads.  
-     * @throws IllegalArgumentException if the initial capacity is
-     * negative or the load factor or concurrencyLevel are
-     * nonpositive.
-     */
-    public ConcurrentHashMap(int initialCapacity,
-                             float loadFactor, int concurrencyLevel) {
-        if (!(loadFactor > 0) || initialCapacity < 0 || concurrencyLevel <= 0)
-            throw new IllegalArgumentException();
-
-        if (concurrencyLevel > MAX_SEGMENTS)
-            concurrencyLevel = MAX_SEGMENTS;
-
-        // Find power-of-two sizes best matching arguments
-        int sshift = 0;
-        int ssize = 1;
-        while (ssize < concurrencyLevel) {
-            ++sshift;
-            ssize <<= 1;
-        }
-        segmentShift = 32 - sshift;
-        segmentMask = ssize - 1;
-        this.segments = new Segment[ssize];
-
-        if (initialCapacity > MAXIMUM_CAPACITY)
-            initialCapacity = MAXIMUM_CAPACITY;
-        int c = initialCapacity / ssize;
-        if (c * ssize < initialCapacity)
-            ++c;
-        int cap = 1;
-        while (cap < c)
-            cap <<= 1;
-
-        for (int i = 0; i < this.segments.length; ++i)
-            this.segments[i] = new Segment<K,V>(cap, loadFactor);
-    }
-
-    /**
-     * Creates a new, empty map with the specified initial
-     * capacity,  and with default load factor and concurrencyLevel.
-     *
-     * @param initialCapacity The implementation performs internal
-     * sizing to accommodate this many elements.
-     * @throws IllegalArgumentException if the initial capacity of
-     * elements is negative.
-     */
-    public ConcurrentHashMap(int initialCapacity) {
-        this(initialCapacity, DEFAULT_LOAD_FACTOR, DEFAULT_SEGMENTS);
-    }
-
-    /**
-     * Creates a new, empty map with a default initial capacity,
-     * load factor, and concurrencyLevel.
-     */
-    public ConcurrentHashMap() {
-        this(DEFAULT_INITIAL_CAPACITY, DEFAULT_LOAD_FACTOR, DEFAULT_SEGMENTS);
-    }
-
-    /**
-     * Creates a new map with the same mappings as the given map.  The
-     * map is created with a capacity of twice the number of mappings in
-     * the given map or 11 (whichever is greater), and a default load factor.
-     * @param t the map
-     */
-    public ConcurrentHashMap(Map<? extends K, ? extends V> t) {
-        this(Math.max((int) (t.size() / DEFAULT_LOAD_FACTOR) + 1,
-                      11),
-             DEFAULT_LOAD_FACTOR, DEFAULT_SEGMENTS);
-        putAll(t);
-    }
-
-    // inherit Map javadoc
-    public boolean isEmpty() {
-        final Segment[] segments = this.segments;
-        /*
-         * We need to keep track of per-segment modCounts to avoid ABA
-         * problems in which an element in one segment was added and
-         * in another removed during traversal, in which case the
-         * table was never actually empty at any point. Note the
-         * similar use of modCounts in the size() and containsValue()
-         * methods, which are the only other methods also susceptible
-         * to ABA problems.
-         */
-        int[] mc = new int[segments.length];
-        int mcsum = 0;
-        for (int i = 0; i < segments.length; ++i) {
-            if (segments[i].count != 0)
-                return false;
-            else 
-                mcsum += mc[i] = segments[i].modCount;
-        }
-        // If mcsum happens to be zero, then we know we got a snapshot
-        // before any modifications at all were made.  This is
-        // probably common enough to bother tracking.
-        if (mcsum != 0) {
-            for (int i = 0; i < segments.length; ++i) {
-                if (segments[i].count != 0 ||
-                    mc[i] != segments[i].modCount) 
-                    return false;
-            }
-        }
-        return true;
-    }
-
-    // inherit Map javadoc
-    public int size() {
-        final Segment[] segments = this.segments;
-        int[] mc = new int[segments.length];
-        for (;;) {
-            long sum = 0;
-            int mcsum = 0;
-            for (int i = 0; i < segments.length; ++i) {
-                sum += segments[i].count;
-                mcsum += mc[i] = segments[i].modCount;
-            }
-            int check = 0;
-            if (mcsum != 0) {
-                for (int i = 0; i < segments.length; ++i) {
-                    check += segments[i].count;
-                    if (mc[i] != segments[i].modCount) {
-                        check = -1; // force retry
-                        break;
-                    }
-                }
-            }
-            if (check == sum) {
-                if (sum > Integer.MAX_VALUE)
-                    return Integer.MAX_VALUE;
-                else
-                    return (int)sum;
-            }
-        }
-    }
-
-
-    /**
-     * Returns the value to which the specified key is mapped in this table.
-     *
-     * @param   key   a key in the table.
-     * @return  the value to which the key is mapped in this table;
-     *          <tt>null</tt> if the key is not mapped to any value in
-     *          this table.
-     * @throws  NullPointerException  if the key is
-     *               <tt>null</tt>.
-     */
-    public V get(Object key) {
-        int hash = hash(key); // throws NullPointerException if key null
-        return segmentFor(hash).get(key, hash);
-    }
-
-    /**
-     * Tests if the specified object is a key in this table.
-     *
-     * @param   key   possible key.
-     * @return  <tt>true</tt> if and only if the specified object
-     *          is a key in this table, as determined by the
-     *          <tt>equals</tt> method; <tt>false</tt> otherwise.
-     * @throws  NullPointerException  if the key is
-     *               <tt>null</tt>.
-     */
-    public boolean containsKey(Object key) {
-        int hash = hash(key); // throws NullPointerException if key null
-        return segmentFor(hash).containsKey(key, hash);
-    }
-
-    /**
-     * Returns <tt>true</tt> if this map maps one or more keys to the
-     * specified value. Note: This method requires a full internal
-     * traversal of the hash table, and so is much slower than
-     * method <tt>containsKey</tt>.
-     *
-     * @param value value whose presence in this map is to be tested.
-     * @return <tt>true</tt> if this map maps one or more keys to the
-     * specified value.
-     * @throws  NullPointerException  if the value is <tt>null</tt>.
-     */
-    public boolean containsValue(Object value) {
-        if (value == null)
-            throw new NullPointerException();
-
-        final Segment[] segments = this.segments;
-        int[] mc = new int[segments.length];
-        for (;;) {
-            int sum = 0;
-            int mcsum = 0;
-            for (int i = 0; i < segments.length; ++i) {
-                int c = segments[i].count;
-                mcsum += mc[i] = segments[i].modCount;
-                if (segments[i].containsValue(value))
-                    return true;
-            }
-            boolean cleanSweep = true;
-            if (mcsum != 0) {
-                for (int i = 0; i < segments.length; ++i) {
-                    int c = segments[i].count;
-                    if (mc[i] != segments[i].modCount) {
-                        cleanSweep = false;
-                        break;
-                    }
-                }
-            }
-            if (cleanSweep)
-                return false;
-        }
-    }
-
-    /**
-     * Legacy method testing if some key maps into the specified value
-     * in this table.  This method is identical in functionality to
-     * {@link #containsValue}, and  exists solely to ensure
-     * full compatibility with class {@link java.util.Hashtable},
-     * which supported this method prior to introduction of the
-     * Java Collections framework.
-
-     * @param      value   a value to search for.
-     * @return     <tt>true</tt> if and only if some key maps to the
-     *             <tt>value</tt> argument in this table as
-     *             determined by the <tt>equals</tt> method;
-     *             <tt>false</tt> otherwise.
-     * @throws  NullPointerException  if the value is <tt>null</tt>.
-     */
-    public boolean contains(Object value) {
-        return containsValue(value);
-    }
-
-    /**
-     * Maps the specified <tt>key</tt> to the specified
-     * <tt>value</tt> in this table. Neither the key nor the
-     * value can be <tt>null</tt>. 
-     *
-     * <p> The value can be retrieved by calling the <tt>get</tt> method
-     * with a key that is equal to the original key.
-     *
-     * @param      key     the table key.
-     * @param      value   the value.
-     * @return     the previous value of the specified key in this table,
-     *             or <tt>null</tt> if it did not have one.
-     * @throws  NullPointerException  if the key or value is
-     *               <tt>null</tt>.
-     */
-    public V put(K key, V value) {
-        if (value == null)
-            throw new NullPointerException();
-        int hash = hash(key);
-        return segmentFor(hash).put(key, hash, value, false);
-    }
-
-    /**
-     * If the specified key is not already associated
-     * with a value, associate it with the given value.
-     * This is equivalent to
-     * <pre>
-     *   if (!map.containsKey(key)) 
-     *      return map.put(key, value);
-     *   else
-     *      return map.get(key);
-     * </pre>
-     * Except that the action is performed atomically.
-     * @param key key with which the specified value is to be associated.
-     * @param value value to be associated with the specified key.
-     * @return previous value associated with specified key, or <tt>null</tt>
-     *         if there was no mapping for key.  A <tt>null</tt> return can
-     *         also indicate that the map previously associated <tt>null</tt>
-     *         with the specified key, if the implementation supports
-     *         <tt>null</tt> values.
-     *
-     * @throws UnsupportedOperationException if the <tt>put</tt> operation is
-     *            not supported by this map.
-     * @throws ClassCastException if the class of the specified key or value
-     *            prevents it from being stored in this map.
-     * @throws NullPointerException if the specified key or value is
-     *            <tt>null</tt>.
-     *
-     **/
-    public V putIfAbsent(K key, V value) {
-        if (value == null)
-            throw new NullPointerException();
-        int hash = hash(key);
-        return segmentFor(hash).put(key, hash, value, true);
-    }
-
-
-    /**
-     * Copies all of the mappings from the specified map to this one.
-     *
-     * These mappings replace any mappings that this map had for any of the
-     * keys currently in the specified Map.
-     *
-     * @param t Mappings to be stored in this map.
-     */
-    public void putAll(Map<? extends K, ? extends V> t) {
-        for (Iterator<? extends Map.Entry<? extends K, ? extends V>> it = (Iterator<? extends Map.Entry<? extends K, ? extends V>>) t.entrySet().iterator(); it.hasNext(); ) {
-            Entry<? extends K, ? extends V> e = it.next();
-            put(e.getKey(), e.getValue());
-        }
-    }
-
-    /**
-     * Removes the key (and its corresponding value) from this
-     * table. This method does nothing if the key is not in the table.
-     *
-     * @param   key   the key that needs to be removed.
-     * @return  the value to which the key had been mapped in this table,
-     *          or <tt>null</tt> if the key did not have a mapping.
-     * @throws  NullPointerException  if the key is
-     *               <tt>null</tt>.
-     */
-    public V remove(Object key) {
-        int hash = hash(key);
-        return segmentFor(hash).remove(key, hash, null);
-    }
-
-    /**
-     * Remove entry for key only if currently mapped to given value.
-     * Acts as
-     * <pre> 
-     *  if (map.get(key).equals(value)) {
-     *     map.remove(key);
-     *     return true;
-     * } else return false;
-     * </pre>
-     * except that the action is performed atomically.
-     * @param key key with which the specified value is associated.
-     * @param value value associated with the specified key.
-     * @return true if the value was removed
-     * @throws NullPointerException if the specified key is
-     *            <tt>null</tt>.
-     */
-    public boolean remove(Object key, Object value) {
-        int hash = hash(key);
-        return segmentFor(hash).remove(key, hash, value) != null;
-    }
-
-
-    /**
-     * Replace entry for key only if currently mapped to given value.
-     * Acts as
-     * <pre> 
-     *  if (map.get(key).equals(oldValue)) {
-     *     map.put(key, newValue);
-     *     return true;
-     * } else return false;
-     * </pre>
-     * except that the action is performed atomically.
-     * @param key key with which the specified value is associated.
-     * @param oldValue value expected to be associated with the specified key.
-     * @param newValue value to be associated with the specified key.
-     * @return true if the value was replaced
-     * @throws NullPointerException if the specified key or values are
-     * <tt>null</tt>.
-     */
-    public boolean replace(K key, V oldValue, V newValue) {
-        if (oldValue == null || newValue == null)
-            throw new NullPointerException();
-        int hash = hash(key);
-        return segmentFor(hash).replace(key, hash, oldValue, newValue);
-    }
-
-    /**
-     * Replace entry for key only if currently mapped to some value.
-     * Acts as
-     * <pre> 
-     *  if ((map.containsKey(key)) {
-     *     return map.put(key, value);
-     * } else return null;
-     * </pre>
-     * except that the action is performed atomically.
-     * @param key key with which the specified value is associated.
-     * @param value value to be associated with the specified key.
-     * @return previous value associated with specified key, or <tt>null</tt>
-     *         if there was no mapping for key.  
-     * @throws NullPointerException if the specified key or value is
-     *            <tt>null</tt>.
-     */
-    public V replace(K key, V value) {
-        if (value == null)
-            throw new NullPointerException();
-        int hash = hash(key);
-        return segmentFor(hash).replace(key, hash, value);
-    }
-
-
-    /**
-     * Removes all mappings from this map.
-     */
-    public void clear() {
-        for (int i = 0; i < segments.length; ++i)
-            segments[i].clear();
-    }
-
-
-    // BEGIN android-removed
-    // /**
-    //  * Returns a shallow copy of this
-    //  * <tt>ConcurrentHashMap</tt> instance: the keys and
-    //  * values themselves are not cloned.
-    //  *
-    //  * @return a shallow copy of this map.
-    //  */
-    // public Object clone() {
-    //     // We cannot call super.clone, since it would share final
-    //     // segments array, and there's no way to reassign finals.
-    //
-    //     float lf = segments[0].loadFactor;
-    //     int segs = segments.length;
-    //     int cap = (int)(size() / lf);
-    //     if (cap < segs) cap = segs;
-    //     ConcurrentHashMap<K,V> t = new ConcurrentHashMap<K,V>(cap, lf, segs);
-    //     t.putAll(this);
-    //     return t;
-    // }
-    // END android-changed
-
-    /**
-     * Returns a set view of the keys contained in this map.  The set is
-     * backed by the map, so changes to the map are reflected in the set, and
-     * vice-versa.  The set supports element removal, which removes the
-     * corresponding mapping from this map, via the <tt>Iterator.remove</tt>,
-     * <tt>Set.remove</tt>, <tt>removeAll</tt>, <tt>retainAll</tt>, and
-     * <tt>clear</tt> operations.  It does not support the <tt>add</tt> or
-     * <tt>addAll</tt> operations.
-     * The returned <tt>iterator</tt> is a "weakly consistent" iterator that
-     * will never throw {@link java.util.ConcurrentModificationException},
-     * and guarantees to traverse elements as they existed upon
-     * construction of the iterator, and may (but is not guaranteed to)
-     * reflect any modifications subsequent to construction.
-     *
-     * @return a set view of the keys contained in this map.
-     */
-    public Set<K> keySet() {
-        Set<K> ks = keySet;
-        return (ks != null) ? ks : (keySet = new KeySet());
-    }
-
-
-    /**
-     * Returns a collection view of the values contained in this map.  The
-     * collection is backed by the map, so changes to the map are reflected in
-     * the collection, and vice-versa.  The collection supports element
-     * removal, which removes the corresponding mapping from this map, via the
-     * <tt>Iterator.remove</tt>, <tt>Collection.remove</tt>,
-     * <tt>removeAll</tt>, <tt>retainAll</tt>, and <tt>clear</tt> operations.
-     * It does not support the <tt>add</tt> or <tt>addAll</tt> operations.
-     * The returned <tt>iterator</tt> is a "weakly consistent" iterator that
-     * will never throw {@link java.util.ConcurrentModificationException},
-     * and guarantees to traverse elements as they existed upon
-     * construction of the iterator, and may (but is not guaranteed to)
-     * reflect any modifications subsequent to construction.
-     *
-     * @return a collection view of the values contained in this map.
-     */
-    public Collection<V> values() {
-        Collection<V> vs = values;
-        return (vs != null) ? vs : (values = new Values());
-    }
-
-
-    /**
-     * Returns a collection view of the mappings contained in this map.  Each
-     * element in the returned collection is a <tt>Map.Entry</tt>.  The
-     * collection is backed by the map, so changes to the map are reflected in
-     * the collection, and vice-versa.  The collection supports element
-     * removal, which removes the corresponding mapping from the map, via the
-     * <tt>Iterator.remove</tt>, <tt>Collection.remove</tt>,
-     * <tt>removeAll</tt>, <tt>retainAll</tt>, and <tt>clear</tt> operations.
-     * It does not support the <tt>add</tt> or <tt>addAll</tt> operations.
-     * The returned <tt>iterator</tt> is a "weakly consistent" iterator that
-     * will never throw {@link java.util.ConcurrentModificationException},
-     * and guarantees to traverse elements as they existed upon
-     * construction of the iterator, and may (but is not guaranteed to)
-     * reflect any modifications subsequent to construction.
-     *
-     * @return a collection view of the mappings contained in this map.
-     */
-    public Set<Map.Entry<K,V>> entrySet() {
-        Set<Map.Entry<K,V>> es = entrySet;
-        return (es != null) ? es : (entrySet = (Set<Map.Entry<K,V>>) (Set) new EntrySet());
-    }
-
-
-    /**
-     * Returns an enumeration of the keys in this table.
-     *
-     * @return  an enumeration of the keys in this table.
-     * @see     #keySet
-     */
-    public Enumeration<K> keys() {
-        return new KeyIterator();
-    }
-
-    /**
-     * Returns an enumeration of the values in this table.
-     *
-     * @return  an enumeration of the values in this table.
-     * @see     #values
-     */
-    public Enumeration<V> elements() {
-        return new ValueIterator();
-    }
-
-    /* ---------------- Iterator Support -------------- */
-
-    abstract class HashIterator {
-        int nextSegmentIndex;
-        int nextTableIndex;
-        HashEntry[] currentTable;
-        HashEntry<K, V> nextEntry;
-        HashEntry<K, V> lastReturned;
-
-        HashIterator() {
-            nextSegmentIndex = segments.length - 1;
-            nextTableIndex = -1;
-            advance();
-        }
-
-        public boolean hasMoreElements() { return hasNext(); }
-
-        final void advance() {
-            if (nextEntry != null && (nextEntry = nextEntry.next) != null)
-                return;
-
-            while (nextTableIndex >= 0) {
-                if ( (nextEntry = (HashEntry<K,V>)currentTable[nextTableIndex--]) != null)
-                    return;
-            }
-
-            while (nextSegmentIndex >= 0) {
-                Segment<K,V> seg = (Segment<K,V>)segments[nextSegmentIndex--];
-                if (seg.count != 0) {
-                    currentTable = seg.table;
-                    for (int j = currentTable.length - 1; j >= 0; --j) {
-                        if ( (nextEntry = (HashEntry<K,V>)currentTable[j]) != null) {
-                            nextTableIndex = j - 1;
-                            return;
-                        }
-                    }
-                }
-            }
-        }
-
-        public boolean hasNext() { return nextEntry != null; }
-
-        HashEntry<K,V> nextEntry() {
-            if (nextEntry == null)
-                throw new NoSuchElementException();
-            lastReturned = nextEntry;
-            advance();
-            return lastReturned;
-        }
-
-        public void remove() {
-            if (lastReturned == null)
-                throw new IllegalStateException();
-            ConcurrentHashMap.this.remove(lastReturned.key);
-            lastReturned = null;
-        }
-    }
-
-    final class KeyIterator extends HashIterator implements Iterator<K>, Enumeration<K> {
-        public K next() { return super.nextEntry().key; }
-        public K nextElement() { return super.nextEntry().key; }
-    }
-
-    final class ValueIterator extends HashIterator implements Iterator<V>, Enumeration<V> {
-        public V next() { return super.nextEntry().value; }
-        public V nextElement() { return super.nextEntry().value; }
-    }
-
-    
-
-    /**
-     * Entry iterator. Exported Entry objects must write-through
-     * changes in setValue, even if the nodes have been cloned. So we
-     * cannot return internal HashEntry objects. Instead, the iterator
-     * itself acts as a forwarding pseudo-entry.
-     */
-    final class EntryIterator extends HashIterator implements Map.Entry<K,V>, Iterator<Entry<K,V>> {
-        public Map.Entry<K,V> next() {
-            nextEntry();
-            return this;
-        }
-
-        public K getKey() {
-            if (lastReturned == null)
-                throw new IllegalStateException("Entry was removed");
-            return lastReturned.key;
-        }
-
-        public V getValue() {
-            if (lastReturned == null)
-                throw new IllegalStateException("Entry was removed");
-            return ConcurrentHashMap.this.get(lastReturned.key);
-        }
-
-        public V setValue(V value) {
-            if (lastReturned == null)
-                throw new IllegalStateException("Entry was removed");
-            return ConcurrentHashMap.this.put(lastReturned.key, value);
-        }
-
-        public boolean equals(Object o) {
-            // If not acting as entry, just use default.
-            if (lastReturned == null)
-                return super.equals(o);
-            if (!(o instanceof Map.Entry))
-                return false;
-            Map.Entry e = (Map.Entry)o;
-            return eq(getKey(), e.getKey()) && eq(getValue(), e.getValue());
-        }
-
-        public int hashCode() {
-            // If not acting as entry, just use default.
-            if (lastReturned == null)
-                return super.hashCode();
-
-            Object k = getKey();
-            Object v = getValue();
-            return ((k == null) ? 0 : k.hashCode()) ^
-                   ((v == null) ? 0 : v.hashCode());
-        }
-
-        public String toString() {
-            // If not acting as entry, just use default.
-            if (lastReturned == null)
-                return super.toString();
-            else
-                return getKey() + "=" + getValue();
-        }
-
-        boolean eq(Object o1, Object o2) {
-            return (o1 == null ? o2 == null : o1.equals(o2));
-        }
-
-    }
-
-    final class KeySet extends AbstractSet<K> {
-        public Iterator<K> iterator() {
-            return new KeyIterator();
-        }
-        public int size() {
-            return ConcurrentHashMap.this.size();
-        }
-        public boolean contains(Object o) {
-            return ConcurrentHashMap.this.containsKey(o);
-        }
-        public boolean remove(Object o) {
-            return ConcurrentHashMap.this.remove(o) != null;
-        }
-        public void clear() {
-            ConcurrentHashMap.this.clear();
-        }
-    }
-
-    final class Values extends AbstractCollection<V> {
-        public Iterator<V> iterator() {
-            return new ValueIterator();
-        }
-        public int size() {
-            return ConcurrentHashMap.this.size();
-        }
-        public boolean contains(Object o) {
-            return ConcurrentHashMap.this.containsValue(o);
-        }
-        public void clear() {
-            ConcurrentHashMap.this.clear();
-        }
-    }
-
-    final class EntrySet extends AbstractSet<Map.Entry<K,V>> {
-        public Iterator<Map.Entry<K,V>> iterator() {
-            return new EntryIterator();
-        }
-        public boolean contains(Object o) {
-            if (!(o instanceof Map.Entry))
-                return false;
-            Map.Entry<K,V> e = (Map.Entry<K,V>)o;
-            V v = ConcurrentHashMap.this.get(e.getKey());
-            return v != null && v.equals(e.getValue());
-        }
-        public boolean remove(Object o) {
-            if (!(o instanceof Map.Entry))
-                return false;
-            Map.Entry<K,V> e = (Map.Entry<K,V>)o;
-            return ConcurrentHashMap.this.remove(e.getKey(), e.getValue());
-        }
-        public int size() {
-            return ConcurrentHashMap.this.size();
-        }
-        public void clear() {
-            ConcurrentHashMap.this.clear();
-        }
-        public Object[] toArray() {
-            // Since we don't ordinarily have distinct Entry objects, we
-            // must pack elements using exportable SimpleEntry
-            Collection<Map.Entry<K,V>> c = new ArrayList<Map.Entry<K,V>>(size());
-            for (Iterator<Map.Entry<K,V>> i = iterator(); i.hasNext(); )
-                c.add(new SimpleEntry<K,V>(i.next()));
-            return c.toArray();
-        }
-        public <T> T[] toArray(T[] a) {
-            Collection<Map.Entry<K,V>> c = new ArrayList<Map.Entry<K,V>>(size());
-            for (Iterator<Map.Entry<K,V>> i = iterator(); i.hasNext(); )
-                c.add(new SimpleEntry<K,V>(i.next()));
-            return c.toArray(a);
-        }
-
-    }
-
-    /**
-     * This duplicates java.util.AbstractMap.SimpleEntry until this class
-     * is made accessible.
-     */
-    static final class SimpleEntry<K,V> implements Entry<K,V> {
-        K key;
-        V value;
-
-        public SimpleEntry(K key, V value) {
-            this.key   = key;
-            this.value = value;
-        }
-
-        public SimpleEntry(Entry<K,V> e) {
-            this.key   = e.getKey();
-            this.value = e.getValue();
-        }
-
-        public K getKey() {
-            return key;
-        }
-
-        public V getValue() {
-            return value;
-        }
-
-        public V setValue(V value) {
-            V oldValue = this.value;
-            this.value = value;
-            return oldValue;
-        }
-
-        public boolean equals(Object o) {
-            if (!(o instanceof Map.Entry))
-                return false;
-            Map.Entry e = (Map.Entry)o;
-            return eq(key, e.getKey()) && eq(value, e.getValue());
-        }
-
-        public int hashCode() {
-            return ((key   == null)   ? 0 :   key.hashCode()) ^
-                   ((value == null)   ? 0 : value.hashCode());
-        }
-
-        public String toString() {
-            return key + "=" + value;
-        }
-
-        static boolean eq(Object o1, Object o2) {
-            return (o1 == null ? o2 == null : o1.equals(o2));
-        }
-    }
-
-    /* ---------------- Serialization Support -------------- */
-
-    /**
-     * Save the state of the <tt>ConcurrentHashMap</tt>
-     * instance to a stream (i.e.,
-     * serialize it).
-     * @param s the stream
-     * @serialData
-     * the key (Object) and value (Object)
-     * for each key-value mapping, followed by a null pair.
-     * The key-value mappings are emitted in no particular order.
-     */
-    private void writeObject(java.io.ObjectOutputStream s) throws IOException  {
-        s.defaultWriteObject();
-
-        for (int k = 0; k < segments.length; ++k) {
-            Segment<K,V> seg = (Segment<K,V>)segments[k];
-            seg.lock();
-            try {
-                HashEntry[] tab = seg.table;
-                for (int i = 0; i < tab.length; ++i) {
-                    for (HashEntry<K,V> e = (HashEntry<K,V>)tab[i]; e != null; e = e.next) {
-                        s.writeObject(e.key);
-                        s.writeObject(e.value);
-                    }
-                }
-            } finally {
-                seg.unlock();
-            }
-        }
-        s.writeObject(null);
-        s.writeObject(null);
-    }
-
-    /**
-     * Reconstitute the <tt>ConcurrentHashMap</tt>
-     * instance from a stream (i.e.,
-     * deserialize it).
-     * @param s the stream
-     */
-    private void readObject(java.io.ObjectInputStream s)
-        throws IOException, ClassNotFoundException  {
-        s.defaultReadObject();
-
-        // Initialize each segment to be minimally sized, and let grow.
-        for (int i = 0; i < segments.length; ++i) {
-            segments[i].setTable(new HashEntry[1]);
-        }
-
-        // Read the keys and values, and put the mappings in the table
-        for (;;) {
-            K key = (K) s.readObject();
-            V value = (V) s.readObject();
-            if (key == null)
-                break;
-            put(key, value);
-        }
-    }
-}
-
diff --git a/concurrent/src/main/java/java/util/concurrent/ConcurrentLinkedQueue.java b/concurrent/src/main/java/java/util/concurrent/ConcurrentLinkedQueue.java
deleted file mode 100644
index 794142d..0000000
--- a/concurrent/src/main/java/java/util/concurrent/ConcurrentLinkedQueue.java
+++ /dev/null
@@ -1,481 +0,0 @@
-/*
- * Written by Doug Lea with assistance from members of JCP JSR-166
- * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
- */
-
-package java.util.concurrent;
-import java.util.*;
-import java.util.concurrent.atomic.*;
-
-
-// BEGIN android-note
-// removed link to collections framework docs
-// END android-note
-
-/**
- * An unbounded thread-safe {@linkplain Queue queue} based on linked nodes.  
- * This queue orders elements FIFO (first-in-first-out).
- * The <em>head</em> of the queue is that element that has been on the
- * queue the longest time.
- * The <em>tail</em> of the queue is that element that has been on the
- * queue the shortest time. New elements
- * are inserted at the tail of the queue, and the queue retrieval
- * operations obtain elements at the head of the queue.
- * A <tt>ConcurrentLinkedQueue</tt> is an appropriate choice when 
- * many threads will share access to a common collection.
- * This queue does not permit <tt>null</tt> elements.
- *
- * <p>This implementation employs an efficient &quot;wait-free&quot; 
- * algorithm based on one described in <a
- * href="http://www.cs.rochester.edu/u/michael/PODC96.html"> Simple,
- * Fast, and Practical Non-Blocking and Blocking Concurrent Queue
- * Algorithms</a> by Maged M. Michael and Michael L. Scott.
- *
- * <p>Beware that, unlike in most collections, the <tt>size</tt> method
- * is <em>NOT</em> a constant-time operation. Because of the
- * asynchronous nature of these queues, determining the current number
- * of elements requires a traversal of the elements.
- *
- * <p>This class implements all of the <em>optional</em> methods
- * of the {@link Collection} and {@link Iterator} interfaces.
- *
- * @since 1.5
- * @author Doug Lea
- * @param <E> the type of elements held in this collection
- *
- */
-public class ConcurrentLinkedQueue<E> extends AbstractQueue<E>
-        implements Queue<E>, java.io.Serializable {
-    private static final long serialVersionUID = 196745693267521676L;
-
-    /*
-     * This is a straight adaptation of Michael & Scott algorithm.
-     * For explanation, read the paper.  The only (minor) algorithmic
-     * difference is that this version supports lazy deletion of
-     * internal nodes (method remove(Object)) -- remove CAS'es item
-     * fields to null. The normal queue operations unlink but then
-     * pass over nodes with null item fields. Similarly, iteration
-     * methods ignore those with nulls.
-     */
-
-    private static class Node<E> {
-        private volatile E item;
-        private volatile Node<E> next;
-        
-        private static final 
-            AtomicReferenceFieldUpdater<Node, Node> 
-            nextUpdater =
-            AtomicReferenceFieldUpdater.newUpdater
-            (Node.class, Node.class, "next");
-        private static final 
-            AtomicReferenceFieldUpdater<Node, Object> 
-            itemUpdater =
-            AtomicReferenceFieldUpdater.newUpdater
-            (Node.class, Object.class, "item");
-        
-        Node(E x) { item = x; }
-        
-        Node(E x, Node<E> n) { item = x; next = n; }
-        
-        E getItem() {
-            return item;
-        }
-        
-        boolean casItem(E cmp, E val) {
-            return itemUpdater.compareAndSet(this, cmp, val);
-        }
-        
-        void setItem(E val) {
-            itemUpdater.set(this, val);
-        }
-        
-        Node<E> getNext() {
-            return next;
-        }
-        
-        boolean casNext(Node<E> cmp, Node<E> val) {
-            return nextUpdater.compareAndSet(this, cmp, val);
-        }
-        
-        void setNext(Node<E> val) {
-            nextUpdater.set(this, val);
-        }
-        
-    }
-
-    private static final 
-        AtomicReferenceFieldUpdater<ConcurrentLinkedQueue, Node> 
-        tailUpdater = 
-        AtomicReferenceFieldUpdater.newUpdater
-        (ConcurrentLinkedQueue.class, Node.class, "tail");
-    private static final 
-        AtomicReferenceFieldUpdater<ConcurrentLinkedQueue, Node> 
-        headUpdater = 
-        AtomicReferenceFieldUpdater.newUpdater
-        (ConcurrentLinkedQueue.class,  Node.class, "head");
-
-    private boolean casTail(Node<E> cmp, Node<E> val) {
-        return tailUpdater.compareAndSet(this, cmp, val);
-    }
-
-    private boolean casHead(Node<E> cmp, Node<E> val) {
-        return headUpdater.compareAndSet(this, cmp, val);
-    }
-
-
-    /**
-     * Pointer to header node, initialized to a dummy node.  The first
-     * actual node is at head.getNext().
-     */
-    private transient volatile Node<E> head = new Node<E>(null, null);
-
-    /** Pointer to last node on list **/
-    private transient volatile Node<E> tail = head;
-
-
-    /**
-     * Creates a <tt>ConcurrentLinkedQueue</tt> that is initially empty.
-     */
-    public ConcurrentLinkedQueue() {}
-
-    /**
-     * Creates a <tt>ConcurrentLinkedQueue</tt> 
-     * initially containing the elements of the given collection,
-     * added in traversal order of the collection's iterator.
-     * @param c the collection of elements to initially contain
-     * @throws NullPointerException if <tt>c</tt> or any element within it
-     * is <tt>null</tt>
-     */
-    public ConcurrentLinkedQueue(Collection<? extends E> c) {
-        for (Iterator<? extends E> it = c.iterator(); it.hasNext();)
-            add(it.next());
-    }
-
-    // Have to override just to update the javadoc 
-
-    /**
-     * Adds the specified element to the tail of this queue.
-     * @param o the element to add.
-     * @return <tt>true</tt> (as per the general contract of
-     * <tt>Collection.add</tt>).
-     *
-     * @throws NullPointerException if the specified element is <tt>null</tt>
-     */
-    public boolean add(E o) {
-        return offer(o);
-    }
-
-    /**
-     * Inserts the specified element to the tail of this queue.
-     *
-     * @param o the element to add.
-     * @return <tt>true</tt> (as per the general contract of
-     * <tt>Queue.offer</tt>).
-     * @throws NullPointerException if the specified element is <tt>null</tt>
-     */
-    public boolean offer(E o) {
-        if (o == null) throw new NullPointerException();
-        Node<E> n = new Node<E>(o, null);
-        for(;;) {
-            Node<E> t = tail;
-            Node<E> s = t.getNext();
-            if (t == tail) {
-                if (s == null) {
-                    if (t.casNext(s, n)) {
-                        casTail(t, n);
-                        return true;
-                    }
-                } else {
-                    casTail(t, s);
-                }
-            }
-        }
-    }
-
-    public E poll() {
-        for (;;) {
-            Node<E> h = head;
-            Node<E> t = tail;
-            Node<E> first = h.getNext();
-            if (h == head) {
-                if (h == t) {
-                    if (first == null)
-                        return null;
-                    else
-                        casTail(t, first);
-                } else if (casHead(h, first)) {
-                    E item = first.getItem();
-                    if (item != null) {
-                        first.setItem(null);
-                        return item;
-                    }
-                    // else skip over deleted item, continue loop,
-                }
-            }
-        }
-    }
-
-    public E peek() { // same as poll except don't remove item
-        for (;;) {
-            Node<E> h = head;
-            Node<E> t = tail;
-            Node<E> first = h.getNext();
-            if (h == head) {
-                if (h == t) {
-                    if (first == null)
-                        return null;
-                    else
-                        casTail(t, first);
-                } else {
-                    E item = first.getItem();
-                    if (item != null)
-                        return item;
-                    else // remove deleted node and continue
-                        casHead(h, first);
-                }
-            }
-        }
-    }
-
-    /**
-     * Returns the first actual (non-header) node on list.  This is yet
-     * another variant of poll/peek; here returning out the first
-     * node, not element (so we cannot collapse with peek() without
-     * introducing race.)
-     */
-    Node<E> first() {
-        for (;;) {
-            Node<E> h = head;
-            Node<E> t = tail;
-            Node<E> first = h.getNext();
-            if (h == head) {
-                if (h == t) {
-                    if (first == null)
-                        return null;
-                    else
-                        casTail(t, first);
-                } else {
-                    if (first.getItem() != null)
-                        return first;
-                    else // remove deleted node and continue
-                        casHead(h, first);
-                }
-            }
-        }
-    }
-
-
-    public boolean isEmpty() {
-        return first() == null;
-    }
-
-    /**
-     * Returns the number of elements in this queue.  If this queue
-     * contains more than <tt>Integer.MAX_VALUE</tt> elements, returns
-     * <tt>Integer.MAX_VALUE</tt>.
-     *
-     * <p>Beware that, unlike in most collections, this method is
-     * <em>NOT</em> a constant-time operation. Because of the
-     * asynchronous nature of these queues, determining the current
-     * number of elements requires an O(n) traversal.
-     *
-     * @return  the number of elements in this queue.
-     */
-    public int size() {
-        int count = 0;
-        for (Node<E> p = first(); p != null; p = p.getNext()) {
-            if (p.getItem() != null) {
-                // Collections.size() spec says to max out
-                if (++count == Integer.MAX_VALUE)
-                    break;
-            }
-        }
-        return count;
-    }
-
-    public boolean contains(Object o) {
-        if (o == null) return false;
-        for (Node<E> p = first(); p != null; p = p.getNext()) {
-            E item = p.getItem();
-            if (item != null &&
-                o.equals(item))
-                return true;
-        }
-        return false;
-    }
-
-    public boolean remove(Object o) {
-        if (o == null) return false;
-        for (Node<E> p = first(); p != null; p = p.getNext()) {
-            E item = p.getItem();
-            if (item != null &&
-                o.equals(item) &&
-                p.casItem(item, null))
-                return true;
-        }
-        return false;
-    }
-
-    public Object[] toArray() {
-        // Use ArrayList to deal with resizing.
-        ArrayList<E> al = new ArrayList<E>();
-        for (Node<E> p = first(); p != null; p = p.getNext()) {
-            E item = p.getItem();
-            if (item != null)
-                al.add(item);
-        }
-        return al.toArray();
-    }
-
-    public <T> T[] toArray(T[] a) {
-        // try to use sent-in array
-        int k = 0;
-        Node<E> p;
-        for (p = first(); p != null && k < a.length; p = p.getNext()) {
-            E item = p.getItem();
-            if (item != null)
-                a[k++] = (T)item;
-        }
-        if (p == null) {
-            if (k < a.length)
-                a[k] = null;
-            return a;
-        }
-
-        // If won't fit, use ArrayList version
-        ArrayList<E> al = new ArrayList<E>();
-        for (Node<E> q = first(); q != null; q = q.getNext()) {
-            E item = q.getItem();
-            if (item != null)
-                al.add(item);
-        }
-        return (T[])al.toArray(a);
-    }
-
-    /**
-     * Returns an iterator over the elements in this queue in proper sequence.
-     * The returned iterator is a "weakly consistent" iterator that
-     * will never throw {@link java.util.ConcurrentModificationException},
-     * and guarantees to traverse elements as they existed upon
-     * construction of the iterator, and may (but is not guaranteed to)
-     * reflect any modifications subsequent to construction.
-     *
-     * @return an iterator over the elements in this queue in proper sequence.
-     */
-    public Iterator<E> iterator() {
-        return new Itr();
-    }
-
-    private class Itr implements Iterator<E> {
-        /**
-         * Next node to return item for.
-         */
-        private Node<E> nextNode;
-
-        /**
-         * nextItem holds on to item fields because once we claim
-         * that an element exists in hasNext(), we must return it in
-         * the following next() call even if it was in the process of
-         * being removed when hasNext() was called.
-         **/
-        private E nextItem;
-
-        /**
-         * Node of the last returned item, to support remove.
-         */
-        private Node<E> lastRet;
-
-        Itr() {
-            advance();
-        }
-
-        /**
-         * Moves to next valid node and returns item to return for
-         * next(), or null if no such.
-         */
-        private E advance() {
-            lastRet = nextNode;
-            E x = nextItem;
-
-            Node<E> p = (nextNode == null)? first() : nextNode.getNext();
-            for (;;) {
-                if (p == null) {
-                    nextNode = null;
-                    nextItem = null;
-                    return x;
-                }
-                E item = p.getItem();
-                if (item != null) {
-                    nextNode = p;
-                    nextItem = item;
-                    return x;
-                } else // skip over nulls
-                    p = p.getNext();
-            }
-        }
-
-        public boolean hasNext() {
-            return nextNode != null;
-        }
-
-        public E next() {
-            if (nextNode == null) throw new NoSuchElementException();
-            return advance();
-        }
-
-        public void remove() {
-            Node<E> l = lastRet;
-            if (l == null) throw new IllegalStateException();
-            // rely on a future traversal to relink.
-            l.setItem(null);
-            lastRet = null;
-        }
-    }
-
-    /**
-     * Save the state to a stream (that is, serialize it).
-     *
-     * @serialData All of the elements (each an <tt>E</tt>) in
-     * the proper order, followed by a null
-     * @param s the stream
-     */
-    private void writeObject(java.io.ObjectOutputStream s)
-        throws java.io.IOException {
-
-        // Write out any hidden stuff
-        s.defaultWriteObject();
-
-        // Write out all elements in the proper order.
-        for (Node<E> p = first(); p != null; p = p.getNext()) {
-            Object item = p.getItem();
-            if (item != null)
-                s.writeObject(item);
-        }
-
-        // Use trailing null as sentinel
-        s.writeObject(null);
-    }
-
-    /**
-     * Reconstitute the Queue instance from a stream (that is,
-     * deserialize it).
-     * @param s the stream
-     */
-    private void readObject(java.io.ObjectInputStream s)
-        throws java.io.IOException, ClassNotFoundException {
-        // Read in capacity, and any hidden stuff
-        s.defaultReadObject();
-        head = new Node<E>(null, null);
-        tail = head;
-        // Read in all elements and place in queue
-        for (;;) {
-            E item = (E)s.readObject();
-            if (item == null)
-                break;
-            else
-                offer(item);
-        }
-    }
-
-}
diff --git a/concurrent/src/main/java/java/util/concurrent/ConcurrentMap.java b/concurrent/src/main/java/java/util/concurrent/ConcurrentMap.java
deleted file mode 100644
index 32dc000..0000000
--- a/concurrent/src/main/java/java/util/concurrent/ConcurrentMap.java
+++ /dev/null
@@ -1,118 +0,0 @@
-/*
- * Written by Doug Lea with assistance from members of JCP JSR-166
- * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
- */
-
-package java.util.concurrent;
-import java.util.Map;
-
-// BEGIN android-note
-// removed link to collections framework docs
-// END android-note
-
-/**
- * A {@link java.util.Map} providing additional atomic
- * <tt>putIfAbsent</tt>, <tt>remove</tt>, and <tt>replace</tt> methods.
- *
- * @since 1.5
- * @author Doug Lea
- * @param <K> the type of keys maintained by this map
- * @param <V> the type of mapped values 
- */
-public interface ConcurrentMap<K, V> extends Map<K, V> {
-    /**
-     * If the specified key is not already associated
-     * with a value, associate it with the given value.
-     * This is equivalent to
-     * <pre>
-     *   if (!map.containsKey(key)) 
-     *      return map.put(key, value);
-     *   else
-     *      return map.get(key);
-     * </pre>
-     * Except that the action is performed atomically.
-     * @param key key with which the specified value is to be associated.
-     * @param value value to be associated with the specified key.
-     * @return previous value associated with specified key, or <tt>null</tt>
-     *         if there was no mapping for key.  A <tt>null</tt> return can
-     *         also indicate that the map previously associated <tt>null</tt>
-     *         with the specified key, if the implementation supports
-     *         <tt>null</tt> values.
-     *
-     * @throws UnsupportedOperationException if the <tt>put</tt> operation is
-     *            not supported by this map.
-     * @throws ClassCastException if the class of the specified key or value
-     *            prevents it from being stored in this map.
-     * @throws IllegalArgumentException if some aspect of this key or value
-     *            prevents it from being stored in this map.
-     * @throws NullPointerException if this map does not permit <tt>null</tt>
-     *            keys or values, and the specified key or value is
-     *            <tt>null</tt>.
-     *
-     */
-    V putIfAbsent(K key, V value);
-
-    /**
-     * Remove entry for key only if currently mapped to given value.
-     * Acts as
-     * <pre> 
-     *  if ((map.containsKey(key) && map.get(key).equals(value)) {
-     *     map.remove(key);
-     *     return true;
-     * } else return false;
-     * </pre>
-     * except that the action is performed atomically.
-     * @param key key with which the specified value is associated.
-     * @param value value associated with the specified key.
-     * @return true if the value was removed, false otherwise
-     * @throws NullPointerException if this map does not permit <tt>null</tt>
-     *            keys or values, and the specified key or value is
-     *            <tt>null</tt>.
-     */
-    boolean remove(Object key, Object value);
-
-
-    /**
-     * Replace entry for key only if currently mapped to given value.
-     * Acts as
-     * <pre> 
-     *  if ((map.containsKey(key) && map.get(key).equals(oldValue)) {
-     *     map.put(key, newValue);
-     *     return true;
-     * } else return false;
-     * </pre>
-     * except that the action is performed atomically.
-     * @param key key with which the specified value is associated.
-     * @param oldValue value expected to be associated with the specified key.
-     * @param newValue value to be associated with the specified key.
-     * @return true if the value was replaced
-     * @throws NullPointerException if this map does not permit <tt>null</tt>
-     *            keys or values, and the specified key or value is
-     *            <tt>null</tt>.
-     */
-    boolean replace(K key, V oldValue, V newValue);
-
-    /**
-     * Replace entry for key only if currently mapped to some value.
-     * Acts as
-     * <pre> 
-     *  if ((map.containsKey(key)) {
-     *     return map.put(key, value);
-     * } else return null;
-     * </pre>
-     * except that the action is performed atomically.
-     * @param key key with which the specified value is associated.
-     * @param value value to be associated with the specified key.
-     * @return previous value associated with specified key, or <tt>null</tt>
-     *         if there was no mapping for key.  A <tt>null</tt> return can
-     *         also indicate that the map previously associated <tt>null</tt>
-     *         with the specified key, if the implementation supports
-     *         <tt>null</tt> values.
-     * @throws NullPointerException if this map does not permit <tt>null</tt>
-     *            keys or values, and the specified key or value is
-     *            <tt>null</tt>.
-     */
-    V replace(K key, V value);
-
-}
diff --git a/concurrent/src/main/java/java/util/concurrent/CopyOnWriteArrayList.java b/concurrent/src/main/java/java/util/concurrent/CopyOnWriteArrayList.java
deleted file mode 100644
index 7274595..0000000
--- a/concurrent/src/main/java/java/util/concurrent/CopyOnWriteArrayList.java
+++ /dev/null
@@ -1,1190 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements. See the NOTICE file distributed with this
- * work for additional information regarding copyright ownership. The ASF
- * licenses this file to you under the Apache License, Version 2.0 (the
- * "License"); you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- * 
- * http://www.apache.org/licenses/LICENSE-2.0
- * 
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
- * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
- * License for the specific language governing permissions and limitations under
- * the License.
- */
-
-package java.util.concurrent;
-
-import java.io.IOException;
-import java.io.ObjectInputStream;
-import java.io.ObjectOutputStream;
-import java.io.Serializable;
-import java.lang.reflect.Array;
-import java.util.Collection;
-import java.util.ConcurrentModificationException;
-import java.util.Iterator;
-import java.util.List;
-import java.util.ListIterator;
-import java.util.NoSuchElementException;
-import java.util.RandomAccess;
-import java.util.concurrent.locks.ReentrantLock;
-
-// BEGIN android-added
-/**
- * Implements a {@link java.util.ArrayList} variant that is thread-safe. All
- * write operation result in a new copy of the underlying data being created.
- * Iterators reflect the state of the CopyOnWriteArrayList at the time they were
- * created. They are not updated to reflect subsequent changes to the list. In
- * addition, these iterators cannot be used for modifying the underlying
- * CopyOnWriteArrayList.
- * 
- * @param <E> the element type
- */
-// END android-added
-public class CopyOnWriteArrayList<E> implements List<E>, RandomAccess, Cloneable, Serializable {
-
-    private static final long serialVersionUID = 8673264195747942595L;
-
-    private transient volatile E[] arr;
-
-    /**
-     * Lock for the queue write methods
-     */
-    private final transient ReentrantLock lock = new ReentrantLock();
-
-    // BEGIN android-added
-    /**
-     * Creates a new, empty instance of CopyOnWriteArrayList. 
-     */
-    // END android-added
-    public CopyOnWriteArrayList() {
-    }
-
-    // BEGIN android-added
-    /**
-     * Creates a new instance of CopyOnWriteArrayList and fills it with the
-     * contents of a given Collection.
-     * 
-     * @param c     the collection the elements of which are to be copied into
-     *              the new instance.
-     */
-    // END android-added
-    public CopyOnWriteArrayList(Collection<? extends E> c) {
-        this((E[]) c.toArray());
-    }
-
-    // BEGIN android-added
-    /**
-     * Creates a new instance of CopyOnWriteArrayList and fills it with the
-     * contents of a given array.
-     * 
-     * @param array the array the elements of which are to be copied into the
-     *              new instance.
-     */
-    // END android-added
-    public CopyOnWriteArrayList(E[] array) {
-        int size = array.length;
-        E[] data = newElementArray(size);
-        for (int i = 0; i < size; i++) {
-            data[i] = array[i];
-        }
-        arr = data;
-    }
-
-    public boolean add(E e) {
-        lock.lock();
-        try {
-            E[] data;
-            E[] old = getData();
-            int size = old.length;
-            data = newElementArray(size + 1);
-            System.arraycopy(old, 0, data, 0, size);
-            data[size] = e;
-            setData(data);
-            return true;
-        } finally {
-            lock.unlock();
-        }
-    }
-
-    public void add(int index, E e) {
-        lock.lock();
-        try {
-            E[] data;
-            E[] old = getData();
-            int size = old.length;
-            checkIndexInclusive(index, size);
-            data = newElementArray(size+1);
-            System.arraycopy(old, 0, data, 0, index);
-            data[index] = e;
-            if (size > index) {
-                System.arraycopy(old, index, data, index + 1, size - index);
-            }
-            setData(data);
-        } finally {
-            lock.unlock();
-        }
-    }
-
-    public boolean addAll(Collection<? extends E> c) {
-        Iterator it = c.iterator();
-        int ssize = c.size();
-        lock.lock();
-        try {
-            int size = size();
-            E[] data;
-            E[] old = getData();
-            int nSize = size + ssize;
-            data = newElementArray(nSize);
-            System.arraycopy(old, 0, data, 0, size);
-            while (it.hasNext()) {
-                data[size++] = (E) it.next();
-            }
-            setData(data);
-        } finally {
-            lock.unlock();
-        }
-        return true;
-    }
-
-    public boolean addAll(int index, Collection<? extends E> c) {
-        Iterator it = c.iterator();
-        int ssize = c.size();
-        lock.lock();
-        try {
-            int size = size();
-            checkIndexInclusive(index, size);
-            E[] data;
-            E[] old = getData();
-            int nSize = size + ssize;
-            data = newElementArray(nSize);
-            System.arraycopy(old, 0, data, 0, index);
-            int i = index;
-            while (it.hasNext()) {
-                data[i++] = (E) it.next();
-            }
-            if (size > index) {
-                System.arraycopy(old, index, data, index + ssize, size - index);
-            }
-            setData(data);
-        } finally {
-            lock.unlock();
-        }
-        return true;
-    }
-
-    // BEGIN android-added
-    /**
-     * Adds to this CopyOnWriteArrayList all those elements from a given
-     * collection that are not yet part of the list.
-     * 
-     * @param c     the collection from which the potential new elements are
-     *              taken.
-     * 
-     * @return the number of elements actually added to this list.
-     */
-    // END android-added
-    public int addAllAbsent(Collection<? extends E> c) {
-        if (c.size() == 0) {
-            return 0;
-        }
-        lock.lock();
-        try {
-            E[] old = getData();
-            int size = old.length;
-            E[] toAdd = newElementArray(c.size());
-            int i = 0;
-            for (Iterator it = c.iterator(); it.hasNext();) {
-                E o = (E) it.next();
-                if (indexOf(o) < 0) {
-                    toAdd[i++] = o;
-                }
-            }
-            E[] data = newElementArray(size + i);
-            System.arraycopy(old, 0, data, 0, size);
-            System.arraycopy(toAdd, 0, data, size, i);
-            setData(data);
-            return i;
-        } finally {
-            lock.unlock();
-        }
-    }
-
-    // BEGIN android-added
-    /**
-     * Adds to this CopyOnWriteArrayList another element, given that this
-     * element is not yet part of the list.
-     * 
-     * @param e     the potential new element.
-     * 
-     * @return true if the element was added, or false otherwise.
-     */
-    // END android-added
-    public boolean addIfAbsent(E e) {
-        lock.lock();
-        try {
-            E[] data;
-            E[] old = getData();
-            int size = old.length;
-            if (size != 0) {
-                if (indexOf(e) >= 0) {
-                    return false;
-                }
-            }
-            data = newElementArray(size + 1);
-            System.arraycopy(old, 0, data, 0, size);
-            data[size] = e;
-            setData(data);
-            return true;
-        } finally {
-            lock.unlock();
-        }
-    }
-
-    public void clear() {
-        lock.lock();
-        try {
-            setData(newElementArray(0));
-        } finally {
-            lock.unlock();
-        }
-    }
-
-    @Override
-    public Object clone() {
-        try {
-            CopyOnWriteArrayList thisClone = (CopyOnWriteArrayList) super.clone();
-            thisClone.setData(this.getData());
-            return thisClone;
-        } catch (CloneNotSupportedException e) {
-            throw new RuntimeException("CloneNotSupportedException is not expected here");
-        }
-    }
-
-    public boolean contains(Object o) {
-        return indexOf(o) >= 0;
-    }
-
-    public boolean containsAll(Collection<?> c) {
-        E[] data = getData();
-        return containsAll(c, data, 0, data.length);
-    }
-
-    public boolean equals(Object o) {
-        if (o == this) {
-            return true;
-        }
-        if (!(o instanceof List)) {
-            return false;
-        }
-        List l = (List) o;
-        Iterator it = l.listIterator();
-        Iterator ourIt = listIterator();
-        while (it.hasNext()) {
-            if (!ourIt.hasNext()) {
-                return false;
-            }
-            Object thisListElem = it.next();
-            Object anotherListElem = ourIt.next();
-            if (!(thisListElem == null ? anotherListElem == null : thisListElem
-                    .equals(anotherListElem))) {
-                return false;
-            }
-        }
-        if (ourIt.hasNext()) {
-            return false;
-        }
-        return true;
-    }
-
-    public E get(int index) {
-        E[] data = getData();
-        return data[index];
-    }
-
-    public int hashCode() {
-        int hashCode = 1;
-        Iterator it = listIterator();
-        while (it.hasNext()) {
-            Object obj = it.next();
-            hashCode = 31 * hashCode + (obj == null ? 0 : obj.hashCode());
-        }
-        return hashCode;
-    }
-
-    // BEGIN android-added
-    /**
-     * Returns the index of a given element, starting the search from a given
-     * position in the list. 
-     * 
-     * @param e     the element to search.
-     * @param index the index at which to start the search.
-     * 
-     * @return the index of the element or null, if the element has not been
-     * found at or beyond the given start index.
-     */
-    // END android-added
-    public int indexOf(E e, int index) {
-        E[] data = getData();
-        return indexOf(e, data, index, data.length - index);
-    }
-
-    public int indexOf(Object o) {
-        E[] data = getData();
-        return indexOf(o, data, 0, data.length);
-    }
-
-    public boolean isEmpty() {
-        return size() == 0;
-    }
-
-    public Iterator<E> iterator() {
-        return new ListIteratorImpl(getData(), 0);
-    }
-
-    // BEGIN android-added
-    /**
-     * Returns the last index of a given element, starting the search from
-     * a given position in the list and going backwards. 
-     * 
-     * @param e     the element to search.
-     * @param index the index at which to start the search.
-     * 
-     * @return the index of the element or null, if the element has not been
-     * found at or before the given start index.
-     */
-    // END android-added
-    public int lastIndexOf(E e, int index) {
-        E[] data = getData();
-        return lastIndexOf(e, data, 0, index);
-    }
-
-    public int lastIndexOf(Object o) {
-        E[] data = getData();
-        return lastIndexOf(o, data, 0, data.length);
-    }
-
-    public ListIterator<E> listIterator() {
-        return new ListIteratorImpl(getData(), 0);
-    }
-
-    public ListIterator<E> listIterator(int index) {
-        E[] data = getData();
-        checkIndexInclusive(index, data.length);
-        return new ListIteratorImpl(data, index);
-    }
-
-    public E remove(int index) {
-        return removeRange(index, 1);
-    }
-
-    public boolean remove(Object o) {
-        lock.lock();
-        try {
-            int index = indexOf(o);
-            if (index == -1) {
-                return false;
-            }
-            remove(index);
-            return true;
-        } finally {
-            lock.unlock();
-        }
-    }
-
-    public boolean removeAll(Collection<?> c) {
-        lock.lock();
-        try {
-            return removeAll(c, 0, getData().length) != 0;
-        } finally {
-            lock.unlock();
-        }
-    }
-
-    public boolean retainAll(Collection<?> c) {
-        if (c == null) {
-            throw new NullPointerException();
-        }
-        lock.lock();
-        try {
-            return retainAll(c, 0, getData().length) != 0;
-        } finally {
-            lock.unlock();
-        }
-    }
-
-    public E set(int index, E e) {
-        lock.lock();
-        try {
-            int size = size();
-            checkIndexExlusive(index, size);
-            E[] data;
-            data = newElementArray(size);
-            E[] oldArr = getData();
-            System.arraycopy(oldArr, 0, data, 0, size);
-            E old = data[index];
-            data[index] = e;
-            setData(data);
-            return old;
-        } finally {
-            lock.unlock();
-        }
-    }
-
-    public int size() {
-        return getData().length;
-    }
-
-    public List<E> subList(int fromIndex, int toIndex) {
-        return new SubList(this, fromIndex, toIndex);
-    }
-
-    public Object[] toArray() {
-        E[] data = getData();
-        return toArray(data, 0, data.length);
-    }
-
-    public <T> T[] toArray(T[] a) {
-        E[] data = getData();
-        return (T[]) toArray(a, data, 0, data.length);
-    }
-
-    @Override
-    public String toString() {
-        StringBuffer sb = new StringBuffer("[");
-
-        Iterator it = listIterator();
-        while (it.hasNext()) {
-            sb.append(String.valueOf(it.next()));
-            sb.append(", ");
-        }
-        if (sb.length() > 1) {
-            sb.setLength(sb.length() - 2);
-        }
-        sb.append("]");
-        return sb.toString();
-    }
-
-    // private and package private methods
-
-    @SuppressWarnings("unchecked")
-    private final E[] newElementArray(int size) {
-        return (E[])new Object[size];
-    }
-
-    /**
-     * sets the internal data array
-     *
-     * @param data array to set
-     */
-    private final void setData(E[] data) {
-        arr = data;
-    }
-
-    /**
-     * gets the internal data array
-     *
-     * @return the data array
-     */
-    final E[] getData() {
-        if (arr == null) {
-            return newElementArray(0);
-        }
-        return arr;
-    }
-
-    /**
-     * Removes from the specified range of this list
-     * all the elements that are contained in the specified collection
-     * <p/>
-     * !should be called under lock
-     *
-     * @return Returns the number of removed elements
-     */
-    final int removeAll(Collection c, int start, int size) {
-        int ssize = c.size();
-        if (ssize == 0) {
-            return 0;
-        }
-        Object[] old = getData();
-        int arrsize = old.length;
-        if (arrsize == 0) {
-            return 0;
-        }
-        Object[] data = new Object[size];
-        int j = 0;
-        for (int i = start; i < (start + size); i++) {
-            if (!c.contains(old[i])) {
-                data[j++] = old[i];
-            }
-        }
-        if (j != size) {
-            E[] result = newElementArray(arrsize - (size - j));
-            System.arraycopy(old, 0, result, 0, start);
-            System.arraycopy(data, 0, result, start, j);
-            System.arraycopy(old, start + size, result, start + j, arrsize
-                    - (start + size));
-            setData(result);
-            return (size - j);
-        }
-        return 0;
-    }
-
-    /**
-     * Retains only the elements in the specified range of this list
-     * that are contained in the specified collection
-     *
-     * @return Returns the number of removed elements
-     */
-    // should be called under lock
-    int retainAll(Collection c, int start, int size) {
-        Object[] old = getData();
-        if (size == 0) {
-            return 0;
-        }
-        if (c.size() == 0) {
-            E[] data;
-            if (size == old.length) {
-                data = newElementArray(0);
-            } else {
-                data = newElementArray(old.length - size);
-                System.arraycopy(old, 0, data, 0, start);
-                System.arraycopy(old, start + size, data, start, old.length
-                        - start - size);
-            }
-            setData(data);
-            return size;
-        }
-        Object[] temp = new Object[size];
-        int pos = 0;
-        for (int i = start; i < (start + size); i++) {
-            if (c.contains(old[i])) {
-                temp[pos++] = old[i];
-            }
-        }
-        if (pos == size) {
-            return 0;
-        }
-        E[] data = newElementArray(pos + old.length - size);
-        System.arraycopy(old, 0, data, 0, start);
-        System.arraycopy(temp, 0, data, start, pos);
-        System.arraycopy(old, start + size, data, start + pos, old.length
-                - start - size);
-        setData(data);
-        return (size - pos);
-    }
-
-    /**
-     * Removes specified range from this list
-     */
-    E removeRange(int start, int size) {
-        lock.lock();
-        try {
-            int sizeArr = size();
-            checkIndexExlusive(start, sizeArr);
-            checkIndexInclusive(start + size, sizeArr);
-            E[] data;
-            data = newElementArray(sizeArr - size);
-            E[] oldArr = getData();
-            System.arraycopy(oldArr, 0, data, 0, start);
-            E old = oldArr[start];
-            if (sizeArr > (start + size)) {
-                System.arraycopy(oldArr, start + size, data, start, sizeArr
-                        - (start + size));
-            }
-            setData(data);
-            return old;
-        } finally {
-            lock.unlock();
-        }
-    }
-
-    // some util static functions to use by iterators and methods
-    /**
-     * Returns an array containing all of the elements
-     * in the specified range of the array in proper sequence
-     */
-    static Object[] toArray(Object[] data, int start, int size) {
-        Object[] result = new Object[size];
-        System.arraycopy(data, start, result, 0, size);
-        return result;
-    }
-
-    /**
-     * Returns an array containing all of the elements
-     * in the specified range of the array in proper sequence,
-     * stores the result in the array, specified by first parameter
-     * (as for public instance method toArray(Object[] to)
-     */
-    static Object[] toArray(Object[] to, Object[] data, int start, int size) {
-        int l = data.length;
-        if (to.length < l) {
-            to = (Object[]) Array.newInstance(to.getClass().getComponentType(),
-                    l);
-        } else {
-            if (to.length > l) {
-                to[l] = null;
-            }
-        }
-        System.arraycopy(data, start, to, 0, size);
-        return to;
-    }
-
-    /**
-     * Checks if the specified range of the
-     * array contains all of the elements in the collection
-     *
-     * @param c     collection with elements
-     * @param data  array where to search the elements
-     * @param start start index
-     * @param size  size of the range
-     */
-    static final boolean containsAll(Collection c, Object[] data, int start,
-                                     int size) {
-        if (size == 0) {
-            return false;
-        }
-        Iterator it = c.iterator();
-        while (it.hasNext()) {
-            Object next = it.next();
-            if (indexOf(next, data, start, size) < 0) {
-                return false;
-            }
-        }
-        return true;
-    }
-
-    /**
-     * Returns the index in the specified range of the data array
-     * of the last occurrence of the specified element
-     *
-     * @param o     element to search
-     * @param data  array where to search
-     * @param start start index
-     * @param size  size of the range
-     * @return
-     */
-    static final int lastIndexOf(Object o, Object[] data, int start, int size) {
-        if (size == 0) {
-            return -1;
-        }
-        if (o != null) {
-            for (int i = start + size - 1; i > start - 1; i--) {
-                if (o.equals(data[i])) {
-                    return i;
-                }
-            }
-        } else {
-            for (int i = start + size - 1; i > start - 1; i--) {
-                if (data[i] == null) {
-                    return i;
-                }
-            }
-        }
-        return -1;
-    }
-
-    /**
-     * Returns the index in the specified range of the data array
-     * of the first occurrence of the specified element
-     *
-     * @param o     element to search
-     * @param data  array where to search
-     * @param start start index
-     * @param size  end index
-     * @return
-     */
-    static final int indexOf(Object o, Object[] data, int start, int size) {
-        if (size == 0) {
-            return -1;
-        }
-        if (o == null) {
-            for (int i = start; i < start + size; i++) {
-                if (data[i] == null) {
-                    return i;
-                }
-            }
-        } else {
-            for (int i = start; i < start + size; i++) {
-                if (o.equals(data[i])) {
-                    return i;
-                }
-            }
-        }
-        return -1;
-    }
-
-    /**
-     * Throws <code>IndexOutOfBoundsException</code> if <code>index</code>
-     * is out of the list bounds.
-     *
-     * @param index element index to check.
-     */
-    static final void checkIndexInclusive(int index, int size) {
-        if (index < 0 || index > size) {
-            throw new IndexOutOfBoundsException("Index is " + index + ", size is " + size);
-        }
-    }
-
-    /**
-     * Throws <code>IndexOutOfBoundsException</code> if <code>index</code>
-     * is out of the list bounds. Excluding the last element.
-     *
-     * @param index element index to check.
-     */
-    static final void checkIndexExlusive(int index, int size) {
-        if (index < 0 || index >= size) {
-            throw new IndexOutOfBoundsException("Index is " + index + ", size is " + size);
-        }
-    }
-
-    /**
-     * list iterator implementation,
-     * when created gets snapshot of the list,
-     * so never throws ConcurrentModificationException
-     */
-    private static class ListIteratorImpl implements ListIterator {
-        private final Object[] arr;
-
-        private int current;
-
-        private final int size;
-
-        final int size() {
-            return size;
-        }
-
-        public ListIteratorImpl(Object[] data, int current) {
-            this.current = current;
-            arr = data;
-            size = data.length;
-        }
-
-        public void add(Object o) {
-            throw new UnsupportedOperationException("Unsupported operation add");
-        }
-
-        public boolean hasNext() {
-            if (current < size) {
-                return true;
-            }
-            return false;
-        }
-
-        public boolean hasPrevious() {
-            return current > 0;
-        }
-
-        public Object next() {
-            if (hasNext()) {
-                return arr[current++];
-            }
-            throw new NoSuchElementException("pos is " + current + ", size is " + size);
-        }
-
-        public int nextIndex() {
-            return current;
-        }
-
-        public Object previous() {
-            if (hasPrevious()) {
-                return arr[--current];
-            }
-            throw new NoSuchElementException("pos is " + (current-1) + ", size is " + size);
-        }
-
-        public int previousIndex() {
-            return current - 1;
-        }
-
-        public void remove() {
-            throw new UnsupportedOperationException("Unsupported operation remove");
-        }
-
-        public void set(Object o) {
-            throw new UnsupportedOperationException("Unsupported operation set");
-        }
-
-    }
-
-    /**
-     * Keeps a state of sublist implementation,
-     * size and array declared as final,
-     * so we'll never get the unconsistent state
-     */
-    static final class SubListReadData {
-        final int size;
-
-        final Object[] data;
-
-        SubListReadData(int size, Object[] data) {
-            this.size = size;
-            this.data = data;
-        }
-    }
-
-    /**
-     * Represents a list returned by <code>sublist()</code>.
-     */
-    static class SubList implements List {
-        private final CopyOnWriteArrayList list;
-
-        private volatile SubListReadData read;
-
-        private final int start;
-
-        /**
-         * Sublist constructor.
-         *
-         * @param list    backing list.
-         * @param fromIdx startingIndex, inclusive
-         * @param toIdx   endIndex, exclusive
-         */
-        public SubList(CopyOnWriteArrayList list, int fromIdx, int toIdx) {
-            this.list = list;
-            Object[] data = list.getData();
-            int size = toIdx - fromIdx;
-            checkIndexExlusive(fromIdx, data.length);
-            checkIndexInclusive(toIdx, data.length);
-            read = new SubListReadData(size, list.getData());
-            start = fromIdx;
-        }
-
-        /**
-         * throws ConcurrentModificationException when the list
-         * is structurally modified in the other way other than via this subList
-         * <p/>
-         * Should be called under lock!
-         */
-        private void checkModifications() {
-            if (read.data != list.getData()) {
-                throw new ConcurrentModificationException();
-            }
-        }
-
-        /**
-         * @see java.util.List#listIterator(int)
-         */
-        public ListIterator listIterator(int startIdx) {
-            return new SubListIterator(startIdx, read);
-        }
-
-        /**
-         * @see java.util.List#set(int, java.lang.Object)
-         */
-        public Object set(int index, Object obj) {
-            list.lock.lock();
-            try {
-                checkIndexExlusive(index, read.size);
-                checkModifications();
-                Object result = list.set(index + start, obj);
-                read = new SubListReadData(read.size, list.getData());
-                return result;
-            } finally {
-                list.lock.unlock();
-            }
-        }
-
-        /**
-         * @see java.util.List#get(int)
-         */
-        public Object get(int index) {
-            SubListReadData data = read;
-            if (data.data != list.getData()) {
-                list.lock.lock();
-                try {
-                    data = read;
-                    if (data.data != list.getData()) {
-                        throw new ConcurrentModificationException();
-                    }
-                } finally {
-                    list.lock.unlock();
-                }
-            }
-            checkIndexExlusive(index, data.size);
-            return data.data[index + start];
-        }
-
-        /**
-         * @see java.util.Collection#size()
-         */
-        public int size() {
-            return read.size;
-        }
-
-        /**
-         * @see java.util.List#remove(int)
-         */
-        public Object remove(int index) {
-            list.lock.lock();
-            try {
-                checkIndexExlusive(index, read.size);
-                checkModifications();
-                Object obj = list.remove(index + start);
-                read = new SubListReadData(read.size - 1, list.getData());
-                return obj;
-            } finally {
-                list.lock.unlock();
-            }
-        }
-
-        /**
-         * @see java.util.List#add(int, java.lang.Object)
-         */
-        public void add(int index, Object object) {
-            list.lock.lock();
-            try {
-                checkIndexInclusive(index, read.size);
-                checkModifications();
-                list.add(index + start, object);
-                read = new SubListReadData(read.size + 1, list.getData());
-            } finally {
-                list.lock.unlock();
-            }
-        }
-
-        public boolean add(Object o) {
-            list.lock.lock();
-            try {
-                checkModifications();
-                list.add(start + read.size, o);
-                read = new SubListReadData(read.size + 1, list.getData());
-                return true;
-            } finally {
-                list.lock.unlock();
-            }
-        }
-
-        public boolean addAll(Collection c) {
-            list.lock.lock();
-            try {
-                checkModifications();
-                int d = list.size();
-                list.addAll(start + read.size, c);
-                read = new SubListReadData(read.size + (list.size() - d), list
-                        .getData());
-                return true;
-            } finally {
-                list.lock.unlock();
-            }
-        }
-
-        public void clear() {
-            list.lock.lock();
-            try {
-                checkModifications();
-                list.removeRange(start, read.size);
-                read = new SubListReadData(0, list.getData());
-            } finally {
-                list.lock.unlock();
-            }
-        }
-
-        public boolean contains(Object o) {
-            return indexOf(o) != -1;
-        }
-
-        public boolean containsAll(Collection c) {
-            SubListReadData b = read;
-            return CopyOnWriteArrayList.containsAll(c, b.data, start, b.size);
-        }
-
-        public int indexOf(Object o) {
-            SubListReadData b = read;
-            int ind = CopyOnWriteArrayList.indexOf(o, b.data, start, b.size)
-                    - start;
-            return ind < 0 ? -1 : ind;
-        }
-
-        public boolean isEmpty() {
-            return read.size == 0;
-        }
-
-        public Iterator iterator() {
-            return new SubListIterator(0, read);
-        }
-
-        public int lastIndexOf(Object o) {
-            SubListReadData b = read;
-            int ind = CopyOnWriteArrayList
-                    .lastIndexOf(o, b.data, start, b.size)
-                    - start;
-            return ind < 0 ? -1 : ind;
-        }
-
-        public ListIterator listIterator() {
-            return new SubListIterator(0, read);
-        }
-
-        public boolean remove(Object o) {
-            list.lock.lock();
-            try {
-                checkModifications();
-                int i = indexOf(o);
-                if (i == -1) {
-                    return false;
-                }
-                boolean result = list.remove(i + start) != null;
-                if (result) {
-                    read = new SubListReadData(read.size - 1, list.getData());
-                }
-                return result;
-            } finally {
-                list.lock.unlock();
-            }
-        }
-
-        public boolean removeAll(Collection c) {
-            list.lock.lock();
-            try {
-                checkModifications();
-                int removed = list.removeAll(c, start, read.size);
-                if (removed > 0) {
-                    read = new SubListReadData(read.size - removed, list
-                            .getData());
-                    return true;
-                }
-            } finally {
-                list.lock.unlock();
-            }
-            return false;
-        }
-
-        public boolean retainAll(Collection c) {
-            list.lock.lock();
-            try {
-                checkModifications();
-                int removed = list.retainAll(c, start, read.size);
-                if (removed > 0) {
-                    read = new SubListReadData(read.size - removed, list
-                            .getData());
-                    return true;
-                }
-                return false;
-            } finally {
-                list.lock.unlock();
-            }
-        }
-
-        public List subList(int fromIndex, int toIndex) {
-            return new SubList(list, start + fromIndex, start + toIndex);
-        }
-
-        public Object[] toArray() {
-            SubListReadData r = read;
-            return CopyOnWriteArrayList.toArray(r.data, start, r.size);
-        }
-
-        public Object[] toArray(Object[] a) {
-            SubListReadData r = read;
-            return CopyOnWriteArrayList.toArray(a, r.data, start, r.size);
-        }
-
-        /**
-         * @see java.util.List#addAll(int, java.util.Collection)
-         */
-        public boolean addAll(int index, Collection collection) {
-            list.lock.lock();
-            try {
-                checkIndexInclusive(index, read.size);
-                checkModifications();
-                int d = list.size();
-                boolean rt = list.addAll(index + start, collection);
-                read = new SubListReadData(read.size + list.size() - d, list
-                        .getData());
-                return rt;
-            } finally {
-                list.lock.unlock();
-            }
-        }
-
-        /**
-         * Implementation of <code>ListIterator</code> for the
-         * <code>SubList</code>
-         * gets a snapshot of the sublist,
-         * never throws ConcurrentModificationException
-         */
-        private class SubListIterator extends ListIteratorImpl {
-            private final SubListReadData dataR;
-
-            /**
-             * Constructs an iterator starting with the given index
-             *
-             * @param index index of the first element to iterate.
-             */
-            private SubListIterator(int index, SubListReadData d) {
-                super(d.data, index + start);
-                this.dataR = d;
-            }
-
-            /**
-             * @see java.util.ListIterator#nextIndex()
-             */
-            public int nextIndex() {
-                return super.nextIndex() - start;
-            }
-
-            /**
-             * @see java.util.ListIterator#previousIndex()
-             */
-            public int previousIndex() {
-                return super.previousIndex() - start;
-            }
-
-            /**
-             * @see java.util.Iterator#hasNext()
-             */
-            public boolean hasNext() {
-                return nextIndex() < dataR.size;
-            }
-
-            /**
-             * @see java.util.ListIterator#hasPrevious()
-             */
-            public boolean hasPrevious() {
-                return previousIndex() > -1;
-            }
-        }
-
-    }
-
-    //serialization support
-    /**
-     * Writes the object state to the ObjectOutputStream.
-     *
-     * @param oos ObjectOutputStream to write object to.
-     * @throws IOException if an I/O error occur.
-     */
-    private void writeObject(ObjectOutputStream oos) throws IOException {
-        E[] back = getData();
-        int size = back.length;
-        oos.defaultWriteObject();
-        oos.writeInt(size);
-        for (int i = 0; i < size; i++) {
-            oos.writeObject(back[i]);
-        }
-    }
-
-    /**
-     * Reads the object state from the ObjectOutputStream.
-     *
-     * @param ois ObjectInputStream to read object from.
-     * @throws IOException if an I/O error occur.
-     */
-    private void readObject(ObjectInputStream ois) throws IOException,
-            ClassNotFoundException {
-        ois.defaultReadObject();
-        int length = ois.readInt();
-        if (length == 0) {
-            setData(newElementArray(0));
-        } else {
-            E[] back = newElementArray(length);
-            for (int i = 0; i < back.length; i++) {
-                back[i] = (E) ois.readObject();
-            }
-            setData(back);
-        }
-    }
-}
diff --git a/concurrent/src/main/java/java/util/concurrent/CopyOnWriteArraySet.java b/concurrent/src/main/java/java/util/concurrent/CopyOnWriteArraySet.java
deleted file mode 100644
index 532952b..0000000
--- a/concurrent/src/main/java/java/util/concurrent/CopyOnWriteArraySet.java
+++ /dev/null
@@ -1,102 +0,0 @@
-/*
- * Written by Doug Lea with assistance from members of JCP JSR-166
- * Expert Group and released to the public domain. Use, modify, and
- * redistribute this code in any way without acknowledgement.
- */
-
-package java.util.concurrent;
-import java.util.*;
-
-// BEGIN android-note
-// removed link to collections framework docs
-// Removed clonable interface to be closer to the RI.
-// END android-note
-
-/**
- * A {@link java.util.Set} that uses {@link
- * java.util.concurrent.CopyOnWriteArrayList} for all of its
- * operations.  Thus, it shares the same basic properties:
- * <ul>
- *  <li>It is best suited for applications in which set sizes generally
- *       stay small, read-only operations
- *       vastly outnumber mutative operations, and you need
- *       to prevent interference among threads during traversal.
- *  <li>Mutative operations(add, set, remove, etc) are expensive
- *      since they usually entail copying the entire underlying array.
- *  <li>Iterators do not support the mutative remove operation
- *  <li>Traversal via iterators is very fast and cannot ever encounter
- *      interference from other threads. Iterators rely on
- *      unchanging snapshots of the array at the time the iterators were
- *     constructed.
- * </ul>
- * <p>
- * <b>Sample Usage.</b> Probably the main application
- * of copy-on-write sets are classes that maintain
- * sets of Handler objects
- * that must be multicasted to upon an update command. This
- * is a classic case where you do not want to be holding a
- * lock while sending a message, and where traversals normally
- * vastly overwhelm additions.
- * <pre>
- * class Handler { void handle(); ... }
- *
- * class X {
- *    private final CopyOnWriteArraySet&lt;Handler&gt; handlers = new CopyOnWriteArraySet&lt;Handler&gt;();
- *    public void addHandler(Handler h) { handlers.add(h); }
- *
- *    private long internalState;
- *    private synchronized void changeState() { internalState = ...; }
- *
- *    public void update() {
- *       changeState();
- *       Iterator it = handlers.iterator();
- *       while (it.hasNext())
- *          it.next().handle();
- *    }
- * }
- * </pre>
- * @see CopyOnWriteArrayList
- *
- * @since 1.5
- * @author Doug Lea
- * @param <E> the type of elements held in this collection
- */
-public class CopyOnWriteArraySet<E> extends AbstractSet<E>
-        implements java.io.Serializable {
-    private static final long serialVersionUID = 5457747651344034263L;
-
-    private final CopyOnWriteArrayList<E> al;
-
-    /**
-     * Creates an empty set.
-     */
-    public CopyOnWriteArraySet() {
-        al = new CopyOnWriteArrayList<E>();
-    }
-
-    /**
-     * Creates a set containing all of the elements of the specified
-     * Collection.
-     * @param c the collection
-     */
-    public CopyOnWriteArraySet(Collection<? extends E> c) {
-        al = new CopyOnWriteArrayList<E>();
-        al.addAllAbsent(c);
-    }
-
-
-    public int      size()                    { return al.size(); }
-    public boolean  isEmpty()                 { return al.isEmpty(); }
-    public boolean  contains(Object o)        { return al.contains(o); }
-    public Object[] toArray()                 { return al.toArray(); }
-    public <T> T[]  toArray(T[] a)            { return al.toArray(a); }
-    public void     clear()                   {        al.clear(); }
-    public Iterator<E>  iterator()            { return al.iterator(); }
-    public boolean  remove(Object o)          { return al.remove(o); }
-    public boolean  add(E o)                  { return al.addIfAbsent(o); }
-    public boolean  containsAll(Collection<?> c)      { return al.containsAll(c); }
-    public boolean  addAll(Collection<? extends E> c) { return al.addAllAbsent(c) > 0; }
-    public boolean  removeAll(Collection<?> c)        { return al.removeAll(c); }
-    public boolean  retainAll(Collection<?> c)        { return al.retainAll(c); }
-
-}
diff --git a/concurrent/src/main/java/java/util/concurrent/CountDownLatch.java b/concurrent/src/main/java/java/util/concurrent/CountDownLatch.java
deleted file mode 100644
index 721744c..0000000
--- a/concurrent/src/main/java/java/util/concurrent/CountDownLatch.java
+++ /dev/null
@@ -1,280 +0,0 @@
-/*
- * Written by Doug Lea with assistance from members of JCP JSR-166
- * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
- */
-
-package java.util.concurrent;
-import java.util.concurrent.locks.*;
-import java.util.concurrent.atomic.*;
-
-/**
- * A synchronization aid that allows one or more threads to wait until
- * a set of operations being performed in other threads completes.
- *
- * <p>A <tt>CountDownLatch</tt> is initialized with a given
- * <em>count</em>.  The {@link #await await} methods block until the current
- * {@link #getCount count} reaches zero due to invocations of the
- * {@link #countDown} method, after which all waiting threads are
- * released and any subsequent invocations of {@link #await await} return
- * immediately. This is a one-shot phenomenon -- the count cannot be
- * reset.  If you need a version that resets the count, consider using
- * a {@link CyclicBarrier}.
- *
- * <p>A <tt>CountDownLatch</tt> is a versatile synchronization tool
- * and can be used for a number of purposes.  A
- * <tt>CountDownLatch</tt> initialized with a count of one serves as a
- * simple on/off latch, or gate: all threads invoking {@link #await await}
- * wait at the gate until it is opened by a thread invoking {@link
- * #countDown}.  A <tt>CountDownLatch</tt> initialized to <em>N</em>
- * can be used to make one thread wait until <em>N</em> threads have
- * completed some action, or some action has been completed N times.
- * <p>A useful property of a <tt>CountDownLatch</tt> is that it
- * doesn't require that threads calling <tt>countDown</tt> wait for
- * the count to reach zero before proceeding, it simply prevents any
- * thread from proceeding past an {@link #await await} until all
- * threads could pass.
- *
- * <p><b>Sample usage:</b> Here is a pair of classes in which a group
- * of worker threads use two countdown latches:
- * <ul>
- * <li>The first is a start signal that prevents any worker from proceeding
- * until the driver is ready for them to proceed;
- * <li>The second is a completion signal that allows the driver to wait
- * until all workers have completed.
- * </ul>
- *
- * <pre>
- * class Driver { // ...
- *   void main() throws InterruptedException {
- *     CountDownLatch startSignal = new CountDownLatch(1);
- *     CountDownLatch doneSignal = new CountDownLatch(N);
- *
- *     for (int i = 0; i < N; ++i) // create and start threads
- *       new Thread(new Worker(startSignal, doneSignal)).start();
- *
- *     doSomethingElse();            // don't let run yet
- *     startSignal.countDown();      // let all threads proceed
- *     doSomethingElse();
- *     doneSignal.await();           // wait for all to finish
- *   }
- * }
- *
- * class Worker implements Runnable {
- *   private final CountDownLatch startSignal;
- *   private final CountDownLatch doneSignal;
- *   Worker(CountDownLatch startSignal, CountDownLatch doneSignal) {
- *      this.startSignal = startSignal;
- *      this.doneSignal = doneSignal;
- *   }
- *   public void run() {
- *      try {
- *        startSignal.await();
- *        doWork();
- *        doneSignal.countDown();
- *      } catch (InterruptedException ex) {} // return;
- *   }
- *
- *   void doWork() { ... }
- * }
- *
- * </pre>
- *
- * <p>Another typical usage would be to divide a problem into N parts,
- * describe each part with a Runnable that executes that portion and
- * counts down on the latch, and queue all the Runnables to an
- * Executor.  When all sub-parts are complete, the coordinating thread
- * will be able to pass through await. (When threads must repeatedly
- * count down in this way, instead use a {@link CyclicBarrier}.)
- *
- * <pre>
- * class Driver2 { // ...
- *   void main() throws InterruptedException {
- *     CountDownLatch doneSignal = new CountDownLatch(N);
- *     Executor e = ...
- *
- *     for (int i = 0; i < N; ++i) // create and start threads
- *       e.execute(new WorkerRunnable(doneSignal, i));
- *
- *     doneSignal.await();           // wait for all to finish
- *   }
- * }
- *
- * class WorkerRunnable implements Runnable {
- *   private final CountDownLatch doneSignal;
- *   private final int i;
- *   WorkerRunnable(CountDownLatch doneSignal, int i) {
- *      this.doneSignal = doneSignal;
- *      this.i = i;
- *   }
- *   public void run() {
- *      try {
- *        doWork(i);
- *        doneSignal.countDown();
- *      } catch (InterruptedException ex) {} // return;
- *   }
- *
- *   void doWork() { ... }
- * }
- *
- * </pre>
- *
- * @since 1.5
- * @author Doug Lea
- */
-public class CountDownLatch {
-    /**
-     * Synchronization control For CountDownLatch.
-     * Uses AQS state to represent count.
-     */
-    private static final class Sync extends AbstractQueuedSynchronizer {
-        Sync(int count) {
-            setState(count); 
-        }
-        
-        int getCount() {
-            return getState();
-        }
-
-        public int tryAcquireShared(int acquires) {
-            return getState() == 0? 1 : -1;
-        }
-        
-        public boolean tryReleaseShared(int releases) {
-            // Decrement count; signal when transition to zero
-            for (;;) {
-                int c = getState();
-                if (c == 0)
-                    return false;
-                int nextc = c-1;
-                if (compareAndSetState(c, nextc)) 
-                    return nextc == 0;
-            }
-        }
-    }
-
-    private final Sync sync;
-    /**
-     * Constructs a <tt>CountDownLatch</tt> initialized with the given
-     * count.
-     * 
-     * @param count the number of times {@link #countDown} must be invoked
-     * before threads can pass through {@link #await}.
-     *
-     * @throws IllegalArgumentException if <tt>count</tt> is less than zero.
-     */
-    public CountDownLatch(int count) { 
-        if (count < 0) throw new IllegalArgumentException("count < 0");
-        this.sync = new Sync(count);
-    }
-
-    /**
-     * Causes the current thread to wait until the latch has counted down to 
-     * zero, unless the thread is {@link Thread#interrupt interrupted}.
-     *
-     * <p>If the current {@link #getCount count} is zero then this method
-     * returns immediately.
-     * <p>If the current {@link #getCount count} is greater than zero then
-     * the current thread becomes disabled for thread scheduling 
-     * purposes and lies dormant until one of two things happen:
-     * <ul>
-     * <li>The count reaches zero due to invocations of the
-     * {@link #countDown} method; or
-     * <li>Some other thread {@link Thread#interrupt interrupts} the current
-     * thread.
-     * </ul>
-     * <p>If the current thread:
-     * <ul>
-     * <li>has its interrupted status set on entry to this method; or 
-     * <li>is {@link Thread#interrupt interrupted} while waiting, 
-     * </ul>
-     * then {@link InterruptedException} is thrown and the current thread's 
-     * interrupted status is cleared. 
-     *
-     * @throws InterruptedException if the current thread is interrupted
-     * while waiting.
-     */
-    public void await() throws InterruptedException {
-        sync.acquireSharedInterruptibly(1);
-    }
-
-    /**
-     * Causes the current thread to wait until the latch has counted down to 
-     * zero, unless the thread is {@link Thread#interrupt interrupted},
-     * or the specified waiting time elapses.
-     *
-     * <p>If the current {@link #getCount count} is zero then this method
-     * returns immediately with the value <tt>true</tt>.
-     *
-     * <p>If the current {@link #getCount count} is greater than zero then
-     * the current thread becomes disabled for thread scheduling 
-     * purposes and lies dormant until one of three things happen:
-     * <ul>
-     * <li>The count reaches zero due to invocations of the
-     * {@link #countDown} method; or
-     * <li>Some other thread {@link Thread#interrupt interrupts} the current
-     * thread; or
-     * <li>The specified waiting time elapses.
-     * </ul>
-     * <p>If the count reaches zero then the method returns with the
-     * value <tt>true</tt>.
-     * <p>If the current thread:
-     * <ul>
-     * <li>has its interrupted status set on entry to this method; or 
-     * <li>is {@link Thread#interrupt interrupted} while waiting, 
-     * </ul>
-     * then {@link InterruptedException} is thrown and the current thread's 
-     * interrupted status is cleared. 
-     *
-     * <p>If the specified waiting time elapses then the value <tt>false</tt>
-     * is returned.
-     * If the time is 
-     * less than or equal to zero, the method will not wait at all.
-     *
-     * @param timeout the maximum time to wait
-     * @param unit the time unit of the <tt>timeout</tt> argument.
-     * @return <tt>true</tt> if the count reached zero  and <tt>false</tt>
-     * if the waiting time elapsed before the count reached zero.
-     *
-     * @throws InterruptedException if the current thread is interrupted
-     * while waiting.
-     */
-    public boolean await(long timeout, TimeUnit unit) 
-        throws InterruptedException {
-        return sync.tryAcquireSharedNanos(1, unit.toNanos(timeout));
-    }
-
-    /**
-     * Decrements the count of the latch, releasing all waiting threads if
-     * the count reaches zero.
-     * <p>If the current {@link #getCount count} is greater than zero then
-     * it is decremented. If the new count is zero then all waiting threads
-     * are re-enabled for thread scheduling purposes.
-     * <p>If the current {@link #getCount count} equals zero then nothing
-     * happens.
-     */
-    public void countDown() {
-        sync.releaseShared(1);
-    }
-
-    /**
-     * Returns the current count.
-     * <p>This method is typically used for debugging and testing purposes.
-     * @return the current count.
-     */
-    public long getCount() {
-        return sync.getCount();
-    }
-
-    /**
-     * Returns a string identifying this latch, as well as its state.
-     * The state, in brackets, includes the String 
-     * &quot;Count =&quot; followed by the current count.
-     * @return a string identifying this latch, as well as its
-     * state
-     */
-    public String toString() {
-        return super.toString() + "[Count = " + sync.getCount() + "]";
-    }
-
-}
diff --git a/concurrent/src/main/java/java/util/concurrent/CyclicBarrier.java b/concurrent/src/main/java/java/util/concurrent/CyclicBarrier.java
deleted file mode 100644
index d70c4c7..0000000
--- a/concurrent/src/main/java/java/util/concurrent/CyclicBarrier.java
+++ /dev/null
@@ -1,430 +0,0 @@
-/*
- * Written by Doug Lea with assistance from members of JCP JSR-166
- * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
- */
-
-package java.util.concurrent;
-import java.util.concurrent.locks.*;
-
-/**
- * A synchronization aid that allows a set of threads to all wait for
- * each other to reach a common barrier point.  CyclicBarriers are
- * useful in programs involving a fixed sized party of threads that
- * must occasionally wait for each other. The barrier is called
- * <em>cyclic</em> because it can be re-used after the waiting threads
- * are released.
- *
- * <p>A <tt>CyclicBarrier</tt> supports an optional {@link Runnable} command
- * that is run once per barrier point, after the last thread in the party
- * arrives, but before any threads are released. 
- * This <em>barrier action</em> is useful
- * for updating shared-state before any of the parties continue.
- * 
- * <p><b>Sample usage:</b> Here is an example of
- *  using a barrier in a parallel decomposition design:
- * <pre>
- * class Solver {
- *   final int N;
- *   final float[][] data;
- *   final CyclicBarrier barrier;
- *   
- *   class Worker implements Runnable {
- *     int myRow;
- *     Worker(int row) { myRow = row; }
- *     public void run() {
- *       while (!done()) {
- *         processRow(myRow);
- *
- *         try {
- *           barrier.await(); 
- *         } catch (InterruptedException ex) { 
- *           return; 
- *         } catch (BrokenBarrierException ex) { 
- *           return; 
- *         }
- *       }
- *     }
- *   }
- *
- *   public Solver(float[][] matrix) {
- *     data = matrix;
- *     N = matrix.length;
- *     barrier = new CyclicBarrier(N, 
- *                                 new Runnable() {
- *                                   public void run() { 
- *                                     mergeRows(...); 
- *                                   }
- *                                 });
- *     for (int i = 0; i < N; ++i) 
- *       new Thread(new Worker(i)).start();
- *
- *     waitUntilDone();
- *   }
- * }
- * </pre>
- * Here, each worker thread processes a row of the matrix then waits at the 
- * barrier until all rows have been processed. When all rows are processed
- * the supplied {@link Runnable} barrier action is executed and merges the 
- * rows. If the merger
- * determines that a solution has been found then <tt>done()</tt> will return
- * <tt>true</tt> and each worker will terminate.
- *
- * <p>If the barrier action does not rely on the parties being suspended when
- * it is executed, then any of the threads in the party could execute that
- * action when it is released. To facilitate this, each invocation of
- * {@link #await} returns the arrival index of that thread at the barrier.
- * You can then choose which thread should execute the barrier action, for 
- * example:
- * <pre>  if (barrier.await() == 0) {
- *     // log the completion of this iteration
- *   }</pre>
- *
- * <p>The <tt>CyclicBarrier</tt> uses a fast-fail all-or-none breakage
- * model for failed synchronization attempts: If a thread leaves a
- * barrier point prematurely because of interruption, failure, or
- * timeout, all other threads, even those that have not yet resumed
- * from a previous {@link #await}. will also leave abnormally via
- * {@link BrokenBarrierException} (or <tt>InterruptedException</tt> if
- * they too were interrupted at about the same time).
- *
- * @since 1.5
- * @see CountDownLatch
- *
- * @author Doug Lea
- */
-public class CyclicBarrier {
-    /** The lock for guarding barrier entry */
-    private final ReentrantLock lock = new ReentrantLock();
-    /** Condition to wait on until tripped */
-    private final Condition trip = lock.newCondition();
-    /** The number of parties */
-    private final int parties;
-    /* The command to run when tripped */
-    private final Runnable barrierCommand;
-
-    /**
-     * The generation number. Incremented upon barrier trip.
-     * Retracted upon reset.
-     */
-    private long generation; 
-
-    /** 
-     * Breakage indicator.
-     */
-    private boolean broken; 
-
-    /**
-     * Number of parties still waiting. Counts down from parties to 0
-     * on each cycle.
-     */
-    private int count; 
-
-    /**
-     * Updates state on barrier trip and wake up everyone.
-     */  
-    private void nextGeneration() {
-        count = parties;
-        ++generation;
-        trip.signalAll();
-    }
-
-    /**
-     * Sets barrier as broken and wake up everyone
-     */
-    private void breakBarrier() {
-        broken = true;
-        trip.signalAll();
-    }
-
-    /**
-     * Main barrier code, covering the various policies.
-     */
-    private int dowait(boolean timed, long nanos) 
-        throws InterruptedException, BrokenBarrierException, TimeoutException {
-        final ReentrantLock lock = this.lock;
-        lock.lock();
-        try {
-            int index = --count;
-            long g = generation;
-
-            if (broken) 
-                throw new BrokenBarrierException();
-
-            if (Thread.interrupted()) {
-                breakBarrier();
-                throw new InterruptedException();
-            }
-
-            if (index == 0) {  // tripped
-                nextGeneration();
-                boolean ranAction = false;
-                try {
-                    Runnable command = barrierCommand;
-                    if (command != null) 
-                        command.run();
-                    ranAction = true;
-                    return 0;
-                } finally {
-                    if (!ranAction)
-                        breakBarrier();
-                }
-            }
-
-            for (;;) {
-                try {
-                    if (!timed) 
-                        trip.await();
-                    else if (nanos > 0L)
-                        nanos = trip.awaitNanos(nanos);
-                } catch (InterruptedException ie) {
-                    breakBarrier();
-                    throw ie;
-                }
-                
-                if (broken || 
-                    g > generation) // true if a reset occurred while waiting
-                    throw new BrokenBarrierException();
-
-                if (g < generation)
-                    return index;
-
-                if (timed && nanos <= 0L) {
-                    breakBarrier();
-                    throw new TimeoutException();
-                }
-            }
-
-        } finally {
-            lock.unlock();
-        }
-    }
-
-    /**
-     * Creates a new <tt>CyclicBarrier</tt> that will trip when the
-     * given number of parties (threads) are waiting upon it, and which
-     * will execute the given barrier action when the barrier is tripped,
-     * performed by the last thread entering the barrier.
-     *
-     * @param parties the number of threads that must invoke {@link #await}
-     * before the barrier is tripped.
-     * @param barrierAction the command to execute when the barrier is
-     * tripped, or <tt>null</tt> if there is no action.
-     *
-     * @throws IllegalArgumentException if <tt>parties</tt> is less than 1.
-     */
-    public CyclicBarrier(int parties, Runnable barrierAction) {
-        if (parties <= 0) throw new IllegalArgumentException();
-        this.parties = parties; 
-        this.count = parties;
-        this.barrierCommand = barrierAction;
-    }
-
-    /**
-     * Creates a new <tt>CyclicBarrier</tt> that will trip when the
-     * given number of parties (threads) are waiting upon it, and
-     * does not perform a predefined action upon each barrier.
-     *
-     * @param parties the number of threads that must invoke {@link #await}
-     * before the barrier is tripped.
-     *
-     * @throws IllegalArgumentException if <tt>parties</tt> is less than 1.
-     */
-    public CyclicBarrier(int parties) {
-        this(parties, null);
-    }
-
-    /**
-     * Returns the number of parties required to trip this barrier.
-     * @return the number of parties required to trip this barrier.
-     **/
-    public int getParties() {
-        return parties;
-    }
-
-    /**
-     * Waits until all {@link #getParties parties} have invoked <tt>await</tt>
-     * on this barrier.
-     *
-     * <p>If the current thread is not the last to arrive then it is
-     * disabled for thread scheduling purposes and lies dormant until
-     * one of following things happens:
-     * <ul>
-     * <li>The last thread arrives; or
-     * <li>Some other thread {@link Thread#interrupt interrupts} the current
-     * thread; or
-     * <li>Some other thread  {@link Thread#interrupt interrupts} one of the
-     * other waiting threads; or
-     * <li>Some other thread times out while waiting for barrier; or
-     * <li>Some other thread invokes {@link #reset} on this barrier.
-     * </ul>
-     * <p>If the current thread:
-     * <ul>
-     * <li>has its interrupted status set on entry to this method; or
-     * <li>is {@link Thread#interrupt interrupted} while waiting
-     * </ul>
-     * then {@link InterruptedException} is thrown and the current thread's
-     * interrupted status is cleared.
-     *
-     * <p>If the barrier is {@link #reset} while any thread is waiting, or if 
-     * the barrier {@link #isBroken is broken} when <tt>await</tt> is invoked,
-     * or while any thread is waiting,
-     * then {@link BrokenBarrierException} is thrown.
-     *
-     * <p>If any thread is {@link Thread#interrupt interrupted} while waiting,
-     * then all other waiting threads will throw 
-     * {@link BrokenBarrierException} and the barrier is placed in the broken
-     * state.
-     *
-     * <p>If the current thread is the last thread to arrive, and a
-     * non-null barrier action was supplied in the constructor, then the
-     * current thread runs the action before allowing the other threads to 
-     * continue.
-     * If an exception occurs during the barrier action then that exception
-     * will be propagated in the current thread and the barrier is placed in
-     * the broken state.
-     *
-     * @return the arrival index of the current thread, where index
-     *  <tt>{@link #getParties()} - 1</tt> indicates the first to arrive and 
-     * zero indicates the last to arrive.
-     *
-     * @throws InterruptedException if the current thread was interrupted 
-     * while waiting
-     * @throws BrokenBarrierException if <em>another</em> thread was
-     * interrupted while the current thread was waiting, or the barrier was
-     * reset, or the barrier was broken when <tt>await</tt> was called,
-     * or the barrier action (if present) failed due an exception.
-     */
-    public int await() throws InterruptedException, BrokenBarrierException {
-        try {
-            return dowait(false, 0L);
-        } catch (TimeoutException toe) {
-            throw new Error(toe); // cannot happen;
-        }
-    }
-
-    /**
-     * Waits until all {@link #getParties parties} have invoked <tt>await</tt>
-     * on this barrier.
-     *
-     * <p>If the current thread is not the last to arrive then it is
-     * disabled for thread scheduling purposes and lies dormant until
-     * one of the following things happens:
-     * <ul>
-     * <li>The last thread arrives; or
-     * <li>The specified timeout elapses; or
-     * <li>Some other thread {@link Thread#interrupt interrupts} the current
-     * thread; or
-     * <li>Some other thread  {@link Thread#interrupt interrupts} one of the
-     * other waiting threads; or
-     * <li>Some other thread times out while waiting for barrier; or
-     * <li>Some other thread invokes {@link #reset} on this barrier.
-     * </ul>
-     * <p>If the current thread:
-     * <ul>
-     * <li>has its interrupted status set on entry to this method; or
-     * <li>is {@link Thread#interrupt interrupted} while waiting
-     * </ul>
-     * then {@link InterruptedException} is thrown and the current thread's
-     * interrupted status is cleared.
-     *
-     * <p>If the barrier is {@link #reset} while any thread is waiting, or if 
-     * the barrier {@link #isBroken is broken} when <tt>await</tt> is invoked,
-     * or while any thread is waiting,
-     * then {@link BrokenBarrierException} is thrown.
-     *
-     * <p>If any thread is {@link Thread#interrupt interrupted} while waiting,
-     * then all other waiting threads will throw 
-     * {@link BrokenBarrierException} and the barrier is placed in the broken
-     * state.
-     *
-     * <p>If the current thread is the last thread to arrive, and a
-     * non-null barrier action was supplied in the constructor, then the
-     * current thread runs the action before allowing the other threads to 
-     * continue.
-     * If an exception occurs during the barrier action then that exception
-     * will be propagated in the current thread and the barrier is placed in
-     * the broken state.
-     *
-     * @param timeout the time to wait for the barrier
-     * @param unit the time unit of the timeout parameter
-     * @return the arrival index of the current thread, where index
-     *  <tt>{@link #getParties()} - 1</tt> indicates the first to arrive and 
-     * zero indicates the last to arrive.
-     *
-     * @throws InterruptedException if the current thread was interrupted 
-     * while waiting
-     * @throws TimeoutException if the specified timeout elapses.
-     * @throws BrokenBarrierException if <em>another</em> thread was
-     * interrupted while the current thread was waiting, or the barrier was
-     * reset, or the barrier was broken when <tt>await</tt> was called,
-     * or the barrier action (if present) failed due an exception.
-     */
-    public int await(long timeout, TimeUnit unit) 
-        throws InterruptedException, 
-        BrokenBarrierException, 
-        TimeoutException {
-        return dowait(true, unit.toNanos(timeout));
-    }
-
-    /**
-     * Queries if this barrier is in a broken state.
-     * @return <tt>true</tt> if one or more parties broke out of this
-     * barrier due to interruption or timeout since construction or
-     * the last reset, or a barrier action failed due to an exception; 
-     * and <tt>false</tt> otherwise.
-     */
-    public boolean isBroken() {
-        final ReentrantLock lock = this.lock;
-        lock.lock();
-        try {
-            return broken;
-        } finally {
-            lock.unlock();
-        }
-    }
-
-    /**
-     * Resets the barrier to its initial state.  If any parties are
-     * currently waiting at the barrier, they will return with a
-     * {@link BrokenBarrierException}. Note that resets <em>after</em>
-     * a breakage has occurred for other reasons can be complicated to
-     * carry out; threads need to re-synchronize in some other way,
-     * and choose one to perform the reset.  It may be preferable to
-     * instead create a new barrier for subsequent use.
-     */
-    public void reset() {
-        final ReentrantLock lock = this.lock;
-        lock.lock();
-        try {
-            /*
-             * Retract generation number enough to cover threads
-             * currently waiting on current and still resuming from
-             * previous generation, plus similarly accommodating spans
-             * after the reset.
-             */
-            generation -= 4;
-            broken = false;
-            trip.signalAll();
-        } finally {
-            lock.unlock();
-        }
-    }
-
-    /**
-     * Returns the number of parties currently waiting at the barrier.
-     * This method is primarily useful for debugging and assertions.
-     *
-     * @return the number of parties currently blocked in {@link #await}
-     **/
-    public int getNumberWaiting() {
-        final ReentrantLock lock = this.lock;
-        lock.lock();
-        try {
-            return parties - count;
-        } finally {
-            lock.unlock();
-        }
-    }
-
-}
diff --git a/concurrent/src/main/java/java/util/concurrent/DelayQueue.java b/concurrent/src/main/java/java/util/concurrent/DelayQueue.java
deleted file mode 100644
index 156dc7e..0000000
--- a/concurrent/src/main/java/java/util/concurrent/DelayQueue.java
+++ /dev/null
@@ -1,366 +0,0 @@
-/*
- * Written by Doug Lea with assistance from members of JCP JSR-166
- * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
- */
-
-
-package java.util.concurrent;
-import java.util.concurrent.locks.*;
-import java.util.*;
-
-// BEGIN android-note
-// removed link to collections framework docs
-// END android-note
-
-/**
- * An unbounded {@linkplain BlockingQueue blocking queue} of <tt>Delayed</tt>
- * elements, in which an element can only be taken when its delay has expired.
- * The <em>head</em> of the queue is that <tt>Delayed</tt> element whose delay
- * expired furthest in the past - if no delay has expired there is no head and
- * <tt>poll</tt> will return <tt>null</tt>.
- * This queue does not permit <tt>null</tt> elements.
- * <p>This class implements all of the <em>optional</em> methods
- * of the {@link Collection} and {@link Iterator} interfaces.
- *
- * @since 1.5
- * @author Doug Lea
- * @param <E> the type of elements held in this collection
- */
-
-public class DelayQueue<E extends Delayed> extends AbstractQueue<E>
-    implements BlockingQueue<E> {
-
-    private transient final ReentrantLock lock = new ReentrantLock();
-    private transient final Condition available = lock.newCondition();
-    private final PriorityQueue<E> q = new PriorityQueue<E>();
-
-    /**
-     * Creates a new <tt>DelayQueue</tt> that is initially empty.
-     */
-    public DelayQueue() {}
-
-    /**
-     * Creates a <tt>DelayQueue</tt> initially containing the elements of the
-     * given collection of {@link Delayed} instances.
-     *
-     * @param c the collection
-     * @throws NullPointerException if <tt>c</tt> or any element within it
-     * is <tt>null</tt>
-     *
-     */
-    public DelayQueue(Collection<? extends E> c) {
-        this.addAll(c);
-    }
-
-    /**
-     * Inserts the specified element into this delay queue.
-     *
-     * @param o the element to add
-     * @return <tt>true</tt>
-     * @throws NullPointerException if the specified element is <tt>null</tt>.
-     */
-    public boolean offer(E o) {
-        final ReentrantLock lock = this.lock;
-        lock.lock();
-        try {
-            E first = q.peek();
-            q.offer(o);
-            if (first == null || o.compareTo(first) < 0)
-                available.signalAll();
-            return true;
-        } finally {
-            lock.unlock();
-        }
-    }
-
-
-    /**
-     * Adds the specified element to this delay queue. As the queue is
-     * unbounded this method will never block.
-     * @param o the element to add
-     * @throws NullPointerException if the specified element is <tt>null</tt>.
-     */
-    public void put(E o) {
-        offer(o);
-    }
-
-    /**
-     * Inserts the specified element into this delay queue. As the queue is
-     * unbounded this method will never block.
-     * @param o the element to add
-     * @param timeout This parameter is ignored as the method never blocks
-     * @param unit This parameter is ignored as the method never blocks
-     * @return <tt>true</tt>
-     * @throws NullPointerException if the specified element is <tt>null</tt>.
-     */
-    public boolean offer(E o, long timeout, TimeUnit unit) {
-        return offer(o);
-    }
-
-    /**
-     * Adds the specified element to this queue.
-     * @param o the element to add
-     * @return <tt>true</tt> (as per the general contract of
-     * <tt>Collection.add</tt>).
-     *
-     * @throws NullPointerException if the specified element is <tt>null</tt>.
-     */
-    public boolean add(E o) {
-        return offer(o);
-    }
-
-    public E take() throws InterruptedException {
-        final ReentrantLock lock = this.lock;
-        lock.lockInterruptibly();
-        try {
-            for (;;) {
-                E first = q.peek();
-                if (first == null) {
-                    available.await();
-                } else {
-                    long delay =  first.getDelay(TimeUnit.NANOSECONDS);
-                    if (delay > 0) {
-                        long tl = available.awaitNanos(delay);
-                    } else {
-                        E x = q.poll();
-                        assert x != null;
-                        if (q.size() != 0)
-                            available.signalAll(); // wake up other takers
-                        return x;
-
-                    }
-                }
-            }
-        } finally {
-            lock.unlock();
-        }
-    }
-
-    public E poll(long time, TimeUnit unit) throws InterruptedException {
-        final ReentrantLock lock = this.lock;
-        lock.lockInterruptibly();
-        long nanos = unit.toNanos(time);
-        try {
-            for (;;) {
-                E first = q.peek();
-                if (first == null) {
-                    if (nanos <= 0)
-                        return null;
-                    else
-                        nanos = available.awaitNanos(nanos);
-                } else {
-                    long delay =  first.getDelay(TimeUnit.NANOSECONDS);
-                    if (delay > 0) {
-                        if (delay > nanos)
-                            delay = nanos;
-                        long timeLeft = available.awaitNanos(delay);
-                        nanos -= delay - timeLeft;
-                    } else {
-                        E x = q.poll();
-                        assert x != null;
-                        if (q.size() != 0)
-                            available.signalAll();
-                        return x;
-                    }
-                }
-            }
-        } finally {
-            lock.unlock();
-        }
-    }
-
-
-    public E poll() {
-        final ReentrantLock lock = this.lock;
-        lock.lock();
-        try {
-            E first = q.peek();
-            if (first == null || first.getDelay(TimeUnit.NANOSECONDS) > 0)
-                return null;
-            else {
-                E x = q.poll();
-                assert x != null;
-                if (q.size() != 0)
-                    available.signalAll();
-                return x;
-            }
-        } finally {
-            lock.unlock();
-        }
-    }
-
-    public E peek() {
-        final ReentrantLock lock = this.lock;
-        lock.lock();
-        try {
-            return q.peek();
-        } finally {
-            lock.unlock();
-        }
-    }
-
-    public int size() {
-        final ReentrantLock lock = this.lock;
-        lock.lock();
-        try {
-            return q.size();
-        } finally {
-            lock.unlock();
-        }
-    }
-
-    public int drainTo(Collection<? super E> c) {
-        if (c == null)
-            throw new NullPointerException();
-        if (c == this)
-            throw new IllegalArgumentException();
-        final ReentrantLock lock = this.lock;
-        lock.lock();
-        try {
-            int n = 0;
-            for (;;) {
-                E first = q.peek();
-                if (first == null || first.getDelay(TimeUnit.NANOSECONDS) > 0)
-                    break;
-                c.add(q.poll());
-                ++n;
-            }
-            if (n > 0)
-                available.signalAll();
-            return n;
-        } finally {
-            lock.unlock();
-        }
-    }
-
-    public int drainTo(Collection<? super E> c, int maxElements) {
-        if (c == null)
-            throw new NullPointerException();
-        if (c == this)
-            throw new IllegalArgumentException();
-        if (maxElements <= 0)
-            return 0;
-        final ReentrantLock lock = this.lock;
-        lock.lock();
-        try {
-            int n = 0;
-            while (n < maxElements) {
-                E first = q.peek();
-                if (first == null || first.getDelay(TimeUnit.NANOSECONDS) > 0)
-                    break;
-                c.add(q.poll());
-                ++n;
-            }
-            if (n > 0)
-                available.signalAll();
-            return n;
-        } finally {
-            lock.unlock();
-        }
-    }
-
-    /**
-     * Atomically removes all of the elements from this delay queue.
-     * The queue will be empty after this call returns.
-     */
-    public void clear() {
-        final ReentrantLock lock = this.lock;
-        lock.lock();
-        try {
-            q.clear();
-        } finally {
-            lock.unlock();
-        }
-    }
-
-    /**
-     * Always returns <tt>Integer.MAX_VALUE</tt> because
-     * a <tt>DelayQueue</tt> is not capacity constrained.
-     * @return <tt>Integer.MAX_VALUE</tt>
-     */
-    public int remainingCapacity() {
-        return Integer.MAX_VALUE;
-    }
-
-    public Object[] toArray() {
-        final ReentrantLock lock = this.lock;
-        lock.lock();
-        try {
-            return q.toArray();
-        } finally {
-            lock.unlock();
-        }
-    }
-
-    public <T> T[] toArray(T[] array) {
-        final ReentrantLock lock = this.lock;
-        lock.lock();
-        try {
-            return q.toArray(array);
-        } finally {
-            lock.unlock();
-        }
-    }
-
-    public boolean remove(Object o) {
-        final ReentrantLock lock = this.lock;
-        lock.lock();
-        try {
-            return q.remove(o);
-        } finally {
-            lock.unlock();
-        }
-    }
-
-    /**
-     * Returns an iterator over the elements in this queue. The iterator
-     * does not return the elements in any particular order. The
-     * returned iterator is a thread-safe "fast-fail" iterator that will
-     * throw {@link java.util.ConcurrentModificationException}
-     * upon detected interference.
-     *
-     * @return an iterator over the elements in this queue.
-     */
-    public Iterator<E> iterator() {
-        final ReentrantLock lock = this.lock;
-        lock.lock();
-        try {
-            return new Itr(q.iterator());
-        } finally {
-            lock.unlock();
-        }
-    }
-
-    private class Itr<E> implements Iterator<E> {
-        private final Iterator<E> iter;
-        Itr(Iterator<E> i) {
-            iter = i;
-        }
-
-        public boolean hasNext() {
-            return iter.hasNext();
-        }
-
-        public E next() {
-            final ReentrantLock lock = DelayQueue.this.lock;
-            lock.lock();
-            try {
-                return iter.next();
-            } finally {
-                lock.unlock();
-            }
-        }
-
-        public void remove() {
-            final ReentrantLock lock = DelayQueue.this.lock;
-            lock.lock();
-            try {
-                iter.remove();
-            } finally {
-                lock.unlock();
-            }
-        }
-    }
-
-}
diff --git a/concurrent/src/main/java/java/util/concurrent/Delayed.java b/concurrent/src/main/java/java/util/concurrent/Delayed.java
deleted file mode 100644
index bd48292..0000000
--- a/concurrent/src/main/java/java/util/concurrent/Delayed.java
+++ /dev/null
@@ -1,36 +0,0 @@
-/*
- * Written by Doug Lea with assistance from members of JCP JSR-166
- * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
- */
-
-package java.util.concurrent;
-
-import java.util.*;
-
-// BEGIN android-note
-// Added generic type Delayed to Comparable to be closer to the RI.
-// END android-note
-
-/**
- * A mix-in style interface for marking objects that should be
- * acted upon after a given delay.
- *
- * <p>An implementation of this interface must define a
- * <tt>compareTo</tt> method that provides an ordering consistent with
- * its <tt>getDelay</tt> method.
- *
- * @since 1.5
- * @author Doug Lea
- */
-public interface Delayed extends Comparable<Delayed> {
-
-    /**
-     * Returns the delay associated with this object, in the given time unit.
-     *
-     * @param unit the time unit
-     * @return the delay; zero or negative values indicate that the
-     * delay has already elapsed
-     */
-    long getDelay(TimeUnit unit);
-}
diff --git a/concurrent/src/main/java/java/util/concurrent/Exchanger.java b/concurrent/src/main/java/java/util/concurrent/Exchanger.java
deleted file mode 100644
index da8c815..0000000
--- a/concurrent/src/main/java/java/util/concurrent/Exchanger.java
+++ /dev/null
@@ -1,247 +0,0 @@
-/*
- * Written by Doug Lea with assistance from members of JCP JSR-166
- * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
- */
-
-package java.util.concurrent;
-import java.util.concurrent.locks.*;
-
-/**
- * A synchronization point at which two threads can exchange objects.
- * Each thread presents some object on entry to the {@link #exchange
- * exchange} method, and receives the object presented by the other
- * thread on return.
- *
- * <p><b>Sample Usage:</b>
- * Here are the highlights of a class that uses an <tt>Exchanger</tt> to
- * swap buffers between threads so that the thread filling the
- * buffer gets a freshly
- * emptied one when it needs it, handing off the filled one to
- * the thread emptying the buffer.
- * <pre>
- * class FillAndEmpty {
- *   Exchanger&lt;DataBuffer&gt; exchanger = new Exchanger();
- *   DataBuffer initialEmptyBuffer = ... a made-up type
- *   DataBuffer initialFullBuffer = ...
- *
- *   class FillingLoop implements Runnable {
- *     public void run() {
- *       DataBuffer currentBuffer = initialEmptyBuffer;
- *       try {
- *         while (currentBuffer != null) {
- *           addToBuffer(currentBuffer);
- *           if (currentBuffer.full())
- *             currentBuffer = exchanger.exchange(currentBuffer);
- *         }
- *       } catch (InterruptedException ex) { ... handle ... }
- *     }
- *   }
- *
- *   class EmptyingLoop implements Runnable {
- *     public void run() {
- *       DataBuffer currentBuffer = initialFullBuffer;
- *       try {
- *         while (currentBuffer != null) {
- *           takeFromBuffer(currentBuffer);
- *           if (currentBuffer.empty())
- *             currentBuffer = exchanger.exchange(currentBuffer);
- *         }
- *       } catch (InterruptedException ex) { ... handle ...}
- *     }
- *   }
- *
- *   void start() {
- *     new Thread(new FillingLoop()).start();
- *     new Thread(new EmptyingLoop()).start();
- *   }
- * }
- * </pre>
- *
- * @since 1.5
- * @author Doug Lea
- * @param <V> The type of objects that may be exchanged
- */
-public class Exchanger<V> {
-    private final ReentrantLock lock = new ReentrantLock();
-    private final Condition taken = lock.newCondition();
-
-    /** Holder for the item being exchanged */
-    private V item;
-    
-    /**
-     * Arrival count transitions from 0 to 1 to 2 then back to 0
-     * during an exchange.
-     */
-    private int arrivalCount;
-
-    /**
-     * Main exchange function, handling the different policy variants.
-     */
-    private V doExchange(V x, boolean timed, long nanos) throws InterruptedException, TimeoutException {
-        lock.lock();
-        try {
-            V other;
-
-            // If arrival count already at two, we must wait for
-            // a previous pair to finish and reset the count;
-            while (arrivalCount == 2) {
-                if (!timed)
-                    taken.await();
-                else if (nanos > 0) 
-                    nanos = taken.awaitNanos(nanos);
-                else 
-                    throw new TimeoutException();
-            }
-
-            int count = ++arrivalCount;
-
-            // If item is already waiting, replace it and signal other thread
-            if (count == 2) { 
-                other = item;
-                item = x;
-                taken.signal();
-                return other;
-            }
-
-            // Otherwise, set item and wait for another thread to
-            // replace it and signal us.
-
-            item = x;
-            InterruptedException interrupted = null;
-            try { 
-                while (arrivalCount != 2) {
-                    if (!timed)
-                        taken.await();
-                    else if (nanos > 0) 
-                        nanos = taken.awaitNanos(nanos);
-                    else 
-                        break; // timed out
-                }
-            } catch (InterruptedException ie) {
-                interrupted = ie;
-            }
-
-            // Get and reset item and count after the wait.
-            // (We need to do this even if wait was aborted.)
-            other = item;
-            item = null;
-            count = arrivalCount;
-            arrivalCount = 0; 
-            taken.signal();
-            
-            // If the other thread replaced item, then we must
-            // continue even if cancelled.
-            if (count == 2) {
-                if (interrupted != null)
-                    Thread.currentThread().interrupt();
-                return other;
-            }
-
-            // If no one is waiting for us, we can back out
-            if (interrupted != null) 
-                throw interrupted;
-            else  // must be timeout
-                throw new TimeoutException();
-        } finally {
-            lock.unlock();
-        }
-    }
-
-    /**
-     * Create a new Exchanger.
-     **/
-    public Exchanger() {
-    }
-
-    /**
-     * Waits for another thread to arrive at this exchange point (unless
-     * it is {@link Thread#interrupt interrupted}),
-     * and then transfers the given object to it, receiving its object
-     * in return.
-     * <p>If another thread is already waiting at the exchange point then
-     * it is resumed for thread scheduling purposes and receives the object
-     * passed in by the current thread. The current thread returns immediately,
-     * receiving the object passed to the exchange by that other thread.
-     * <p>If no other thread is already waiting at the exchange then the 
-     * current thread is disabled for thread scheduling purposes and lies
-     * dormant until one of two things happens:
-     * <ul>
-     * <li>Some other thread enters the exchange; or
-     * <li>Some other thread {@link Thread#interrupt interrupts} the current
-     * thread.
-     * </ul>
-     * <p>If the current thread:
-     * <ul>
-     * <li>has its interrupted status set on entry to this method; or 
-     * <li>is {@link Thread#interrupt interrupted} while waiting
-     * for the exchange, 
-     * </ul>
-     * then {@link InterruptedException} is thrown and the current thread's 
-     * interrupted status is cleared. 
-     *
-     * @param x the object to exchange
-     * @return the object provided by the other thread.
-     * @throws InterruptedException if current thread was interrupted 
-     * while waiting
-     **/
-    public V exchange(V x) throws InterruptedException {
-        try {
-            return doExchange(x, false, 0);
-        } catch (TimeoutException cannotHappen) { 
-            throw new Error(cannotHappen);
-        }
-    }
-
-    /**
-     * Waits for another thread to arrive at this exchange point (unless
-     * it is {@link Thread#interrupt interrupted}, or the specified waiting
-     * time elapses),
-     * and then transfers the given object to it, receiving its object
-     * in return.
-     *
-     * <p>If another thread is already waiting at the exchange point then
-     * it is resumed for thread scheduling purposes and receives the object
-     * passed in by the current thread. The current thread returns immediately,
-     * receiving the object passed to the exchange by that other thread.
-     *
-     * <p>If no other thread is already waiting at the exchange then the 
-     * current thread is disabled for thread scheduling purposes and lies
-     * dormant until one of three things happens:
-     * <ul>
-     * <li>Some other thread enters the exchange; or
-     * <li>Some other thread {@link Thread#interrupt interrupts} the current
-     * thread; or
-     * <li>The specified waiting time elapses.
-     * </ul>
-     * <p>If the current thread:
-     * <ul>
-     * <li>has its interrupted status set on entry to this method; or 
-     * <li>is {@link Thread#interrupt interrupted} while waiting
-     * for the exchange, 
-     * </ul>
-     * then {@link InterruptedException} is thrown and the current thread's 
-     * interrupted status is cleared. 
-     *
-     * <p>If the specified waiting time elapses then {@link TimeoutException}
-     * is thrown.
-     * If the time is 
-     * less than or equal to zero, the method will not wait at all.
-     *
-     * @param x the object to exchange
-     * @param timeout the maximum time to wait
-     * @param unit the time unit of the <tt>timeout</tt> argument.
-     * @return the object provided by the other thread.
-     * @throws InterruptedException if current thread was interrupted
-     * while waiting
-     * @throws TimeoutException if the specified waiting time elapses before
-     * another thread enters the exchange.
-     **/
-    public V exchange(V x, long timeout, TimeUnit unit) 
-        throws InterruptedException, TimeoutException {
-        return doExchange(x, true, unit.toNanos(timeout));
-    }
-
-}
-
-
diff --git a/concurrent/src/main/java/java/util/concurrent/ExecutionException.java b/concurrent/src/main/java/java/util/concurrent/ExecutionException.java
deleted file mode 100644
index 8f0e448..0000000
--- a/concurrent/src/main/java/java/util/concurrent/ExecutionException.java
+++ /dev/null
@@ -1,65 +0,0 @@
-/*
- * Written by Doug Lea with assistance from members of JCP JSR-166
- * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
- */
-
-package java.util.concurrent;
-
-/**
- * Exception thrown when attempting to retrieve the result of a task
- * that aborted by throwing an exception. This exception can be
- * inspected using the {@link #getCause()} method.
- *
- * @see Future
- * @since 1.5
- * @author Doug Lea
- */
-public class ExecutionException extends Exception {
-    private static final long serialVersionUID = 7830266012832686185L;
-
-    /**
-     * Constructs a <tt>ExecutionException</tt> with no detail message.
-     * The cause is not initialized, and may subsequently be
-     * initialized by a call to {@link #initCause(Throwable) initCause}.
-     */
-    protected ExecutionException() { }
-
-    /**
-     * Constructs a <tt>ExecutionException</tt> with the specified detail
-     * message. The cause is not initialized, and may subsequently be
-     * initialized by a call to {@link #initCause(Throwable) initCause}.
-     *
-     * @param message the detail message
-     */
-    protected ExecutionException(String message) {
-        super(message);
-    }
-
-    /**
-     * Constructs a <tt>ExecutionException</tt> with the specified detail
-     * message and cause.
-     *
-     * @param  message the detail message
-     * @param  cause the cause (which is saved for later retrieval by the
-     *         {@link #getCause()} method)
-     */
-    public ExecutionException(String message, Throwable cause) {
-        super(message, cause);
-    }
-
-    /**
-     * Constructs a <tt>ExecutionException</tt> with the specified cause.
-     * The detail message is set to:
-     * <pre>
-     *  (cause == null ? null : cause.toString())</pre>
-     * (which typically contains the class and detail message of
-     * <tt>cause</tt>).
-     *
-     * @param  cause the cause (which is saved for later retrieval by the
-     *         {@link #getCause()} method)
-     */
-    public ExecutionException(Throwable cause) {
-        super(cause);
-    }
-}
diff --git a/concurrent/src/main/java/java/util/concurrent/Executor.java b/concurrent/src/main/java/java/util/concurrent/Executor.java
deleted file mode 100644
index 60fe193..0000000
--- a/concurrent/src/main/java/java/util/concurrent/Executor.java
+++ /dev/null
@@ -1,107 +0,0 @@
-/*
- * Written by Doug Lea with assistance from members of JCP JSR-166
- * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
- */
-
-package java.util.concurrent;
-
-/**
- * An object that executes submitted {@link Runnable} tasks. This
- * interface provides a way of decoupling task submission from the
- * mechanics of how each task will be run, including details of thread
- * use, scheduling, etc.  An <tt>Executor</tt> is normally used
- * instead of explicitly creating threads. For example, rather than
- * invoking <tt>new Thread(new(RunnableTask())).start()</tt> for each
- * of a set of tasks, you might use:
- *
- * <pre>
- * Executor executor = <em>anExecutor</em>;
- * executor.execute(new RunnableTask1());
- * executor.execute(new RunnableTask2());
- * ...
- * </pre>
- * 
- * However, the <tt>Executor</tt> interface does not strictly
- * require that execution be asynchronous. In the simplest case, an
- * executor can run the submitted task immediately in the caller's
- * thread:
- *
- * <pre>
- * class DirectExecutor implements Executor {
- *     public void execute(Runnable r) {
- *         r.run();
- *     }
- * }</pre>
- *
- * More typically, tasks are executed in some thread other
- * than the caller's thread.  The executor below spawns a new thread
- * for each task.
- *
- * <pre>
- * class ThreadPerTaskExecutor implements Executor {
- *     public void execute(Runnable r) {
- *         new Thread(r).start();
- *     }
- * }</pre>
- *
- * Many <tt>Executor</tt> implementations impose some sort of
- * limitation on how and when tasks are scheduled.  The executor below
- * serializes the submission of tasks to a second executor,
- * illustrating a composite executor.
- *
- * <pre>
- * class SerialExecutor implements Executor {
- *     final Queue&lt;Runnable&gt; tasks = new LinkedBlockingQueue&lt;Runnable&gt;();
- *     final Executor executor;
- *     Runnable active;
- *
- *     SerialExecutor(Executor executor) {
- *         this.executor = executor;
- *     }
- *
- *     public synchronized void execute(final Runnable r) {
- *         tasks.offer(new Runnable() {
- *             public void run() {
- *                 try {
- *                     r.run();
- *                 } finally {
- *                     scheduleNext();
- *                 }
- *             }
- *         });
- *         if (active == null) {
- *             scheduleNext();
- *         }
- *     }
- *
- *     protected synchronized void scheduleNext() {
- *         if ((active = tasks.poll()) != null) {
- *             executor.execute(active);
- *         }
- *     }
- * }</pre>
- *
- * The <tt>Executor</tt> implementations provided in this package
- * implement {@link ExecutorService}, which is a more extensive
- * interface.  The {@link ThreadPoolExecutor} class provides an
- * extensible thread pool implementation. The {@link Executors} class
- * provides convenient factory methods for these Executors.
- *
- * @since 1.5
- * @author Doug Lea
- */
-public interface Executor {
-
-    /**
-     * Executes the given command at some time in the future.  The command
-     * may execute in a new thread, in a pooled thread, or in the calling
-     * thread, at the discretion of the <tt>Executor</tt> implementation.
-     *
-     * @param command the runnable task
-     * @throws RejectedExecutionException if this task cannot be
-     * accepted for execution.
-     * @throws NullPointerException if command is null
-     */
-    void execute(Runnable command);
-}
diff --git a/concurrent/src/main/java/java/util/concurrent/ExecutorCompletionService.java b/concurrent/src/main/java/java/util/concurrent/ExecutorCompletionService.java
deleted file mode 100644
index 4f9c9d9..0000000
--- a/concurrent/src/main/java/java/util/concurrent/ExecutorCompletionService.java
+++ /dev/null
@@ -1,148 +0,0 @@
-/*
- * Written by Doug Lea with assistance from members of JCP JSR-166
- * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
- */
-
-package java.util.concurrent;
-
-
-/**
- * A {@link CompletionService} that uses a supplied {@link Executor}
- * to execute tasks.  This class arranges that submitted tasks are,
- * upon completion, placed on a queue accessible using <tt>take</tt>.
- * The class is lightweight enough to be suitable for transient use
- * when processing groups of tasks.
- *
- * <p>
- *
- * <b>Usage Examples.</b>
- *
- * Suppose you have a set of solvers for a certain problem, each
- * returning a value of some type <tt>Result</tt>, and would like to
- * run them concurrently, processing the results of each of them that
- * return a non-null value, in some method <tt>use(Result r)</tt>. You
- * could write this as:
- *
- * <pre>
- *    void solve(Executor e, Collection&lt;Callable&lt;Result&gt;&gt; solvers)
- *      throws InterruptedException, ExecutionException {
- *        CompletionService&lt;Result&gt; ecs = new ExecutorCompletionService&lt;Result&gt;(e);
- *        for (Callable&lt;Result&gt; s : solvers)
- *            ecs.submit(s);
- *        int n = solvers.size();
- *        for (int i = 0; i &lt; n; ++i) {
- *            Result r = ecs.take().get();
- *            if (r != null) 
- *                use(r);
- *        }
- *    }
- * </pre>
- *
- * Suppose instead that you would like to use the first non-null result
- * of the set of tasks, ignoring any that encounter exceptions,
- * and cancelling all other tasks when the first one is ready:
- *
- * <pre>
- *    void solve(Executor e, Collection&lt;Callable&lt;Result&gt;&gt; solvers) 
- *      throws InterruptedException {
- *        CompletionService&lt;Result&gt; ecs = new ExecutorCompletionService&lt;Result&gt;(e);
- *        int n = solvers.size();
- *        List&lt;Future&lt;Result&gt;&gt; futures = new ArrayList&lt;Future&lt;Result&gt;&gt;(n);
- *        Result result = null;
- *        try {
- *            for (Callable&lt;Result&gt; s : solvers)
- *                futures.add(ecs.submit(s));
- *            for (int i = 0; i &lt; n; ++i) {
- *                try {
- *                    Result r = ecs.take().get();
- *                    if (r != null) {
- *                        result = r;
- *                        break;
- *                    }
- *                } catch(ExecutionException ignore) {}
- *            }
- *        }
- *        finally {
- *            for (Future&lt;Result&gt; f : futures)
- *                f.cancel(true);
- *        }
- *
- *        if (result != null)
- *            use(result);
- *    }
- * </pre>
- */
-public class ExecutorCompletionService<V> implements CompletionService<V> {
-    private final Executor executor;
-    private final BlockingQueue<Future<V>> completionQueue;
-
-    /**
-     * FutureTask extension to enqueue upon completion
-     */
-    private class QueueingFuture extends FutureTask<V> {
-        QueueingFuture(Callable<V> c) { super(c); }
-        QueueingFuture(Runnable t, V r) { super(t, r); }
-        protected void done() { completionQueue.add(this); }
-    }
-
-    /**
-     * Creates an ExecutorCompletionService using the supplied
-     * executor for base task execution and a
-     * {@link LinkedBlockingQueue} as a completion queue.
-     * @param executor the executor to use
-     * @throws NullPointerException if executor is <tt>null</tt>
-     */
-    public ExecutorCompletionService(Executor executor) {
-        if (executor == null) 
-            throw new NullPointerException();
-        this.executor = executor;
-        this.completionQueue = new LinkedBlockingQueue<Future<V>>();
-    }
-
-    /**
-     * Creates an ExecutorCompletionService using the supplied
-     * executor for base task execution and the supplied queue as its
-     * completion queue.
-     * @param executor the executor to use
-     * @param completionQueue the queue to use as the completion queue
-     * normally one dedicated for use by this service
-     * @throws NullPointerException if executor or completionQueue are <tt>null</tt>
-     */
-    public ExecutorCompletionService(Executor executor,
-                                     BlockingQueue<Future<V>> completionQueue) {
-        if (executor == null || completionQueue == null) 
-            throw new NullPointerException();
-        this.executor = executor;
-        this.completionQueue = completionQueue;
-    }
-
-    public Future<V> submit(Callable<V> task) {
-        if (task == null) throw new NullPointerException();
-        QueueingFuture f = new QueueingFuture(task);
-        executor.execute(f);
-        return f;
-    }
-
-    public Future<V> submit(Runnable task, V result) {
-        if (task == null) throw new NullPointerException();
-        QueueingFuture f = new QueueingFuture(task, result);
-        executor.execute(f);
-        return f;
-    }
-
-    public Future<V> take() throws InterruptedException {
-        return completionQueue.take();
-    }
-
-    public Future<V> poll() {
-        return completionQueue.poll();
-    }
-
-    public Future<V> poll(long timeout, TimeUnit unit) throws InterruptedException {
-        return completionQueue.poll(timeout, unit);
-    }
-
-}
-
-
diff --git a/concurrent/src/main/java/java/util/concurrent/ExecutorService.java b/concurrent/src/main/java/java/util/concurrent/ExecutorService.java
deleted file mode 100644
index e178eb2..0000000
--- a/concurrent/src/main/java/java/util/concurrent/ExecutorService.java
+++ /dev/null
@@ -1,286 +0,0 @@
-/*
- * Written by Doug Lea with assistance from members of JCP JSR-166
- * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
- */
-
-package java.util.concurrent;
-
-import java.util.List;
-import java.util.Collection;
-import java.security.PrivilegedAction;
-import java.security.PrivilegedExceptionAction;
-
-/**
- * An {@link Executor} that provides methods to manage termination and
- * methods that can produce a {@link Future} for tracking progress of
- * one or more asynchronous tasks.  
- *
- * <p>
- * An <tt>ExecutorService</tt> can be shut down, which will cause it
- * to stop accepting new tasks.  After being shut down, the executor
- * will eventually terminate, at which point no tasks are actively
- * executing, no tasks are awaiting execution, and no new tasks can be
- * submitted.
- *
- * <p> Method <tt>submit</tt> extends base method {@link
- * Executor#execute} by creating and returning a {@link Future} that
- * can be used to cancel execution and/or wait for completion.
- * Methods <tt>invokeAny</tt> and <tt>invokeAll</tt> perform the most
- * commonly useful forms of bulk execution, executing a collection of
- * tasks and then waiting for at least one, or all, to
- * complete. (Class {@link ExecutorCompletionService} can be used to
- * write customized variants of these methods.)
- *
- * <p>The {@link Executors} class provides factory methods for the
- * executor services provided in this package.
- *
- * <h3>Usage Example</h3>
- *
- * Here is a sketch of a network service in which threads in a thread
- * pool service incoming requests. It uses the preconfigured {@link
- * Executors#newFixedThreadPool} factory method:
- *
- * <pre>
- * class NetworkService {
- *    private final ServerSocket serverSocket;
- *    private final ExecutorService pool;
- *
- *    public NetworkService(int port, int poolSize) throws IOException {
- *      serverSocket = new ServerSocket(port);
- *      pool = Executors.newFixedThreadPool(poolSize);
- *    }
- * 
- *    public void serve() {
- *      try {
- *        for (;;) {
- *          pool.execute(new Handler(serverSocket.accept()));
- *        }
- *      } catch (IOException ex) {
- *        pool.shutdown();
- *      }
- *    }
- *  }
- *
- *  class Handler implements Runnable {
- *    private final Socket socket;
- *    Handler(Socket socket) { this.socket = socket; }
- *    public void run() {
- *      // read and service request
- *    }
- * }
- * </pre>
- * @since 1.5
- * @author Doug Lea
- */
-public interface ExecutorService extends Executor {
-
-    /**
-     * Initiates an orderly shutdown in which previously submitted
-     * tasks are executed, but no new tasks will be
-     * accepted. Invocation has no additional effect if already shut
-     * down.
-     * @throws SecurityException if a security manager exists and
-     * shutting down this ExecutorService may manipulate threads that
-     * the caller is not permitted to modify because it does not hold
-     * {@link java.lang.RuntimePermission}<tt>("modifyThread")</tt>,
-     * or the security manager's <tt>checkAccess</tt>  method denies access.
-     */
-    void shutdown();
-
-    /**
-     * Attempts to stop all actively executing tasks, halts the
-     * processing of waiting tasks, and returns a list of the tasks that were
-     * awaiting execution. 
-     *  
-     * <p>There are no guarantees beyond best-effort attempts to stop
-     * processing actively executing tasks.  For example, typical
-     * implementations will cancel via {@link Thread#interrupt}, so if any
-     * tasks mask or fail to respond to interrupts, they may never terminate.
-     *
-     * @return list of tasks that never commenced execution
-     * @throws SecurityException if a security manager exists and
-     * shutting down this ExecutorService may manipulate threads that
-     * the caller is not permitted to modify because it does not hold
-     * {@link java.lang.RuntimePermission}<tt>("modifyThread")</tt>,
-     * or the security manager's <tt>checkAccess</tt> method denies access.
-     */
-    List<Runnable> shutdownNow();
-
-    /**
-     * Returns <tt>true</tt> if this executor has been shut down.
-     *
-     * @return <tt>true</tt> if this executor has been shut down
-     */
-    boolean isShutdown();
-
-    /**
-     * Returns <tt>true</tt> if all tasks have completed following shut down.
-     * Note that <tt>isTerminated</tt> is never <tt>true</tt> unless
-     * either <tt>shutdown</tt> or <tt>shutdownNow</tt> was called first.
-     *
-     * @return <tt>true</tt> if all tasks have completed following shut down
-     */
-    boolean isTerminated();
-
-    /**
-     * Blocks until all tasks have completed execution after a shutdown
-     * request, or the timeout occurs, or the current thread is
-     * interrupted, whichever happens first.
-     *
-     * @param timeout the maximum time to wait
-     * @param unit the time unit of the timeout argument
-     * @return <tt>true</tt> if this executor terminated and <tt>false</tt>
-     * if the timeout elapsed before termination
-     * @throws InterruptedException if interrupted while waiting
-     */
-    boolean awaitTermination(long timeout, TimeUnit unit)
-        throws InterruptedException;
-
-
-    /**
-     * Submits a value-returning task for execution and returns a Future
-     * representing the pending results of the task. 
-     *
-     * <p>
-     * If you would like to immediately block waiting
-     * for a task, you can use constructions of the form
-     * <tt>result = exec.submit(aCallable).get();</tt>
-     *
-     * <p> Note: The {@link Executors} class includes a set of methods
-     * that can convert some other common closure-like objects,
-     * for example, {@link java.security.PrivilegedAction} to
-     * {@link Callable} form so they can be submitted.
-     *
-     * @param task the task to submit
-     * @return a Future representing pending completion of the task
-     * @throws RejectedExecutionException if task cannot be scheduled
-     * for execution
-     * @throws NullPointerException if task null
-     */
-    <T> Future<T> submit(Callable<T> task);
-
-    /**
-     * Submits a Runnable task for execution and returns a Future 
-     * representing that task that will upon completion return 
-     * the given result
-     *
-     * @param task the task to submit
-     * @param result the result to return
-     * @return a Future representing pending completion of the task,
-     * and whose <tt>get()</tt> method will return the given result
-     * upon completion.
-     * @throws RejectedExecutionException if task cannot be scheduled
-     * for execution
-     * @throws NullPointerException if task null     
-     */
-    <T> Future<T> submit(Runnable task, T result);
-
-    /**
-     * Submits a Runnable task for execution and returns a Future 
-     * representing that task.
-     *
-     * @param task the task to submit
-     * @return a Future representing pending completion of the task,
-     * and whose <tt>get()</tt> method will return <tt>null</tt>
-     * upon completion.
-     * @throws RejectedExecutionException if task cannot be scheduled
-     * for execution
-     * @throws NullPointerException if task null
-     */
-    Future<?> submit(Runnable task);
-
-    /**
-     * Executes the given tasks, returning their results
-     * when all complete.
-     * Note that a <em>completed</em> task could have
-     * terminated either normally or by throwing an exception.
-     * The results of this method are undefined if the given
-     * collection is modified while this operation is in progress.
-     * @param tasks the collection of tasks
-     * @return A list of Futures representing the tasks, in the same
-     * sequential order as produced by the iterator for the given task
-     * list, each of which has completed.
-     * @throws InterruptedException if interrupted while waiting, in
-     * which case unfinished tasks are cancelled.
-     * @throws NullPointerException if tasks or any of its elements are <tt>null</tt>
-     * @throws RejectedExecutionException if any task cannot be scheduled
-     * for execution
-     */
-
-    <T> List<Future<T>> invokeAll(Collection<Callable<T>> tasks)
-        throws InterruptedException;
-
-    /**
-     * Executes the given tasks, returning their results
-     * when all complete or the timeout expires, whichever happens first.
-     * Upon return, tasks that have not completed are cancelled.
-     * Note that a <em>completed</em> task could have
-     * terminated either normally or by throwing an exception.
-     * The results of this method are undefined if the given
-     * collection is modified while this operation is in progress.
-     * @param tasks the collection of tasks
-     * @param timeout the maximum time to wait
-     * @param unit the time unit of the timeout argument
-     * @return A list of Futures representing the tasks, in the same
-     * sequential order as produced by the iterator for the given
-     * task list. If the operation did not time out, each task will
-     * have completed. If it did time out, some of thiese tasks will
-     * not have completed.
-     * @throws InterruptedException if interrupted while waiting, in
-     * which case unfinished tasks are cancelled.
-     * @throws NullPointerException if tasks, any of its elements, or
-     * unit are <tt>null</tt>
-     * @throws RejectedExecutionException if any task cannot be scheduled
-     * for execution
-     */
-    <T> List<Future<T>> invokeAll(Collection<Callable<T>> tasks, 
-                                  long timeout, TimeUnit unit) 
-        throws InterruptedException;
-
-    /**
-     * Executes the given tasks, returning the result
-     * of one that has completed successfully (i.e., without throwing
-     * an exception), if any do. Upon normal or exceptional return,
-     * tasks that have not completed are cancelled.
-     * The results of this method are undefined if the given
-     * collection is modified while this operation is in progress.
-     * @param tasks the collection of tasks
-     * @return The result returned by one of the tasks.
-     * @throws InterruptedException if interrupted while waiting
-     * @throws NullPointerException if tasks or any of its elements
-     * are <tt>null</tt>
-     * @throws IllegalArgumentException if tasks empty
-     * @throws ExecutionException if no task successfully completes
-     * @throws RejectedExecutionException if tasks cannot be scheduled
-     * for execution
-     */
-    <T> T invokeAny(Collection<Callable<T>> tasks)
-        throws InterruptedException, ExecutionException;
-
-    /**
-     * Executes the given tasks, returning the result
-     * of one that has completed successfully (i.e., without throwing
-     * an exception), if any do before the given timeout elapses.
-     * Upon normal or exceptional return, tasks that have not
-     * completed are cancelled.
-     * The results of this method are undefined if the given
-     * collection is modified while this operation is in progress.
-     * @param tasks the collection of tasks
-     * @param timeout the maximum time to wait
-     * @param unit the time unit of the timeout argument
-     * @return The result returned by one of the tasks.
-     * @throws InterruptedException if interrupted while waiting
-     * @throws NullPointerException if tasks, any of its elements, or
-     * unit are <tt>null</tt>
-     * @throws TimeoutException if the given timeout elapses before
-     * any task successfully completes
-     * @throws ExecutionException if no task successfully completes
-     * @throws RejectedExecutionException if tasks cannot be scheduled
-     * for execution
-     */
-    <T> T invokeAny(Collection<Callable<T>> tasks, 
-                    long timeout, TimeUnit unit) 
-        throws InterruptedException, ExecutionException, TimeoutException;
-
-}
diff --git a/concurrent/src/main/java/java/util/concurrent/Executors.java b/concurrent/src/main/java/java/util/concurrent/Executors.java
deleted file mode 100644
index 23f1b75..0000000
--- a/concurrent/src/main/java/java/util/concurrent/Executors.java
+++ /dev/null
@@ -1,659 +0,0 @@
-/*
- * Written by Doug Lea with assistance from members of JCP JSR-166
- * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
- */
-
-package java.util.concurrent;
-import java.util.*;
-import java.util.concurrent.atomic.AtomicInteger;
-import java.security.AccessControlContext;
-import java.security.AccessController;
-import java.security.PrivilegedAction;
-import java.security.PrivilegedExceptionAction;
-import java.security.AccessControlException;
-
-/**
- * Factory and utility methods for {@link Executor}, {@link
- * ExecutorService}, {@link ScheduledExecutorService}, {@link
- * ThreadFactory}, and {@link Callable} classes defined in this
- * package. This class supports the following kinds of methods:
- * 
- * <ul>
- *   <li> Methods that create and return an {@link ExecutorService} 
- *        set up with commonly useful configuration settings. 
- *   <li> Methods that create and return a {@link ScheduledExecutorService} 
- *        set up with commonly useful configuration settings. 
- *   <li> Methods that create and return a "wrapped" ExecutorService, that
- *        disables reconfiguration by making implementation-specific methods
- *        inaccessible.
- *   <li> Methods that create and return a {@link ThreadFactory}
- *        that sets newly created threads to a known state.
- *   <li> Methods that create and return a {@link Callable} 
- *        out of other closure-like forms, so they can be used
- *        in execution methods requiring <tt>Callable</tt>.
- * </ul>
- *
- * @since 1.5
- * @author Doug Lea
- */
-public class Executors {
-
-    /**
-     * Creates a thread pool that reuses a fixed set of threads
-     * operating off a shared unbounded queue. If any thread
-     * terminates due to a failure during execution prior to shutdown,
-     * a new one will take its place if needed to execute subsequent
-     * tasks.
-     *
-     * @param nThreads the number of threads in the pool
-     * @return the newly created thread pool
-     */
-    public static ExecutorService newFixedThreadPool(int nThreads) {
-        return new ThreadPoolExecutor(nThreads, nThreads,
-                                      0L, TimeUnit.MILLISECONDS,
-                                      new LinkedBlockingQueue<Runnable>());
-    }
-
-    /**
-     * Creates a thread pool that reuses a fixed set of threads
-     * operating off a shared unbounded queue, using the provided
-     * ThreadFactory to create new threads when needed.
-     *
-     * @param nThreads the number of threads in the pool
-     * @param threadFactory the factory to use when creating new threads
-     * @return the newly created thread pool
-     */
-    public static ExecutorService newFixedThreadPool(int nThreads, ThreadFactory threadFactory) {
-        return new ThreadPoolExecutor(nThreads, nThreads,
-                                      0L, TimeUnit.MILLISECONDS,
-                                      new LinkedBlockingQueue<Runnable>(),
-                                      threadFactory);
-    }
-
-    /**
-     * Creates an Executor that uses a single worker thread operating
-     * off an unbounded queue. (Note however that if this single
-     * thread terminates due to a failure during execution prior to
-     * shutdown, a new one will take its place if needed to execute
-     * subsequent tasks.)  Tasks are guaranteed to execute
-     * sequentially, and no more than one task will be active at any
-     * given time. Unlike the otherwise equivalent
-     * <tt>newFixedThreadPool(1)</tt> the returned executor is
-     * guaranteed not to be reconfigurable to use additional threads.
-     *
-     * @return the newly created single-threaded Executor
-     */
-    public static ExecutorService newSingleThreadExecutor() {
-        return new DelegatedExecutorService
-            (new ThreadPoolExecutor(1, 1,
-                                    0L, TimeUnit.MILLISECONDS,
-                                    new LinkedBlockingQueue<Runnable>()));
-    }
-
-    /**
-     * Creates an Executor that uses a single worker thread operating
-     * off an unbounded queue, and uses the provided ThreadFactory to
-     * create a new thread when needed. Unlike the otherwise
-     * equivalent <tt>newFixedThreadPool(1, threadFactory)</tt> the returned executor
-     * is guaranteed not to be reconfigurable to use additional
-     * threads.
-     * 
-     * @param threadFactory the factory to use when creating new
-     * threads
-     *
-     * @return the newly created single-threaded Executor
-     */
-    public static ExecutorService newSingleThreadExecutor(ThreadFactory threadFactory) {
-        return new DelegatedExecutorService
-            (new ThreadPoolExecutor(1, 1,
-                                    0L, TimeUnit.MILLISECONDS,
-                                    new LinkedBlockingQueue<Runnable>(),
-                                    threadFactory));
-    }
-
-    /**
-     * Creates a thread pool that creates new threads as needed, but
-     * will reuse previously constructed threads when they are
-     * available.  These pools will typically improve the performance
-     * of programs that execute many short-lived asynchronous tasks.
-     * Calls to <tt>execute</tt> will reuse previously constructed
-     * threads if available. If no existing thread is available, a new
-     * thread will be created and added to the pool. Threads that have
-     * not been used for sixty seconds are terminated and removed from
-     * the cache. Thus, a pool that remains idle for long enough will
-     * not consume any resources. Note that pools with similar
-     * properties but different details (for example, timeout parameters)
-     * may be created using {@link ThreadPoolExecutor} constructors.
-     *
-     * @return the newly created thread pool
-     */
-    public static ExecutorService newCachedThreadPool() {
-        return new ThreadPoolExecutor(0, Integer.MAX_VALUE,
-                                      60L, TimeUnit.SECONDS,
-                                      new SynchronousQueue<Runnable>());
-    }
-
-    /**
-     * Creates a thread pool that creates new threads as needed, but
-     * will reuse previously constructed threads when they are
-     * available, and uses the provided
-     * ThreadFactory to create new threads when needed.
-     * @param threadFactory the factory to use when creating new threads
-     * @return the newly created thread pool
-     */
-    public static ExecutorService newCachedThreadPool(ThreadFactory threadFactory) {
-        return new ThreadPoolExecutor(0, Integer.MAX_VALUE,
-                                      60L, TimeUnit.SECONDS,
-                                      new SynchronousQueue<Runnable>(),
-                                      threadFactory);
-    }
-   
-    /**
-     * Creates a single-threaded executor that can schedule commands
-     * to run after a given delay, or to execute periodically.
-     * (Note however that if this single
-     * thread terminates due to a failure during execution prior to
-     * shutdown, a new one will take its place if needed to execute
-     * subsequent tasks.)  Tasks are guaranteed to execute
-     * sequentially, and no more than one task will be active at any
-     * given time. Unlike the otherwise equivalent
-     * <tt>newScheduledThreadPool(1)</tt> the returned executor is
-     * guaranteed not to be reconfigurable to use additional threads.
-     * @return the newly created scheduled executor
-     */
-    public static ScheduledExecutorService newSingleThreadScheduledExecutor() {
-        return new DelegatedScheduledExecutorService
-            (new ScheduledThreadPoolExecutor(1));
-    }
-
-    /**
-     * Creates a single-threaded executor that can schedule commands
-     * to run after a given delay, or to execute periodically.  (Note
-     * however that if this single thread terminates due to a failure
-     * during execution prior to shutdown, a new one will take its
-     * place if needed to execute subsequent tasks.)  Tasks are
-     * guaranteed to execute sequentially, and no more than one task
-     * will be active at any given time. Unlike the otherwise
-     * equivalent <tt>newScheduledThreadPool(1, threadFactory)</tt>
-     * the returned executor is guaranteed not to be reconfigurable to
-     * use additional threads.
-     * @param threadFactory the factory to use when creating new
-     * threads
-     * @return a newly created scheduled executor
-     */
-    public static ScheduledExecutorService newSingleThreadScheduledExecutor(ThreadFactory threadFactory) {
-        return new DelegatedScheduledExecutorService
-            (new ScheduledThreadPoolExecutor(1, threadFactory));
-    }
-    
-    /**
-     * Creates a thread pool that can schedule commands to run after a 
-     * given delay, or to execute periodically.
-     * @param corePoolSize the number of threads to keep in the pool,
-     * even if they are idle.
-     * @return a newly created scheduled thread pool
-     */
-    public static ScheduledExecutorService newScheduledThreadPool(int corePoolSize) {
-        return new ScheduledThreadPoolExecutor(corePoolSize);
-    }
-
-    /**
-     * Creates a thread pool that can schedule commands to run after a 
-     * given delay, or to execute periodically.
-     * @param corePoolSize the number of threads to keep in the pool,
-     * even if they are idle.
-     * @param threadFactory the factory to use when the executor
-     * creates a new thread. 
-     * @return a newly created scheduled thread pool
-     */
-    public static ScheduledExecutorService newScheduledThreadPool(
-            int corePoolSize, ThreadFactory threadFactory) {
-        return new ScheduledThreadPoolExecutor(corePoolSize, threadFactory);
-    }
-
-
-    /**
-     * Returns an object that delegates all defined {@link
-     * ExecutorService} methods to the given executor, but not any
-     * other methods that might otherwise be accessible using
-     * casts. This provides a way to safely "freeze" configuration and
-     * disallow tuning of a given concrete implementation.
-     * @param executor the underlying implementation
-     * @return an <tt>ExecutorService</tt> instance
-     * @throws NullPointerException if executor null
-     */
-    public static ExecutorService unconfigurableExecutorService(ExecutorService executor) {
-        if (executor == null)
-            throw new NullPointerException();
-        return new DelegatedExecutorService(executor);
-    }
-
-    /**
-     * Returns an object that delegates all defined {@link
-     * ScheduledExecutorService} methods to the given executor, but
-     * not any other methods that might otherwise be accessible using
-     * casts. This provides a way to safely "freeze" configuration and
-     * disallow tuning of a given concrete implementation.
-     * @param executor the underlying implementation
-     * @return a <tt>ScheduledExecutorService</tt> instance
-     * @throws NullPointerException if executor null
-     */
-    public static ScheduledExecutorService unconfigurableScheduledExecutorService(ScheduledExecutorService executor) {
-        if (executor == null)
-            throw new NullPointerException();
-        return new DelegatedScheduledExecutorService(executor);
-    }
-        
-    /**
-     * Returns a default thread factory used to create new threads.
-     * This factory creates all new threads used by an Executor in the
-     * same {@link ThreadGroup}. If there is a {@link
-     * java.lang.SecurityManager}, it uses the group of {@link
-     * System#getSecurityManager}, else the group of the thread
-     * invoking this <tt>defaultThreadFactory</tt> method. Each new
-     * thread is created as a non-daemon thread with priority
-     * <tt>Thread.NORM_PRIORITY</tt>. New threads have names
-     * accessible via {@link Thread#getName} of
-     * <em>pool-N-thread-M</em>, where <em>N</em> is the sequence
-     * number of this factory, and <em>M</em> is the sequence number
-     * of the thread created by this factory.
-     * @return a thread factory
-     */
-    public static ThreadFactory defaultThreadFactory() {
-        return new DefaultThreadFactory();
-    }
-
-    /**
-     * Returns a thread factory used to create new threads that
-     * have the same permissions as the current thread.
-     * This factory creates threads with the same settings as {@link
-     * Executors#defaultThreadFactory}, additionally setting the
-     * AccessControlContext and contextClassLoader of new threads to
-     * be the same as the thread invoking this
-     * <tt>privilegedThreadFactory</tt> method.  A new
-     * <tt>privilegedThreadFactory</tt> can be created within an
-     * {@link AccessController#doPrivileged} action setting the
-     * current thread's access control context to create threads with
-     * the selected permission settings holding within that action.
-     *
-     * <p> Note that while tasks running within such threads will have
-     * the same access control and class loader settings as the
-     * current thread, they need not have the same {@link
-     * java.lang.ThreadLocal} or {@link
-     * java.lang.InheritableThreadLocal} values. If necessary,
-     * particular values of thread locals can be set or reset before
-     * any task runs in {@link ThreadPoolExecutor} subclasses using
-     * {@link ThreadPoolExecutor#beforeExecute}. Also, if it is
-     * necessary to initialize worker threads to have the same
-     * InheritableThreadLocal settings as some other designated
-     * thread, you can create a custom ThreadFactory in which that
-     * thread waits for and services requests to create others that
-     * will inherit its values.
-     *
-     * @return a thread factory
-     * @throws AccessControlException if the current access control
-     * context does not have permission to both get and set context
-     * class loader.
-     */
-    public static ThreadFactory privilegedThreadFactory() {
-        return new PrivilegedThreadFactory();
-    }
-
-    /**
-     * Returns a {@link Callable} object that, when
-     * called, runs the given task and returns the given result.  This
-     * can be useful when applying methods requiring a
-     * <tt>Callable</tt> to an otherwise resultless action.
-     * @param task the task to run
-     * @param result the result to return
-     * @throws NullPointerException if task null
-     * @return a callable object
-     */
-    public static <T> Callable<T> callable(Runnable task, T result) {
-        if (task == null)
-            throw new NullPointerException();
-        return new RunnableAdapter<T>(task, result);
-    }
-
-    /**
-     * Returns a {@link Callable} object that, when
-     * called, runs the given task and returns <tt>null</tt>.
-     * @param task the task to run
-     * @return a callable object
-     * @throws NullPointerException if task null
-     */
-    public static Callable<Object> callable(Runnable task) {
-        if (task == null)
-            throw new NullPointerException();
-        return new RunnableAdapter<Object>(task, null);
-    }
-
-    /**
-     * Returns a {@link Callable} object that, when
-     * called, runs the given privileged action and returns its result.
-     * @param action the privileged action to run
-     * @return a callable object
-     * @throws NullPointerException if action null
-     */
-    public static Callable<Object> callable(PrivilegedAction action) {
-        if (action == null)
-            throw new NullPointerException();
-        return new PrivilegedActionAdapter(action);
-    }
-
-    /**
-     * Returns a {@link Callable} object that, when
-     * called, runs the given privileged exception action and returns
-     * its result.
-     * @param action the privileged exception action to run
-     * @return a callable object
-     * @throws NullPointerException if action null
-     */
-    public static Callable<Object> callable(PrivilegedExceptionAction action) {
-        if (action == null)
-            throw new NullPointerException();
-        return new PrivilegedExceptionActionAdapter(action);
-    }
-
-    /**
-     * Returns a {@link Callable} object that will, when
-     * called, execute the given <tt>callable</tt> under the current
-     * access control context. This method should normally be
-     * invoked within an {@link AccessController#doPrivileged} action
-     * to create callables that will, if possible, execute under the
-     * selected permission settings holding within that action; or if
-     * not possible, throw an associated {@link
-     * AccessControlException}.
-     * @param callable the underlying task
-     * @return a callable object
-     * @throws NullPointerException if callable null
-     *
-     */
-    public static <T> Callable<T> privilegedCallable(Callable<T> callable) {
-        if (callable == null)
-            throw new NullPointerException();
-        return new PrivilegedCallable(callable);
-    }
-    
-    /**
-     * Returns a {@link Callable} object that will, when
-     * called, execute the given <tt>callable</tt> under the current
-     * access control context, with the current context class loader
-     * as the context class loader. This method should normally be
-     * invoked within an {@link AccessController#doPrivileged} action
-     * to create callables that will, if possible, execute under the
-     * selected permission settings holding within that action; or if
-     * not possible, throw an associated {@link
-     * AccessControlException}.
-     * @param callable the underlying task
-     *
-     * @return a callable object
-     * @throws NullPointerException if callable null
-     * @throws AccessControlException if the current access control
-     * context does not have permission to both set and get context
-     * class loader.
-     */
-    public static <T> Callable<T> privilegedCallableUsingCurrentClassLoader(Callable<T> callable) {
-        if (callable == null)
-            throw new NullPointerException();
-        return new PrivilegedCallableUsingCurrentClassLoader(callable);
-    }
-
-    // Non-public classes supporting the public methods
-
-    /**
-     * A callable that runs given task and returns given result
-     */
-    static final class RunnableAdapter<T> implements Callable<T> {
-        final Runnable task;
-        final T result;
-        RunnableAdapter(Runnable  task, T result) {
-            this.task = task; 
-            this.result = result;
-        }
-        public T call() { 
-            task.run(); 
-            return result; 
-        }
-    }
-
-    /**
-     * A callable that runs given privileged action and returns its result
-     */
-    static final class PrivilegedActionAdapter implements Callable<Object> {
-        PrivilegedActionAdapter(PrivilegedAction action) {
-            this.action = action;
-        }
-        public Object call () {
-            return action.run();
-        }
-        private final PrivilegedAction action;
-    }
-
-    /**
-     * A callable that runs given privileged exception action and returns its result
-     */
-    static final class PrivilegedExceptionActionAdapter implements Callable<Object> {
-        PrivilegedExceptionActionAdapter(PrivilegedExceptionAction action) {
-            this.action = action;
-        }
-        public Object call () throws Exception {
-            return action.run();
-        }
-        private final PrivilegedExceptionAction action;
-    }
-
-
-    /**
-     * A callable that runs under established access control settings
-     */
-    static final class PrivilegedCallable<T> implements Callable<T> {
-        private final AccessControlContext acc;
-        private final Callable<T> task;
-        private T result;
-        private Exception exception;
-        PrivilegedCallable(Callable<T> task) {
-            this.task = task;
-            this.acc = AccessController.getContext();
-        }
-
-        public T call() throws Exception {
-            AccessController.doPrivileged(new PrivilegedAction() {
-                    public Object run() {
-                        try {
-                            result = task.call();
-                        } catch(Exception ex) {
-                            exception = ex;
-                        }
-                        return null;
-                    }
-                }, acc);
-            if (exception != null)
-                throw exception;
-            else 
-                return result;
-        }
-    }
-
-    /**
-     * A callable that runs under established access control settings and
-     * current ClassLoader
-     */
-    static final class PrivilegedCallableUsingCurrentClassLoader<T> implements Callable<T> {
-        private final ClassLoader ccl;
-        private final AccessControlContext acc;
-        private final Callable<T> task;
-        private T result;
-        private Exception exception;
-        PrivilegedCallableUsingCurrentClassLoader(Callable<T> task) {
-            this.task = task;
-            this.ccl = Thread.currentThread().getContextClassLoader();
-            this.acc = AccessController.getContext();
-            acc.checkPermission(new RuntimePermission("getContextClassLoader"));
-            acc.checkPermission(new RuntimePermission("setContextClassLoader"));
-        }
-
-        public T call() throws Exception {
-            AccessController.doPrivileged(new PrivilegedAction() {
-                    public Object run() {
-                        ClassLoader savedcl = null;
-                        Thread t = Thread.currentThread();
-                        try {
-                            ClassLoader cl = t.getContextClassLoader();
-                            if (ccl != cl) {
-                                t.setContextClassLoader(ccl);
-                                savedcl = cl;
-                            }
-                            result = task.call();
-                        } catch(Exception ex) {
-                            exception = ex;
-                        } finally {
-                            if (savedcl != null)
-                                t.setContextClassLoader(savedcl);
-                        }
-                        return null;
-                    }
-                }, acc);
-            if (exception != null)
-                throw exception;
-            else 
-                return result;
-        }
-    }
-
-    /**
-     * The default thread factory
-     */
-    static class DefaultThreadFactory implements ThreadFactory {
-        static final AtomicInteger poolNumber = new AtomicInteger(1);
-        final ThreadGroup group;
-        final AtomicInteger threadNumber = new AtomicInteger(1);
-        final String namePrefix;
-
-        DefaultThreadFactory() {
-            SecurityManager s = System.getSecurityManager();
-            group = (s != null)? s.getThreadGroup() :
-                                 Thread.currentThread().getThreadGroup();
-            namePrefix = "pool-" + 
-                          poolNumber.getAndIncrement() + 
-                         "-thread-";
-        }
-
-        public Thread newThread(Runnable r) {
-            Thread t = new Thread(group, r, 
-                                  namePrefix + threadNumber.getAndIncrement(),
-                                  0);
-            if (t.isDaemon())
-                t.setDaemon(false);
-            if (t.getPriority() != Thread.NORM_PRIORITY)
-                t.setPriority(Thread.NORM_PRIORITY);
-            return t;
-        }
-    }
-
-    /**
-     *  Thread factory capturing access control and class loader
-     */
-    static class PrivilegedThreadFactory extends DefaultThreadFactory {
-        private final ClassLoader ccl;
-        private final AccessControlContext acc;
-
-        PrivilegedThreadFactory() {
-            super();
-            this.ccl = Thread.currentThread().getContextClassLoader();
-            this.acc = AccessController.getContext();
-            acc.checkPermission(new RuntimePermission("setContextClassLoader"));
-        }
-        
-        public Thread newThread(final Runnable r) {
-            return super.newThread(new Runnable() {
-                public void run() {
-                    AccessController.doPrivileged(new PrivilegedAction() {
-                        public Object run() { 
-                            Thread.currentThread().setContextClassLoader(ccl);
-                            r.run();
-                            return null; 
-                        }
-                    }, acc);
-                }
-            });
-        }
-        
-    }
-
-   /**
-     * A wrapper class that exposes only the ExecutorService methods
-     * of an implementation.
-     */
-    static class DelegatedExecutorService extends AbstractExecutorService {
-        private final ExecutorService e;
-        DelegatedExecutorService(ExecutorService executor) { e = executor; }
-        public void execute(Runnable command) { e.execute(command); }
-        public void shutdown() { e.shutdown(); }
-        public List<Runnable> shutdownNow() { return e.shutdownNow(); }
-        public boolean isShutdown() { return e.isShutdown(); }
-        public boolean isTerminated() { return e.isTerminated(); }
-        public boolean awaitTermination(long timeout, TimeUnit unit)
-            throws InterruptedException {
-            return e.awaitTermination(timeout, unit);
-        }
-        public Future<?> submit(Runnable task) {
-            return e.submit(task);
-        }
-        public <T> Future<T> submit(Callable<T> task) {
-            return e.submit(task);
-        }
-        public <T> Future<T> submit(Runnable task, T result) {
-            return e.submit(task, result);
-        }
-        public <T> List<Future<T>> invokeAll(Collection<Callable<T>> tasks)
-            throws InterruptedException {
-            return e.invokeAll(tasks);
-        }
-        public <T> List<Future<T>> invokeAll(Collection<Callable<T>> tasks, 
-                                             long timeout, TimeUnit unit) 
-            throws InterruptedException {
-            return e.invokeAll(tasks, timeout, unit);
-        }
-        public <T> T invokeAny(Collection<Callable<T>> tasks)
-            throws InterruptedException, ExecutionException {
-            return e.invokeAny(tasks);
-        }
-        public <T> T invokeAny(Collection<Callable<T>> tasks, 
-                               long timeout, TimeUnit unit) 
-            throws InterruptedException, ExecutionException, TimeoutException {
-            return e.invokeAny(tasks, timeout, unit);
-        }
-    }
-    
-    /**
-     * A wrapper class that exposes only the ExecutorService and 
-     * ScheduleExecutor methods of a ScheduledExecutorService implementation.
-     */
-    static class DelegatedScheduledExecutorService
-            extends DelegatedExecutorService 
-            implements ScheduledExecutorService {
-        private final ScheduledExecutorService e;
-        DelegatedScheduledExecutorService(ScheduledExecutorService executor) {
-            super(executor);
-            e = executor;
-        }
-        public ScheduledFuture<?> schedule(Runnable command, long delay,  TimeUnit unit) {
-            return e.schedule(command, delay, unit);
-        }
-        public <V> ScheduledFuture<V> schedule(Callable<V> callable, long delay, TimeUnit unit) {
-            return e.schedule(callable, delay, unit);
-        }
-        public ScheduledFuture<?> scheduleAtFixedRate(Runnable command, long initialDelay,  long period, TimeUnit unit) {
-            return e.scheduleAtFixedRate(command, initialDelay, period, unit);
-        }
-        public ScheduledFuture<?> scheduleWithFixedDelay(Runnable command, long initialDelay,  long delay, TimeUnit unit) {
-            return e.scheduleWithFixedDelay(command, initialDelay, delay, unit);
-        }
-    }
-
-        
-    /** Cannot instantiate. */
-    private Executors() {}
-}
diff --git a/concurrent/src/main/java/java/util/concurrent/Future.java b/concurrent/src/main/java/java/util/concurrent/Future.java
deleted file mode 100644
index 38fa8c6..0000000
--- a/concurrent/src/main/java/java/util/concurrent/Future.java
+++ /dev/null
@@ -1,133 +0,0 @@
-/*
- * Written by Doug Lea with assistance from members of JCP JSR-166
- * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
- */
-
-package java.util.concurrent;
-
-/**
- * A <tt>Future</tt> represents the result of an asynchronous
- * computation.  Methods are provided to check if the computation is
- * complete, to wait for its completion, and to retrieve the result of
- * the computation.  The result can only be retrieved using method
- * <tt>get</tt> when the computation has completed, blocking if
- * necessary until it is ready.  Cancellation is performed by the
- * <tt>cancel</tt> method.  Additional methods are provided to
- * determine if the task completed normally or was cancelled. Once a
- * computation has completed, the computation cannot be cancelled.
- * If you would like to use a <tt>Future</tt> for the sake
- * of cancellability but not provide a usable result, you can
- * declare types of the form <tt>Future&lt;?&gt;</tt> and
- * return <tt>null</tt> as a result of the underlying task.
- *
- * <p>
- * <b>Sample Usage</b> (Note that the following classes are all
- * made-up.) <p>
- * <pre>
- * interface ArchiveSearcher { String search(String target); }
- * class App {
- *   ExecutorService executor = ...
- *   ArchiveSearcher searcher = ...
- *   void showSearch(final String target) throws InterruptedException {
- *     Future&lt;String&gt; future = executor.submit(new Callable&lt;String&gt;() {
- *         public String call() { return searcher.search(target); }
- *     });
- *     displayOtherThings(); // do other things while searching
- *     try {
- *       displayText(future.get()); // use future
- *     } catch (ExecutionException ex) { cleanup(); return; }
- *   }
- * }
- * </pre>
- *
- * The {@link FutureTask} class is an implementation of <tt>Future</tt> that 
- * implements <tt>Runnable</tt>, and so may be executed by an <tt>Executor</tt>. 
- * For example, the above construction with <tt>submit</tt> could be replaced by:
- * <pre>
- *     FutureTask&lt;String&gt; future =
- *       new FutureTask&lt;String&gt;(new Callable&lt;String&gt;() {
- *         public String call() {
- *           return searcher.search(target);
- *       }});
- *     executor.execute(future);
- * </pre>
- * @see FutureTask
- * @see Executor
- * @since 1.5
- * @author Doug Lea
- * @param <V> The result type returned by this Future's <tt>get</tt> method
- */
-public interface Future<V> {
-
-    /**
-     * Attempts to cancel execution of this task.  This attempt will
-     * fail if the task has already completed, already been cancelled,
-     * or could not be cancelled for some other reason. If successful,
-     * and this task has not started when <tt>cancel</tt> is called,
-     * this task should never run.  If the task has already started,
-     * then the <tt>mayInterruptIfRunning</tt> parameter determines
-     * whether the thread executing this task should be interrupted in
-     * an attempt to stop the task.
-     *
-     * @param mayInterruptIfRunning <tt>true</tt> if the thread executing this
-     * task should be interrupted; otherwise, in-progress tasks are allowed
-     * to complete
-     * @return <tt>false</tt> if the task could not be cancelled,
-     * typically because it has already completed normally;
-     * <tt>true</tt> otherwise
-     */
-    boolean cancel(boolean mayInterruptIfRunning);
-
-    /**
-     * Returns <tt>true</tt> if this task was cancelled before it completed
-     * normally.
-     *
-     * @return <tt>true</tt> if task was cancelled before it completed
-     */
-    boolean isCancelled();
-
-    /**
-     * Returns <tt>true</tt> if this task completed.  
-     *
-     * Completion may be due to normal termination, an exception, or
-     * cancellation -- in all of these cases, this method will return
-     * <tt>true</tt>.
-     * 
-     * @return <tt>true</tt> if this task completed.
-     */
-    boolean isDone();
-
-    /**
-     * Waits if necessary for the computation to complete, and then
-     * retrieves its result.
-     *
-     * @return the computed result
-     * @throws CancellationException if the computation was cancelled
-     * @throws ExecutionException if the computation threw an
-     * exception
-     * @throws InterruptedException if the current thread was interrupted
-     * while waiting
-     */
-    V get() throws InterruptedException, ExecutionException;
-
-    /**
-     * Waits if necessary for at most the given time for the computation
-     * to complete, and then retrieves its result, if available.
-     *
-     * @param timeout the maximum time to wait
-     * @param unit the time unit of the timeout argument
-     * @return the computed result
-     * @throws CancellationException if the computation was cancelled
-     * @throws ExecutionException if the computation threw an
-     * exception
-     * @throws InterruptedException if the current thread was interrupted
-     * while waiting
-     * @throws TimeoutException if the wait timed out
-     */
-    V get(long timeout, TimeUnit unit)
-        throws InterruptedException, ExecutionException, TimeoutException;
-}
-
-
-
diff --git a/concurrent/src/main/java/java/util/concurrent/FutureTask.java b/concurrent/src/main/java/java/util/concurrent/FutureTask.java
deleted file mode 100644
index 87db1cd..0000000
--- a/concurrent/src/main/java/java/util/concurrent/FutureTask.java
+++ /dev/null
@@ -1,276 +0,0 @@
-/*
- * Written by Doug Lea with assistance from members of JCP JSR-166
- * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
- */
-
-package java.util.concurrent;
-import java.util.concurrent.locks.*;
-
-/**
- * A cancellable asynchronous computation.  This class provides a base
- * implementation of {@link Future}, with methods to start and cancel
- * a computation, query to see if the computation is complete, and
- * retrieve the result of the computation.  The result can only be
- * retrieved when the computation has completed; the <tt>get</tt>
- * method will block if the computation has not yet completed.  Once
- * the computation has completed, the computation cannot be restarted
- * or cancelled.
- *
- * <p>A <tt>FutureTask</tt> can be used to wrap a {@link Callable} or
- * {@link java.lang.Runnable} object.  Because <tt>FutureTask</tt>
- * implements <tt>Runnable</tt>, a <tt>FutureTask</tt> can be
- * submitted to an {@link Executor} for execution.
- *
- * <p>In addition to serving as a standalone class, this class provides
- * <tt>protected</tt> functionality that may be useful when creating
- * customized task classes.
- *
- * @since 1.5
- * @author Doug Lea
- * @param <V> The result type returned by this FutureTask's <tt>get</tt> method
- */
-public class FutureTask<V> implements Future<V>, Runnable {
-    /** Synchronization control for FutureTask */
-    private final Sync sync;
-
-    /**
-     * Creates a <tt>FutureTask</tt> that will upon running, execute the
-     * given <tt>Callable</tt>.
-     *
-     * @param  callable the callable task
-     * @throws NullPointerException if callable is null
-     */
-    public FutureTask(Callable<V> callable) {
-        if (callable == null)
-            throw new NullPointerException();
-        sync = new Sync(callable);
-    }
-
-    /**
-     * Creates a <tt>FutureTask</tt> that will upon running, execute the
-     * given <tt>Runnable</tt>, and arrange that <tt>get</tt> will return the
-     * given result on successful completion.
-     *
-     * @param  runnable the runnable task
-     * @param result the result to return on successful completion. If
-     * you don't need a particular result, consider using
-     * constructions of the form:
-     * <tt>Future&lt;?&gt; f = new FutureTask&lt;Object&gt;(runnable, null)</tt>
-     * @throws NullPointerException if runnable is null
-     */
-    public FutureTask(Runnable runnable, V result) {
-        sync = new Sync(Executors.callable(runnable, result));
-    }
-
-    public boolean isCancelled() {
-        return sync.innerIsCancelled();
-    }
-    
-    public boolean isDone() {
-        return sync.innerIsDone();
-    }
-
-    public boolean cancel(boolean mayInterruptIfRunning) {
-        return sync.innerCancel(mayInterruptIfRunning);
-    }
-    
-    public V get() throws InterruptedException, ExecutionException {
-        return sync.innerGet();
-    }
-
-    public V get(long timeout, TimeUnit unit)
-        throws InterruptedException, ExecutionException, TimeoutException {
-        return sync.innerGet(unit.toNanos(timeout));
-    }
-
-    /**
-     * Protected method invoked when this task transitions to state
-     * <tt>isDone</tt> (whether normally or via cancellation). The
-     * default implementation does nothing.  Subclasses may override
-     * this method to invoke completion callbacks or perform
-     * bookkeeping. Note that you can query status inside the
-     * implementation of this method to determine whether this task
-     * has been cancelled.
-     */
-    protected void done() { }
-
-    /**
-     * Sets the result of this Future to the given value unless
-     * this future has already been set or has been cancelled.
-     * @param v the value
-     */ 
-    protected void set(V v) {
-        sync.innerSet(v);
-    }
-
-    /**
-     * Causes this future to report an <tt>ExecutionException</tt>
-     * with the given throwable as its cause, unless this Future has
-     * already been set or has been cancelled.
-     * @param t the cause of failure.
-     */ 
-    protected void setException(Throwable t) {
-        sync.innerSetException(t);
-    }
-    
-    /**
-     * Sets this Future to the result of computation unless
-     * it has been cancelled.
-     */
-    public void run() {
-        sync.innerRun();
-    }
-
-    /**
-     * Executes the computation without setting its result, and then
-     * resets this Future to initial state, failing to do so if the
-     * computation encounters an exception or is cancelled.  This is
-     * designed for use with tasks that intrinsically execute more
-     * than once.
-     * @return true if successfully run and reset
-     */
-    protected boolean runAndReset() {
-        return sync.innerRunAndReset();
-    }
-
-    /**
-     * Synchronization control for FutureTask. Note that this must be
-     * a non-static inner class in order to invoke the protected
-     * <tt>done</tt> method. For clarity, all inner class support
-     * methods are same as outer, prefixed with "inner".
-     *
-     * Uses AQS sync state to represent run status
-     */
-    private final class Sync extends AbstractQueuedSynchronizer {
-        /** State value representing that task is running */
-        private static final int RUNNING   = 1;
-        /** State value representing that task ran */
-        private static final int RAN       = 2;
-        /** State value representing that task was cancelled */
-        private static final int CANCELLED = 4;
-
-        /** The underlying callable */
-        private final Callable<V> callable;
-        /** The result to return from get() */
-        private V result;
-        /** The exception to throw from get() */
-        private Throwable exception;
-
-        /** 
-         * The thread running task. When nulled after set/cancel, this
-         * indicates that the results are accessible.  Must be
-         * volatile, to serve as write barrier on completion.
-         */
-        private volatile Thread runner;
-
-        Sync(Callable<V> callable) {
-            this.callable = callable;
-        }
-
-        private boolean ranOrCancelled(int state) {
-            return (state & (RAN | CANCELLED)) != 0;
-        }
-
-        /**
-         * Implements AQS base acquire to succeed if ran or cancelled
-         */
-        protected int tryAcquireShared(int ignore) {
-            return innerIsDone()? 1 : -1;
-        }
-
-        /**
-         * Implements AQS base release to always signal after setting
-         * final done status by nulling runner thread.
-         */
-        protected boolean tryReleaseShared(int ignore) {
-            runner = null;
-            return true; 
-        }
-
-        boolean innerIsCancelled() {
-            return getState() == CANCELLED;
-        }
-        
-        boolean innerIsDone() {
-            return ranOrCancelled(getState()) && runner == null;
-        }
-
-        V innerGet() throws InterruptedException, ExecutionException {
-            acquireSharedInterruptibly(0);
-            if (getState() == CANCELLED)
-                throw new CancellationException();
-            if (exception != null)
-                throw new ExecutionException(exception);
-            return result;
-        }
-
-        V innerGet(long nanosTimeout) throws InterruptedException, ExecutionException, TimeoutException {
-            if (!tryAcquireSharedNanos(0, nanosTimeout))
-                throw new TimeoutException();                
-            if (getState() == CANCELLED)
-                throw new CancellationException();
-            if (exception != null)
-                throw new ExecutionException(exception);
-            return result;
-        }
-
-        void innerSet(V v) {
-            int s = getState();
-            if (ranOrCancelled(s) || !compareAndSetState(s, RAN))
-                return;
-            result = v;
-            releaseShared(0);
-            done();
-        }
-
-        void innerSetException(Throwable t) {
-            int s = getState();
-            if (ranOrCancelled(s) || !compareAndSetState(s, RAN)) 
-                return;
-            exception = t;
-            result = null;
-            releaseShared(0);
-            done();
-        }
-
-        boolean innerCancel(boolean mayInterruptIfRunning) {
-            int s = getState();
-            if (ranOrCancelled(s) || !compareAndSetState(s, CANCELLED)) 
-                return false;
-            if (mayInterruptIfRunning) {
-                Thread r = runner;
-                if (r != null)
-                    r.interrupt();
-            }
-            releaseShared(0);
-            done();
-            return true;
-        }
-
-        void innerRun() {
-            if (!compareAndSetState(0, RUNNING)) 
-                return;
-            try {
-                runner = Thread.currentThread();
-                innerSet(callable.call());
-            } catch(Throwable ex) {
-                innerSetException(ex);
-            } 
-        }
-
-        boolean innerRunAndReset() {
-            if (!compareAndSetState(0, RUNNING)) 
-                return false;
-            try {
-                runner = Thread.currentThread();
-                callable.call(); // don't set result
-                runner = null;
-                return compareAndSetState(RUNNING, 0);
-            } catch(Throwable ex) {
-                innerSetException(ex);
-                return false;
-            } 
-        }
-    }
-}
diff --git a/concurrent/src/main/java/java/util/concurrent/LinkedBlockingQueue.java b/concurrent/src/main/java/java/util/concurrent/LinkedBlockingQueue.java
deleted file mode 100644
index 662f63e..0000000
--- a/concurrent/src/main/java/java/util/concurrent/LinkedBlockingQueue.java
+++ /dev/null
@@ -1,722 +0,0 @@
-/*
- * Written by Doug Lea with assistance from members of JCP JSR-166
- * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
- */
-
-package java.util.concurrent;
-import java.util.concurrent.atomic.*;
-import java.util.concurrent.locks.*;
-import java.util.*;
-
-// BEGIN android-note
-// removed link to collections framework docs
-// END android-note
-
-/**
- * An optionally-bounded {@linkplain BlockingQueue blocking queue} based on
- * linked nodes.
- * This queue orders elements FIFO (first-in-first-out).
- * The <em>head</em> of the queue is that element that has been on the
- * queue the longest time.
- * The <em>tail</em> of the queue is that element that has been on the
- * queue the shortest time. New elements
- * are inserted at the tail of the queue, and the queue retrieval
- * operations obtain elements at the head of the queue.
- * Linked queues typically have higher throughput than array-based queues but
- * less predictable performance in most concurrent applications.
- *
- * <p> The optional capacity bound constructor argument serves as a
- * way to prevent excessive queue expansion. The capacity, if unspecified,
- * is equal to {@link Integer#MAX_VALUE}.  Linked nodes are
- * dynamically created upon each insertion unless this would bring the
- * queue above capacity.
- *
- * <p>This class implements all of the <em>optional</em> methods
- * of the {@link Collection} and {@link Iterator} interfaces.
- *
- * @since 1.5
- * @author Doug Lea
- * @param <E> the type of elements held in this collection
- *
- **/
-public class LinkedBlockingQueue<E> extends AbstractQueue<E>
-        implements BlockingQueue<E>, java.io.Serializable {
-    private static final long serialVersionUID = -6903933977591709194L;
-
-    /*
-     * A variant of the "two lock queue" algorithm.  The putLock gates
-     * entry to put (and offer), and has an associated condition for
-     * waiting puts.  Similarly for the takeLock.  The "count" field
-     * that they both rely on is maintained as an atomic to avoid
-     * needing to get both locks in most cases. Also, to minimize need
-     * for puts to get takeLock and vice-versa, cascading notifies are
-     * used. When a put notices that it has enabled at least one take,
-     * it signals taker. That taker in turn signals others if more
-     * items have been entered since the signal. And symmetrically for
-     * takes signalling puts. Operations such as remove(Object) and
-     * iterators acquire both locks.
-    */
-
-    /**
-     * Linked list node class
-     */
-    static class Node<E> {
-        /** The item, volatile to ensure barrier separating write and read */
-        volatile E item;
-        Node<E> next;
-        Node(E x) { item = x; }
-    }
-
-    /** The capacity bound, or Integer.MAX_VALUE if none */
-    private final int capacity;
-
-    /** Current number of elements */
-    private final AtomicInteger count = new AtomicInteger(0);
-
-    /** Head of linked list */
-    private transient Node<E> head;
-
-    /** Tail of linked list */
-    private transient Node<E> last;
-
-    /** Lock held by take, poll, etc */
-    private final ReentrantLock takeLock = new ReentrantLock();
-
-    /** Wait queue for waiting takes */
-    private final Condition notEmpty = takeLock.newCondition();
-
-    /** Lock held by put, offer, etc */
-    private final ReentrantLock putLock = new ReentrantLock();
-
-    /** Wait queue for waiting puts */
-    private final Condition notFull = putLock.newCondition();
-
-    /**
-     * Signal a waiting take. Called only from put/offer (which do not
-     * otherwise ordinarily lock takeLock.)
-     */
-    private void signalNotEmpty() {
-        final ReentrantLock takeLock = this.takeLock;
-        takeLock.lock();
-        try {
-            notEmpty.signal();
-        } finally {
-            takeLock.unlock();
-        }
-    }
-
-    /**
-     * Signal a waiting put. Called only from take/poll.
-     */
-    private void signalNotFull() {
-        final ReentrantLock putLock = this.putLock;
-        putLock.lock();
-        try {
-            notFull.signal();
-        } finally {
-            putLock.unlock();
-        }
-    }
-
-    /**
-     * Create a node and link it at end of queue
-     * @param x the item
-     */
-    private void insert(E x) {
-        last = last.next = new Node<E>(x);
-    }
-
-    /**
-     * Remove a node from head of queue,
-     * @return the node
-     */
-    private E extract() {
-        Node<E> first = head.next;
-        head = first;
-        E x = first.item;
-        first.item = null;
-        return x;
-    }
-
-    /**
-     * Lock to prevent both puts and takes.
-     */
-    private void fullyLock() {
-        putLock.lock();
-        takeLock.lock();
-    }
-
-    /**
-     * Unlock to allow both puts and takes.
-     */
-    private void fullyUnlock() {
-        takeLock.unlock();
-        putLock.unlock();
-    }
-
-
-    /**
-     * Creates a <tt>LinkedBlockingQueue</tt> with a capacity of
-     * {@link Integer#MAX_VALUE}.
-     */
-    public LinkedBlockingQueue() {
-        this(Integer.MAX_VALUE);
-    }
-
-    /**
-     * Creates a <tt>LinkedBlockingQueue</tt> with the given (fixed) capacity.
-     *
-     * @param capacity the capacity of this queue.
-     * @throws IllegalArgumentException if <tt>capacity</tt> is not greater
-     *         than zero.
-     */
-    public LinkedBlockingQueue(int capacity) {
-        if (capacity <= 0) throw new IllegalArgumentException();
-        this.capacity = capacity;
-        last = head = new Node<E>(null);
-    }
-
-    /**
-     * Creates a <tt>LinkedBlockingQueue</tt> with a capacity of
-     * {@link Integer#MAX_VALUE}, initially containing the elements of the
-     * given collection,
-     * added in traversal order of the collection's iterator.
-     * @param c the collection of elements to initially contain
-     * @throws NullPointerException if <tt>c</tt> or any element within it
-     * is <tt>null</tt>
-     */
-    public LinkedBlockingQueue(Collection<? extends E> c) {
-        this(Integer.MAX_VALUE);
-        for (Iterator<? extends E> it = c.iterator(); it.hasNext();)
-            add(it.next());
-    }
-
-
-    // this doc comment is overridden to remove the reference to collections
-    // greater in size than Integer.MAX_VALUE
-    /**
-     * Returns the number of elements in this queue.
-     *
-     * @return  the number of elements in this queue.
-     */
-    public int size() {
-        return count.get();
-    }
-
-    // this doc comment is a modified copy of the inherited doc comment,
-    // without the reference to unlimited queues.
-    /**
-     * Returns the number of elements that this queue can ideally (in
-     * the absence of memory or resource constraints) accept without
-     * blocking. This is always equal to the initial capacity of this queue
-     * less the current <tt>size</tt> of this queue.
-     * <p>Note that you <em>cannot</em> always tell if
-     * an attempt to <tt>add</tt> an element will succeed by
-     * inspecting <tt>remainingCapacity</tt> because it may be the
-     * case that a waiting consumer is ready to <tt>take</tt> an
-     * element out of an otherwise full queue.
-     * 
-     * @return the remaining capacity
-     */
-    public int remainingCapacity() {
-        return capacity - count.get();
-    }
-
-    /**
-     * Adds the specified element to the tail of this queue, waiting if
-     * necessary for space to become available.
-     * @param o the element to add
-     * @throws InterruptedException if interrupted while waiting.
-     * @throws NullPointerException if the specified element is <tt>null</tt>.
-     */
-    public void put(E o) throws InterruptedException {
-        if (o == null) throw new NullPointerException();
-        // Note: convention in all put/take/etc is to preset
-        // local var holding count  negative to indicate failure unless set.
-        int c = -1;
-        final ReentrantLock putLock = this.putLock;
-        final AtomicInteger count = this.count;
-        putLock.lockInterruptibly();
-        try {
-            /*
-             * Note that count is used in wait guard even though it is
-             * not protected by lock. This works because count can
-             * only decrease at this point (all other puts are shut
-             * out by lock), and we (or some other waiting put) are
-             * signalled if it ever changes from
-             * capacity. Similarly for all other uses of count in
-             * other wait guards.
-             */
-            try {
-                while (count.get() == capacity)
-                    notFull.await();
-            } catch (InterruptedException ie) {
-                notFull.signal(); // propagate to a non-interrupted thread
-                throw ie;
-            }
-            insert(o);
-            c = count.getAndIncrement();
-            if (c + 1 < capacity)
-                notFull.signal();
-        } finally {
-            putLock.unlock();
-        }
-        if (c == 0)
-            signalNotEmpty();
-    }
-
-    /**
-     * Inserts the specified element at the tail of this queue, waiting if
-     * necessary up to the specified wait time for space to become available.
-     * @param o the element to add
-     * @param timeout how long to wait before giving up, in units of
-     * <tt>unit</tt>
-     * @param unit a <tt>TimeUnit</tt> determining how to interpret the
-     * <tt>timeout</tt> parameter
-     * @return <tt>true</tt> if successful, or <tt>false</tt> if
-     * the specified waiting time elapses before space is available.
-     * @throws InterruptedException if interrupted while waiting.
-     * @throws NullPointerException if the specified element is <tt>null</tt>.
-     */
-    public boolean offer(E o, long timeout, TimeUnit unit)
-        throws InterruptedException {
-
-        if (o == null) throw new NullPointerException();
-        long nanos = unit.toNanos(timeout);
-        int c = -1;
-        final ReentrantLock putLock = this.putLock;
-        final AtomicInteger count = this.count;
-        putLock.lockInterruptibly();
-        try {
-            for (;;) {
-                if (count.get() < capacity) {
-                    insert(o);
-                    c = count.getAndIncrement();
-                    if (c + 1 < capacity)
-                        notFull.signal();
-                    break;
-                }
-                if (nanos <= 0)
-                    return false;
-                try {
-                    nanos = notFull.awaitNanos(nanos);
-                } catch (InterruptedException ie) {
-                    notFull.signal(); // propagate to a non-interrupted thread
-                    throw ie;
-                }
-            }
-        } finally {
-            putLock.unlock();
-        }
-        if (c == 0)
-            signalNotEmpty();
-        return true;
-    }
-
-    /**
-     * Inserts the specified element at the tail of this queue if possible,
-     * returning immediately if this queue is full.
-     *
-     * @param o the element to add.
-     * @return <tt>true</tt> if it was possible to add the element to
-     *         this queue, else <tt>false</tt>
-     * @throws NullPointerException if the specified element is <tt>null</tt>
-     */
-    public boolean offer(E o) {
-        if (o == null) throw new NullPointerException();
-        final AtomicInteger count = this.count;
-        if (count.get() == capacity)
-            return false;
-        int c = -1;
-        final ReentrantLock putLock = this.putLock;
-        putLock.lock();
-        try {
-            if (count.get() < capacity) {
-                insert(o);
-                c = count.getAndIncrement();
-                if (c + 1 < capacity)
-                    notFull.signal();
-            }
-        } finally {
-            putLock.unlock();
-        }
-        if (c == 0)
-            signalNotEmpty();
-        return c >= 0;
-    }
-
-
-    public E take() throws InterruptedException {
-        E x;
-        int c = -1;
-        final AtomicInteger count = this.count;
-        final ReentrantLock takeLock = this.takeLock;
-        takeLock.lockInterruptibly();
-        try {
-            try {
-                while (count.get() == 0)
-                    notEmpty.await();
-            } catch (InterruptedException ie) {
-                notEmpty.signal(); // propagate to a non-interrupted thread
-                throw ie;
-            }
-
-            x = extract();
-            c = count.getAndDecrement();
-            if (c > 1)
-                notEmpty.signal();
-        } finally {
-            takeLock.unlock();
-        }
-        if (c == capacity)
-            signalNotFull();
-        return x;
-    }
-
-    public E poll(long timeout, TimeUnit unit) throws InterruptedException {
-        E x = null;
-        int c = -1;
-        long nanos = unit.toNanos(timeout);
-        final AtomicInteger count = this.count;
-        final ReentrantLock takeLock = this.takeLock;
-        takeLock.lockInterruptibly();
-        try {
-            for (;;) {
-                if (count.get() > 0) {
-                    x = extract();
-                    c = count.getAndDecrement();
-                    if (c > 1)
-                        notEmpty.signal();
-                    break;
-                }
-                if (nanos <= 0)
-                    return null;
-                try {
-                    nanos = notEmpty.awaitNanos(nanos);
-                } catch (InterruptedException ie) {
-                    notEmpty.signal(); // propagate to a non-interrupted thread
-                    throw ie;
-                }
-            }
-        } finally {
-            takeLock.unlock();
-        }
-        if (c == capacity)
-            signalNotFull();
-        return x;
-    }
-
-    public E poll() {
-        final AtomicInteger count = this.count;
-        if (count.get() == 0)
-            return null;
-        E x = null;
-        int c = -1;
-        final ReentrantLock takeLock = this.takeLock;
-        takeLock.lock();
-        try {
-            if (count.get() > 0) {
-                x = extract();
-                c = count.getAndDecrement();
-                if (c > 1)
-                    notEmpty.signal();
-            }
-        } finally {
-            takeLock.unlock();
-        }
-        if (c == capacity)
-            signalNotFull();
-        return x;
-    }
-
-
-    public E peek() {
-        if (count.get() == 0)
-            return null;
-        final ReentrantLock takeLock = this.takeLock;
-        takeLock.lock();
-        try {
-            Node<E> first = head.next;
-            if (first == null)
-                return null;
-            else
-                return first.item;
-        } finally {
-            takeLock.unlock();
-        }
-    }
-
-    public boolean remove(Object o) {
-        if (o == null) return false;
-        boolean removed = false;
-        fullyLock();
-        try {
-            Node<E> trail = head;
-            Node<E> p = head.next;
-            while (p != null) {
-                if (o.equals(p.item)) {
-                    removed = true;
-                    break;
-                }
-                trail = p;
-                p = p.next;
-            }
-            if (removed) {
-                p.item = null;
-                trail.next = p.next;
-                if (count.getAndDecrement() == capacity)
-                    notFull.signalAll();
-            }
-        } finally {
-            fullyUnlock();
-        }
-        return removed;
-    }
-
-    public Object[] toArray() {
-        fullyLock();
-        try {
-            int size = count.get();
-            Object[] a = new Object[size];
-            int k = 0;
-            for (Node<E> p = head.next; p != null; p = p.next)
-                a[k++] = p.item;
-            return a;
-        } finally {
-            fullyUnlock();
-        }
-    }
-
-    public <T> T[] toArray(T[] a) {
-        fullyLock();
-        try {
-            int size = count.get();
-            if (a.length < size)
-                a = (T[])java.lang.reflect.Array.newInstance
-                    (a.getClass().getComponentType(), size);
-
-            int k = 0;
-            for (Node p = head.next; p != null; p = p.next)
-                a[k++] = (T)p.item;
-            return a;
-        } finally {
-            fullyUnlock();
-        }
-    }
-
-    public String toString() {
-        fullyLock();
-        try {
-            return super.toString();
-        } finally {
-            fullyUnlock();
-        }
-    }
-
-    public void clear() {
-        fullyLock();
-        try {
-            head.next = null;
-            if (count.getAndSet(0) == capacity)
-                notFull.signalAll();
-        } finally {
-            fullyUnlock();
-        }
-    }
-
-    public int drainTo(Collection<? super E> c) {
-        if (c == null)
-            throw new NullPointerException();
-        if (c == this)
-            throw new IllegalArgumentException();
-        Node first;
-        fullyLock();
-        try {
-            first = head.next;
-            head.next = null;
-            if (count.getAndSet(0) == capacity)
-                notFull.signalAll();
-        } finally {
-            fullyUnlock();
-        }
-        // Transfer the elements outside of locks
-        int n = 0;
-        for (Node<E> p = first; p != null; p = p.next) {
-            c.add(p.item);
-            p.item = null;
-            ++n;
-        }
-        return n;
-    }
-        
-    public int drainTo(Collection<? super E> c, int maxElements) {
-        if (c == null)
-            throw new NullPointerException();
-        if (c == this)
-            throw new IllegalArgumentException();
-        if (maxElements <= 0)
-            return 0;
-        fullyLock();
-        try {
-            int n = 0;
-            Node<E> p = head.next;
-            while (p != null && n < maxElements) {
-                c.add(p.item);
-                p.item = null;
-                p = p.next;
-                ++n;
-            }
-            if (n != 0) {
-                head.next = p;
-                if (count.getAndAdd(-n) == capacity)
-                    notFull.signalAll();
-            }
-            return n;
-        } finally {
-            fullyUnlock();
-        }
-    }
-
-    /**
-     * Returns an iterator over the elements in this queue in proper sequence.
-     * The returned <tt>Iterator</tt> is a "weakly consistent" iterator that
-     * will never throw {@link java.util.ConcurrentModificationException},
-     * and guarantees to traverse elements as they existed upon
-     * construction of the iterator, and may (but is not guaranteed to)
-     * reflect any modifications subsequent to construction.
-     *
-     * @return an iterator over the elements in this queue in proper sequence.
-     */
-    public Iterator<E> iterator() {
-      return new Itr();
-    }
-
-    private class Itr implements Iterator<E> {
-        /*
-         * Basic weak-consistent iterator.  At all times hold the next
-         * item to hand out so that if hasNext() reports true, we will
-         * still have it to return even if lost race with a take etc.
-         */
-        private Node<E> current;
-        private Node<E> lastRet;
-        private E currentElement;
-
-        Itr() {
-            final ReentrantLock putLock = LinkedBlockingQueue.this.putLock;
-            final ReentrantLock takeLock = LinkedBlockingQueue.this.takeLock;
-            putLock.lock();
-            takeLock.lock();
-            try {
-                current = head.next;
-                if (current != null)
-                    currentElement = current.item;
-            } finally {
-                takeLock.unlock();
-                putLock.unlock();
-            }
-        }
-
-        public boolean hasNext() {
-            return current != null;
-        }
-
-        public E next() {
-            final ReentrantLock putLock = LinkedBlockingQueue.this.putLock;
-            final ReentrantLock takeLock = LinkedBlockingQueue.this.takeLock;
-            putLock.lock();
-            takeLock.lock();
-            try {
-                if (current == null)
-                    throw new NoSuchElementException();
-                E x = currentElement;
-                lastRet = current;
-                current = current.next;
-                if (current != null)
-                    currentElement = current.item;
-                return x;
-            } finally {
-                takeLock.unlock();
-                putLock.unlock();
-            }
-        }
-
-        public void remove() {
-            if (lastRet == null)
-                throw new IllegalStateException();
-            final ReentrantLock putLock = LinkedBlockingQueue.this.putLock;
-            final ReentrantLock takeLock = LinkedBlockingQueue.this.takeLock;
-            putLock.lock();
-            takeLock.lock();
-            try {
-                Node<E> node = lastRet;
-                lastRet = null;
-                Node<E> trail = head;
-                Node<E> p = head.next;
-                while (p != null && p != node) {
-                    trail = p;
-                    p = p.next;
-                }
-                if (p == node) {
-                    p.item = null;
-                    trail.next = p.next;
-                    int c = count.getAndDecrement();
-                    if (c == capacity)
-                        notFull.signalAll();
-                }
-            } finally {
-                takeLock.unlock();
-                putLock.unlock();
-            }
-        }
-    }
-
-    /**
-     * Save the state to a stream (that is, serialize it).
-     *
-     * @serialData The capacity is emitted (int), followed by all of
-     * its elements (each an <tt>Object</tt>) in the proper order,
-     * followed by a null
-     * @param s the stream
-     */
-    private void writeObject(java.io.ObjectOutputStream s)
-        throws java.io.IOException {
-
-        fullyLock();
-        try {
-            // Write out any hidden stuff, plus capacity
-            s.defaultWriteObject();
-
-            // Write out all elements in the proper order.
-            for (Node<E> p = head.next; p != null; p = p.next)
-                s.writeObject(p.item);
-
-            // Use trailing null as sentinel
-            s.writeObject(null);
-        } finally {
-            fullyUnlock();
-        }
-    }
-
-    /**
-     * Reconstitute this queue instance from a stream (that is,
-     * deserialize it).
-     * @param s the stream
-     */
-    private void readObject(java.io.ObjectInputStream s)
-        throws java.io.IOException, ClassNotFoundException {
-        // Read in capacity, and any hidden stuff
-        s.defaultReadObject();
-
-        count.set(0);
-        last = head = new Node<E>(null);
-
-        // Read in all elements and place in queue
-        for (;;) {
-            E item = (E)s.readObject();
-            if (item == null)
-                break;
-            add(item);
-        }
-    }
-}
diff --git a/concurrent/src/main/java/java/util/concurrent/PriorityBlockingQueue.java b/concurrent/src/main/java/java/util/concurrent/PriorityBlockingQueue.java
deleted file mode 100644
index 83f1040..0000000
--- a/concurrent/src/main/java/java/util/concurrent/PriorityBlockingQueue.java
+++ /dev/null
@@ -1,457 +0,0 @@
-/*
- * Written by Doug Lea with assistance from members of JCP JSR-166
- * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
- */
-
-package java.util.concurrent;
-
-import java.util.concurrent.locks.*;
-import java.util.*;
-
-// BEGIN android-note
-// removed link to collections framework docs
-// END android-note
-
-/**
- * An unbounded {@linkplain BlockingQueue blocking queue} that uses
- * the same ordering rules as class {@link PriorityQueue} and supplies
- * blocking retrieval operations.  While this queue is logically
- * unbounded, attempted additions may fail due to resource exhaustion
- * (causing <tt>OutOfMemoryError</tt>). This class does not permit
- * <tt>null</tt> elements.  A priority queue relying on natural
- * ordering also does not permit insertion of non-comparable objects
- * (doing so results in <tt>ClassCastException</tt>).
- *
- * <p>This class implements all of the <em>optional</em> methods
- * of the {@link Collection} and {@link Iterator} interfaces.
- * <p>The Iterator provided in method {@link #iterator()} is
- * <em>not</em> guaranteed to traverse the elements of the
- * PriorityBlockingQueue in any particular order. If you need ordered
- * traversal, consider using <tt>Arrays.sort(pq.toArray())</tt>.
- *
- * @since 1.5
- * @author Doug Lea
- * @param <E> the type of elements held in this collection
- */
-public class PriorityBlockingQueue<E> extends AbstractQueue<E>
-    implements BlockingQueue<E>, java.io.Serializable {
-    private static final long serialVersionUID = 5595510919245408276L;
-
-    private final PriorityQueue<E> q;
-    private final ReentrantLock lock = new ReentrantLock(true);
-    private final Condition notEmpty = lock.newCondition();
-
-    /**
-     * Creates a <tt>PriorityBlockingQueue</tt> with the default initial 
-     * capacity
-     * (11) that orders its elements according to their natural
-     * ordering (using <tt>Comparable</tt>).
-     */
-    public PriorityBlockingQueue() {
-        q = new PriorityQueue<E>();
-    }
-
-    /**
-     * Creates a <tt>PriorityBlockingQueue</tt> with the specified initial
-     * capacity
-     * that orders its elements according to their natural ordering
-     * (using <tt>Comparable</tt>).
-     *
-     * @param initialCapacity the initial capacity for this priority queue.
-     * @throws IllegalArgumentException if <tt>initialCapacity</tt> is less
-     * than 1
-     */
-    public PriorityBlockingQueue(int initialCapacity) {
-        q = new PriorityQueue<E>(initialCapacity, null);
-    }
-
-    /**
-     * Creates a <tt>PriorityBlockingQueue</tt> with the specified initial
-     * capacity
-     * that orders its elements according to the specified comparator.
-     *
-     * @param initialCapacity the initial capacity for this priority queue.
-     * @param comparator the comparator used to order this priority queue.
-     * If <tt>null</tt> then the order depends on the elements' natural
-     * ordering.
-     * @throws IllegalArgumentException if <tt>initialCapacity</tt> is less
-     * than 1
-     */
-    public PriorityBlockingQueue(int initialCapacity,
-                                 Comparator<? super E> comparator) {
-        q = new PriorityQueue<E>(initialCapacity, comparator);
-    }
-
-    /**
-     * Creates a <tt>PriorityBlockingQueue</tt> containing the elements
-     * in the specified collection.  The priority queue has an initial
-     * capacity of 110% of the size of the specified collection. If
-     * the specified collection is a {@link SortedSet} or a {@link
-     * PriorityQueue}, this priority queue will be sorted according to
-     * the same comparator, or according to its elements' natural
-     * order if the collection is sorted according to its elements'
-     * natural order.  Otherwise, this priority queue is ordered
-     * according to its elements' natural order.
-     *
-     * @param c the collection whose elements are to be placed
-     *        into this priority queue.
-     * @throws ClassCastException if elements of the specified collection
-     *         cannot be compared to one another according to the priority
-     *         queue's ordering.
-     * @throws NullPointerException if <tt>c</tt> or any element within it
-     * is <tt>null</tt>
-     */
-    public PriorityBlockingQueue(Collection<? extends E> c) {
-        q = new PriorityQueue<E>(c);
-    }
-
-
-    // these first few override just to update doc comments
-
-    /**
-     * Adds the specified element to this queue.
-     * @param o the element to add
-     * @return <tt>true</tt> (as per the general contract of
-     * <tt>Collection.add</tt>).
-     *
-     * @throws NullPointerException if the specified element is <tt>null</tt>.
-     * @throws ClassCastException if the specified element cannot be compared
-     * with elements currently in the priority queue according
-     * to the priority queue's ordering.
-     */
-    public boolean add(E o) {
-        return super.add(o);
-    }
-
-    // BEGIN android-changed
-    /**
-     * Returns the comparator used to order this collection, or <tt>null</tt>
-     * if this collection is sorted according to its elements natural ordering
-     * (using <tt>Comparable</tt>).
-     *
-     * @return the comparator used to order this collection, or <tt>null</tt>
-     * if this collection is sorted according to its elements natural ordering.
-     */
-    public Comparator<? super E> comparator() {
-        return q.comparator();
-    }
-    // END android-changed
-
-    /**
-     * Inserts the specified element into this priority queue.
-     *
-     * @param o the element to add
-     * @return <tt>true</tt>
-     * @throws ClassCastException if the specified element cannot be compared
-     * with elements currently in the priority queue according
-     * to the priority queue's ordering.
-     * @throws NullPointerException if the specified element is <tt>null</tt>.
-     */
-    public boolean offer(E o) {
-        if (o == null) throw new NullPointerException();
-        final ReentrantLock lock = this.lock;
-        lock.lock();
-        try {
-            boolean ok = q.offer(o);
-            assert ok;
-            notEmpty.signal();
-            return true;
-        } finally {
-            lock.unlock();
-        }
-    }
-
-    /**
-     * Adds the specified element to this priority queue. As the queue is
-     * unbounded this method will never block.
-     * @param o the element to add
-     * @throws ClassCastException if the element cannot be compared
-     * with elements currently in the priority queue according
-     * to the priority queue's ordering.
-     * @throws NullPointerException if the specified element is <tt>null</tt>.
-     */
-    public void put(E o) {
-        offer(o); // never need to block
-    }
-
-    /**
-     * Inserts the specified element into this priority queue. As the queue is
-     * unbounded this method will never block.
-     * @param o the element to add
-     * @param timeout This parameter is ignored as the method never blocks
-     * @param unit This parameter is ignored as the method never blocks
-     * @return <tt>true</tt>
-     * @throws ClassCastException if the element cannot be compared
-     * with elements currently in the priority queue according
-     * to the priority queue's ordering.
-     * @throws NullPointerException if the specified element is <tt>null</tt>.
-     */
-    public boolean offer(E o, long timeout, TimeUnit unit) {
-        return offer(o); // never need to block
-    }
-
-    public E take() throws InterruptedException {
-        final ReentrantLock lock = this.lock;
-        lock.lockInterruptibly();
-        try {
-            try {
-                while (q.size() == 0)
-                    notEmpty.await();
-            } catch (InterruptedException ie) {
-                notEmpty.signal(); // propagate to non-interrupted thread
-                throw ie;
-            }
-            E x = q.poll();
-            assert x != null;
-            return x;
-        } finally {
-            lock.unlock();
-        }
-    }
-
-
-    public E poll() {
-        final ReentrantLock lock = this.lock;
-        lock.lock();
-        try {
-            return q.poll();
-        } finally {
-            lock.unlock();
-        }
-    }
-
-    public E poll(long timeout, TimeUnit unit) throws InterruptedException {
-        long nanos = unit.toNanos(timeout);
-        final ReentrantLock lock = this.lock;
-        lock.lockInterruptibly();
-        try {
-            for (;;) {
-                E x = q.poll();
-                if (x != null)
-                    return x;
-                if (nanos <= 0)
-                    return null;
-                try {
-                    nanos = notEmpty.awaitNanos(nanos);
-                } catch (InterruptedException ie) {
-                    notEmpty.signal(); // propagate to non-interrupted thread
-                    throw ie;
-                }
-            }
-        } finally {
-            lock.unlock();
-        }
-    }
-
-    public E peek() {
-        final ReentrantLock lock = this.lock;
-        lock.lock();
-        try {
-            return q.peek();
-        } finally {
-            lock.unlock();
-        }
-    }
-
-    public int size() {
-        final ReentrantLock lock = this.lock;
-        lock.lock();
-        try {
-            return q.size();
-        } finally {
-            lock.unlock();
-        }
-    }
-
-    /**
-     * Always returns <tt>Integer.MAX_VALUE</tt> because
-     * a <tt>PriorityBlockingQueue</tt> is not capacity constrained.
-     * @return <tt>Integer.MAX_VALUE</tt>
-     */
-    public int remainingCapacity() {
-        return Integer.MAX_VALUE;
-    }
-
-    public boolean remove(Object o) {
-        final ReentrantLock lock = this.lock;
-        lock.lock();
-        try {
-            return q.remove(o);
-        } finally {
-            lock.unlock();
-        }
-    }
-
-    public boolean contains(Object o) {
-        final ReentrantLock lock = this.lock;
-        lock.lock();
-        try {
-            return q.contains(o);
-        } finally {
-            lock.unlock();
-        }
-    }
-
-    public Object[] toArray() {
-        final ReentrantLock lock = this.lock;
-        lock.lock();
-        try {
-            return q.toArray();
-        } finally {
-            lock.unlock();
-        }
-    }
-
-
-    public String toString() {
-        final ReentrantLock lock = this.lock;
-        lock.lock();
-        try {
-            return q.toString();
-        } finally {
-            lock.unlock();
-        }
-    }
-
-    public int drainTo(Collection<? super E> c) {
-        if (c == null)
-            throw new NullPointerException();
-        if (c == this)
-            throw new IllegalArgumentException();
-        final ReentrantLock lock = this.lock;
-        lock.lock();
-        try {
-            int n = 0;
-            E e;
-            while ( (e = q.poll()) != null) {
-                c.add(e);
-                ++n;
-            }
-            return n;
-        } finally {
-            lock.unlock();
-        }
-    }
-
-    public int drainTo(Collection<? super E> c, int maxElements) {
-        if (c == null)
-            throw new NullPointerException();
-        if (c == this)
-            throw new IllegalArgumentException();
-        if (maxElements <= 0)
-            return 0;
-        final ReentrantLock lock = this.lock;
-        lock.lock();
-        try {
-            int n = 0;
-            E e;
-            while (n < maxElements && (e = q.poll()) != null) {
-                c.add(e);
-                ++n;
-            }
-            return n;
-        } finally {
-            lock.unlock();
-        }
-    }
-
-    /**
-     * Atomically removes all of the elements from this delay queue.
-     * The queue will be empty after this call returns.
-     */
-    public void clear() {
-        final ReentrantLock lock = this.lock;
-        lock.lock();
-        try {
-            q.clear();
-        } finally {
-            lock.unlock();
-        }
-    }
-
-    public <T> T[] toArray(T[] a) {
-        final ReentrantLock lock = this.lock;
-        lock.lock();
-        try {
-            return q.toArray(a);
-        } finally {
-            lock.unlock();
-        }
-    }
-
-    /**
-     * Returns an iterator over the elements in this queue. The
-     * iterator does not return the elements in any particular order.
-     * The returned iterator is a thread-safe "fast-fail" iterator
-     * that will throw {@link
-     * java.util.ConcurrentModificationException} upon detected
-     * interference.
-     *
-     * @return an iterator over the elements in this queue.
-     */
-    public Iterator<E> iterator() {
-        final ReentrantLock lock = this.lock;
-        lock.lock();
-        try {
-            return new Itr(q.iterator());
-        } finally {
-            lock.unlock();
-        }
-    }
-
-    private class Itr<E> implements Iterator<E> {
-        private final Iterator<E> iter;
-        Itr(Iterator<E> i) {
-            iter = i;
-        }
-
-        public boolean hasNext() {
-            /*
-             * No sync -- we rely on underlying hasNext to be
-             * stateless, in which case we can return true by mistake
-             * only when next() will subsequently throw
-             * ConcurrentModificationException.
-             */
-            return iter.hasNext();
-        }
-
-        public E next() {
-            ReentrantLock lock = PriorityBlockingQueue.this.lock;
-            lock.lock();
-            try {
-                return iter.next();
-            } finally {
-                lock.unlock();
-            }
-        }
-
-        public void remove() {
-            ReentrantLock lock = PriorityBlockingQueue.this.lock;
-            lock.lock();
-            try {
-                iter.remove();
-            } finally {
-                lock.unlock();
-            }
-        }
-    }
-
-    /**
-     * Save the state to a stream (that is, serialize it).  This
-     * merely wraps default serialization within lock.  The
-     * serialization strategy for items is left to underlying
-     * Queue. Note that locking is not needed on deserialization, so
-     * readObject is not defined, just relying on default.
-     */
-    private void writeObject(java.io.ObjectOutputStream s)
-        throws java.io.IOException {
-        lock.lock();
-        try {
-            s.defaultWriteObject();
-        } finally {
-            lock.unlock();
-        }
-    }
-
-}
diff --git a/concurrent/src/main/java/java/util/concurrent/RejectedExecutionException.java b/concurrent/src/main/java/java/util/concurrent/RejectedExecutionException.java
deleted file mode 100644
index 199b9de..0000000
--- a/concurrent/src/main/java/java/util/concurrent/RejectedExecutionException.java
+++ /dev/null
@@ -1,62 +0,0 @@
-/*
- * Written by Doug Lea with assistance from members of JCP JSR-166
- * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
- */
-
-package java.util.concurrent;
-
-/**
- * Exception thrown by an {@link Executor} when a task cannot be
- * accepted for execution.
- * 
- * @since 1.5
- * @author Doug Lea
- */
-public class RejectedExecutionException extends RuntimeException {
-    private static final long serialVersionUID = -375805702767069545L;
-
-    /**
-     * Constructs a <tt>RejectedExecutionException</tt> with no detail message.
-     * The cause is not initialized, and may subsequently be
-     * initialized by a call to {@link #initCause(Throwable) initCause}.
-     */
-    public RejectedExecutionException() { }
-
-    /**
-     * Constructs a <tt>RejectedExecutionException</tt> with the
-     * specified detail message. The cause is not initialized, and may
-     * subsequently be initialized by a call to {@link
-     * #initCause(Throwable) initCause}.
-     *
-     * @param message the detail message
-     */
-    public RejectedExecutionException(String message) {
-        super(message);
-    }
-
-    /**
-     * Constructs a <tt>RejectedExecutionException</tt> with the
-     * specified detail message and cause.
-     *
-     * @param  message the detail message
-     * @param  cause the cause (which is saved for later retrieval by the
-     *         {@link #getCause()} method)
-     */
-    public RejectedExecutionException(String message, Throwable cause) {
-        super(message, cause);
-    }
-
-    /**
-     * Constructs a <tt>RejectedExecutionException</tt> with the
-     * specified cause.  The detail message is set to: <pre> (cause ==
-     * null ? null : cause.toString())</pre> (which typically contains
-     * the class and detail message of <tt>cause</tt>).
-     *
-     * @param  cause the cause (which is saved for later retrieval by the
-     *         {@link #getCause()} method)
-     */
-    public RejectedExecutionException(Throwable cause) {
-        super(cause);
-    }
-}
diff --git a/concurrent/src/main/java/java/util/concurrent/RejectedExecutionHandler.java b/concurrent/src/main/java/java/util/concurrent/RejectedExecutionHandler.java
deleted file mode 100644
index 4b4bbea..0000000
--- a/concurrent/src/main/java/java/util/concurrent/RejectedExecutionHandler.java
+++ /dev/null
@@ -1,33 +0,0 @@
-/*
- * Written by Doug Lea with assistance from members of JCP JSR-166
- * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
- */
-
-package java.util.concurrent;
-
-/**
- * A handler for tasks that cannot be executed by a {@link
- * ThreadPoolExecutor}.
- *
- * @since 1.5
- * @author Doug Lea
- */
-public interface RejectedExecutionHandler {
-
-    /**
-     * Method that may be invoked by a {@link ThreadPoolExecutor} when
-     * <tt>execute</tt> cannot accept a task. This may occur when no
-     * more threads or queue slots are available because their bounds
-     * would be exceeded, or upon shutdown of the Executor.
-     *
-     * In the absence other alternatives, the method may throw an
-     * unchecked {@link RejectedExecutionException}, which will be
-     * propagated to the caller of <tt>execute</tt>.
-     *
-     * @param r the runnable task requested to be executed
-     * @param executor the executor attempting to execute this task
-     * @throws RejectedExecutionException if there is no remedy
-     */
-    void rejectedExecution(Runnable r, ThreadPoolExecutor executor);
-}
diff --git a/concurrent/src/main/java/java/util/concurrent/ScheduledExecutorService.java b/concurrent/src/main/java/java/util/concurrent/ScheduledExecutorService.java
deleted file mode 100644
index 9579fef..0000000
--- a/concurrent/src/main/java/java/util/concurrent/ScheduledExecutorService.java
+++ /dev/null
@@ -1,145 +0,0 @@
-/*
- * Written by Doug Lea with assistance from members of JCP JSR-166
- * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
- */
-
-package java.util.concurrent;
-import java.util.concurrent.atomic.*;
-import java.util.*;
-
-/**
- * An {@link ExecutorService} that can schedule commands to run after a given
- * delay, or to execute periodically. 
- *
- * <p> The <tt>schedule</tt> methods create tasks with various delays
- * and return a task object that can be used to cancel or check
- * execution. The <tt>scheduleAtFixedRate</tt> and
- * <tt>scheduleWithFixedDelay</tt> methods create and execute tasks
- * that run periodically until cancelled.  
- *
- * <p> Commands submitted using the {@link Executor#execute} and
- * {@link ExecutorService} <tt>submit</tt> methods are scheduled with
- * a requested delay of zero. Zero and negative delays (but not
- * periods) are also allowed in <tt>schedule</tt> methods, and are
- * treated as requests for immediate execution.
- *
- * <p>All <tt>schedule</tt> methods accept <em>relative</em> delays and
- * periods as arguments, not absolute times or dates. It is a simple
- * matter to transform an absolute time represented as a {@link
- * java.util.Date} to the required form. For example, to schedule at
- * a certain future <tt>date</tt>, you can use: <tt>schedule(task,
- * date.getTime() - System.currentTimeMillis(),
- * TimeUnit.MILLISECONDS)</tt>. Beware however that expiration of a
- * relative delay need not coincide with the current <tt>Date</tt> at
- * which the task is enabled due to network time synchronization
- * protocols, clock drift, or other factors. 
- *
- * The {@link Executors} class provides convenient factory methods for
- * the ScheduledExecutorService implementations provided in this package.
- *
- * <h3>Usage Example</h3>
- * 
- * Here is a class with a method that sets up a ScheduledExecutorService
- * to beep every ten seconds for an hour:
- *
- * <pre>
- * import static java.util.concurrent.TimeUnit;
- * class BeeperControl {
- *    private final ScheduledExecutorService scheduler = 
- *       Executors.newScheduledThreadPool(1);
- *
- *    public void beepForAnHour() {
- *        final Runnable beeper = new Runnable() {
- *                public void run() { System.out.println("beep"); }
- *            };
- *        final ScheduledFuture&lt;?&gt; beeperHandle = 
- *            scheduler.scheduleAtFixedRate(beeper, 10, 10, SECONDS);
- *        scheduler.schedule(new Runnable() {
- *                public void run() { beeperHandle.cancel(true); }
- *            }, 60 * 60, SECONDS);
- *    }
- * }
- * </pre>
- *
- * @since 1.5
- * @author Doug Lea
- */
-public interface ScheduledExecutorService extends ExecutorService {
-
-    /**
-     * Creates and executes a one-shot action that becomes enabled
-     * after the given delay.
-     * @param command the task to execute.
-     * @param delay the time from now to delay execution.
-     * @param unit the time unit of the delay parameter.
-     * @return a Future representing pending completion of the task,
-     * and whose <tt>get()</tt> method will return <tt>null</tt>
-     * upon completion.
-     * @throws RejectedExecutionException if task cannot be scheduled
-     * for execution.
-     * @throws NullPointerException if command is null
-     */
-    public ScheduledFuture<?> schedule(Runnable command, long delay,  TimeUnit unit);
-
-    /**
-     * Creates and executes a ScheduledFuture that becomes enabled after the
-     * given delay.
-     * @param callable the function to execute.
-     * @param delay the time from now to delay execution.
-     * @param unit the time unit of the delay parameter.
-     * @return a ScheduledFuture that can be used to extract result or cancel.
-     * @throws RejectedExecutionException if task cannot be scheduled
-     * for execution.
-     * @throws NullPointerException if callable is null
-     */
-    public <V> ScheduledFuture<V> schedule(Callable<V> callable, long delay, TimeUnit unit);
-
-    /**
-     * Creates and executes a periodic action that becomes enabled first
-     * after the given initial delay, and subsequently with the given
-     * period; that is executions will commence after
-     * <tt>initialDelay</tt> then <tt>initialDelay+period</tt>, then
-     * <tt>initialDelay + 2 * period</tt>, and so on.  
-     * If any execution of the task
-     * encounters an exception, subsequent executions are suppressed.
-     * Otherwise, the task will only terminate via cancellation or
-     * termination of the executor.
-     * @param command the task to execute.
-     * @param initialDelay the time to delay first execution.
-     * @param period the period between successive executions.
-     * @param unit the time unit of the initialDelay and period parameters
-     * @return a Future representing pending completion of the task,
-     * and whose <tt>get()</tt> method will throw an exception upon
-     * cancellation.
-     * @throws RejectedExecutionException if task cannot be scheduled
-     * for execution.
-     * @throws NullPointerException if command is null
-     * @throws IllegalArgumentException if period less than or equal to zero.
-     */
-    public ScheduledFuture<?> scheduleAtFixedRate(Runnable command, long initialDelay,  long period, TimeUnit unit);
-    
-    /**
-     * Creates and executes a periodic action that becomes enabled first
-     * after the given initial delay, and subsequently with the
-     * given delay between the termination of one execution and the
-     * commencement of the next. If any execution of the task
-     * encounters an exception, subsequent executions are suppressed.
-     * Otherwise, the task will only terminate via cancellation or
-     * termination of the executor.
-     * @param command the task to execute.
-     * @param initialDelay the time to delay first execution.
-     * @param delay the delay between the termination of one
-     * execution and the commencement of the next.
-     * @param unit the time unit of the initialDelay and delay parameters
-     * @return a Future representing pending completion of the task,
-     * and whose <tt>get()</tt> method will throw an exception upon
-     * cancellation.
-     * @throws RejectedExecutionException if task cannot be scheduled
-     * for execution.
-     * @throws NullPointerException if command is null
-     * @throws IllegalArgumentException if delay less than or equal to zero.
-     */
-    public ScheduledFuture<?> scheduleWithFixedDelay(Runnable command, long initialDelay,  long delay, TimeUnit unit);
-
-}
diff --git a/concurrent/src/main/java/java/util/concurrent/ScheduledFuture.java b/concurrent/src/main/java/java/util/concurrent/ScheduledFuture.java
deleted file mode 100644
index 239d681..0000000
--- a/concurrent/src/main/java/java/util/concurrent/ScheduledFuture.java
+++ /dev/null
@@ -1,19 +0,0 @@
-/*
- * Written by Doug Lea with assistance from members of JCP JSR-166
- * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
- */
-
-package java.util.concurrent;
-
-/**
- * A delayed result-bearing action that can be cancelled.
- * Usually a scheduled future is the result of scheduling
- * a task with a {@link ScheduledExecutorService}.
- *
- * @since 1.5
- * @author Doug Lea
- * @param <V> The result type returned by this Future
- */
-public interface ScheduledFuture<V> extends Delayed, Future<V> {
-}
diff --git a/concurrent/src/main/java/java/util/concurrent/ScheduledThreadPoolExecutor.java b/concurrent/src/main/java/java/util/concurrent/ScheduledThreadPoolExecutor.java
deleted file mode 100644
index 09ec681..0000000
--- a/concurrent/src/main/java/java/util/concurrent/ScheduledThreadPoolExecutor.java
+++ /dev/null
@@ -1,541 +0,0 @@
-/*
- * Written by Doug Lea with assistance from members of JCP JSR-166
- * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
- */
-
-package java.util.concurrent;
-import java.util.concurrent.atomic.*;
-import java.util.*;
-
-/**
- * A {@link ThreadPoolExecutor} that can additionally schedule
- * commands to run after a given delay, or to execute
- * periodically. This class is preferable to {@link java.util.Timer}
- * when multiple worker threads are needed, or when the additional
- * flexibility or capabilities of {@link ThreadPoolExecutor} (which
- * this class extends) are required.
- *
- * <p> Delayed tasks execute no sooner than they are enabled, but
- * without any real-time guarantees about when, after they are
- * enabled, they will commence. Tasks scheduled for exactly the same
- * execution time are enabled in first-in-first-out (FIFO) order of
- * submission.
- *
- * <p>While this class inherits from {@link ThreadPoolExecutor}, a few
- * of the inherited tuning methods are not useful for it. In
- * particular, because it acts as a fixed-sized pool using
- * <tt>corePoolSize</tt> threads and an unbounded queue, adjustments
- * to <tt>maximumPoolSize</tt> have no useful effect.
- *
- * @since 1.5
- * @author Doug Lea
- */
-public class ScheduledThreadPoolExecutor 
-        extends ThreadPoolExecutor 
-        implements ScheduledExecutorService {
-
-    /**
-     * False if should cancel/suppress periodic tasks on shutdown.
-     */
-    private volatile boolean continueExistingPeriodicTasksAfterShutdown;
-
-    /**
-     * False if should cancel non-periodic tasks on shutdown.
-     */
-    private volatile boolean executeExistingDelayedTasksAfterShutdown = true;
-
-    /**
-     * Sequence number to break scheduling ties, and in turn to
-     * guarantee FIFO order among tied entries.
-     */
-    private static final AtomicLong sequencer = new AtomicLong(0);
-
-    /** Base of nanosecond timings, to avoid wrapping */
-    private static final long NANO_ORIGIN = System.nanoTime();
-
-    /**
-     * Returns nanosecond time offset by origin
-     */
-    final long now() {
-        return System.nanoTime() - NANO_ORIGIN;
-    }
-
-    private class ScheduledFutureTask<V> 
-            extends FutureTask<V> implements ScheduledFuture<V> {
-        
-        /** Sequence number to break ties FIFO */
-        private final long sequenceNumber;
-        /** The time the task is enabled to execute in nanoTime units */
-        private long time;
-        /**
-         * Period in nanoseconds for repeating tasks.  A positive
-         * value indicates fixed-rate execution.  A negative value
-         * indicates fixed-delay execution.  A value of 0 indicates a
-         * non-repeating task.
-         */
-        private final long period;
-
-        /**
-         * Creates a one-shot action with given nanoTime-based trigger time
-         */
-        ScheduledFutureTask(Runnable r, V result, long ns) {
-            super(r, result);
-            this.time = ns;
-            this.period = 0;
-            this.sequenceNumber = sequencer.getAndIncrement();
-        }
-
-        /**
-         * Creates a periodic action with given nano time and period
-         */
-        ScheduledFutureTask(Runnable r, V result, long ns,  long period) {
-            super(r, result);
-            this.time = ns;
-            this.period = period;
-            this.sequenceNumber = sequencer.getAndIncrement();
-        }
-
-        /**
-         * Creates a one-shot action with given nanoTime-based trigger
-         */
-        ScheduledFutureTask(Callable<V> callable, long ns) {
-            super(callable);
-            this.time = ns;
-            this.period = 0;
-            this.sequenceNumber = sequencer.getAndIncrement();
-        }
-
-        public long getDelay(TimeUnit unit) {
-            long d = unit.convert(time - now(), TimeUnit.NANOSECONDS);
-            return d;
-        }
-
-        public int compareTo(Delayed other) {
-            if (other == this) // compare zero ONLY if same object
-                return 0;
-            ScheduledFutureTask<?> x = (ScheduledFutureTask<?>)other;
-            long diff = time - x.time;
-            if (diff < 0)
-                return -1;
-            else if (diff > 0)
-                return 1;
-            else if (sequenceNumber < x.sequenceNumber)
-                return -1;
-            else
-                return 1;
-        }
-
-        /**
-         * Returns true if this is a periodic (not a one-shot) action.
-         * @return true if periodic
-         */
-        boolean isPeriodic() {
-            return period != 0;
-        }
-
-        /**
-         * Run a periodic task
-         */
-        private void runPeriodic() {
-            boolean ok = ScheduledFutureTask.super.runAndReset();
-            boolean down = isShutdown();
-            // Reschedule if not cancelled and not shutdown or policy allows
-            if (ok && (!down ||
-                       (getContinueExistingPeriodicTasksAfterShutdownPolicy() && 
-                        !isTerminating()))) {
-                long p = period;
-                if (p > 0)
-                    time += p;
-                else
-                    time = now() - p;
-                ScheduledThreadPoolExecutor.super.getQueue().add(this);
-            }
-            // This might have been the final executed delayed
-            // task.  Wake up threads to check.
-            else if (down) 
-                interruptIdleWorkers();
-        }
-
-        /**
-         * Overrides FutureTask version so as to reset/requeue if periodic.
-         */ 
-        public void run() {
-            if (isPeriodic())
-                runPeriodic();
-            else 
-                ScheduledFutureTask.super.run();
-        }
-    }
-
-    /**
-     * Specialized variant of ThreadPoolExecutor.execute for delayed tasks.
-     */
-    private void delayedExecute(Runnable command) {
-        if (isShutdown()) {
-            reject(command);
-            return;
-        }
-        // Prestart a thread if necessary. We cannot prestart it
-        // running the task because the task (probably) shouldn't be
-        // run yet, so thread will just idle until delay elapses.
-        if (getPoolSize() < getCorePoolSize())
-            prestartCoreThread();
-            
-        super.getQueue().add(command);
-    }
-
-    /**
-     * Cancel and clear the queue of all tasks that should not be run
-     * due to shutdown policy.
-     */
-    private void cancelUnwantedTasks() {
-        boolean keepDelayed = getExecuteExistingDelayedTasksAfterShutdownPolicy();
-        boolean keepPeriodic = getContinueExistingPeriodicTasksAfterShutdownPolicy();
-        if (!keepDelayed && !keepPeriodic) 
-            super.getQueue().clear();
-        else if (keepDelayed || keepPeriodic) {
-            Object[] entries = super.getQueue().toArray();
-            for (int i = 0; i < entries.length; ++i) {
-                Object e = entries[i];
-                if (e instanceof ScheduledFutureTask) {
-                    ScheduledFutureTask<?> t = (ScheduledFutureTask<?>)e;
-                    if (t.isPeriodic()? !keepPeriodic : !keepDelayed)
-                        t.cancel(false);
-                }
-            }
-            entries = null;
-            purge();
-        }
-    }
-
-    public boolean remove(Runnable task) {
-        if (!(task instanceof ScheduledFutureTask))
-            return false;
-        return getQueue().remove(task);
-    }
-
-    /**
-     * Creates a new ScheduledThreadPoolExecutor with the given core
-     * pool size.
-     * 
-     * @param corePoolSize the number of threads to keep in the pool,
-     * even if they are idle.
-     * @throws IllegalArgumentException if corePoolSize less than or
-     * equal to zero
-     */
-    public ScheduledThreadPoolExecutor(int corePoolSize) {
-        super(corePoolSize, Integer.MAX_VALUE, 0, TimeUnit.NANOSECONDS,
-              new DelayedWorkQueue());
-    }
-
-    /**
-     * Creates a new ScheduledThreadPoolExecutor with the given
-     * initial parameters.
-     * 
-     * @param corePoolSize the number of threads to keep in the pool,
-     * even if they are idle.
-     * @param threadFactory the factory to use when the executor
-     * creates a new thread. 
-     * @throws NullPointerException if threadFactory is null
-     */
-    public ScheduledThreadPoolExecutor(int corePoolSize,
-                             ThreadFactory threadFactory) {
-        super(corePoolSize, Integer.MAX_VALUE, 0, TimeUnit.NANOSECONDS,
-              new DelayedWorkQueue(), threadFactory);
-    }
-
-    /**
-     * Creates a new ScheduledThreadPoolExecutor with the given
-     * initial parameters.
-     * 
-     * @param corePoolSize the number of threads to keep in the pool,
-     * even if they are idle.
-     * @param handler the handler to use when execution is blocked
-     * because the thread bounds and queue capacities are reached.
-     * @throws NullPointerException if handler is null
-     */
-    public ScheduledThreadPoolExecutor(int corePoolSize,
-                              RejectedExecutionHandler handler) {
-        super(corePoolSize, Integer.MAX_VALUE, 0, TimeUnit.NANOSECONDS,
-              new DelayedWorkQueue(), handler);
-    }
-
-    /**
-     * Creates a new ScheduledThreadPoolExecutor with the given
-     * initial parameters.
-     * 
-     * @param corePoolSize the number of threads to keep in the pool,
-     * even if they are idle.
-     * @param threadFactory the factory to use when the executor
-     * creates a new thread. 
-     * @param handler the handler to use when execution is blocked
-     * because the thread bounds and queue capacities are reached.
-     * @throws NullPointerException if threadFactory or handler is null
-     */
-    public ScheduledThreadPoolExecutor(int corePoolSize,
-                              ThreadFactory threadFactory,
-                              RejectedExecutionHandler handler) {
-        super(corePoolSize, Integer.MAX_VALUE, 0, TimeUnit.NANOSECONDS,
-              new DelayedWorkQueue(), threadFactory, handler);
-    }
-
-    public ScheduledFuture<?> schedule(Runnable command, 
-                                       long delay, 
-                                       TimeUnit unit) {
-        if (command == null || unit == null)
-            throw new NullPointerException();
-        long triggerTime = now() + unit.toNanos(delay);
-        ScheduledFutureTask<?> t = 
-            new ScheduledFutureTask<Boolean>(command, null, triggerTime);
-        delayedExecute(t);
-        return t;
-    }
-
-    public <V> ScheduledFuture<V> schedule(Callable<V> callable, 
-                                           long delay, 
-                                           TimeUnit unit) {
-        if (callable == null || unit == null)
-            throw new NullPointerException();
-        if (delay < 0) delay = 0;
-        long triggerTime = now() + unit.toNanos(delay);
-        ScheduledFutureTask<V> t = 
-            new ScheduledFutureTask<V>(callable, triggerTime);
-        delayedExecute(t);
-        return t;
-    }
-
-    public ScheduledFuture<?> scheduleAtFixedRate(Runnable command, 
-                                                  long initialDelay,  
-                                                  long period, 
-                                                  TimeUnit unit) {
-        if (command == null || unit == null)
-            throw new NullPointerException();
-        if (period <= 0)
-            throw new IllegalArgumentException();
-        if (initialDelay < 0) initialDelay = 0;
-        long triggerTime = now() + unit.toNanos(initialDelay);
-        ScheduledFutureTask<?> t = 
-            new ScheduledFutureTask<Object>(command, 
-                                            null,
-                                            triggerTime,
-                                            unit.toNanos(period));
-        delayedExecute(t);
-        return t;
-    }
-    
-    public ScheduledFuture<?> scheduleWithFixedDelay(Runnable command, 
-                                                     long initialDelay,  
-                                                     long delay, 
-                                                     TimeUnit unit) {
-        if (command == null || unit == null)
-            throw new NullPointerException();
-        if (delay <= 0)
-            throw new IllegalArgumentException();
-        if (initialDelay < 0) initialDelay = 0;
-        long triggerTime = now() + unit.toNanos(initialDelay);
-        ScheduledFutureTask<?> t = 
-            new ScheduledFutureTask<Boolean>(command, 
-                                             null,
-                                             triggerTime,
-                                             unit.toNanos(-delay));
-        delayedExecute(t);
-        return t;
-    }
-    
-
-    /**
-     * Execute command with zero required delay. This has effect
-     * equivalent to <tt>schedule(command, 0, anyUnit)</tt>.  Note
-     * that inspections of the queue and of the list returned by
-     * <tt>shutdownNow</tt> will access the zero-delayed
-     * {@link ScheduledFuture}, not the <tt>command</tt> itself.
-     *
-     * @param command the task to execute
-     * @throws RejectedExecutionException at discretion of
-     * <tt>RejectedExecutionHandler</tt>, if task cannot be accepted
-     * for execution because the executor has been shut down.
-     * @throws NullPointerException if command is null
-     */
-    public void execute(Runnable command) {
-        if (command == null)
-            throw new NullPointerException();
-        schedule(command, 0, TimeUnit.NANOSECONDS);
-    }
-
-    // Override AbstractExecutorService methods
-
-    public Future<?> submit(Runnable task) {
-        return schedule(task, 0, TimeUnit.NANOSECONDS);
-    }
-
-    public <T> Future<T> submit(Runnable task, T result) {
-        return schedule(Executors.callable(task, result), 
-                        0, TimeUnit.NANOSECONDS);
-    }
-
-    public <T> Future<T> submit(Callable<T> task) {
-        return schedule(task, 0, TimeUnit.NANOSECONDS);
-    }
-
-    /**
-     * Set policy on whether to continue executing existing periodic
-     * tasks even when this executor has been <tt>shutdown</tt>. In
-     * this case, these tasks will only terminate upon
-     * <tt>shutdownNow</tt>, or after setting the policy to
-     * <tt>false</tt> when already shutdown. This value is by default
-     * false.
-     * @param value if true, continue after shutdown, else don't.
-     * @see #getExecuteExistingDelayedTasksAfterShutdownPolicy
-     */
-    public void setContinueExistingPeriodicTasksAfterShutdownPolicy(boolean value) {
-        continueExistingPeriodicTasksAfterShutdown = value;
-        if (!value && isShutdown())
-            cancelUnwantedTasks();
-    }
-
-    /**
-     * Get the policy on whether to continue executing existing
-     * periodic tasks even when this executor has been
-     * <tt>shutdown</tt>. In this case, these tasks will only
-     * terminate upon <tt>shutdownNow</tt> or after setting the policy
-     * to <tt>false</tt> when already shutdown. This value is by
-     * default false.
-     * @return true if will continue after shutdown.
-     * @see #setContinueExistingPeriodicTasksAfterShutdownPolicy
-     */
-    public boolean getContinueExistingPeriodicTasksAfterShutdownPolicy() {
-        return continueExistingPeriodicTasksAfterShutdown;
-    }
-
-    /**
-     * Set policy on whether to execute existing delayed
-     * tasks even when this executor has been <tt>shutdown</tt>. In
-     * this case, these tasks will only terminate upon
-     * <tt>shutdownNow</tt>, or after setting the policy to
-     * <tt>false</tt> when already shutdown. This value is by default
-     * true.
-     * @param value if true, execute after shutdown, else don't.
-     * @see #getExecuteExistingDelayedTasksAfterShutdownPolicy
-     */
-    public void setExecuteExistingDelayedTasksAfterShutdownPolicy(boolean value) {
-        executeExistingDelayedTasksAfterShutdown = value;
-        if (!value && isShutdown())
-            cancelUnwantedTasks();
-    }
-
-    /**
-     * Get policy on whether to execute existing delayed
-     * tasks even when this executor has been <tt>shutdown</tt>. In
-     * this case, these tasks will only terminate upon
-     * <tt>shutdownNow</tt>, or after setting the policy to
-     * <tt>false</tt> when already shutdown. This value is by default
-     * true.
-     * @return true if will execute after shutdown.
-     * @see #setExecuteExistingDelayedTasksAfterShutdownPolicy
-     */
-    public boolean getExecuteExistingDelayedTasksAfterShutdownPolicy() {
-        return executeExistingDelayedTasksAfterShutdown;
-    }
-
-
-    /**
-     * Initiates an orderly shutdown in which previously submitted
-     * tasks are executed, but no new tasks will be accepted. If the
-     * <tt>ExecuteExistingDelayedTasksAfterShutdownPolicy</tt> has
-     * been set <tt>false</tt>, existing delayed tasks whose delays
-     * have not yet elapsed are cancelled. And unless the
-     * <tt>ContinueExistingPeriodicTasksAfterShutdownPolicy</tt> has
-     * been set <tt>true</tt>, future executions of existing periodic
-     * tasks will be cancelled.
-     */
-    public void shutdown() {
-        cancelUnwantedTasks();
-        super.shutdown();
-    }
-
-    /**
-     * Attempts to stop all actively executing tasks, halts the
-     * processing of waiting tasks, and returns a list of the tasks that were
-     * awaiting execution. 
-     *  
-     * <p>There are no guarantees beyond best-effort attempts to stop
-     * processing actively executing tasks.  This implementation
-     * cancels tasks via {@link Thread#interrupt}, so if any tasks mask or
-     * fail to respond to interrupts, they may never terminate.
-     *
-     * @return list of tasks that never commenced execution.  Each
-     * element of this list is a {@link ScheduledFuture},
-     * including those tasks submitted using <tt>execute</tt>, which
-     * are for scheduling purposes used as the basis of a zero-delay
-     * <tt>ScheduledFuture</tt>.
-     */
-    public List<Runnable> shutdownNow() {
-        return super.shutdownNow();
-    }
-
-    /**
-     * Returns the task queue used by this executor.  Each element of
-     * this queue is a {@link ScheduledFuture}, including those
-     * tasks submitted using <tt>execute</tt> which are for scheduling
-     * purposes used as the basis of a zero-delay
-     * <tt>ScheduledFuture</tt>. Iteration over this queue is
-     * <em>not</em> guaranteed to traverse tasks in the order in
-     * which they will execute.
-     *
-     * @return the task queue
-     */
-    public BlockingQueue<Runnable> getQueue() {
-        return super.getQueue();
-    }
-
-    /**
-     * An annoying wrapper class to convince generics compiler to
-     * use a DelayQueue<ScheduledFutureTask> as a BlockingQueue<Runnable>
-     */ 
-    private static class DelayedWorkQueue 
-        extends AbstractCollection<Runnable> 
-        implements BlockingQueue<Runnable> {
-        
-        private final DelayQueue<ScheduledFutureTask> dq = new DelayQueue<ScheduledFutureTask>();
-        public Runnable poll() { return dq.poll(); }
-        public Runnable peek() { return dq.peek(); }
-        public Runnable take() throws InterruptedException { return dq.take(); }
-        public Runnable poll(long timeout, TimeUnit unit) throws InterruptedException {
-            return dq.poll(timeout, unit);
-        }
-
-        public boolean add(Runnable x) { return dq.add((ScheduledFutureTask)x); }
-        public boolean offer(Runnable x) { return dq.offer((ScheduledFutureTask)x); }
-        public void put(Runnable x)  {
-            dq.put((ScheduledFutureTask)x); 
-        }
-        public boolean offer(Runnable x, long timeout, TimeUnit unit) {
-            return dq.offer((ScheduledFutureTask)x, timeout, unit);
-        }
-
-        public Runnable remove() { return dq.remove(); }
-        public Runnable element() { return dq.element(); }
-        public void clear() { dq.clear(); }
-        public int drainTo(Collection<? super Runnable> c) { return dq.drainTo(c); }
-        public int drainTo(Collection<? super Runnable> c, int maxElements) { 
-            return dq.drainTo(c, maxElements); 
-        }
-
-        public int remainingCapacity() { return dq.remainingCapacity(); }
-        public boolean remove(Object x) { return dq.remove(x); }
-        public boolean contains(Object x) { return dq.contains(x); }
-        public int size() { return dq.size(); }
-        public boolean isEmpty() { return dq.isEmpty(); }
-        public Object[] toArray() { return dq.toArray(); }
-        public <T> T[] toArray(T[] array) { return dq.toArray(array); }
-        public Iterator<Runnable> iterator() { 
-            return new Iterator<Runnable>() {
-                private Iterator<ScheduledFutureTask> it = dq.iterator();
-                public boolean hasNext() { return it.hasNext(); }
-                public Runnable next() { return it.next(); }
-                public void remove() {  it.remove(); }
-            };
-        }
-    }
-}
diff --git a/concurrent/src/main/java/java/util/concurrent/Semaphore.java b/concurrent/src/main/java/java/util/concurrent/Semaphore.java
deleted file mode 100644
index 6eb80bc..0000000
--- a/concurrent/src/main/java/java/util/concurrent/Semaphore.java
+++ /dev/null
@@ -1,665 +0,0 @@
-/*
- * Written by Doug Lea with assistance from members of JCP JSR-166
- * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
- */
-
-package java.util.concurrent;
-import java.util.*;
-import java.util.concurrent.locks.*;
-import java.util.concurrent.atomic.*;
-
-/**
- * A counting semaphore.  Conceptually, a semaphore maintains a set of
- * permits.  Each {@link #acquire} blocks if necessary until a permit is
- * available, and then takes it.  Each {@link #release} adds a permit,
- * potentially releasing a blocking acquirer.
- * However, no actual permit objects are used; the <tt>Semaphore</tt> just
- * keeps a count of the number available and acts accordingly.
- *
- * <p>Semaphores are often used to restrict the number of threads than can
- * access some (physical or logical) resource. For example, here is
- * a class that uses a semaphore to control access to a pool of items:
- * <pre>
- * class Pool {
- *   private static final MAX_AVAILABLE = 100;
- *   private final Semaphore available = new Semaphore(MAX_AVAILABLE, true);
- *
- *   public Object getItem() throws InterruptedException {
- *     available.acquire();
- *     return getNextAvailableItem();
- *   }
- *
- *   public void putItem(Object x) {
- *     if (markAsUnused(x))
- *       available.release();
- *   }
- *
- *   // Not a particularly efficient data structure; just for demo
- *
- *   protected Object[] items = ... whatever kinds of items being managed
- *   protected boolean[] used = new boolean[MAX_AVAILABLE];
- *
- *   protected synchronized Object getNextAvailableItem() {
- *     for (int i = 0; i < MAX_AVAILABLE; ++i) {
- *       if (!used[i]) {
- *          used[i] = true;
- *          return items[i];
- *       }
- *     }
- *     return null; // not reached
- *   }
- *
- *   protected synchronized boolean markAsUnused(Object item) {
- *     for (int i = 0; i < MAX_AVAILABLE; ++i) {
- *       if (item == items[i]) {
- *          if (used[i]) {
- *            used[i] = false;
- *            return true;
- *          } else
- *            return false;
- *       }
- *     }
- *     return false;
- *   }
- *
- * }
- * </pre>
- *
- * <p>Before obtaining an item each thread must acquire a permit from
- * the semaphore, guaranteeing that an item is available for use. When
- * the thread has finished with the item it is returned back to the
- * pool and a permit is returned to the semaphore, allowing another
- * thread to acquire that item.  Note that no synchronization lock is
- * held when {@link #acquire} is called as that would prevent an item
- * from being returned to the pool.  The semaphore encapsulates the
- * synchronization needed to restrict access to the pool, separately
- * from any synchronization needed to maintain the consistency of the
- * pool itself.
- *
- * <p>A semaphore initialized to one, and which is used such that it
- * only has at most one permit available, can serve as a mutual
- * exclusion lock.  This is more commonly known as a <em>binary
- * semaphore</em>, because it only has two states: one permit
- * available, or zero permits available.  When used in this way, the
- * binary semaphore has the property (unlike many {@link Lock}
- * implementations), that the &quot;lock&quot; can be released by a
- * thread other than the owner (as semaphores have no notion of
- * ownership).  This can be useful in some specialized contexts, such
- * as deadlock recovery.
- *
- * <p> The constructor for this class optionally accepts a
- * <em>fairness</em> parameter. When set false, this class makes no
- * guarantees about the order in which threads acquire permits. In
- * particular, <em>barging</em> is permitted, that is, a thread
- * invoking {@link #acquire} can be allocated a permit ahead of a
- * thread that has been waiting.  When fairness is set true, the
- * semaphore guarantees that threads invoking any of the {@link
- * #acquire() acquire} methods are allocated permits in the order in
- * which their invocation of those methods was processed
- * (first-in-first-out; FIFO). Note that FIFO ordering necessarily
- * applies to specific internal points of execution within these
- * methods.  So, it is possible for one thread to invoke
- * <tt>acquire</tt> before another, but reach the ordering point after
- * the other, and similarly upon return from the method.
- *
- * <p>Generally, semaphores used to control resource access should be
- * initialized as fair, to ensure that no thread is starved out from
- * accessing a resource. When using semaphores for other kinds of
- * synchronization control, the throughput advantages of non-fair
- * ordering often outweigh fairness considerations.
- *
- * <p>This class also provides convenience methods to {@link
- * #acquire(int) acquire} and {@link #release(int) release} multiple
- * permits at a time.  Beware of the increased risk of indefinite
- * postponement when these methods are used without fairness set true.
- *
- * @since 1.5
- * @author Doug Lea
- *
- */
-
-public class Semaphore implements java.io.Serializable {
-    private static final long serialVersionUID = -3222578661600680210L;
-    /** All mechanics via AbstractQueuedSynchronizer subclass */
-    private final Sync sync;
-
-    /**
-     * Synchronization implementation for semaphore.  Uses AQS state
-     * to represent permits. Subclassed into fair and nonfair
-     * versions.
-     */
-    abstract static class Sync extends AbstractQueuedSynchronizer {
-        Sync(int permits) {
-            setState(permits);
-        }
-        
-        final int getPermits() {
-            return getState();
-        }
-
-        final int nonfairTryAcquireShared(int acquires) {
-            for (;;) {
-                int available = getState();
-                int remaining = available - acquires;
-                if (remaining < 0 ||
-                    compareAndSetState(available, remaining))
-                    return remaining;
-            }
-        }
-        
-        protected final boolean tryReleaseShared(int releases) {
-            for (;;) {
-                int p = getState();
-                if (compareAndSetState(p, p + releases)) 
-                    return true;
-            }
-        }
-
-        final void reducePermits(int reductions) {
-            for (;;) {
-                int current = getState();
-                int next = current - reductions;
-                if (compareAndSetState(current, next))
-                    return;
-            }
-        }
-
-        final int drainPermits() {
-            for (;;) {
-                int current = getState();
-                if (current == 0 || compareAndSetState(current, 0))
-                    return current;
-            }
-        }
-    }
-
-    /**
-     * NonFair version
-     */
-    final static class NonfairSync extends Sync {
-        NonfairSync(int permits) {
-            super(permits);
-        }
-       
-        protected int tryAcquireShared(int acquires) {
-            return nonfairTryAcquireShared(acquires);
-        }
-    }
-
-    /**
-     * Fair version
-     */
-    final static class FairSync extends Sync {
-        FairSync(int permits) {
-            super(permits);
-        }
-        
-        protected int tryAcquireShared(int acquires) {
-            Thread current = Thread.currentThread();
-            for (;;) {
-                Thread first = getFirstQueuedThread();
-                if (first != null && first != current)
-                    return -1;
-                int available = getState();
-                int remaining = available - acquires;
-                if (remaining < 0 ||
-                    compareAndSetState(available, remaining))
-                    return remaining;
-            }
-        }
-    }
-
-    /**
-     * Creates a <tt>Semaphore</tt> with the given number of
-     * permits and nonfair fairness setting.
-     * @param permits the initial number of permits available. This
-     * value may be negative, in which case releases must
-     * occur before any acquires will be granted.
-     */
-    public Semaphore(int permits) { 
-        sync = new NonfairSync(permits);
-    }
-
-    /**
-     * Creates a <tt>Semaphore</tt> with the given number of
-     * permits and the given fairness setting.
-     * @param permits the initial number of permits available. This
-     * value may be negative, in which case releases must
-     * occur before any acquires will be granted.
-     * @param fair true if this semaphore will guarantee first-in
-     * first-out granting of permits under contention, else false.
-     */
-    public Semaphore(int permits, boolean fair) { 
-        sync = (fair)? new FairSync(permits) : new NonfairSync(permits);
-    }
-
-    /**
-     * Acquires a permit from this semaphore, blocking until one is
-     * available, or the thread is {@link Thread#interrupt interrupted}.
-     *
-     * <p>Acquires a permit, if one is available and returns immediately,
-     * reducing the number of available permits by one.
-     * <p>If no permit is available then the current thread becomes
-     * disabled for thread scheduling purposes and lies dormant until
-     * one of two things happens:
-     * <ul>
-     * <li>Some other thread invokes the {@link #release} method for this
-     * semaphore and the current thread is next to be assigned a permit; or
-     * <li>Some other thread {@link Thread#interrupt interrupts} the current
-     * thread.
-     * </ul>
-     *
-     * <p>If the current thread:
-     * <ul>
-     * <li>has its interrupted status set on entry to this method; or
-     * <li>is {@link Thread#interrupt interrupted} while waiting
-     * for a permit,
-     * </ul>
-     * then {@link InterruptedException} is thrown and the current thread's
-     * interrupted status is cleared.
-     *
-     * @throws InterruptedException if the current thread is interrupted
-     *
-     * @see Thread#interrupt
-     */
-    public void acquire() throws InterruptedException {
-        sync.acquireSharedInterruptibly(1);
-    }
-
-    /**
-     * Acquires a permit from this semaphore, blocking until one is
-     * available.
-     *
-     * <p>Acquires a permit, if one is available and returns immediately,
-     * reducing the number of available permits by one.
-     * <p>If no permit is available then the current thread becomes
-     * disabled for thread scheduling purposes and lies dormant until
-     * some other thread invokes the {@link #release} method for this
-     * semaphore and the current thread is next to be assigned a permit.
-     *
-     * <p>If the current thread
-     * is {@link Thread#interrupt interrupted} while waiting
-     * for a permit then it will continue to wait, but the time at which
-     * the thread is assigned a permit may change compared to the time it
-     * would have received the permit had no interruption occurred. When the
-     * thread does return from this method its interrupt status will be set.
-     *
-     */
-    public void acquireUninterruptibly() {
-        sync.acquireShared(1);
-    }
-
-    /**
-     * Acquires a permit from this semaphore, only if one is available at the 
-     * time of invocation.
-     * <p>Acquires a permit, if one is available and returns immediately,
-     * with the value <tt>true</tt>,
-     * reducing the number of available permits by one.
-     *
-     * <p>If no permit is available then this method will return
-     * immediately with the value <tt>false</tt>.
-     *
-     * <p>Even when this semaphore has been set to use a
-     * fair ordering policy, a call to <tt>tryAcquire()</tt> <em>will</em>
-     * immediately acquire a permit if one is available, whether or not
-     * other threads are currently waiting. 
-     * This &quot;barging&quot; behavior can be useful in certain 
-     * circumstances, even though it breaks fairness. If you want to honor
-     * the fairness setting, then use 
-     * {@link #tryAcquire(long, TimeUnit) tryAcquire(0, TimeUnit.SECONDS) }
-     * which is almost equivalent (it also detects interruption).
-     *
-     * @return <tt>true</tt> if a permit was acquired and <tt>false</tt>
-     * otherwise.
-     */
-    public boolean tryAcquire() {
-        return sync.nonfairTryAcquireShared(1) >= 0;
-    }
-
-    /**
-     * Acquires a permit from this semaphore, if one becomes available 
-     * within the given waiting time and the
-     * current thread has not been {@link Thread#interrupt interrupted}.
-     * <p>Acquires a permit, if one is available and returns immediately,
-     * with the value <tt>true</tt>,
-     * reducing the number of available permits by one.
-     * <p>If no permit is available then
-     * the current thread becomes disabled for thread scheduling
-     * purposes and lies dormant until one of three things happens:
-     * <ul>
-     * <li>Some other thread invokes the {@link #release} method for this
-     * semaphore and the current thread is next to be assigned a permit; or
-     * <li>Some other thread {@link Thread#interrupt interrupts} the current
-     * thread; or
-     * <li>The specified waiting time elapses.
-     * </ul>
-     * <p>If a permit is acquired then the value <tt>true</tt> is returned.
-     * <p>If the current thread:
-     * <ul>
-     * <li>has its interrupted status set on entry to this method; or
-     * <li>is {@link Thread#interrupt interrupted} while waiting to acquire
-     * a permit,
-     * </ul>
-     * then {@link InterruptedException} is thrown and the current thread's
-     * interrupted status is cleared.
-     * <p>If the specified waiting time elapses then the value <tt>false</tt>
-     * is returned.
-     * If the time is less than or equal to zero, the method will not wait 
-     * at all.
-     *
-     * @param timeout the maximum time to wait for a permit
-     * @param unit the time unit of the <tt>timeout</tt> argument.
-     * @return <tt>true</tt> if a permit was acquired and <tt>false</tt>
-     * if the waiting time elapsed before a permit was acquired.
-     *
-     * @throws InterruptedException if the current thread is interrupted
-     *
-     * @see Thread#interrupt
-     *
-     */
-    public boolean tryAcquire(long timeout, TimeUnit unit) 
-        throws InterruptedException {
-        return sync.tryAcquireSharedNanos(1, unit.toNanos(timeout));
-    }
-
-    /**
-     * Releases a permit, returning it to the semaphore.
-     * <p>Releases a permit, increasing the number of available permits
-     * by one.
-     * If any threads are blocking trying to acquire a permit, then one
-     * is selected and given the permit that was just released.
-     * That thread is re-enabled for thread scheduling purposes.
-     * <p>There is no requirement that a thread that releases a permit must
-     * have acquired that permit by calling {@link #acquire}.
-     * Correct usage of a semaphore is established by programming convention
-     * in the application.
-     */
-    public void release() {
-        sync.releaseShared(1);
-    }
-       
-    /**
-     * Acquires the given number of permits from this semaphore, 
-     * blocking until all are available, 
-     * or the thread is {@link Thread#interrupt interrupted}.
-     *
-     * <p>Acquires the given number of permits, if they are available,
-     * and returns immediately,
-     * reducing the number of available permits by the given amount.
-     *
-     * <p>If insufficient permits are available then the current thread becomes
-     * disabled for thread scheduling purposes and lies dormant until
-     * one of two things happens:
-     * <ul>
-     * <li>Some other thread invokes one of the {@link #release() release} 
-     * methods for this semaphore, the current thread is next to be assigned
-     * permits and the number of available permits satisfies this request; or
-     * <li>Some other thread {@link Thread#interrupt interrupts} the current
-     * thread.
-     * </ul>
-     *
-     * <p>If the current thread:
-     * <ul>
-     * <li>has its interrupted status set on entry to this method; or
-     * <li>is {@link Thread#interrupt interrupted} while waiting
-     * for a permit,
-     * </ul>
-     * then {@link InterruptedException} is thrown and the current thread's
-     * interrupted status is cleared. 
-     * Any permits that were to be assigned to this thread are instead 
-     * assigned to the next waiting thread(s), as if
-     * they had been made available by a call to {@link #release()}.
-     *
-     * @param permits the number of permits to acquire
-     *
-     * @throws InterruptedException if the current thread is interrupted
-     * @throws IllegalArgumentException if permits less than zero.
-     *
-     * @see Thread#interrupt
-     */
-    public void acquire(int permits) throws InterruptedException {
-        if (permits < 0) throw new IllegalArgumentException();
-        sync.acquireSharedInterruptibly(permits);
-    }
-
-    /**
-     * Acquires the given number of permits from this semaphore, 
-     * blocking until all are available.
-     *
-     * <p>Acquires the given number of permits, if they are available,
-     * and returns immediately,
-     * reducing the number of available permits by the given amount.
-     *
-     * <p>If insufficient permits are available then the current thread becomes
-     * disabled for thread scheduling purposes and lies dormant until
-     * some other thread invokes one of the {@link #release() release} 
-     * methods for this semaphore, the current thread is next to be assigned
-     * permits and the number of available permits satisfies this request.
-     *
-     * <p>If the current thread
-     * is {@link Thread#interrupt interrupted} while waiting
-     * for permits then it will continue to wait and its position in the
-     * queue is not affected. When the
-     * thread does return from this method its interrupt status will be set.
-     *
-     * @param permits the number of permits to acquire
-     * @throws IllegalArgumentException if permits less than zero.
-     *
-     */
-    public void acquireUninterruptibly(int permits) {
-        if (permits < 0) throw new IllegalArgumentException();
-        sync.acquireShared(permits);
-    }
-
-    /**
-     * Acquires the given number of permits from this semaphore, only
-     * if all are available at the time of invocation.
-     *
-     * <p>Acquires the given number of permits, if they are available, and 
-     * returns immediately, with the value <tt>true</tt>,
-     * reducing the number of available permits by the given amount.
-     *
-     * <p>If insufficient permits are available then this method will return
-     * immediately with the value <tt>false</tt> and the number of available
-     * permits is unchanged.
-     *
-     * <p>Even when this semaphore has been set to use a fair ordering
-     * policy, a call to <tt>tryAcquire</tt> <em>will</em>
-     * immediately acquire a permit if one is available, whether or
-     * not other threads are currently waiting.  This
-     * &quot;barging&quot; behavior can be useful in certain
-     * circumstances, even though it breaks fairness. If you want to
-     * honor the fairness setting, then use {@link #tryAcquire(int,
-     * long, TimeUnit) tryAcquire(permits, 0, TimeUnit.SECONDS) }
-     * which is almost equivalent (it also detects interruption).
-     *
-     * @param permits the number of permits to acquire
-     *
-     * @return <tt>true</tt> if the permits were acquired and <tt>false</tt>
-     * otherwise.
-     * @throws IllegalArgumentException if permits less than zero.
-     */
-    public boolean tryAcquire(int permits) {
-        if (permits < 0) throw new IllegalArgumentException();
-        return sync.nonfairTryAcquireShared(permits) >= 0;
-    }
-
-    /**
-     * Acquires the given number of permits from this semaphore, if all 
-     * become available within the given waiting time and the
-     * current thread has not been {@link Thread#interrupt interrupted}.
-     * <p>Acquires the given number of permits, if they are available and 
-     * returns immediately, with the value <tt>true</tt>,
-     * reducing the number of available permits by the given amount.
-     * <p>If insufficient permits are available then
-     * the current thread becomes disabled for thread scheduling
-     * purposes and lies dormant until one of three things happens:
-     * <ul>
-     * <li>Some other thread invokes one of the {@link #release() release} 
-     * methods for this semaphore, the current thread is next to be assigned
-     * permits and the number of available permits satisfies this request; or
-     * <li>Some other thread {@link Thread#interrupt interrupts} the current
-     * thread; or
-     * <li>The specified waiting time elapses.
-     * </ul>
-     * <p>If the permits are acquired then the value <tt>true</tt> is returned.
-     * <p>If the current thread:
-     * <ul>
-     * <li>has its interrupted status set on entry to this method; or
-     * <li>is {@link Thread#interrupt interrupted} while waiting to acquire
-     * the permits,
-     * </ul>
-     * then {@link InterruptedException} is thrown and the current thread's
-     * interrupted status is cleared.
-     * Any permits that were to be assigned to this thread, are instead 
-     * assigned to the next waiting thread(s), as if
-     * they had been made available by a call to {@link #release()}.
-     *
-     * <p>If the specified waiting time elapses then the value <tt>false</tt>
-     * is returned.
-     * If the time is
-     * less than or equal to zero, the method will not wait at all.
-     * Any permits that were to be assigned to this thread, are instead 
-     * assigned to the next waiting thread(s), as if
-     * they had been made available by a call to {@link #release()}.
-     *
-     * @param permits the number of permits to acquire
-     * @param timeout the maximum time to wait for the permits
-     * @param unit the time unit of the <tt>timeout</tt> argument.
-     * @return <tt>true</tt> if all permits were acquired and <tt>false</tt>
-     * if the waiting time elapsed before all permits were acquired.
-     *
-     * @throws InterruptedException if the current thread is interrupted
-     * @throws IllegalArgumentException if permits less than zero.
-     *
-     * @see Thread#interrupt
-     *
-     */
-    public boolean tryAcquire(int permits, long timeout, TimeUnit unit)
-        throws InterruptedException {
-        if (permits < 0) throw new IllegalArgumentException();
-        return sync.tryAcquireSharedNanos(permits, unit.toNanos(timeout));
-    }
-
-    /**
-     * Releases the given number of permits, returning them to the semaphore.
-     * <p>Releases the given number of permits, increasing the number of 
-     * available permits by that amount.
-     * If any threads are blocking trying to acquire permits, then the
-     * one that has been waiting the longest
-     * is selected and given the permits that were just released.
-     * If the number of available permits satisfies that thread's request
-     * then that thread is re-enabled for thread scheduling purposes; otherwise
-     * the thread continues to wait. If there are still permits available
-     * after the first thread's request has been satisfied, then those permits
-     * are assigned to the next waiting thread. If it is satisfied then it is
-     * re-enabled for thread scheduling purposes. This continues until there
-     * are insufficient permits to satisfy the next waiting thread, or there
-     * are no more waiting threads.
-     *
-     * <p>There is no requirement that a thread that releases a permit must
-     * have acquired that permit by calling {@link Semaphore#acquire acquire}.
-     * Correct usage of a semaphore is established by programming convention
-     * in the application.
-     *
-     * @param permits the number of permits to release
-     * @throws IllegalArgumentException if permits less than zero.
-     */
-    public void release(int permits) {
-        if (permits < 0) throw new IllegalArgumentException();
-        sync.releaseShared(permits);
-    }
-
-    /**
-     * Returns the current number of permits available in this semaphore.
-     * <p>This method is typically used for debugging and testing purposes.
-     * @return the number of permits available in this semaphore.
-     */
-    public int availablePermits() {
-        return sync.getPermits();
-    }
-
-    /**
-     * Acquire and return all permits that are immediately available.
-     * @return the number of permits 
-     */
-    public int drainPermits() {
-        return sync.drainPermits();
-    }
-
-    /**
-     * Shrinks the number of available permits by the indicated
-     * reduction. This method can be useful in subclasses that use
-     * semaphores to track resources that become unavailable. This
-     * method differs from <tt>acquire</tt> in that it does not block
-     * waiting for permits to become available.
-     * @param reduction the number of permits to remove
-     * @throws IllegalArgumentException if reduction is negative
-     */
-    protected void reducePermits(int reduction) {
-    if (reduction < 0) throw new IllegalArgumentException();
-        sync.reducePermits(reduction);
-    }
-
-    /**
-     * Returns true if this semaphore has fairness set true.
-     * @return true if this semaphore has fairness set true.
-     */
-    public boolean isFair() {
-        return sync instanceof FairSync;
-    }
-
-    /**
-     * Queries whether any threads are waiting to acquire. Note that
-     * because cancellations may occur at any time, a <tt>true</tt>
-     * return does not guarantee that any other thread will ever
-     * acquire.  This method is designed primarily for use in
-     * monitoring of the system state.
-     *
-     * @return true if there may be other threads waiting to acquire
-     * the lock.
-     */
-    public final boolean hasQueuedThreads() { 
-        return sync.hasQueuedThreads();
-    }
-
-    /**
-     * Returns an estimate of the number of threads waiting to
-     * acquire.  The value is only an estimate because the number of
-     * threads may change dynamically while this method traverses
-     * internal data structures.  This method is designed for use in
-     * monitoring of the system state, not for synchronization
-     * control.
-     * @return the estimated number of threads waiting for this lock
-     */
-    public final int getQueueLength() {
-        return sync.getQueueLength();
-    }
-
-    /**
-     * Returns a collection containing threads that may be waiting to
-     * acquire.  Because the actual set of threads may change
-     * dynamically while constructing this result, the returned
-     * collection is only a best-effort estimate.  The elements of the
-     * returned collection are in no particular order.  This method is
-     * designed to facilitate construction of subclasses that provide
-     * more extensive monitoring facilities.
-     * @return the collection of threads
-     */
-    protected Collection<Thread> getQueuedThreads() {
-        return sync.getQueuedThreads();
-    }
-
-    /**
-     * Returns a string identifying this semaphore, as well as its state.
-     * The state, in brackets, includes the String 
-     * &quot;Permits =&quot; followed by the number of permits.
-     * @return a string identifying this semaphore, as well as its
-     * state
-     */
-    public String toString() {
-        return super.toString() + "[Permits = " + sync.getPermits() + "]";
-    }
-
-}
diff --git a/concurrent/src/main/java/java/util/concurrent/SynchronousQueue.java b/concurrent/src/main/java/java/util/concurrent/SynchronousQueue.java
deleted file mode 100644
index b8d3536..0000000
--- a/concurrent/src/main/java/java/util/concurrent/SynchronousQueue.java
+++ /dev/null
@@ -1,685 +0,0 @@
-/*
- * Written by Doug Lea with assistance from members of JCP JSR-166
- * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
- */
-
-package java.util.concurrent;
-import java.util.concurrent.locks.*;
-import java.util.*;
-
-// BEGIN android-note
-// removed link to collections framework docs
-// END android-note
-
-/**
- * A {@linkplain BlockingQueue blocking queue} in which each
- * <tt>put</tt> must wait for a <tt>take</tt>, and vice versa.  A
- * synchronous queue does not have any internal capacity, not even a
- * capacity of one. You cannot <tt>peek</tt> at a synchronous queue
- * because an element is only present when you try to take it; you
- * cannot add an element (using any method) unless another thread is
- * trying to remove it; you cannot iterate as there is nothing to
- * iterate.  The <em>head</em> of the queue is the element that the
- * first queued thread is trying to add to the queue; if there are no
- * queued threads then no element is being added and the head is
- * <tt>null</tt>.  For purposes of other <tt>Collection</tt> methods
- * (for example <tt>contains</tt>), a <tt>SynchronousQueue</tt> acts
- * as an empty collection.  This queue does not permit <tt>null</tt>
- * elements.
- *
- * <p>Synchronous queues are similar to rendezvous channels used in
- * CSP and Ada. They are well suited for handoff designs, in which an
- * object running in one thread must sync up with an object running
- * in another thread in order to hand it some information, event, or
- * task.
- *
- * <p> This class supports an optional fairness policy for ordering
- * waiting producer and consumer threads.  By default, this ordering
- * is not guaranteed. However, a queue constructed with fairness set
- * to <tt>true</tt> grants threads access in FIFO order. Fairness
- * generally decreases throughput but reduces variability and avoids
- * starvation.
- *
- * <p>This class implements all of the <em>optional</em> methods
- * of the {@link Collection} and {@link Iterator} interfaces.
- *
- * @since 1.5
- * @author Doug Lea
- * @param <E> the type of elements held in this collection
- */
-public class SynchronousQueue<E> extends AbstractQueue<E>
-        implements BlockingQueue<E>, java.io.Serializable {
-    private static final long serialVersionUID = -3223113410248163686L;
-
-    /*
-      This implementation divides actions into two cases for puts:
-
-      * An arriving producer that does not already have a waiting consumer
-      creates a node holding item, and then waits for a consumer to take it.
-      * An arriving producer that does already have a waiting consumer fills
-      the slot node created by the consumer, and notifies it to continue.
-
-      And symmetrically, two for takes:
-
-      * An arriving consumer that does not already have a waiting producer
-      creates an empty slot node, and then waits for a producer to fill it.
-      * An arriving consumer that does already have a waiting producer takes
-      item from the node created by the producer, and notifies it to continue.
-
-      When a put or take waiting for the actions of its counterpart
-      aborts due to interruption or timeout, it marks the node
-      it created as "CANCELLED", which causes its counterpart to retry
-      the entire put or take sequence.
-
-      This requires keeping two simple queues, waitingProducers and
-      waitingConsumers. Each of these can be FIFO (preserves fairness)
-      or LIFO (improves throughput).
-    */
-
-    /** Lock protecting both wait queues */
-    private final ReentrantLock qlock;
-    /** Queue holding waiting puts */
-    private final WaitQueue waitingProducers;
-    /** Queue holding waiting takes */
-    private final WaitQueue waitingConsumers;
-
-    /**
-     * Creates a <tt>SynchronousQueue</tt> with nonfair access policy.
-     */
-    public SynchronousQueue() {
-        this(false);
-    }
-
-    /**
-     * Creates a <tt>SynchronousQueue</tt> with specified fairness policy.
-     * @param fair if true, threads contend in FIFO order for access;
-     * otherwise the order is unspecified.
-     */
-    public SynchronousQueue(boolean fair) {
-        if (fair) {
-            qlock = new ReentrantLock(true);
-            waitingProducers = new FifoWaitQueue();
-            waitingConsumers = new FifoWaitQueue();
-        }
-        else {
-            qlock = new ReentrantLock();
-            waitingProducers = new LifoWaitQueue();
-            waitingConsumers = new LifoWaitQueue();
-        }
-    }
-
-    /**
-     * Queue to hold waiting puts/takes; specialized to Fifo/Lifo below.
-     * These queues have all transient fields, but are serializable
-     * in order to recover fairness settings when deserialized.
-     */
-    static abstract class WaitQueue implements java.io.Serializable {
-        /** Create, add, and return node for x */
-        abstract Node enq(Object x);
-        /** Remove and return node, or null if empty */
-        abstract Node deq();
-    }
-
-    /**
-     * FIFO queue to hold waiting puts/takes.
-     */
-    static final class FifoWaitQueue extends WaitQueue implements java.io.Serializable {
-        private static final long serialVersionUID = -3623113410248163686L;
-        private transient Node head;
-        private transient Node last;
-
-        Node enq(Object x) {
-            Node p = new Node(x);
-            if (last == null)
-                last = head = p;
-            else
-                last = last.next = p;
-            return p;
-        }
-
-        Node deq() {
-            Node p = head;
-            if (p != null) {
-                if ((head = p.next) == null)
-                    last = null;
-                p.next = null;
-            }
-            return p;
-        }
-    }
-
-    /**
-     * LIFO queue to hold waiting puts/takes.
-     */
-    static final class LifoWaitQueue extends WaitQueue implements java.io.Serializable {
-        private static final long serialVersionUID = -3633113410248163686L;
-        private transient Node head;
-
-        Node enq(Object x) {
-            return head = new Node(x, head);
-        }
-
-        Node deq() {
-            Node p = head;
-            if (p != null) {
-                head = p.next;
-                p.next = null;
-            }
-            return p;
-        }
-    }
-
-    /**
-     * Nodes each maintain an item and handle waits and signals for
-     * getting and setting it. The class extends
-     * AbstractQueuedSynchronizer to manage blocking, using AQS state
-     *  0 for waiting, 1 for ack, -1 for cancelled.
-     */
-    static final class Node extends AbstractQueuedSynchronizer {
-        /** Synchronization state value representing that node acked */
-        private static final int ACK    =  1;
-        /** Synchronization state value representing that node cancelled */
-        private static final int CANCEL = -1;
-
-        /** The item being transferred */
-        Object item;
-        /** Next node in wait queue */
-        Node next;
-
-        /** Creates a node with initial item */
-        Node(Object x) { item = x; }
-
-        /** Creates a node with initial item and next */
-        Node(Object x, Node n) { item = x; next = n; }
-
-        /**
-         * Implements AQS base acquire to succeed if not in WAITING state
-         */
-        protected boolean tryAcquire(int ignore) {
-            return getState() != 0;
-        }
-
-        /**
-         * Implements AQS base release to signal if state changed
-         */
-        protected boolean tryRelease(int newState) {
-            return compareAndSetState(0, newState);
-        }
-
-        /**
-         * Takes item and nulls out field (for sake of GC)
-         */
-        private Object extract() {
-            Object x = item;
-            item = null;
-            return x;
-        }
-
-        /**
-         * Tries to cancel on interrupt; if so rethrowing,
-         * else setting interrupt state
-         */
-        private void checkCancellationOnInterrupt(InterruptedException ie) 
-            throws InterruptedException {
-            if (release(CANCEL)) 
-                throw ie;
-            Thread.currentThread().interrupt();
-        }
-
-        /**
-         * Fills in the slot created by the consumer and signal consumer to
-         * continue.
-         */
-        boolean setItem(Object x) {
-            item = x; // can place in slot even if cancelled
-            return release(ACK);
-        }
-
-        /**
-         * Removes item from slot created by producer and signal producer
-         * to continue.
-         */
-        Object getItem() {
-            return (release(ACK))? extract() : null;
-        }
-
-        /**
-         * Waits for a consumer to take item placed by producer.
-         */
-        void waitForTake() throws InterruptedException {
-            try {
-                acquireInterruptibly(0);
-            } catch (InterruptedException ie) {
-                checkCancellationOnInterrupt(ie);
-            }
-        }
-
-        /**
-         * Waits for a producer to put item placed by consumer.
-         */
-        Object waitForPut() throws InterruptedException {
-            try {
-                acquireInterruptibly(0);
-            } catch (InterruptedException ie) {
-                checkCancellationOnInterrupt(ie);
-            }
-            return extract();
-        }
-
-        /**
-         * Waits for a consumer to take item placed by producer or time out.
-         */
-        boolean waitForTake(long nanos) throws InterruptedException {
-            try {
-                if (!tryAcquireNanos(0, nanos) &&
-                    release(CANCEL))
-                    return false;
-            } catch (InterruptedException ie) {
-                checkCancellationOnInterrupt(ie);
-            }
-            return true;
-        }
-
-        /**
-         * Waits for a producer to put item placed by consumer, or time out.
-         */
-        Object waitForPut(long nanos) throws InterruptedException {
-            try {
-                if (!tryAcquireNanos(0, nanos) &&
-                    release(CANCEL))
-                    return null;
-            } catch (InterruptedException ie) {
-                checkCancellationOnInterrupt(ie);
-            }
-            return extract();
-        }
-    }
-
-    /**
-     * Adds the specified element to this queue, waiting if necessary for
-     * another thread to receive it.
-     * @param o the element to add
-     * @throws InterruptedException if interrupted while waiting.
-     * @throws NullPointerException if the specified element is <tt>null</tt>.
-     */
-    public void put(E o) throws InterruptedException {
-        if (o == null) throw new NullPointerException();
-        final ReentrantLock qlock = this.qlock;
-
-        for (;;) {
-            Node node;
-            boolean mustWait;
-            if (Thread.interrupted()) throw new InterruptedException();
-            qlock.lock();
-            try {
-                node = waitingConsumers.deq();
-                if ( (mustWait = (node == null)) )
-                    node = waitingProducers.enq(o);
-            } finally {
-                qlock.unlock();
-            }
-
-            if (mustWait) {
-                node.waitForTake();
-                return;
-            }
-
-            else if (node.setItem(o))
-                return;
-
-            // else consumer cancelled, so retry
-        }
-    }
-
-    /**
-     * Inserts the specified element into this queue, waiting if necessary
-     * up to the specified wait time for another thread to receive it.
-     * @param o the element to add
-     * @param timeout how long to wait before giving up, in units of
-     * <tt>unit</tt>
-     * @param unit a <tt>TimeUnit</tt> determining how to interpret the
-     * <tt>timeout</tt> parameter
-     * @return <tt>true</tt> if successful, or <tt>false</tt> if
-     * the specified waiting time elapses before a consumer appears.
-     * @throws InterruptedException if interrupted while waiting.
-     * @throws NullPointerException if the specified element is <tt>null</tt>.
-     */
-    public boolean offer(E o, long timeout, TimeUnit unit) throws InterruptedException {
-        if (o == null) throw new NullPointerException();
-        long nanos = unit.toNanos(timeout);
-        final ReentrantLock qlock = this.qlock;
-        for (;;) {
-            Node node;
-            boolean mustWait;
-            if (Thread.interrupted()) throw new InterruptedException();
-            qlock.lock();
-            try {
-                node = waitingConsumers.deq();
-                if ( (mustWait = (node == null)) )
-                    node = waitingProducers.enq(o);
-            } finally {
-                qlock.unlock();
-            }
-
-            if (mustWait) 
-                return node.waitForTake(nanos);
-
-            else if (node.setItem(o))
-                return true;
-
-            // else consumer cancelled, so retry
-        }
-    }
-
-    /**
-     * Retrieves and removes the head of this queue, waiting if necessary
-     * for another thread to insert it.
-     * @throws InterruptedException if interrupted while waiting.
-     * @return the head of this queue
-     */
-    public E take() throws InterruptedException {
-        final ReentrantLock qlock = this.qlock;
-        for (;;) {
-            Node node;
-            boolean mustWait;
-
-            if (Thread.interrupted()) throw new InterruptedException();
-            qlock.lock();
-            try {
-                node = waitingProducers.deq();
-                if ( (mustWait = (node == null)) )
-                    node = waitingConsumers.enq(null);
-            } finally {
-                qlock.unlock();
-            }
-
-            if (mustWait) {
-                Object x = node.waitForPut();
-                return (E)x;
-            }
-            else {
-                Object x = node.getItem();
-                if (x != null)
-                    return (E)x;
-                // else cancelled, so retry
-            }
-        }
-    }
-
-    /**
-     * Retrieves and removes the head of this queue, waiting
-     * if necessary up to the specified wait time, for another thread
-     * to insert it.
-     * @param timeout how long to wait before giving up, in units of
-     * <tt>unit</tt>
-     * @param unit a <tt>TimeUnit</tt> determining how to interpret the
-     * <tt>timeout</tt> parameter
-     * @return the head of this queue, or <tt>null</tt> if the
-     * specified waiting time elapses before an element is present.
-     * @throws InterruptedException if interrupted while waiting.
-     */
-    public E poll(long timeout, TimeUnit unit) throws InterruptedException {
-        long nanos = unit.toNanos(timeout);
-        final ReentrantLock qlock = this.qlock;
-
-        for (;;) {
-            Node node;
-            boolean mustWait;
-
-            if (Thread.interrupted()) throw new InterruptedException();
-            qlock.lock();
-            try {
-                node = waitingProducers.deq();
-                if ( (mustWait = (node == null)) )
-                    node = waitingConsumers.enq(null);
-            } finally {
-                qlock.unlock();
-            }
-
-            if (mustWait) {
-                Object x = node.waitForPut(nanos);
-                return (E)x;
-            }
-            else {
-                Object x = node.getItem();
-                if (x != null)
-                    return (E)x;
-                // else cancelled, so retry
-            }
-        }
-    }
-
-    // Untimed nonblocking versions
-
-   /**
-    * Inserts the specified element into this queue, if another thread is
-    * waiting to receive it.
-    *
-    * @param o the element to add.
-    * @return <tt>true</tt> if it was possible to add the element to
-    *         this queue, else <tt>false</tt>
-    * @throws NullPointerException if the specified element is <tt>null</tt>
-    */
-    public boolean offer(E o) {
-        if (o == null) throw new NullPointerException();
-        final ReentrantLock qlock = this.qlock;
-
-        for (;;) {
-            Node node;
-            qlock.lock();
-            try {
-                node = waitingConsumers.deq();
-            } finally {
-                qlock.unlock();
-            }
-            if (node == null)
-                return false;
-
-            else if (node.setItem(o))
-                return true;
-            // else retry
-        }
-    }
-
-    /**
-     * Retrieves and removes the head of this queue, if another thread
-     * is currently making an element available.
-     *
-     * @return the head of this queue, or <tt>null</tt> if no
-     *         element is available.
-     */
-    public E poll() {
-        final ReentrantLock qlock = this.qlock;
-        for (;;) {
-            Node node;
-            qlock.lock();
-            try {
-                node = waitingProducers.deq();
-            } finally {
-                qlock.unlock();
-            }
-            if (node == null)
-                return null;
-
-            else {
-                Object x = node.getItem();
-                if (x != null)
-                    return (E)x;
-                // else retry
-            }
-        }
-    }
-
-    /**
-     * Always returns <tt>true</tt>. 
-     * A <tt>SynchronousQueue</tt> has no internal capacity.
-     * @return <tt>true</tt>
-     */
-    public boolean isEmpty() {
-        return true;
-    }
-
-    /**
-     * Always returns zero.
-     * A <tt>SynchronousQueue</tt> has no internal capacity.
-     * @return zero.
-     */
-    public int size() {
-        return 0;
-    }
-
-    /**
-     * Always returns zero.
-     * A <tt>SynchronousQueue</tt> has no internal capacity.
-     * @return zero.
-     */
-    public int remainingCapacity() {
-        return 0;
-    }
-
-    /**
-     * Does nothing.
-     * A <tt>SynchronousQueue</tt> has no internal capacity.
-     */
-    public void clear() {}
-
-    /**
-     * Always returns <tt>false</tt>.
-     * A <tt>SynchronousQueue</tt> has no internal capacity.
-     * @param o the element
-     * @return <tt>false</tt>
-     */
-    public boolean contains(Object o) {
-        return false;
-    }
-
-    /**
-     * Always returns <tt>false</tt>.
-     * A <tt>SynchronousQueue</tt> has no internal capacity.
-     *
-     * @param o the element to remove
-     * @return <tt>false</tt>
-     */
-    public boolean remove(Object o) {
-        return false;
-    }
-
-    /**
-     * Returns <tt>false</tt> unless given collection is empty.
-     * A <tt>SynchronousQueue</tt> has no internal capacity.
-     * @param c the collection
-     * @return <tt>false</tt> unless given collection is empty
-     */
-    public boolean containsAll(Collection<?> c) {
-        return c.isEmpty();
-    }
-
-    /**
-     * Always returns <tt>false</tt>.
-     * A <tt>SynchronousQueue</tt> has no internal capacity.
-     * @param c the collection
-     * @return <tt>false</tt>
-     */
-    public boolean removeAll(Collection<?> c) {
-        return false;
-    }
-
-    /**
-     * Always returns <tt>false</tt>.
-     * A <tt>SynchronousQueue</tt> has no internal capacity.
-     * @param c the collection
-     * @return <tt>false</tt>
-     */
-    public boolean retainAll(Collection<?> c) {
-        return false;
-    }
-
-    /**
-     * Always returns <tt>null</tt>. 
-     * A <tt>SynchronousQueue</tt> does not return elements
-     * unless actively waited on.
-     * @return <tt>null</tt>
-     */
-    public E peek() {
-        return null;
-    }
-
-
-    static class EmptyIterator<E> implements Iterator<E> {
-        public boolean hasNext() {
-            return false;
-        }
-        public E next() {
-            throw new NoSuchElementException();
-        }
-        public void remove() {
-            throw new IllegalStateException();
-        }
-    }
-
-    /**
-     * Returns an empty iterator in which <tt>hasNext</tt> always returns
-     * <tt>false</tt>.
-     *
-     * @return an empty iterator
-     */
-    public Iterator<E> iterator() {
-        return new EmptyIterator<E>();
-    }
-
-
-    /**
-     * Returns a zero-length array.
-     * @return a zero-length array
-     */
-    public Object[] toArray() {
-        return new Object[0];
-    }
-
-    /**
-     * Sets the zeroeth element of the specified array to <tt>null</tt>
-     * (if the array has non-zero length) and returns it.
-     * @param a the array
-     * @return the specified array
-     */
-    public <T> T[] toArray(T[] a) {
-        if (a.length > 0)
-            a[0] = null;
-        return a;
-    }
-
-
-    public int drainTo(Collection<? super E> c) {
-        if (c == null)
-            throw new NullPointerException();
-        if (c == this)
-            throw new IllegalArgumentException();
-        int n = 0;
-        E e;
-        while ( (e = poll()) != null) {
-            c.add(e);
-            ++n;
-        }
-        return n;
-    }
-
-    public int drainTo(Collection<? super E> c, int maxElements) {
-        if (c == null)
-            throw new NullPointerException();
-        if (c == this)
-            throw new IllegalArgumentException();
-        int n = 0;
-        E e;
-        while (n < maxElements && (e = poll()) != null) {
-            c.add(e);
-            ++n;
-        }
-        return n;
-    }
-}
-
-
-
-
-
diff --git a/concurrent/src/main/java/java/util/concurrent/ThreadFactory.java b/concurrent/src/main/java/java/util/concurrent/ThreadFactory.java
deleted file mode 100644
index 04c63e1..0000000
--- a/concurrent/src/main/java/java/util/concurrent/ThreadFactory.java
+++ /dev/null
@@ -1,40 +0,0 @@
-/*
- * Written by Doug Lea with assistance from members of JCP JSR-166
- * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
- */
-
-package java.util.concurrent;
-
-/**
- * An object that creates new threads on demand.  Using thread factories
- * removes hardwiring of calls to {@link Thread#Thread(Runnable) new Thread},
- * enabling applications to use special thread subclasses, priorities, etc.
- *
- * <p> 
- * The simplest implementation of this interface is just:
- * <pre>
- * class SimpleThreadFactory implements ThreadFactory {
- *   public Thread newThread(Runnable r) {
- *     return new Thread(r);
- *   }
- * }
- * </pre>
- *
- * The {@link Executors#defaultThreadFactory} method provides a more
- * useful simple implementation, that sets the created thread context
- * to known values before returning it. 
- * @since 1.5
- * @author Doug Lea
- */
-public interface ThreadFactory { 
-
-    /**
-     * Constructs a new <tt>Thread</tt>.  Implementations may also initialize
-     * priority, name, daemon status, <tt>ThreadGroup</tt>, etc.
-     *
-     * @param r a runnable to be executed by new thread instance
-     * @return constructed thread
-     */
-    Thread newThread(Runnable r);
-}
diff --git a/concurrent/src/main/java/java/util/concurrent/ThreadPoolExecutor.java b/concurrent/src/main/java/java/util/concurrent/ThreadPoolExecutor.java
deleted file mode 100644
index 1aa8e55..0000000
--- a/concurrent/src/main/java/java/util/concurrent/ThreadPoolExecutor.java
+++ /dev/null
@@ -1,1513 +0,0 @@
-/*
- * Written by Doug Lea with assistance from members of JCP JSR-166
- * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
- */
-
-package java.util.concurrent;
-import java.util.concurrent.locks.*;
-import java.util.*;
-
-// BEGIN android-note
-// Altered {@link TimeUnit#NANOSECONDS} because our javadoc tool doesn't
-// like it.
-// END android-note
-
-/**
- * An {@link ExecutorService} that executes each submitted task using
- * one of possibly several pooled threads, normally configured
- * using {@link Executors} factory methods.
- *
- * <p>Thread pools address two different problems: they usually
- * provide improved performance when executing large numbers of
- * asynchronous tasks, due to reduced per-task invocation overhead,
- * and they provide a means of bounding and managing the resources,
- * including threads, consumed when executing a collection of tasks.
- * Each <tt>ThreadPoolExecutor</tt> also maintains some basic
- * statistics, such as the number of completed tasks.
- *
- * <p>To be useful across a wide range of contexts, this class
- * provides many adjustable parameters and extensibility
- * hooks. However, programmers are urged to use the more convenient
- * {@link Executors} factory methods {@link
- * Executors#newCachedThreadPool} (unbounded thread pool, with
- * automatic thread reclamation), {@link Executors#newFixedThreadPool}
- * (fixed size thread pool) and {@link
- * Executors#newSingleThreadExecutor} (single background thread), that
- * preconfigure settings for the most common usage
- * scenarios. Otherwise, use the following guide when manually
- * configuring and tuning this class:
- *
- * <dl>
- *
- * <dt>Core and maximum pool sizes</dt>
- *
- * <dd>A <tt>ThreadPoolExecutor</tt> will automatically adjust the
- * pool size 
- * (see {@link ThreadPoolExecutor#getPoolSize})
- * according to the bounds set by corePoolSize 
- * (see {@link ThreadPoolExecutor#getCorePoolSize})
- * and
- * maximumPoolSize
- * (see {@link ThreadPoolExecutor#getMaximumPoolSize}).
- * When a new task is submitted in method {@link
- * ThreadPoolExecutor#execute}, and fewer than corePoolSize threads
- * are running, a new thread is created to handle the request, even if
- * other worker threads are idle.  If there are more than
- * corePoolSize but less than maximumPoolSize threads running, a new
- * thread will be created only if the queue is full.  By setting
- * corePoolSize and maximumPoolSize the same, you create a fixed-size
- * thread pool. By setting maximumPoolSize to an essentially unbounded
- * value such as <tt>Integer.MAX_VALUE</tt>, you allow the pool to
- * accommodate an arbitrary number of concurrent tasks. Most typically,
- * core and maximum pool sizes are set only upon construction, but they
- * may also be changed dynamically using {@link
- * ThreadPoolExecutor#setCorePoolSize} and {@link
- * ThreadPoolExecutor#setMaximumPoolSize}. <dd>
- *
- * <dt> On-demand construction
- *
- * <dd> By default, even core threads are initially created and
- * started only when needed by new tasks, but this can be overridden
- * dynamically using method {@link
- * ThreadPoolExecutor#prestartCoreThread} or
- * {@link ThreadPoolExecutor#prestartAllCoreThreads}.  </dd>
- *
- * <dt>Creating new threads</dt>
- *
- * <dd>New threads are created using a {@link
- * java.util.concurrent.ThreadFactory}.  If not otherwise specified, a
- * {@link Executors#defaultThreadFactory} is used, that creates threads to all
- * be in the same {@link ThreadGroup} and with the same
- * <tt>NORM_PRIORITY</tt> priority and non-daemon status. By supplying
- * a different ThreadFactory, you can alter the thread's name, thread
- * group, priority, daemon status, etc.  </dd>
- *
- * <dt>Keep-alive times</dt>
- *
- * <dd>If the pool currently has more than corePoolSize threads,
- * excess threads will be terminated if they have been idle for more
- * than the keepAliveTime (see {@link
- * ThreadPoolExecutor#getKeepAliveTime}). This provides a means of
- * reducing resource consumption when the pool is not being actively
- * used. If the pool becomes more active later, new threads will be
- * constructed. This parameter can also be changed dynamically
- * using method {@link ThreadPoolExecutor#setKeepAliveTime}. Using
- * a value of <tt>Long.MAX_VALUE</tt> <code>TimeUnit.NANOSECONDS</code>
- * effectively disables idle threads from ever terminating prior
- * to shut down.
- * </dd>
- *
- * <dt>Queuing</dt>
- *
- * <dd>Any {@link BlockingQueue} may be used to transfer and hold
- * submitted tasks.  The use of this queue interacts with pool sizing:
- *
- * <ul>
- *
- * <li> If fewer than corePoolSize threads are running, the Executor
- * always prefers adding a new thread
- * rather than queuing.</li>
- *
- * <li> If corePoolSize or more threads are running, the Executor
- * always prefers queuing a request rather than adding a new
- * thread.</li>
- * 
- * <li> If a request cannot be queued, a new thread is created unless
- * this would exceed maximumPoolSize, in which case, the task will be
- * rejected.</li>
- *
- * </ul>
- *
- * There are three general strategies for queuing:
- * <ol>
- *
- * <li> <em> Direct handoffs.</em> A good default choice for a work
- * queue is a {@link SynchronousQueue} that hands off tasks to threads
- * without otherwise holding them. Here, an attempt to queue a task
- * will fail if no threads are immediately available to run it, so a
- * new thread will be constructed. This policy avoids lockups when
- * handling sets of requests that might have internal dependencies.
- * Direct handoffs generally require unbounded maximumPoolSizes to
- * avoid rejection of new submitted tasks. This in turn admits the
- * possibility of unbounded thread growth when commands continue to
- * arrive on average faster than they can be processed.  </li>
- *
- * <li><em> Unbounded queues.</em> Using an unbounded queue (for
- * example a {@link LinkedBlockingQueue} without a predefined
- * capacity) will cause new tasks to be queued in cases where all
- * corePoolSize threads are busy. Thus, no more than corePoolSize
- * threads will ever be created. (And the value of the maximumPoolSize
- * therefore doesn't have any effect.)  This may be appropriate when
- * each task is completely independent of others, so tasks cannot
- * affect each others execution; for example, in a web page server.
- * While this style of queuing can be useful in smoothing out
- * transient bursts of requests, it admits the possibility of
- * unbounded work queue growth when commands continue to arrive on
- * average faster than they can be processed.  </li>
- *
- * <li><em>Bounded queues.</em> A bounded queue (for example, an
- * {@link ArrayBlockingQueue}) helps prevent resource exhaustion when
- * used with finite maximumPoolSizes, but can be more difficult to
- * tune and control.  Queue sizes and maximum pool sizes may be traded
- * off for each other: Using large queues and small pools minimizes
- * CPU usage, OS resources, and context-switching overhead, but can
- * lead to artificially low throughput.  If tasks frequently block (for
- * example if they are I/O bound), a system may be able to schedule
- * time for more threads than you otherwise allow. Use of small queues
- * generally requires larger pool sizes, which keeps CPUs busier but
- * may encounter unacceptable scheduling overhead, which also
- * decreases throughput.  </li>
- *
- * </ol>
- *
- * </dd>
- *
- * <dt>Rejected tasks</dt>
- *
- * <dd> New tasks submitted in method {@link
- * ThreadPoolExecutor#execute} will be <em>rejected</em> when the
- * Executor has been shut down, and also when the Executor uses finite
- * bounds for both maximum threads and work queue capacity, and is
- * saturated.  In either case, the <tt>execute</tt> method invokes the
- * {@link RejectedExecutionHandler#rejectedExecution} method of its
- * {@link RejectedExecutionHandler}.  Four predefined handler policies
- * are provided:
- *
- * <ol>
- *
- * <li> In the
- * default {@link ThreadPoolExecutor.AbortPolicy}, the handler throws a
- * runtime {@link RejectedExecutionException} upon rejection. </li>
- * 
- * <li> In {@link
- * ThreadPoolExecutor.CallerRunsPolicy}, the thread that invokes
- * <tt>execute</tt> itself runs the task. This provides a simple
- * feedback control mechanism that will slow down the rate that new
- * tasks are submitted. </li>
- *
- * <li> In {@link ThreadPoolExecutor.DiscardPolicy},
- * a task that cannot be executed is simply dropped.  </li>
- *
- * <li>In {@link
- * ThreadPoolExecutor.DiscardOldestPolicy}, if the executor is not
- * shut down, the task at the head of the work queue is dropped, and
- * then execution is retried (which can fail again, causing this to be
- * repeated.) </li>
- *
- * </ol>
- *
- * It is possible to define and use other kinds of {@link
- * RejectedExecutionHandler} classes. Doing so requires some care
- * especially when policies are designed to work only under particular
- * capacity or queuing policies. </dd>
- *
- * <dt>Hook methods</dt>
- *
- * <dd>This class provides <tt>protected</tt> overridable {@link
- * ThreadPoolExecutor#beforeExecute} and {@link
- * ThreadPoolExecutor#afterExecute} methods that are called before and
- * after execution of each task.  These can be used to manipulate the
- * execution environment, for example, reinitializing ThreadLocals,
- * gathering statistics, or adding log entries. Additionally, method
- * {@link ThreadPoolExecutor#terminated} can be overridden to perform
- * any special processing that needs to be done once the Executor has
- * fully terminated.</dd>
- *
- * <dt>Queue maintenance</dt>
- *
- * <dd> Method {@link ThreadPoolExecutor#getQueue} allows access to
- * the work queue for purposes of monitoring and debugging.  Use of
- * this method for any other purpose is strongly discouraged.  Two
- * supplied methods, {@link ThreadPoolExecutor#remove} and {@link
- * ThreadPoolExecutor#purge} are available to assist in storage
- * reclamation when large numbers of queued tasks become
- * cancelled.</dd> </dl>
- *
- * <p> <b>Extension example</b>. Most extensions of this class
- * override one or more of the protected hook methods. For example,
- * here is a subclass that adds a simple pause/resume feature:
- *
- * <pre>
- * class PausableThreadPoolExecutor extends ThreadPoolExecutor {
- *   private boolean isPaused;
- *   private ReentrantLock pauseLock = new ReentrantLock();
- *   private Condition unpaused = pauseLock.newCondition();
- *
- *   public PausableThreadPoolExecutor(...) { super(...); }
- * 
- *   protected void beforeExecute(Thread t, Runnable r) {
- *     super.beforeExecute(t, r);
- *     pauseLock.lock();
- *     try {
- *       while (isPaused) unpaused.await();
- *     } catch(InterruptedException ie) {
- *       t.interrupt();
- *     } finally {
- *       pauseLock.unlock();
- *     }
- *   }
- * 
- *   public void pause() {
- *     pauseLock.lock();
- *     try {
- *       isPaused = true;
- *     } finally {
- *       pauseLock.unlock();
- *     }
- *   }
- * 
- *   public void resume() {
- *     pauseLock.lock();
- *     try {
- *       isPaused = false;
- *       unpaused.signalAll();
- *     } finally {
- *       pauseLock.unlock();
- *     }
- *   }
- * }
- * </pre>
- * @since 1.5
- * @author Doug Lea
- */
-public class ThreadPoolExecutor extends AbstractExecutorService {
-    /**
-     * Only used to force toArray() to produce a Runnable[].
-     */
-    private static final Runnable[] EMPTY_RUNNABLE_ARRAY = new Runnable[0];
-
-    /**
-     * Permission for checking shutdown
-     */
-    private static final RuntimePermission shutdownPerm =
-        new RuntimePermission("modifyThread");
-
-    /**
-     * Queue used for holding tasks and handing off to worker threads.
-     */
-    private final BlockingQueue<Runnable> workQueue;
-
-    /**
-     * Lock held on updates to poolSize, corePoolSize, maximumPoolSize, and
-     * workers set.
-     */
-    private final ReentrantLock mainLock = new ReentrantLock();
-
-    /**
-     * Wait condition to support awaitTermination
-     */
-    private final Condition termination = mainLock.newCondition();
-
-    /**
-     * Set containing all worker threads in pool.
-     */
-    private final HashSet<Worker> workers = new HashSet<Worker>();
-
-    /**
-     * Timeout in nanoseconds for idle threads waiting for work.
-     * Threads use this timeout only when there are more than
-     * corePoolSize present. Otherwise they wait forever for new work.
-     */
-    private volatile long  keepAliveTime;
-
-    /**
-     * Core pool size, updated only while holding mainLock,
-     * but volatile to allow concurrent readability even
-     * during updates.
-     */
-    private volatile int   corePoolSize;
-
-    /**
-     * Maximum pool size, updated only while holding mainLock
-     * but volatile to allow concurrent readability even
-     * during updates.
-     */
-    private volatile int   maximumPoolSize;
-
-    /**
-     * Current pool size, updated only while holding mainLock
-     * but volatile to allow concurrent readability even
-     * during updates.
-     */
-    private volatile int   poolSize;
-
-    /**
-     * Lifecycle state
-     */
-    volatile int runState;
-
-    // Special values for runState
-    /** Normal, not-shutdown mode */
-    static final int RUNNING    = 0;
-    /** Controlled shutdown mode */
-    static final int SHUTDOWN   = 1;
-    /** Immediate shutdown mode */
-    static final int STOP       = 2;
-    /** Final state */
-    static final int TERMINATED = 3;
-
-    /**
-     * Handler called when saturated or shutdown in execute.
-     */
-    private volatile RejectedExecutionHandler handler;
-
-    /**
-     * Factory for new threads.
-     */
-    private volatile ThreadFactory threadFactory;
-
-    /**
-     * Tracks largest attained pool size.
-     */
-    private int largestPoolSize;
-
-    /**
-     * Counter for completed tasks. Updated only on termination of
-     * worker threads.
-     */
-    private long completedTaskCount;
-    
-    /**
-     * The default rejected execution handler
-     */
-    private static final RejectedExecutionHandler defaultHandler =
-        new AbortPolicy();
-
-    /**
-     * Invoke the rejected execution handler for the given command.
-     */
-    void reject(Runnable command) {
-        handler.rejectedExecution(command, this);
-    }
-
-    /**
-     * Create and return a new thread running firstTask as its first
-     * task. Call only while holding mainLock
-     * @param firstTask the task the new thread should run first (or
-     * null if none)
-     * @return the new thread
-     */
-    private Thread addThread(Runnable firstTask) {
-        Worker w = new Worker(firstTask);
-        Thread t = threadFactory.newThread(w);
-        w.thread = t;
-        workers.add(w);
-        int nt = ++poolSize;
-        if (nt > largestPoolSize)
-            largestPoolSize = nt;
-        return t;
-    }
-
-    /**
-     * Create and start a new thread running firstTask as its first
-     * task, only if fewer than corePoolSize threads are running.
-     * @param firstTask the task the new thread should run first (or
-     * null if none)
-     * @return true if successful.
-     */
-    private boolean addIfUnderCorePoolSize(Runnable firstTask) {
-        Thread t = null;
-        final ReentrantLock mainLock = this.mainLock;
-        mainLock.lock();
-        try {
-            if (poolSize < corePoolSize)
-                t = addThread(firstTask);
-        } finally {
-            mainLock.unlock();
-        }
-        if (t == null)
-            return false;
-        t.start();
-        return true;
-    }
-
-    /**
-     * Create and start a new thread only if fewer than maximumPoolSize
-     * threads are running.  The new thread runs as its first task the
-     * next task in queue, or if there is none, the given task.
-     * @param firstTask the task the new thread should run first (or
-     * null if none)
-     * @return null on failure, else the first task to be run by new thread.
-     */
-    private Runnable addIfUnderMaximumPoolSize(Runnable firstTask) {
-        Thread t = null;
-        Runnable next = null;
-        final ReentrantLock mainLock = this.mainLock;
-        mainLock.lock();
-        try {
-            if (poolSize < maximumPoolSize) {
-                next = workQueue.poll();
-                if (next == null)
-                    next = firstTask;
-                t = addThread(next);
-            }
-        } finally {
-            mainLock.unlock();
-        }
-        if (t == null)
-            return null;
-        t.start();
-        return next;
-    }
-
-
-    /**
-     * Get the next task for a worker thread to run.
-     * @return the task
-     * @throws InterruptedException if interrupted while waiting for task
-     */
-    Runnable getTask() throws InterruptedException {
-        for (;;) {
-            switch(runState) {
-            case RUNNING: {
-                if (poolSize <= corePoolSize)   // untimed wait if core
-                    return workQueue.take();
-                
-                long timeout = keepAliveTime;
-                if (timeout <= 0) // die immediately for 0 timeout
-                    return null;
-                Runnable r =  workQueue.poll(timeout, TimeUnit.NANOSECONDS);
-                if (r != null)
-                    return r;
-                if (poolSize > corePoolSize) // timed out
-                    return null;
-                // else, after timeout, pool shrank so shouldn't die, so retry
-                break;
-            }
-
-            case SHUTDOWN: {
-                // Help drain queue 
-                Runnable r = workQueue.poll();
-                if (r != null)
-                    return r;
-                    
-                // Check if can terminate
-                if (workQueue.isEmpty()) {
-                    interruptIdleWorkers();
-                    return null;
-                }
-
-                // There could still be delayed tasks in queue.
-                // Wait for one, re-checking state upon interruption
-                try {
-                    return workQueue.take();
-                } catch(InterruptedException ignore) {}
-                break;
-            }
-
-            case STOP:
-                return null;
-            default:
-                assert false; 
-            }
-        }
-    }
-
-    /**
-     * Wake up all threads that might be waiting for tasks.
-     */
-    void interruptIdleWorkers() {
-        final ReentrantLock mainLock = this.mainLock;
-        mainLock.lock();
-        try {
-            for (Worker w : workers)
-                w.interruptIfIdle();
-        } finally {
-            mainLock.unlock();
-        }
-    }
-
-    /**
-     * Perform bookkeeping for a terminated worker thread.
-     * @param w the worker
-     */
-    void workerDone(Worker w) {
-        final ReentrantLock mainLock = this.mainLock;
-        mainLock.lock();
-        try {
-            completedTaskCount += w.completedTasks;
-            workers.remove(w);
-            if (--poolSize > 0)
-                return;
-
-            // Else, this is the last thread. Deal with potential shutdown.
-
-            int state = runState;
-            assert state != TERMINATED;
-
-            if (state != STOP) {
-                // If there are queued tasks but no threads, create
-                // replacement.
-                Runnable r = workQueue.poll();
-                if (r != null) {
-                    addThread(r).start();
-                    return;
-                }
-
-                // If there are some (presumably delayed) tasks but
-                // none pollable, create an idle replacement to wait.
-                if (!workQueue.isEmpty()) { 
-                    addThread(null).start();
-                    return;
-                }
-
-                // Otherwise, we can exit without replacement
-                if (state == RUNNING)
-                    return;
-            }
-
-            // Either state is STOP, or state is SHUTDOWN and there is
-            // no work to do. So we can terminate.
-            termination.signalAll();
-            runState = TERMINATED;
-            // fall through to call terminate() outside of lock.
-        } finally {
-            mainLock.unlock();
-        }
-
-        assert runState == TERMINATED;
-        terminated(); 
-    }
-
-    /**
-     *  Worker threads
-     */
-    private class Worker implements Runnable {
-
-        /**
-         * The runLock is acquired and released surrounding each task
-         * execution. It mainly protects against interrupts that are
-         * intended to cancel the worker thread from instead
-         * interrupting the task being run.
-         */
-        private final ReentrantLock runLock = new ReentrantLock();
-
-        /**
-         * Initial task to run before entering run loop
-         */
-        private Runnable firstTask;
-
-        /**
-         * Per thread completed task counter; accumulated
-         * into completedTaskCount upon termination.
-         */
-        volatile long completedTasks;
-
-        /**
-         * Thread this worker is running in.  Acts as a final field,
-         * but cannot be set until thread is created.
-         */
-        Thread thread;
-
-        Worker(Runnable firstTask) {
-            this.firstTask = firstTask;
-        }
-
-        boolean isActive() {
-            return runLock.isLocked();
-        }
-
-        /**
-         * Interrupt thread if not running a task
-         */
-        void interruptIfIdle() {
-            final ReentrantLock runLock = this.runLock;
-            if (runLock.tryLock()) {
-                try {
-                    thread.interrupt();
-                } finally {
-                    runLock.unlock();
-                }
-            }
-        }
-
-        /**
-         * Cause thread to die even if running a task.
-         */
-        void interruptNow() {
-            thread.interrupt();
-        }
-
-        /**
-         * Run a single task between before/after methods.
-         */
-        private void runTask(Runnable task) {
-            final ReentrantLock runLock = this.runLock;
-            runLock.lock();
-            try {
-                // Abort now if immediate cancel.  Otherwise, we have
-                // committed to run this task.
-                if (runState == STOP)
-                    return;
-
-                Thread.interrupted(); // clear interrupt status on entry
-                boolean ran = false;
-                beforeExecute(thread, task);
-                try {
-                    task.run();
-                    ran = true;
-                    afterExecute(task, null);
-                    ++completedTasks;
-                } catch(RuntimeException ex) {
-                    if (!ran)
-                        afterExecute(task, ex);
-                    // Else the exception occurred within
-                    // afterExecute itself in which case we don't
-                    // want to call it again.
-                    throw ex;
-                }
-            } finally {
-                runLock.unlock();
-            }
-        }
-
-        /**
-         * Main run loop
-         */
-        public void run() {
-            try {
-                Runnable task = firstTask;
-                firstTask = null;
-                while (task != null || (task = getTask()) != null) {
-                    runTask(task);
-                    task = null; // unnecessary but can help GC
-                }
-            } catch(InterruptedException ie) {
-                // fall through
-            } finally {
-                workerDone(this);
-            }
-        }
-    }
-
-    // Public methods
-
-    /**
-     * Creates a new <tt>ThreadPoolExecutor</tt> with the given
-     * initial parameters and default thread factory and handler.  It
-     * may be more convenient to use one of the {@link Executors}
-     * factory methods instead of this general purpose constructor.
-     *
-     * @param corePoolSize the number of threads to keep in the
-     * pool, even if they are idle.
-     * @param maximumPoolSize the maximum number of threads to allow in the
-     * pool.
-     * @param keepAliveTime when the number of threads is greater than
-     * the core, this is the maximum time that excess idle threads
-     * will wait for new tasks before terminating.
-     * @param unit the time unit for the keepAliveTime
-     * argument.
-     * @param workQueue the queue to use for holding tasks before they
-     * are executed. This queue will hold only the <tt>Runnable</tt>
-     * tasks submitted by the <tt>execute</tt> method.
-     * @throws IllegalArgumentException if corePoolSize, or
-     * keepAliveTime less than zero, or if maximumPoolSize less than or
-     * equal to zero, or if corePoolSize greater than maximumPoolSize.
-     * @throws NullPointerException if <tt>workQueue</tt> is null
-     */
-    public ThreadPoolExecutor(int corePoolSize,
-                              int maximumPoolSize,
-                              long keepAliveTime,
-                              TimeUnit unit,
-                              BlockingQueue<Runnable> workQueue) {
-        this(corePoolSize, maximumPoolSize, keepAliveTime, unit, workQueue,
-             Executors.defaultThreadFactory(), defaultHandler);
-    }
-
-    /**
-     * Creates a new <tt>ThreadPoolExecutor</tt> with the given initial
-     * parameters.
-     *
-     * @param corePoolSize the number of threads to keep in the
-     * pool, even if they are idle.
-     * @param maximumPoolSize the maximum number of threads to allow in the
-     * pool.
-     * @param keepAliveTime when the number of threads is greater than
-     * the core, this is the maximum time that excess idle threads
-     * will wait for new tasks before terminating.
-     * @param unit the time unit for the keepAliveTime
-     * argument.
-     * @param workQueue the queue to use for holding tasks before they
-     * are executed. This queue will hold only the <tt>Runnable</tt>
-     * tasks submitted by the <tt>execute</tt> method.
-     * @param threadFactory the factory to use when the executor
-     * creates a new thread.
-     * @throws IllegalArgumentException if corePoolSize, or
-     * keepAliveTime less than zero, or if maximumPoolSize less than or
-     * equal to zero, or if corePoolSize greater than maximumPoolSize.
-     * @throws NullPointerException if <tt>workQueue</tt>
-     * or <tt>threadFactory</tt> are null.
-     */
-    public ThreadPoolExecutor(int corePoolSize,
-                              int maximumPoolSize,
-                              long keepAliveTime,
-                              TimeUnit unit,
-                              BlockingQueue<Runnable> workQueue,
-                              ThreadFactory threadFactory) {
-        this(corePoolSize, maximumPoolSize, keepAliveTime, unit, workQueue,
-             threadFactory, defaultHandler);
-    }
-
-    /**
-     * Creates a new <tt>ThreadPoolExecutor</tt> with the given initial
-     * parameters.
-     *
-     * @param corePoolSize the number of threads to keep in the
-     * pool, even if they are idle.
-     * @param maximumPoolSize the maximum number of threads to allow in the
-     * pool.
-     * @param keepAliveTime when the number of threads is greater than
-     * the core, this is the maximum time that excess idle threads
-     * will wait for new tasks before terminating.
-     * @param unit the time unit for the keepAliveTime
-     * argument.
-     * @param workQueue the queue to use for holding tasks before they
-     * are executed. This queue will hold only the <tt>Runnable</tt>
-     * tasks submitted by the <tt>execute</tt> method.
-     * @param handler the handler to use when execution is blocked
-     * because the thread bounds and queue capacities are reached.
-     * @throws IllegalArgumentException if corePoolSize, or
-     * keepAliveTime less than zero, or if maximumPoolSize less than or
-     * equal to zero, or if corePoolSize greater than maximumPoolSize.
-     * @throws NullPointerException if <tt>workQueue</tt>
-     * or  <tt>handler</tt> are null.
-     */
-    public ThreadPoolExecutor(int corePoolSize,
-                              int maximumPoolSize,
-                              long keepAliveTime,
-                              TimeUnit unit,
-                              BlockingQueue<Runnable> workQueue,
-                              RejectedExecutionHandler handler) {
-        this(corePoolSize, maximumPoolSize, keepAliveTime, unit, workQueue,
-             Executors.defaultThreadFactory(), handler);
-    }
-
-    /**
-     * Creates a new <tt>ThreadPoolExecutor</tt> with the given initial
-     * parameters.
-     *
-     * @param corePoolSize the number of threads to keep in the
-     * pool, even if they are idle.
-     * @param maximumPoolSize the maximum number of threads to allow in the
-     * pool.
-     * @param keepAliveTime when the number of threads is greater than
-     * the core, this is the maximum time that excess idle threads
-     * will wait for new tasks before terminating.
-     * @param unit the time unit for the keepAliveTime
-     * argument.
-     * @param workQueue the queue to use for holding tasks before they
-     * are executed. This queue will hold only the <tt>Runnable</tt>
-     * tasks submitted by the <tt>execute</tt> method.
-     * @param threadFactory the factory to use when the executor
-     * creates a new thread.
-     * @param handler the handler to use when execution is blocked
-     * because the thread bounds and queue capacities are reached.
-     * @throws IllegalArgumentException if corePoolSize, or
-     * keepAliveTime less than zero, or if maximumPoolSize less than or
-     * equal to zero, or if corePoolSize greater than maximumPoolSize.
-     * @throws NullPointerException if <tt>workQueue</tt>
-     * or <tt>threadFactory</tt> or <tt>handler</tt> are null.
-     */
-    public ThreadPoolExecutor(int corePoolSize,
-                              int maximumPoolSize,
-                              long keepAliveTime,
-                              TimeUnit unit,
-                              BlockingQueue<Runnable> workQueue,
-                              ThreadFactory threadFactory,
-                              RejectedExecutionHandler handler) {
-        if (corePoolSize < 0 ||
-            maximumPoolSize <= 0 ||
-            maximumPoolSize < corePoolSize ||
-            keepAliveTime < 0)
-            throw new IllegalArgumentException();
-        if (workQueue == null || threadFactory == null || handler == null)
-            throw new NullPointerException();
-        this.corePoolSize = corePoolSize;
-        this.maximumPoolSize = maximumPoolSize;
-        this.workQueue = workQueue;
-        this.keepAliveTime = unit.toNanos(keepAliveTime);
-        this.threadFactory = threadFactory;
-        this.handler = handler;
-    }
-
-
-    /**
-     * Executes the given task sometime in the future.  The task
-     * may execute in a new thread or in an existing pooled thread.
-     *
-     * If the task cannot be submitted for execution, either because this
-     * executor has been shutdown or because its capacity has been reached,
-     * the task is handled by the current <tt>RejectedExecutionHandler</tt>.
-     *
-     * @param command the task to execute
-     * @throws RejectedExecutionException at discretion of
-     * <tt>RejectedExecutionHandler</tt>, if task cannot be accepted
-     * for execution
-     * @throws NullPointerException if command is null
-     */
-    public void execute(Runnable command) {
-        if (command == null)
-            throw new NullPointerException();
-        for (;;) {
-            if (runState != RUNNING) {
-                reject(command);
-                return;
-            }
-            if (poolSize < corePoolSize && addIfUnderCorePoolSize(command))
-                return;
-            if (workQueue.offer(command))
-                return;
-            Runnable r = addIfUnderMaximumPoolSize(command);
-            if (r == command)
-                return;
-            if (r == null) {
-                reject(command);
-                return;
-            }
-            // else retry
-        }
-    }
-
-    /**
-     * Initiates an orderly shutdown in which previously submitted
-     * tasks are executed, but no new tasks will be
-     * accepted. Invocation has no additional effect if already shut
-     * down.
-     * @throws SecurityException if a security manager exists and
-     * shutting down this ExecutorService may manipulate threads that
-     * the caller is not permitted to modify because it does not hold
-     * {@link java.lang.RuntimePermission}<tt>("modifyThread")</tt>,
-     * or the security manager's <tt>checkAccess</tt>  method denies access.
-     */
-    public void shutdown() {
-        // Fail if caller doesn't have modifyThread permission
-        SecurityManager security = System.getSecurityManager();
-        if (security != null) 
-            java.security.AccessController.checkPermission(shutdownPerm);
-
-        boolean fullyTerminated = false;
-        final ReentrantLock mainLock = this.mainLock;
-        mainLock.lock();
-        try {
-            if (workers.size() > 0) {
-                // Check if caller can modify worker threads.  This
-                // might not be true even if passed above check, if
-                // the SecurityManager treats some threads specially.
-                if (security != null) {
-                    for (Worker w: workers)
-                        security.checkAccess(w.thread);
-                }
-
-                int state = runState;
-                if (state == RUNNING) // don't override shutdownNow
-                    runState = SHUTDOWN;
-
-                try {
-                    for (Worker w: workers)
-                        w.interruptIfIdle();
-                } catch(SecurityException se) {
-                    // If SecurityManager allows above checks, but
-                    // then unexpectedly throws exception when
-                    // interrupting threads (which it ought not do),
-                    // back out as cleanly as we can. Some threads may
-                    // have been killed but we remain in non-shutdown
-                    // state.
-                    runState = state; 
-                    throw se;
-                }
-            }
-            else { // If no workers, trigger full termination now
-                fullyTerminated = true;
-                runState = TERMINATED;
-                termination.signalAll();
-            }
-        } finally {
-            mainLock.unlock();
-        }
-        if (fullyTerminated)
-            terminated();
-    }
-
-
-    /**
-     * Attempts to stop all actively executing tasks, halts the
-     * processing of waiting tasks, and returns a list of the tasks that were
-     * awaiting execution. 
-     *  
-     * <p>This implementation cancels tasks via {@link
-     * Thread#interrupt}, so if any tasks mask or fail to respond to
-     * interrupts, they may never terminate.
-     *
-     * @return list of tasks that never commenced execution
-     * @throws SecurityException if a security manager exists and
-     * shutting down this ExecutorService may manipulate threads that
-     * the caller is not permitted to modify because it does not hold
-     * {@link java.lang.RuntimePermission}<tt>("modifyThread")</tt>,
-     * or the security manager's <tt>checkAccess</tt> method denies access.
-     */
-    public List<Runnable> shutdownNow() {
-        // Almost the same code as shutdown()
-        SecurityManager security = System.getSecurityManager();
-        if (security != null) 
-            java.security.AccessController.checkPermission(shutdownPerm);
-
-        boolean fullyTerminated = false;
-        final ReentrantLock mainLock = this.mainLock;
-        mainLock.lock();
-        try {
-            if (workers.size() > 0) {
-                if (security != null) {
-                    for (Worker w: workers)
-                        security.checkAccess(w.thread);
-                }
-
-                int state = runState;
-                if (state != TERMINATED)
-                    runState = STOP;
-                try {
-                    for (Worker w : workers)
-                        w.interruptNow();
-                } catch(SecurityException se) {
-                    runState = state; // back out;
-                    throw se;
-                }
-            }
-            else { // If no workers, trigger full termination now
-                fullyTerminated = true;
-                runState = TERMINATED;
-                termination.signalAll();
-            }
-        } finally {
-            mainLock.unlock();
-        }
-        if (fullyTerminated)
-            terminated();
-        return Arrays.asList(workQueue.toArray(EMPTY_RUNNABLE_ARRAY));
-    }
-
-    public boolean isShutdown() {
-        return runState != RUNNING;
-    }
-
-    /** 
-     * Returns true if this executor is in the process of terminating
-     * after <tt>shutdown</tt> or <tt>shutdownNow</tt> but has not
-     * completely terminated.  This method may be useful for
-     * debugging. A return of <tt>true</tt> reported a sufficient
-     * period after shutdown may indicate that submitted tasks have
-     * ignored or suppressed interruption, causing this executor not
-     * to properly terminate.
-     * @return true if terminating but not yet terminated.
-     */
-    public boolean isTerminating() {
-        return runState == STOP;
-    }
-
-    public boolean isTerminated() {
-        return runState == TERMINATED;
-    }
-
-    public boolean awaitTermination(long timeout, TimeUnit unit)
-        throws InterruptedException {
-        long nanos = unit.toNanos(timeout);
-        final ReentrantLock mainLock = this.mainLock;
-        mainLock.lock();
-        try {
-            for (;;) {
-                if (runState == TERMINATED) 
-                    return true;
-                if (nanos <= 0)
-                    return false;
-                nanos = termination.awaitNanos(nanos);
-            }
-        } finally {
-            mainLock.unlock();
-        }
-    }
-
-    /**
-     * Invokes <tt>shutdown</tt> when this executor is no longer
-     * referenced.
-     */ 
-    protected void finalize()  {
-        shutdown();
-    }
-
-    /**
-     * Sets the thread factory used to create new threads.
-     *
-     * @param threadFactory the new thread factory
-     * @throws NullPointerException if threadFactory is null
-     * @see #getThreadFactory
-     */
-    public void setThreadFactory(ThreadFactory threadFactory) {
-        if (threadFactory == null)
-            throw new NullPointerException();
-        this.threadFactory = threadFactory;
-    }
-
-    /**
-     * Returns the thread factory used to create new threads.
-     *
-     * @return the current thread factory
-     * @see #setThreadFactory
-     */
-    public ThreadFactory getThreadFactory() {
-        return threadFactory;
-    }
-
-    /**
-     * Sets a new handler for unexecutable tasks.
-     *
-     * @param handler the new handler
-     * @throws NullPointerException if handler is null
-     * @see #getRejectedExecutionHandler
-     */
-    public void setRejectedExecutionHandler(RejectedExecutionHandler handler) {
-        if (handler == null)
-            throw new NullPointerException();
-        this.handler = handler;
-    }
-
-    /**
-     * Returns the current handler for unexecutable tasks.
-     *
-     * @return the current handler
-     * @see #setRejectedExecutionHandler
-     */
-    public RejectedExecutionHandler getRejectedExecutionHandler() {
-        return handler;
-    }
-
-    /**
-     * Returns the task queue used by this executor. Access to the
-     * task queue is intended primarily for debugging and monitoring.
-     * This queue may be in active use.  Retrieving the task queue
-     * does not prevent queued tasks from executing.
-     *
-     * @return the task queue
-     */
-    public BlockingQueue<Runnable> getQueue() {
-        return workQueue;
-    }
-
-    /**
-     * Removes this task from the executor's internal queue if it is
-     * present, thus causing it not to be run if it has not already
-     * started.
-     * 
-     * <p> This method may be useful as one part of a cancellation
-     * scheme.  It may fail to remove tasks that have been converted
-     * into other forms before being placed on the internal queue. For
-     * example, a task entered using <tt>submit</tt> might be
-     * converted into a form that maintains <tt>Future</tt> status.
-     * However, in such cases, method {@link ThreadPoolExecutor#purge}
-     * may be used to remove those Futures that have been cancelled.
-     * 
-     *
-     * @param task the task to remove
-     * @return true if the task was removed
-     */
-    public boolean remove(Runnable task) {
-        return getQueue().remove(task);
-    }
-
-
-    /**
-     * Tries to remove from the work queue all {@link Future}
-     * tasks that have been cancelled. This method can be useful as a
-     * storage reclamation operation, that has no other impact on
-     * functionality. Cancelled tasks are never executed, but may
-     * accumulate in work queues until worker threads can actively
-     * remove them. Invoking this method instead tries to remove them now.
-     * However, this method may fail to remove tasks in
-     * the presence of interference by other threads.
-     */
-    public void purge() {
-        // Fail if we encounter interference during traversal
-        try {
-            Iterator<Runnable> it = getQueue().iterator();
-            while (it.hasNext()) {
-                Runnable r = it.next();
-                if (r instanceof Future<?>) {
-                    Future<?> c = (Future<?>)r;
-                    if (c.isCancelled())
-                        it.remove();
-                }
-            }
-        }
-        catch(ConcurrentModificationException ex) {
-            return; 
-        }
-    }
-
-    /**
-     * Sets the core number of threads.  This overrides any value set
-     * in the constructor.  If the new value is smaller than the
-     * current value, excess existing threads will be terminated when
-     * they next become idle. If larger, new threads will, if needed,
-     * be started to execute any queued tasks.
-     *
-     * @param corePoolSize the new core size
-     * @throws IllegalArgumentException if <tt>corePoolSize</tt>
-     * less than zero
-     * @see #getCorePoolSize
-     */
-    public void setCorePoolSize(int corePoolSize) {
-        if (corePoolSize < 0)
-            throw new IllegalArgumentException();
-        final ReentrantLock mainLock = this.mainLock;
-        mainLock.lock();
-        try {
-            int extra = this.corePoolSize - corePoolSize;
-            this.corePoolSize = corePoolSize;
-            if (extra < 0) {
-                Runnable r;
-                while (extra++ < 0 && poolSize < corePoolSize &&
-                       (r = workQueue.poll()) != null)
-                    addThread(r).start();
-            }
-            else if (extra > 0 && poolSize > corePoolSize) {
-                Iterator<Worker> it = workers.iterator();
-                while (it.hasNext() &&
-                       extra-- > 0 &&
-                       poolSize > corePoolSize &&
-                       workQueue.remainingCapacity() == 0) 
-                    it.next().interruptIfIdle();
-            }
-        } finally {
-            mainLock.unlock();
-        }
-    }
-
-    /**
-     * Returns the core number of threads.
-     *
-     * @return the core number of threads
-     * @see #setCorePoolSize
-     */
-    public int getCorePoolSize() {
-        return corePoolSize;
-    }
-
-    /**
-     * Starts a core thread, causing it to idly wait for work. This
-     * overrides the default policy of starting core threads only when
-     * new tasks are executed. This method will return <tt>false</tt>
-     * if all core threads have already been started.
-     * @return true if a thread was started
-     */ 
-    public boolean prestartCoreThread() {
-        return addIfUnderCorePoolSize(null);
-    }
-
-    /**
-     * Starts all core threads, causing them to idly wait for work. This
-     * overrides the default policy of starting core threads only when
-     * new tasks are executed. 
-     * @return the number of threads started.
-     */ 
-    public int prestartAllCoreThreads() {
-        int n = 0;
-        while (addIfUnderCorePoolSize(null))
-            ++n;
-        return n;
-    }
-
-    /**
-     * Sets the maximum allowed number of threads. This overrides any
-     * value set in the constructor. If the new value is smaller than
-     * the current value, excess existing threads will be
-     * terminated when they next become idle.
-     *
-     * @param maximumPoolSize the new maximum
-     * @throws IllegalArgumentException if maximumPoolSize less than zero or
-     * the {@link #getCorePoolSize core pool size}
-     * @see #getMaximumPoolSize
-     */
-    public void setMaximumPoolSize(int maximumPoolSize) {
-        if (maximumPoolSize <= 0 || maximumPoolSize < corePoolSize)
-            throw new IllegalArgumentException();
-        final ReentrantLock mainLock = this.mainLock;
-        mainLock.lock();
-        try {
-            int extra = this.maximumPoolSize - maximumPoolSize;
-            this.maximumPoolSize = maximumPoolSize;
-            if (extra > 0 && poolSize > maximumPoolSize) {
-                Iterator<Worker> it = workers.iterator();
-                while (it.hasNext() &&
-                       extra > 0 &&
-                       poolSize > maximumPoolSize) {
-                    it.next().interruptIfIdle();
-                    --extra;
-                }
-            }
-        } finally {
-            mainLock.unlock();
-        }
-    }
-
-    /**
-     * Returns the maximum allowed number of threads.
-     *
-     * @return the maximum allowed number of threads
-     * @see #setMaximumPoolSize
-     */
-    public int getMaximumPoolSize() {
-        return maximumPoolSize;
-    }
-
-    /**
-     * Sets the time limit for which threads may remain idle before
-     * being terminated.  If there are more than the core number of
-     * threads currently in the pool, after waiting this amount of
-     * time without processing a task, excess threads will be
-     * terminated.  This overrides any value set in the constructor.
-     * @param time the time to wait.  A time value of zero will cause
-     * excess threads to terminate immediately after executing tasks.
-     * @param unit  the time unit of the time argument
-     * @throws IllegalArgumentException if time less than zero
-     * @see #getKeepAliveTime
-     */
-    public void setKeepAliveTime(long time, TimeUnit unit) {
-        if (time < 0)
-            throw new IllegalArgumentException();
-        this.keepAliveTime = unit.toNanos(time);
-    }
-
-    /**
-     * Returns the thread keep-alive time, which is the amount of time
-     * which threads in excess of the core pool size may remain
-     * idle before being terminated.
-     *
-     * @param unit the desired time unit of the result
-     * @return the time limit
-     * @see #setKeepAliveTime
-     */
-    public long getKeepAliveTime(TimeUnit unit) {
-        return unit.convert(keepAliveTime, TimeUnit.NANOSECONDS);
-    }
-
-    /* Statistics */
-
-    /**
-     * Returns the current number of threads in the pool.
-     *
-     * @return the number of threads
-     */
-    public int getPoolSize() {
-        return poolSize;
-    }
-
-    /**
-     * Returns the approximate number of threads that are actively
-     * executing tasks.
-     *
-     * @return the number of threads
-     */
-    public int getActiveCount() {
-        final ReentrantLock mainLock = this.mainLock;
-        mainLock.lock();
-        try {
-            int n = 0;
-            for (Worker w : workers) {
-                if (w.isActive())
-                    ++n;
-            }
-            return n;
-        } finally {
-            mainLock.unlock();
-        }
-    }
-
-    /**
-     * Returns the largest number of threads that have ever
-     * simultaneously been in the pool.
-     *
-     * @return the number of threads
-     */
-    public int getLargestPoolSize() {
-        final ReentrantLock mainLock = this.mainLock;
-        mainLock.lock();
-        try {
-            return largestPoolSize;
-        } finally {
-            mainLock.unlock();
-        }
-    }
-
-    /**
-     * Returns the approximate total number of tasks that have been
-     * scheduled for execution. Because the states of tasks and
-     * threads may change dynamically during computation, the returned
-     * value is only an approximation, but one that does not ever
-     * decrease across successive calls.
-     *
-     * @return the number of tasks
-     */
-    public long getTaskCount() {
-        final ReentrantLock mainLock = this.mainLock;
-        mainLock.lock();
-        try {
-            long n = completedTaskCount;
-            for (Worker w : workers) {
-                n += w.completedTasks;
-                if (w.isActive())
-                    ++n;
-            }
-            return n + workQueue.size();
-        } finally {
-            mainLock.unlock();
-        }
-    }
-
-    /**
-     * Returns the approximate total number of tasks that have
-     * completed execution. Because the states of tasks and threads
-     * may change dynamically during computation, the returned value
-     * is only an approximation, but one that does not ever decrease
-     * across successive calls.
-     *
-     * @return the number of tasks
-     */
-    public long getCompletedTaskCount() {
-        final ReentrantLock mainLock = this.mainLock;
-        mainLock.lock();
-        try {
-            long n = completedTaskCount;
-            for (Worker w : workers)
-                n += w.completedTasks;
-            return n;
-        } finally {
-            mainLock.unlock();
-        }
-    }
-
-    /**
-     * Method invoked prior to executing the given Runnable in the
-     * given thread.  This method is invoked by thread <tt>t</tt> that
-     * will execute task <tt>r</tt>, and may be used to re-initialize
-     * ThreadLocals, or to perform logging. Note: To properly nest
-     * multiple overridings, subclasses should generally invoke
-     * <tt>super.beforeExecute</tt> at the end of this method.
-     *
-     * @param t the thread that will run task r.
-     * @param r the task that will be executed.
-     */
-    protected void beforeExecute(Thread t, Runnable r) { }
-
-    /**
-     * Method invoked upon completion of execution of the given
-     * Runnable.  This method is invoked by the thread that executed
-     * the task. If non-null, the Throwable is the uncaught exception
-     * that caused execution to terminate abruptly. Note: To properly
-     * nest multiple overridings, subclasses should generally invoke
-     * <tt>super.afterExecute</tt> at the beginning of this method.
-     *
-     * @param r the runnable that has completed.
-     * @param t the exception that caused termination, or null if
-     * execution completed normally.
-     */
-    protected void afterExecute(Runnable r, Throwable t) { }
-
-    /**
-     * Method invoked when the Executor has terminated.  Default
-     * implementation does nothing. Note: To properly nest multiple
-     * overridings, subclasses should generally invoke
-     * <tt>super.terminated</tt> within this method.
-     */
-    protected void terminated() { }
-
-    /**
-     * A handler for rejected tasks that runs the rejected task
-     * directly in the calling thread of the <tt>execute</tt> method,
-     * unless the executor has been shut down, in which case the task
-     * is discarded.
-     */
-   public static class CallerRunsPolicy implements RejectedExecutionHandler {
-        /**
-         * Creates a <tt>CallerRunsPolicy</tt>.
-         */
-        public CallerRunsPolicy() { }
-
-        /**
-         * Executes task r in the caller's thread, unless the executor
-         * has been shut down, in which case the task is discarded.
-         * @param r the runnable task requested to be executed
-         * @param e the executor attempting to execute this task
-         */
-        public void rejectedExecution(Runnable r, ThreadPoolExecutor e) {
-            if (!e.isShutdown()) {
-                r.run();
-            }
-        }
-    }
-
-    /**
-     * A handler for rejected tasks that throws a
-     * <tt>RejectedExecutionException</tt>.
-     */
-    public static class AbortPolicy implements RejectedExecutionHandler {
-        /**
-         * Creates an <tt>AbortPolicy</tt>.
-         */
-        public AbortPolicy() { }
-
-        /**
-         * Always throws RejectedExecutionException.
-         * @param r the runnable task requested to be executed
-         * @param e the executor attempting to execute this task
-         * @throws RejectedExecutionException always.
-         */
-        public void rejectedExecution(Runnable r, ThreadPoolExecutor e) {
-            throw new RejectedExecutionException();
-        }
-    }
-
-    /**
-     * A handler for rejected tasks that silently discards the
-     * rejected task.
-     */
-    public static class DiscardPolicy implements RejectedExecutionHandler {
-        /**
-         * Creates a <tt>DiscardPolicy</tt>.
-         */
-        public DiscardPolicy() { }
-
-        /**
-         * Does nothing, which has the effect of discarding task r.
-         * @param r the runnable task requested to be executed
-         * @param e the executor attempting to execute this task
-         */
-        public void rejectedExecution(Runnable r, ThreadPoolExecutor e) {
-        }
-    }
-
-    /**
-     * A handler for rejected tasks that discards the oldest unhandled
-     * request and then retries <tt>execute</tt>, unless the executor
-     * is shut down, in which case the task is discarded.
-     */
-    public static class DiscardOldestPolicy implements RejectedExecutionHandler {
-        /**
-         * Creates a <tt>DiscardOldestPolicy</tt> for the given executor.
-         */
-        public DiscardOldestPolicy() { }
-
-        /**
-         * Obtains and ignores the next task that the executor
-         * would otherwise execute, if one is immediately available,
-         * and then retries execution of task r, unless the executor
-         * is shut down, in which case task r is instead discarded.
-         * @param r the runnable task requested to be executed
-         * @param e the executor attempting to execute this task
-         */
-        public void rejectedExecution(Runnable r, ThreadPoolExecutor e) {
-            if (!e.isShutdown()) {
-                e.getQueue().poll();
-                e.execute(r);
-            }
-        }
-    }
-}
diff --git a/concurrent/src/main/java/java/util/concurrent/TimeUnit.java b/concurrent/src/main/java/java/util/concurrent/TimeUnit.java
deleted file mode 100644
index b186aeb..0000000
--- a/concurrent/src/main/java/java/util/concurrent/TimeUnit.java
+++ /dev/null
@@ -1,238 +0,0 @@
-/*
- * Written by Doug Lea with assistance from members of JCP JSR-166
- * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
- */
-
-package java.util.concurrent;
-
-/**
- * A <tt>TimeUnit</tt> represents time durations at a given unit of
- * granularity and provides utility methods to convert across units,
- * and to perform timing and delay operations in these units.  A
- * <tt>TimeUnit</tt> does not maintain time information, but only
- * helps organize and use time representations that may be maintained
- * separately across various contexts.
- *
- * <p>A <tt>TimeUnit</tt> is mainly used to inform time-based methods
- * how a given timing parameter should be interpreted. For example,
- * the following code will timeout in 50 milliseconds if the {@link
- * java.util.concurrent.locks.Lock lock} is not available:
- *
- * <pre>  Lock lock = ...;
- *  if ( lock.tryLock(50L, TimeUnit.MILLISECONDS) ) ...
- * </pre>
- * while this code will timeout in 50 seconds:
- * <pre>
- *  Lock lock = ...;
- *  if ( lock.tryLock(50L, TimeUnit.SECONDS) ) ...
- * </pre>
- *
- * Note however, that there is no guarantee that a particular timeout
- * implementation will be able to notice the passage of time at the
- * same granularity as the given <tt>TimeUnit</tt>.
- *
- * @since 1.5
- * @author Doug Lea
- */
-public enum TimeUnit {
-    /** TimeUnit which represents one nanosecond. */
-    NANOSECONDS(0), 
-    /** TimeUnit which represents one microsecond. */
-    MICROSECONDS(1), 
-    /** TimeUnit which represents one millisecond. */
-    MILLISECONDS(2), 
-    /** TimeUnit which represents one second. */
-    SECONDS(3);
-
-    /** the index of this unit */
-    private final int index;
-
-    /** Internal constructor */
-    TimeUnit(int index) { 
-        this.index = index; 
-    }
-
-    /** Lookup table for conversion factors */
-    private static final int[] multipliers = { 
-        1, 
-        1000, 
-        1000 * 1000, 
-        1000 * 1000 * 1000 
-    };
-    
-    /** 
-     * Lookup table to check saturation.  Note that because we are
-     * dividing these down, we don't have to deal with asymmetry of
-     * MIN/MAX values.
-     */
-    private static final long[] overflows = { 
-        0, // unused
-        Long.MAX_VALUE / 1000,
-        Long.MAX_VALUE / (1000 * 1000),
-        Long.MAX_VALUE / (1000 * 1000 * 1000) 
-    };
-
-    /**
-     * Perform conversion based on given delta representing the
-     * difference between units
-     * @param delta the difference in index values of source and target units
-     * @param duration the duration
-     * @return converted duration or saturated value
-     */
-    private static long doConvert(int delta, long duration) {
-        if (delta == 0)
-            return duration;
-        if (delta < 0) 
-            return duration / multipliers[-delta];
-        if (duration > overflows[delta])
-            return Long.MAX_VALUE;
-        if (duration < -overflows[delta])
-            return Long.MIN_VALUE;
-        return duration * multipliers[delta];
-    }
-
-    /**
-     * Convert the given time duration in the given unit to this
-     * unit.  Conversions from finer to coarser granularities
-     * truncate, so lose precision. For example converting
-     * <tt>999</tt> milliseconds to seconds results in
-     * <tt>0</tt>. Conversions from coarser to finer granularities
-     * with arguments that would numerically overflow saturate to
-     * <tt>Long.MIN_VALUE</tt> if negative or <tt>Long.MAX_VALUE</tt>
-     * if positive.
-     *
-     * @param duration the time duration in the given <tt>unit</tt>
-     * @param unit the unit of the <tt>duration</tt> argument
-     * @return the converted duration in this unit,
-     * or <tt>Long.MIN_VALUE</tt> if conversion would negatively
-     * overflow, or <tt>Long.MAX_VALUE</tt> if it would positively overflow.
-     */
-    public long convert(long duration, TimeUnit unit) {
-        return doConvert(unit.index - index, duration);
-    }
-
-    /**
-     * Equivalent to <tt>NANOSECONDS.convert(duration, this)</tt>.
-     * @param duration the duration
-     * @return the converted duration,
-     * or <tt>Long.MIN_VALUE</tt> if conversion would negatively
-     * overflow, or <tt>Long.MAX_VALUE</tt> if it would positively overflow.
-     * @see #convert
-     */
-    public long toNanos(long duration) {
-        return doConvert(index, duration);
-    }
-
-    /**
-     * Equivalent to <tt>MICROSECONDS.convert(duration, this)</tt>.
-     * @param duration the duration
-     * @return the converted duration,
-     * or <tt>Long.MIN_VALUE</tt> if conversion would negatively
-     * overflow, or <tt>Long.MAX_VALUE</tt> if it would positively overflow.
-     * @see #convert
-     */
-    public long toMicros(long duration) {
-        return doConvert(index - MICROSECONDS.index, duration);
-    }
-
-    /**
-     * Equivalent to <tt>MILLISECONDS.convert(duration, this)</tt>.
-     * @param duration the duration
-     * @return the converted duration,
-     * or <tt>Long.MIN_VALUE</tt> if conversion would negatively
-     * overflow, or <tt>Long.MAX_VALUE</tt> if it would positively overflow.
-     * @see #convert
-     */
-    public long toMillis(long duration) {
-        return doConvert(index - MILLISECONDS.index, duration);
-    }
-
-    /**
-     * Equivalent to <tt>SECONDS.convert(duration, this)</tt>.
-     * @param duration the duration
-     * @return the converted duration.
-     * @see #convert
-     */
-    public long toSeconds(long duration) {
-        return doConvert(index - SECONDS.index, duration);
-    }
-
-
-    /**
-     * Utility method to compute the excess-nanosecond argument to
-     * wait, sleep, join.
-     */
-    private int excessNanos(long time, long ms) {
-        if (this == NANOSECONDS)
-            return (int) (time  - (ms * 1000 * 1000));
-        if (this == MICROSECONDS)
-            return (int) ((time * 1000) - (ms * 1000 * 1000));
-        return 0;
-    }
-
-    /**
-     * Perform a timed <tt>Object.wait</tt> using this time unit.
-     * This is a convenience method that converts timeout arguments
-     * into the form required by the <tt>Object.wait</tt> method.
-     *
-     * <p>For example, you could implement a blocking <tt>poll</tt>
-     * method (see {@link BlockingQueue#poll BlockingQueue.poll})
-     * using:
-     *
-     * <pre>  public synchronized  Object poll(long timeout, TimeUnit unit) throws InterruptedException {
-     *    while (empty) {
-     *      unit.timedWait(this, timeout);
-     *      ...
-     *    }
-     *  }</pre>
-     *
-     * @param obj the object to wait on
-     * @param timeout the maximum time to wait. 
-     * @throws InterruptedException if interrupted while waiting.
-     * @see Object#wait(long, int)
-     */
-    public void timedWait(Object obj, long timeout)
-        throws InterruptedException {
-        if (timeout > 0) {
-            long ms = toMillis(timeout);
-            int ns = excessNanos(timeout, ms);
-            obj.wait(ms, ns);
-        }
-    }
-
-    /**
-     * Perform a timed <tt>Thread.join</tt> using this time unit.
-     * This is a convenience method that converts time arguments into the
-     * form required by the <tt>Thread.join</tt> method.
-     * @param thread the thread to wait for
-     * @param timeout the maximum time to wait
-     * @throws InterruptedException if interrupted while waiting.
-     * @see Thread#join(long, int)
-     */
-    public void timedJoin(Thread thread, long timeout)
-        throws InterruptedException {
-        if (timeout > 0) {
-            long ms = toMillis(timeout);
-            int ns = excessNanos(timeout, ms);
-            thread.join(ms, ns);
-        }
-    }
-
-    /**
-     * Perform a <tt>Thread.sleep</tt> using this unit.
-     * This is a convenience method that converts time arguments into the
-     * form required by the <tt>Thread.sleep</tt> method.
-     * @param timeout the minimum time to sleep
-     * @throws InterruptedException if interrupted while sleeping.
-     * @see Thread#sleep
-     */
-    public void sleep(long timeout) throws InterruptedException {
-        if (timeout > 0) {
-            long ms = toMillis(timeout);
-            int ns = excessNanos(timeout, ms);
-            Thread.sleep(ms, ns);
-        }
-    }
-
-}
diff --git a/concurrent/src/main/java/java/util/concurrent/TimeoutException.java b/concurrent/src/main/java/java/util/concurrent/TimeoutException.java
deleted file mode 100644
index 8b84f28..0000000
--- a/concurrent/src/main/java/java/util/concurrent/TimeoutException.java
+++ /dev/null
@@ -1,38 +0,0 @@
-/*
- * Written by Doug Lea with assistance from members of JCP JSR-166
- * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
- */
-
-package java.util.concurrent;
-
-/**
- * Exception thrown when a blocking operation times out.  Blocking
- * operations for which a timeout is specified need a means to
- * indicate that the timeout has occurred. For many such operations it
- * is possible to return a value that indicates timeout; when that is
- * not possible or desirable then <tt>TimeoutException</tt> should be
- * declared and thrown.
- *
- * @since 1.5
- * @author Doug Lea
- */
-public class TimeoutException extends Exception {
-    private static final long serialVersionUID = 1900926677490660714L;
-
-    /**
-     * Constructs a <tt>TimeoutException</tt> with no specified detail
-     * message.
-     */
-    public TimeoutException() {}
-
-    /**
-     * Constructs a <tt>TimeoutException</tt> with the specified detail
-     * message.
-     *
-     * @param message the detail message
-     */
-    public TimeoutException(String message) {
-        super(message);
-    }
-}
diff --git a/concurrent/src/main/java/java/util/concurrent/atomic/AtomicBoolean.java b/concurrent/src/main/java/java/util/concurrent/atomic/AtomicBoolean.java
deleted file mode 100644
index fdd3d49..0000000
--- a/concurrent/src/main/java/java/util/concurrent/atomic/AtomicBoolean.java
+++ /dev/null
@@ -1,126 +0,0 @@
-/*
- * Written by Doug Lea with assistance from members of JCP JSR-166
- * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
- */
-
-package java.util.concurrent.atomic;
-import sun.misc.Unsafe;
-
-/**
- * A <tt>boolean</tt> value that may be updated atomically. See the
- * {@link java.util.concurrent.atomic} package specification for
- * description of the properties of atomic variables. An
- * <tt>AtomicBoolean</tt> is used in applications such as atomically
- * updated flags, and cannot be used as a replacement for a
- * {@link java.lang.Boolean}.
- *
- * @since 1.5
- * @author Doug Lea
- */
-public class AtomicBoolean implements java.io.Serializable {
-    private static final long serialVersionUID = 4654671469794556979L;
-    // setup to use Unsafe.compareAndSwapInt for updates
-    // BEGIN android-changed
-    private static final Unsafe unsafe = UnsafeAccess.THE_ONE;
-    // END android-changed
-
-    private static final long valueOffset;
-
-    static {
-      try {
-        valueOffset = unsafe.objectFieldOffset
-            (AtomicBoolean.class.getDeclaredField("value"));
-      } catch (Exception ex) { throw new Error(ex); }
-    }
-
-    private volatile int value;
-
-    /**
-     * Creates a new <tt>AtomicBoolean</tt> with the given initial value.
-     *
-     * @param initialValue the initial value
-     */
-    public AtomicBoolean(boolean initialValue) {
-        value = initialValue ? 1 : 0;
-    }
-
-    /**
-     * Creates a new <tt>AtomicBoolean</tt> with initial value <tt>false</tt>.
-     */
-    public AtomicBoolean() {
-    }
-
-    /**
-     * Returns the current value.
-     *
-     * @return the current value
-     */
-    public final boolean get() {
-        return value != 0;
-    }
-
-    /**
-     * Atomically sets the value to the given update value if the
-     * current value is equal to the expected value.  Any given
-     * invocation of this operation may fail (return
-     * <tt>false</tt>) spuriously, but repeated invocation when
-     * the current value holds the expected value and no other thread
-     * is also attempting to set the value will eventually succeed.
-     *
-     * @param expect the expected value
-     * @param update the new value
-     * @return true if successful
-     */
-    public final boolean compareAndSet(boolean expect, boolean update) {
-        int e = expect ? 1 : 0;
-        int u = update ? 1 : 0;
-        return unsafe.compareAndSwapInt(this, valueOffset, e, u);
-    }
-
-    /**
-     * Atomically set the value to the given updated value
-     * if the current value <tt>==</tt> the expected value.
-     * May fail spuriously.
-     * @param expect the expected value
-     * @param update the new value
-     * @return true if successful.
-     */
-    public boolean weakCompareAndSet(boolean expect, boolean update) {
-        int e = expect ? 1 : 0;
-        int u = update ? 1 : 0;
-        return unsafe.compareAndSwapInt(this, valueOffset, e, u);
-    }
-
-    /**
-     * Unconditionally sets to the given value.
-     *
-     * @param newValue the new value
-     */
-    public final void set(boolean newValue) {
-        value = newValue ? 1 : 0;
-    }
-
-    /**
-     * Sets to the given value and returns the previous value.
-     *
-     * @param newValue the new value
-     * @return the previous value
-     */
-    public final boolean getAndSet(boolean newValue) {
-        for (;;) {
-            boolean current = get();
-            if (compareAndSet(current, newValue))
-                return current;
-        }
-    }
-
-    /**
-     * Returns the String representation of the current value.
-     * @return the String representation of the current value.
-     */
-    public String toString() {
-        return Boolean.toString(get());
-    }
-
-}
diff --git a/concurrent/src/main/java/java/util/concurrent/atomic/AtomicInteger.java b/concurrent/src/main/java/java/util/concurrent/atomic/AtomicInteger.java
deleted file mode 100644
index 2b9d15c..0000000
--- a/concurrent/src/main/java/java/util/concurrent/atomic/AtomicInteger.java
+++ /dev/null
@@ -1,223 +0,0 @@
-/*
- * Written by Doug Lea with assistance from members of JCP JSR-166
- * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
- */
-
-package java.util.concurrent.atomic;
-import sun.misc.Unsafe;
-
-/**
- * An <tt>int</tt> value that may be updated atomically. See the
- * {@link java.util.concurrent.atomic} package specification for
- * description of the properties of atomic variables. An
- * <tt>AtomicInteger</tt> is used in applications such as atomically
- * incremented counters, and cannot be used as a replacement for an
- * {@link java.lang.Integer}. However, this class does extend
- * <tt>Number</tt> to allow uniform access by tools and utilities that
- * deal with numerically-based classes.
- * 
- *
- * @since 1.5
- * @author Doug Lea
-*/
-public class AtomicInteger extends Number implements java.io.Serializable { 
-    private static final long serialVersionUID = 6214790243416807050L;
-
-    // setup to use Unsafe.compareAndSwapInt for updates
-    // BEGIN android-changed
-    private static final Unsafe unsafe = UnsafeAccess.THE_ONE;
-    // END android-changed
-    private static final long valueOffset;
-
-    static {
-      try {
-        valueOffset = unsafe.objectFieldOffset
-            (AtomicInteger.class.getDeclaredField("value"));
-      } catch(Exception ex) { throw new Error(ex); }
-    }
-
-    private volatile int value;
-
-    /**
-     * Create a new AtomicInteger with the given initial value.
-     *
-     * @param initialValue the initial value
-     */
-    public AtomicInteger(int initialValue) {
-        value = initialValue;
-    }
-
-    /**
-     * Create a new AtomicInteger with initial value <tt>0</tt>.
-     */
-    public AtomicInteger() {
-    }
-
-    /**
-     * Get the current value.
-     *
-     * @return the current value
-     */
-    public final int get() {
-        return value;
-    }
-  
-    /**
-     * Set to the given value.
-     *
-     * @param newValue the new value
-     */
-    public final void set(int newValue) {
-        value = newValue;
-    }
-
-    /**
-     * Set to the give value and return the old value.
-     *
-     * @param newValue the new value
-     * @return the previous value
-     */
-    public final int getAndSet(int newValue) {
-        for (;;) {
-            int current = get();
-            if (compareAndSet(current, newValue))
-                return current;
-        }
-    }
-  
-  
-    /**
-     * Atomically set the value to the given updated value
-     * if the current value <tt>==</tt> the expected value.
-     * @param expect the expected value
-     * @param update the new value
-     * @return true if successful. False return indicates that
-     * the actual value was not equal to the expected value.
-     */
-    public final boolean compareAndSet(int expect, int update) {
-      return unsafe.compareAndSwapInt(this, valueOffset, expect, update);
-    }
-
-    /**
-     * Atomically set the value to the given updated value
-     * if the current value <tt>==</tt> the expected value.
-     * May fail spuriously.
-     * @param expect the expected value
-     * @param update the new value
-     * @return true if successful.
-     */
-    public final boolean weakCompareAndSet(int expect, int update) {
-      return unsafe.compareAndSwapInt(this, valueOffset, expect, update);
-    }
-
-
-    /**
-     * Atomically increment by one the current value.
-     * @return the previous value
-     */
-    public final int getAndIncrement() {
-        for (;;) {
-            int current = get();
-            int next = current + 1;
-            if (compareAndSet(current, next))
-                return current;
-        }
-    }
-  
-  
-    /**
-     * Atomically decrement by one the current value.
-     * @return the previous value
-     */
-    public final int getAndDecrement() {
-        for (;;) {
-            int current = get();
-            int next = current - 1;
-            if (compareAndSet(current, next))
-                return current;
-        }
-    }
-  
-  
-    /**
-     * Atomically add the given value to current value.
-     * @param delta the value to add
-     * @return the previous value
-     */
-    public final int getAndAdd(int delta) {
-        for (;;) {
-            int current = get();
-            int next = current + delta;
-            if (compareAndSet(current, next))
-                return current;
-        }
-    }
-
-    /**
-     * Atomically increment by one the current value.
-     * @return the updated value
-     */
-    public final int incrementAndGet() {
-        for (;;) {
-            int current = get();
-            int next = current + 1;
-            if (compareAndSet(current, next))
-                return next;
-        }
-    }
-    
-    /**
-     * Atomically decrement by one the current value.
-     * @return the updated value
-     */
-    public final int decrementAndGet() {
-        for (;;) {
-            int current = get();
-            int next = current - 1;
-            if (compareAndSet(current, next))
-                return next;
-        }
-    }
-  
-  
-    /**
-     * Atomically add the given value to current value.
-     * @param delta the value to add
-     * @return the updated value
-     */
-    public final int addAndGet(int delta) {
-        for (;;) {
-            int current = get();
-            int next = current + delta;
-            if (compareAndSet(current, next))
-                return next;
-        }
-    }
-
-    /**
-     * Returns the String representation of the current value.
-     * @return the String representation of the current value.
-     */
-    public String toString() {
-        return Integer.toString(get());
-    }
-
-
-    public int intValue() {
-        return get();
-    }
-
-    public long longValue() {
-        return (long)get();
-    }
-
-    public float floatValue() {
-        return (float)get();
-    }
-
-    public double doubleValue() {
-        return (double)get();
-    }
-
-}
diff --git a/concurrent/src/main/java/java/util/concurrent/atomic/AtomicIntegerArray.java b/concurrent/src/main/java/java/util/concurrent/atomic/AtomicIntegerArray.java
deleted file mode 100644
index 95807f3..0000000
--- a/concurrent/src/main/java/java/util/concurrent/atomic/AtomicIntegerArray.java
+++ /dev/null
@@ -1,245 +0,0 @@
-/*
- * Written by Doug Lea with assistance from members of JCP JSR-166
- * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
- */
-
-package java.util.concurrent.atomic;
-import sun.misc.Unsafe;
-import java.util.*;
-
-/**
- * An <tt>int</tt> array in which elements may be updated atomically.
- * See the {@link java.util.concurrent.atomic} package
- * specification for description of the properties of atomic
- * variables.
- * @since 1.5
- * @author Doug Lea
- */
-public class AtomicIntegerArray implements java.io.Serializable { 
-    private static final long serialVersionUID = 2862133569453604235L;
-
-   // setup to use Unsafe.compareAndSwapInt for updates
-    // BEGIN android-changed
-    private static final Unsafe unsafe = UnsafeAccess.THE_ONE;
-    // END android-changed
-    private static final int base = unsafe.arrayBaseOffset(int[].class);
-    private static final int scale = unsafe.arrayIndexScale(int[].class);
-    private final int[] array;
-
-    private long rawIndex(int i) {
-        if (i < 0 || i >= array.length)
-            throw new IndexOutOfBoundsException("index " + i);
-        return base + i * scale;
-    }
-
-    /**
-     * Create a new AtomicIntegerArray of given length.
-     *
-     * @param length the length of the array
-     */
-    public AtomicIntegerArray(int length) {
-        array = new int[length];
-        // must perform at least one volatile write to conform to JMM
-        if (length > 0)
-            unsafe.putIntVolatile(array, rawIndex(0), 0);
-    }
-
-    /**
-     * Create a new AtomicIntegerArray with the same length as, and
-     * all elements copied from, the given array.
-     *
-     * @param array the array to copy elements from
-     * @throws NullPointerException if array is null
-     */
-    public AtomicIntegerArray(int[] array) {
-        if (array == null) 
-            throw new NullPointerException();
-        int length = array.length;
-        this.array = new int[length];
-        if (length > 0) {
-            int last = length-1;
-            for (int i = 0; i < last; ++i)
-                this.array[i] = array[i];
-            // Do the last write as volatile
-            unsafe.putIntVolatile(this.array, rawIndex(last), array[last]);
-        }
-    }
-
-    /**
-     * Returns the length of the array.
-     *
-     * @return the length of the array
-     */
-    public final int length() {
-        return array.length;
-    }
-
-    /**
-     * Get the current value at position <tt>i</tt>.
-     *
-     * @param i the index
-     * @return the current value
-     */
-    public final int get(int i) {
-        return unsafe.getIntVolatile(array, rawIndex(i));
-    }
- 
-    /**
-     * Set the element at position <tt>i</tt> to the given value.
-     *
-     * @param i the index
-     * @param newValue the new value
-     */
-    public final void set(int i, int newValue) {
-        unsafe.putIntVolatile(array, rawIndex(i), newValue);
-    }
-  
-    /**
-     * Set the element at position <tt>i</tt> to the given value and return the
-     * old value.
-     *
-     * @param i the index
-     * @param newValue the new value
-     * @return the previous value
-     */
-    public final int getAndSet(int i, int newValue) {
-        while (true) {
-            int current = get(i);
-            if (compareAndSet(i, current, newValue))
-                return current;
-        }
-    }
-  
-    /**
-     * Atomically set the value to the given updated value
-     * if the current value <tt>==</tt> the expected value.
-     *
-     * @param i the index
-     * @param expect the expected value
-     * @param update the new value
-     * @return true if successful. False return indicates that
-     * the actual value was not equal to the expected value.
-     */
-    public final boolean compareAndSet(int i, int expect, int update) {
-        return unsafe.compareAndSwapInt(array, rawIndex(i), 
-                                        expect, update);
-    }
-
-    /**
-     * Atomically set the value to the given updated value
-     * if the current value <tt>==</tt> the expected value.
-     * May fail spuriously.
-     *
-     * @param i the index
-     * @param expect the expected value
-     * @param update the new value
-     * @return true if successful.
-     */
-    public final boolean weakCompareAndSet(int i, int expect, int update) {
-        return compareAndSet(i, expect, update);
-    }
-
-    /**
-     * Atomically increment by one the element at index <tt>i</tt>.
-     *
-     * @param i the index
-     * @return the previous value;
-     */
-    public final int getAndIncrement(int i) {
-        while (true) {
-            int current = get(i);
-            int next = current + 1;
-            if (compareAndSet(i, current, next))
-                return current;
-        }
-    }
-  
-    /**
-     * Atomically decrement by one the element at index <tt>i</tt>.
-     *
-     * @param i the index
-     * @return the previous value;
-     */
-    public final int getAndDecrement(int i) {
-        while (true) {
-            int current = get(i);
-            int next = current - 1;
-            if (compareAndSet(i, current, next))
-                return current;
-        }
-    }
-  
-    /**
-     * Atomically add the given value to element at index <tt>i</tt>.
-     *
-     * @param i the index
-     * @param delta the value to add
-     * @return the previous value;
-     */
-    public final int getAndAdd(int i, int delta) {
-        while (true) {
-            int current = get(i);
-            int next = current + delta;
-            if (compareAndSet(i, current, next))
-                return current;
-        }
-    }
-
-    /**
-     * Atomically increment by one the element at index <tt>i</tt>.
-     *
-     * @param i the index
-     * @return the updated value;
-     */
-    public final int incrementAndGet(int i) {
-        while (true) {
-            int current = get(i);
-            int next = current + 1;
-            if (compareAndSet(i, current, next))
-                return next;
-        }
-    }
-  
-    /**
-     * Atomically decrement by one the element at index <tt>i</tt>.
-     *
-     * @param i the index
-     * @return the updated value;
-     */
-    public final int decrementAndGet(int i) {
-        while (true) {
-            int current = get(i);
-            int next = current - 1;
-            if (compareAndSet(i, current, next))
-                return next;
-        }
-    }
-  
-    /**
-     * Atomically add the given value to element at index <tt>i</tt>.
-     *
-     * @param i the index
-     * @param delta the value to add
-     * @return the updated value;
-     */
-    public final int addAndGet(int i, int delta) {
-        while (true) {
-            int current = get(i);
-            int next = current + delta;
-            if (compareAndSet(i, current, next))
-                return next;
-        }
-    }
- 
-    /**
-     * Returns the String representation of the current values of array.
-     * @return the String representation of the current values of array.
-     */
-    public String toString() {
-        if (array.length > 0) // force volatile read
-            get(0);
-        return Arrays.toString(array);
-    }
-
-}
diff --git a/concurrent/src/main/java/java/util/concurrent/atomic/AtomicIntegerFieldUpdater.java b/concurrent/src/main/java/java/util/concurrent/atomic/AtomicIntegerFieldUpdater.java
deleted file mode 100644
index 5f289c2..0000000
--- a/concurrent/src/main/java/java/util/concurrent/atomic/AtomicIntegerFieldUpdater.java
+++ /dev/null
@@ -1,260 +0,0 @@
-/*
- * Written by Doug Lea with assistance from members of JCP JSR-166
- * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
- */
-
-package java.util.concurrent.atomic;
-import sun.misc.Unsafe;
-import java.lang.reflect.*;
-
-/**
- * A reflection-based utility that enables atomic updates to
- * designated <tt>volatile int</tt> fields of designated classes.
- * This class is designed for use in atomic data structures in which
- * several fields of the same node are independently subject to atomic
- * updates.
- *
- * <p> Note that the guarantees of the <tt>compareAndSet</tt> method
- * in this class are weaker than in other atomic classes. Because this
- * class cannot ensure that all uses of the field are appropriate for
- * purposes of atomic access, it can guarantee atomicity and volatile
- * semantics only with respect to other invocations of
- * <tt>compareAndSet</tt> and <tt>set</tt>.
- * @since 1.5
- * @author Doug Lea
- * @param <T> The type of the object holding the updatable field
- */
-public abstract class  AtomicIntegerFieldUpdater<T>  {
-    /**
-     * Creates an updater for objects with the given field.  The Class
-     * argument is needed to check that reflective types and generic
-     * types match.
-     * @param tclass the class of the objects holding the field
-     * @param fieldName the name of the field to be updated.
-     * @return the updater
-     * @throws IllegalArgumentException if the field is not a
-     * volatile integer type.
-     * @throws RuntimeException with a nested reflection-based
-     * exception if the class does not hold field or is the wrong type.
-     */
-    public static <U> AtomicIntegerFieldUpdater<U> newUpdater(Class<U> tclass, String fieldName) {
-        return new AtomicIntegerFieldUpdaterImpl<U>(tclass, fieldName);
-    }
-
-    /**
-     * Protected do-nothing constructor for use by subclasses.
-     */
-    protected AtomicIntegerFieldUpdater() {
-    }
-
-    /**
-     * Atomically set the value of the field of the given object managed
-     * by this Updater to the given updated value if the current value
-     * <tt>==</tt> the expected value. This method is guaranteed to be
-     * atomic with respect to other calls to <tt>compareAndSet</tt> and
-     * <tt>set</tt>, but not necessarily with respect to other
-     * changes in the field.
-     * @param obj An object whose field to conditionally set
-     * @param expect the expected value
-     * @param update the new value
-     * @return true if successful.
-     * @throws ClassCastException if <tt>obj</tt> is not an instance
-     * of the class possessing the field established in the constructor.
-     */
-
-    public abstract boolean compareAndSet(T obj, int expect, int update);
-
-    /**
-     * Atomically set the value of the field of the given object managed
-     * by this Updater to the given updated value if the current value
-     * <tt>==</tt> the expected value. This method is guaranteed to be
-     * atomic with respect to other calls to <tt>compareAndSet</tt> and
-     * <tt>set</tt>, but not necessarily with respect to other
-     * changes in the field, and may fail spuriously.
-     * @param obj An object whose field to conditionally set
-     * @param expect the expected value
-     * @param update the new value
-     * @return true if successful.
-     * @throws ClassCastException if <tt>obj</tt> is not an instance
-     * of the class possessing the field established in the constructor.
-     */
-
-    public abstract boolean weakCompareAndSet(T obj, int expect, int update);
-
-    /**
-     * Set the field of the given object managed by this updater. This
-     * operation is guaranteed to act as a volatile store with respect
-     * to subsequent invocations of <tt>compareAndSet</tt>.
-     * @param obj An object whose field to set
-     * @param newValue the new value
-     */
-    public abstract void set(T obj, int newValue);
-
-    /**
-     * Get the current value held in the field by the given object.
-     * @param obj An object whose field to get
-     * @return the current value
-     */
-    public abstract int get(T obj);
-
-    /**
-     * Set to the given value and return the old value.
-     *
-     * @param obj An object whose field to get and set
-     * @param newValue the new value
-     * @return the previous value
-     */
-    public int getAndSet(T obj, int newValue) {
-        for (;;) {
-            int current = get(obj);
-            if (compareAndSet(obj, current, newValue))
-                return current;
-        }
-    }
-
-    /**
-     * Atomically increment by one the current value.
-     * @param obj An object whose field to get and set
-     * @return the previous value;
-     */
-    public int getAndIncrement(T obj) {
-        for (;;) {
-            int current = get(obj);
-            int next = current + 1;
-            if (compareAndSet(obj, current, next))
-                return current;
-        }
-    }
-
-
-    /**
-     * Atomically decrement by one the current value.
-     * @param obj An object whose field to get and set
-     * @return the previous value;
-     */
-    public int getAndDecrement(T obj) {
-        for (;;) {
-            int current = get(obj);
-            int next = current - 1;
-            if (compareAndSet(obj, current, next))
-                return current;
-        }
-    }
-
-
-    /**
-     * Atomically add the given value to current value.
-     * @param obj An object whose field to get and set
-     * @param delta the value to add
-     * @return the previous value;
-     */
-    public int getAndAdd(T obj, int delta) {
-        for (;;) {
-            int current = get(obj);
-            int next = current + delta;
-            if (compareAndSet(obj, current, next))
-                return current;
-        }
-    }
-
-    /**
-     * Atomically increment by one the current value.
-     * @param obj An object whose field to get and set
-     * @return the updated value;
-     */
-    public int incrementAndGet(T obj) {
-        for (;;) {
-            int current = get(obj);
-            int next = current + 1;
-            if (compareAndSet(obj, current, next))
-                return next;
-        }
-    }
-
-
-    /**
-     * Atomically decrement by one the current value.
-     * @param obj An object whose field to get and set
-     * @return the updated value;
-     */
-    public int decrementAndGet(T obj) {
-        for (;;) {
-            int current = get(obj);
-            int next = current - 1;
-            if (compareAndSet(obj, current, next))
-                return next;
-        }
-    }
-
-
-    /**
-     * Atomically add the given value to current value.
-     * @param obj An object whose field to get and set
-     * @param delta the value to add
-     * @return the updated value;
-     */
-    public int addAndGet(T obj, int delta) {
-        for (;;) {
-            int current = get(obj);
-            int next = current + delta;
-            if (compareAndSet(obj, current, next))
-                return next;
-        }
-    }
-
-    /**
-     * Standard hotspot implementation using intrinsics
-     */
-    private static class AtomicIntegerFieldUpdaterImpl<T> extends AtomicIntegerFieldUpdater<T> {
-        // BEGIN android-changed
-        private static final Unsafe unsafe = UnsafeAccess.THE_ONE;
-        // END android-changed
-        private final long offset;
-        private final Class<T> tclass;
-
-        AtomicIntegerFieldUpdaterImpl(Class<T> tclass, String fieldName) {
-            Field field = null;
-            try {
-                field = tclass.getDeclaredField(fieldName);
-            } catch(Exception ex) {
-                throw new RuntimeException(ex);
-            }
-            
-            Class fieldt = field.getType();
-            if (fieldt != int.class)
-                throw new IllegalArgumentException("Must be integer type");
-            
-            if (!Modifier.isVolatile(field.getModifiers()))
-                throw new IllegalArgumentException("Must be volatile type");
-         
-            this.tclass = tclass;
-            offset = unsafe.objectFieldOffset(field);
-        }
-
-        public boolean compareAndSet(T obj, int expect, int update) {
-            if (!tclass.isInstance(obj))
-                throw new ClassCastException();
-            return unsafe.compareAndSwapInt(obj, offset, expect, update);
-        }
-
-        public boolean weakCompareAndSet(T obj, int expect, int update) {
-            if (!tclass.isInstance(obj))
-                throw new ClassCastException();
-            return unsafe.compareAndSwapInt(obj, offset, expect, update);
-        }
-
-        public void set(T obj, int newValue) {
-            if (!tclass.isInstance(obj))
-                throw new ClassCastException();
-            unsafe.putIntVolatile(obj, offset, newValue);
-        }
-
-        public final int get(T obj) {
-            if (!tclass.isInstance(obj))
-                throw new ClassCastException();
-            return unsafe.getIntVolatile(obj, offset);
-        }
-    }
-}
-
diff --git a/concurrent/src/main/java/java/util/concurrent/atomic/AtomicLong.java b/concurrent/src/main/java/java/util/concurrent/atomic/AtomicLong.java
deleted file mode 100644
index 7f41364..0000000
--- a/concurrent/src/main/java/java/util/concurrent/atomic/AtomicLong.java
+++ /dev/null
@@ -1,234 +0,0 @@
-/*
- * Written by Doug Lea with assistance from members of JCP JSR-166
- * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
- */
-
-package java.util.concurrent.atomic;
-import sun.misc.Unsafe;
-
-/**
- * A <tt>long</tt> value that may be updated atomically.  See the
- * {@link java.util.concurrent.atomic} package specification for
- * description of the properties of atomic variables. An
- * <tt>AtomicLong</tt> is used in applications such as atomically
- * incremented sequence numbers, and cannot be used as a replacement
- * for a {@link java.lang.Long}. However, this class does extend
- * <tt>Number</tt> to allow uniform access by tools and utilities that
- * deal with numerically-based classes.
- *
- * @since 1.5
- * @author Doug Lea
- */
-public class AtomicLong extends Number implements java.io.Serializable { 
-    private static final long serialVersionUID = 1927816293512124184L;
-
-    // setup to use Unsafe.compareAndSwapLong for updates
-    // BEGIN android-changed
-    private static final Unsafe unsafe = UnsafeAccess.THE_ONE;
-    // END android-changed
-    private static final long valueOffset;
-
-    /**
-     * Record whether the underlying JVM supports lockless
-     * CompareAndSet for longs. While the unsafe.CompareAndSetLong
-     * method works in either case, some constructions should be
-     * handled at Java level to avoid locking user-visible locks.
-     */
-    static final boolean VM_SUPPORTS_LONG_CAS = VMSupportsCS8();
-
-    /**
-     * Returns whether underlying JVM supports lockless CompareAndSet
-     * for longs. Called only once and cached in VM_SUPPORTS_LONG_CAS.
-     */
-    private static native boolean VMSupportsCS8();
-
-    static {
-      try {
-        valueOffset = unsafe.objectFieldOffset
-            (AtomicLong.class.getDeclaredField("value"));
-      } catch(Exception ex) { throw new Error(ex); }
-    }
-
-    private volatile long value;
-
-    /**
-     * Create a new AtomicLong with the given initial value.
-     *
-     * @param initialValue the initial value
-     */
-    public AtomicLong(long initialValue) {
-        value = initialValue;
-    }
-
-    /**
-     * Create a new AtomicLong with initial value <tt>0</tt>.
-     */
-    public AtomicLong() {
-    }
-  
-    /**
-     * Get the current value.
-     *
-     * @return the current value
-     */
-    public final long get() {
-        return value;
-    }
- 
-    /**
-     * Set to the given value.
-     *
-     * @param newValue the new value
-     */
-    public final void set(long newValue) {
-        value = newValue;
-    }
-  
-    /**
-     * Set to the give value and return the old value.
-     *
-     * @param newValue the new value
-     * @return the previous value
-     */
-    public final long getAndSet(long newValue) {
-        while (true) {
-            long current = get();
-            if (compareAndSet(current, newValue))
-                return current;
-        }
-    }
-  
-    /**
-     * Atomically set the value to the given updated value
-     * if the current value <tt>==</tt> the expected value.
-     * @param expect the expected value
-     * @param update the new value
-     * @return true if successful. False return indicates that
-     * the actual value was not equal to the expected value.
-     */
-    public final boolean compareAndSet(long expect, long update) {
-      return unsafe.compareAndSwapLong(this, valueOffset, expect, update);
-    }
-
-    /**
-     * Atomically set the value to the given updated value
-     * if the current value <tt>==</tt> the expected value.
-     * May fail spuriously.
-     * @param expect the expected value
-     * @param update the new value
-     * @return true if successful.
-     */
-    public final boolean weakCompareAndSet(long expect, long update) {
-      return unsafe.compareAndSwapLong(this, valueOffset, expect, update);
-    }
-  
-    /**
-     * Atomically increment by one the current value.
-     * @return the previous value
-     */
-    public final long getAndIncrement() {
-        while (true) {
-            long current = get();
-            long next = current + 1;
-            if (compareAndSet(current, next))
-                return current;
-        }
-    }
-  
-  
-    /**
-     * Atomically decrement by one the current value.
-     * @return the previous value
-     */
-    public final long getAndDecrement() {
-        while (true) {
-            long current = get();
-            long next = current - 1;
-            if (compareAndSet(current, next))
-                return current;
-        }
-    }
-  
-  
-    /**
-     * Atomically add the given value to current value.
-     * @param delta the value to add
-     * @return the previous value
-     */
-    public final long getAndAdd(long delta) {
-        while (true) {
-            long current = get();
-            long next = current + delta;
-            if (compareAndSet(current, next))
-                return current;
-        }
-    }
-  
-    /**
-     * Atomically increment by one the current value.
-     * @return the updated value
-     */
-    public final long incrementAndGet() {
-        for (;;) {
-            long current = get();
-            long next = current + 1;
-            if (compareAndSet(current, next))
-                return next;
-        }
-    }
-    
-    /**
-     * Atomically decrement by one the current value.
-     * @return the updated value
-     */
-    public final long decrementAndGet() {
-        for (;;) {
-            long current = get();
-            long next = current - 1;
-            if (compareAndSet(current, next))
-                return next;
-        }
-    }
-  
-  
-    /**
-     * Atomically add the given value to current value.
-     * @param delta the value to add
-     * @return the updated value
-     */
-    public final long addAndGet(long delta) {
-        for (;;) {
-            long current = get();
-            long next = current + delta;
-            if (compareAndSet(current, next))
-                return next;
-        }
-    }
-  
-    /**
-     * Returns the String representation of the current value.
-     * @return the String representation of the current value.
-     */
-    public String toString() {
-        return Long.toString(get());
-    }
-
-
-    public int intValue() {
-        return (int)get();
-    }
-
-    public long longValue() {
-        return (long)get();
-    }
-
-    public float floatValue() {
-        return (float)get();
-    }
-
-    public double doubleValue() {
-        return (double)get();
-    }
-  
-}
diff --git a/concurrent/src/main/java/java/util/concurrent/atomic/AtomicLongArray.java b/concurrent/src/main/java/java/util/concurrent/atomic/AtomicLongArray.java
deleted file mode 100644
index a0e76b4..0000000
--- a/concurrent/src/main/java/java/util/concurrent/atomic/AtomicLongArray.java
+++ /dev/null
@@ -1,242 +0,0 @@
-/*
- * Written by Doug Lea with assistance from members of JCP JSR-166
- * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
- */
-
-package java.util.concurrent.atomic;
-import sun.misc.Unsafe;
-import java.util.*;
-
-/**
- * A <tt>long</tt> array in which elements may be updated atomically.
- * See the {@link java.util.concurrent.atomic} package specification
- * for description of the properties of atomic variables.
- * @since 1.5
- * @author Doug Lea
- */
-public class AtomicLongArray implements java.io.Serializable { 
-    private static final long serialVersionUID = -2308431214976778248L;
-
-    // setup to use Unsafe.compareAndSwapInt for updates
-    // BEGIN android-changed
-    private static final Unsafe unsafe = UnsafeAccess.THE_ONE;
-    // END android-changed
-    private static final int base = unsafe.arrayBaseOffset(long[].class);
-    private static final int scale = unsafe.arrayIndexScale(long[].class);
-    private final long[] array;
-
-    private long rawIndex(int i) {
-        if (i < 0 || i >= array.length)
-            throw new IndexOutOfBoundsException("index " + i);
-        return base + i * scale;
-    }
-
-    /**
-     * Create a new AtomicLongArray of given length.
-     * @param length the length of the array
-     */
-    public AtomicLongArray(int length) {
-        array = new long[length];
-        // must perform at least one volatile write to conform to JMM
-        if (length > 0) 
-            unsafe.putLongVolatile(array, rawIndex(0), 0);
-    }
-
-    /**
-     * Create a new AtomicLongArray with the same length as, and
-     * all elements copied from, the given array.
-     *
-     * @param array the array to copy elements from
-     * @throws NullPointerException if array is null
-     */
-    public AtomicLongArray(long[] array) {
-        if (array == null) 
-            throw new NullPointerException();
-        int length = array.length;
-        this.array = new long[length];
-        if (length > 0) {
-            int last = length-1;
-            for (int i = 0; i < last; ++i)
-                this.array[i] = array[i];
-            // Do the last write as volatile
-            unsafe.putLongVolatile(this.array, rawIndex(last), array[last]);
-        }
-    }
-
-    /**
-     * Returns the length of the array.
-     *
-     * @return the length of the array
-     */
-    public final int length() {
-        return array.length;
-    }
-
-    /**
-     * Get the current value at position <tt>i</tt>.
-     *
-     * @param i the index
-     * @return the current value
-     */
-    public final long get(int i) {
-        return unsafe.getLongVolatile(array, rawIndex(i));
-    }
- 
-    /**
-     * Set the element at position <tt>i</tt> to the given value.
-     *
-     * @param i the index
-     * @param newValue the new value
-     */
-    public final void set(int i, long newValue) {
-        unsafe.putLongVolatile(array, rawIndex(i), newValue);
-    }
-  
-    /**
-     * Set the element at position <tt>i</tt> to the given value and return the
-     * old value.
-     *
-     * @param i the index
-     * @param newValue the new value
-     * @return the previous value
-     */
-    public final long getAndSet(int i, long newValue) {
-        while (true) {
-            long current = get(i);
-            if (compareAndSet(i, current, newValue))
-                return current;
-        }
-    }
-  
-    /**
-     * Atomically set the value to the given updated value
-     * if the current value <tt>==</tt> the expected value.
-     * @param i the index
-     * @param expect the expected value
-     * @param update the new value
-     * @return true if successful. False return indicates that
-     * the actual value was not equal to the expected value.
-     */
-    public final boolean compareAndSet(int i, long expect, long update) {
-        return unsafe.compareAndSwapLong(array, rawIndex(i), 
-                                         expect, update);
-    }
-
-    /**
-     * Atomically set the value to the given updated value
-     * if the current value <tt>==</tt> the expected value.
-     * May fail spuriously.
-     * @param i the index
-     * @param expect the expected value
-     * @param update the new value
-     * @return true if successful.
-     */
-    public final boolean weakCompareAndSet(int i, long expect, long update) {
-        return compareAndSet(i, expect, update);
-    }
-
-    /**
-     * Atomically increment by one the element at index <tt>i</tt>.
-     *
-     * @param i the index
-     * @return the previous value;
-     */
-    public final long getAndIncrement(int i) {
-        while (true) {
-            long current = get(i);
-            long next = current + 1;
-            if (compareAndSet(i, current, next))
-                return current;
-        }
-    }
-  
-    /**
-     * Atomically decrement by one the element at index <tt>i</tt>.
-     *
-     * @param i the index
-     * @return the previous value;
-     */
-    public final long getAndDecrement(int i) {
-        while (true) {
-            long current = get(i);
-            long next = current - 1;
-            if (compareAndSet(i, current, next))
-                return current;
-        }
-    }
-  
-    /**
-     * Atomically add the given value to element at index <tt>i</tt>.
-     *
-     * @param i the index
-     * @param delta the value to add
-     * @return the previous value;
-     */
-    public final long getAndAdd(int i, long delta) {
-        while (true) {
-            long current = get(i);
-            long next = current + delta;
-            if (compareAndSet(i, current, next))
-                return current;
-        }
-    }
-  
-
-    /**
-     * Atomically increment the element at index <tt>i</tt>.
-     *
-     * @param i the index
-     * @return the updated value;
-     */
-    public final long incrementAndGet(int i) {
-        while (true) {
-            long current = get(i);
-            long next = current + 1;
-            if (compareAndSet(i, current, next))
-                return next;
-        }
-    }
-  
-    /**
-     * Atomically decrement the element at index <tt>i</tt>.
-     *
-     * @param i the index
-     * @return the updated value;
-     */
-    public final long decrementAndGet(int i) {
-        while (true) {
-            long current = get(i);
-            long next = current - 1;
-            if (compareAndSet(i, current, next))
-                return next;
-        }
-    }
-  
-    /**
-     * Atomically add the given value to element at index <tt>i</tt>.
-     *
-     * @param i the index
-     * @param delta the value to add
-     * @return the updated value;
-     */
-    public long addAndGet(int i, long delta) {
-        while (true) {
-            long current = get(i);
-            long next = current + delta;
-            if (compareAndSet(i, current, next))
-                return next;
-        }
-    }
-
-    /**
-     * Returns the String representation of the current values of array.
-     * @return the String representation of the current values of array.
-     */
-    public String toString() {
-        if (array.length > 0) // force volatile read
-            get(0);
-        return Arrays.toString(array);
-    }
-  
-}
diff --git a/concurrent/src/main/java/java/util/concurrent/atomic/AtomicLongFieldUpdater.java b/concurrent/src/main/java/java/util/concurrent/atomic/AtomicLongFieldUpdater.java
deleted file mode 100644
index dcb8b2e..0000000
--- a/concurrent/src/main/java/java/util/concurrent/atomic/AtomicLongFieldUpdater.java
+++ /dev/null
@@ -1,321 +0,0 @@
-/*
- * Written by Doug Lea with assistance from members of JCP JSR-166
- * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
- */
-
-package java.util.concurrent.atomic;
-import sun.misc.Unsafe;
-import java.lang.reflect.*;
-
-/**
- * A reflection-based utility that enables atomic updates to
- * designated <tt>volatile long</tt> fields of designated classes.
- * This class is designed for use in atomic data structures in which
- * several fields of the same node are independently subject to atomic
- * updates.
- *
- * <p> Note that the guarantees of the <tt>compareAndSet</tt> method
- * in this class are weaker than in other atomic classes. Because this
- * class cannot ensure that all uses of the field are appropriate for
- * purposes of atomic access, it can guarantee atomicity and volatile
- * semantics only with respect to other invocations of
- * <tt>compareAndSet</tt> and <tt>set</tt>.
- *
- * @since 1.5
- * @author Doug Lea
- * @param <T> The type of the object holding the updatable field
- */
-public abstract class  AtomicLongFieldUpdater<T>  {
-    /**
-     * Creates an updater for objects with the given field.  The Class
-     * argument is needed to check that reflective types and generic
-     * types match.
-     * @param tclass the class of the objects holding the field
-     * @param fieldName the name of the field to be updated.
-     * @return the updater
-     * @throws IllegalArgumentException if the field is not a
-     * volatile long type.
-     * @throws RuntimeException with a nested reflection-based
-     * exception if the class does not hold field or is the wrong type.
-     */
-    public static <U> AtomicLongFieldUpdater<U> newUpdater(Class<U> tclass, String fieldName) {
-        if (AtomicLong.VM_SUPPORTS_LONG_CAS)
-            return new CASUpdater<U>(tclass, fieldName);
-        else
-            return new LockedUpdater<U>(tclass, fieldName);
-    }
-
-    /**
-     * Protected do-nothing constructor for use by subclasses.
-     */
-    protected AtomicLongFieldUpdater() {
-    }
-
-    /**
-     * Atomically set the value of the field of the given object managed
-     * by this Updater to the given updated value if the current value
-     * <tt>==</tt> the expected value. This method is guaranteed to be
-     * atomic with respect to other calls to <tt>compareAndSet</tt> and
-     * <tt>set</tt>, but not necessarily with respect to other
-     * changes in the field.
-     * @param obj An object whose field to conditionally set
-     * @param expect the expected value
-     * @param update the new value
-     * @return true if successful.
-     * @throws ClassCastException if <tt>obj</tt> is not an instance
-     * of the class possessing the field established in the constructor.
-     */
-
-    public abstract boolean compareAndSet(T obj, long expect, long update);
-
-    /**
-     * Atomically set the value of the field of the given object managed
-     * by this Updater to the given updated value if the current value
-     * <tt>==</tt> the expected value. This method is guaranteed to be
-     * atomic with respect to other calls to <tt>compareAndSet</tt> and
-     * <tt>set</tt>, but not necessarily with respect to other
-     * changes in the field, and may fail spuriously.
-     * @param obj An object whose field to conditionally set
-     * @param expect the expected value
-     * @param update the new value
-     * @return true if successful.
-     * @throws ClassCastException if <tt>obj</tt> is not an instance
-     * of the class possessing the field established in the constructor.
-     */
-
-    public abstract boolean weakCompareAndSet(T obj, long expect, long update);
-
-    /**
-     * Set the field of the given object managed by this updater. This
-     * operation is guaranteed to act as a volatile store with respect
-     * to subsequent invocations of <tt>compareAndSet</tt>.
-     * @param obj An object whose field to set
-     * @param newValue the new value
-     */
-    public abstract void set(T obj, long newValue);
-
-    /**
-     * Get the current value held in the field by the given object.
-     * @param obj An object whose field to get
-     * @return the current value
-     */
-    public abstract long get(T obj);
-
-    /**
-     * Set to the given value and return the old value.
-     *
-     * @param obj An object whose field to get and set
-     * @param newValue the new value
-     * @return the previous value
-     */
-    public long getAndSet(T obj, long newValue) {
-        for (;;) {
-            long current = get(obj);
-            if (compareAndSet(obj, current, newValue))
-                return current;
-        }
-    }
-
-    /**
-     * Atomically increment by one the current value.
-     * @param obj An object whose field to get and set
-     * @return the previous value;
-     */
-    public long getAndIncrement(T obj) {
-        for (;;) {
-            long current = get(obj);
-            long next = current + 1;
-            if (compareAndSet(obj, current, next))
-                return current;
-        }
-    }
-
-
-    /**
-     * Atomically decrement by one the current value.
-     * @param obj An object whose field to get and set
-     * @return the previous value;
-     */
-    public long getAndDecrement(T obj) {
-        for (;;) {
-            long current = get(obj);
-            long next = current - 1;
-            if (compareAndSet(obj, current, next))
-                return current;
-        }
-    }
-
-
-    /**
-     * Atomically add the given value to current value.
-     * @param obj An object whose field to get and set
-     * @param delta the value to add
-     * @return the previous value;
-     */
-    public long getAndAdd(T obj, long delta) {
-        for (;;) {
-            long current = get(obj);
-            long next = current + delta;
-            if (compareAndSet(obj, current, next))
-                return current;
-        }
-    }
-
-    /**
-     * Atomically increment by one the current value.
-     * @param obj An object whose field to get and set
-     * @return the updated value;
-     */
-    public long incrementAndGet(T obj) {
-        for (;;) {
-            long current = get(obj);
-            long next = current + 1;
-            if (compareAndSet(obj, current, next))
-                return next;
-        }
-    }
-
-
-    /**
-     * Atomically decrement by one the current value.
-     * @param obj An object whose field to get and set
-     * @return the updated value;
-     */
-    public long decrementAndGet(T obj) {
-        for (;;) {
-            long current = get(obj);
-            long next = current - 1;
-            if (compareAndSet(obj, current, next))
-                return next;
-        }
-    }
-
-
-    /**
-     * Atomically add the given value to current value.
-     * @param obj An object whose field to get and set
-     * @param delta the value to add
-     * @return the updated value;
-     */
-    public long addAndGet(T obj, long delta) {
-        for (;;) {
-            long current = get(obj);
-            long next = current + delta;
-            if (compareAndSet(obj, current, next))
-                return next;
-        }
-    }
-
-    private static class CASUpdater<T> extends AtomicLongFieldUpdater<T> {
-        // BEGIN android-changed
-        private static final Unsafe unsafe = UnsafeAccess.THE_ONE;
-        // END android-changed
-        private final long offset;
-        private final Class<T> tclass;
-
-        CASUpdater(Class<T> tclass, String fieldName) {
-            Field field = null;
-            try {
-                field = tclass.getDeclaredField(fieldName);
-            } catch(Exception ex) {
-                throw new RuntimeException(ex);
-            }
-            
-            Class fieldt = field.getType();
-            if (fieldt != long.class)
-                throw new IllegalArgumentException("Must be long type");
-            
-            if (!Modifier.isVolatile(field.getModifiers()))
-                throw new IllegalArgumentException("Must be volatile type");
-            
-            this.tclass = tclass;
-            offset = unsafe.objectFieldOffset(field);
-        }
-
-        public boolean compareAndSet(T obj, long expect, long update) {
-            if (!tclass.isInstance(obj))
-                throw new ClassCastException();
-            return unsafe.compareAndSwapLong(obj, offset, expect, update);
-        }
-
-        public boolean weakCompareAndSet(T obj, long expect, long update) {
-            if (!tclass.isInstance(obj))
-                throw new ClassCastException();
-            return unsafe.compareAndSwapLong(obj, offset, expect, update);
-        }
-
-        public void set(T obj, long newValue) {
-            if (!tclass.isInstance(obj))
-                throw new ClassCastException();
-            unsafe.putLongVolatile(obj, offset, newValue);
-        }
-
-        public long get(T obj) {
-            if (!tclass.isInstance(obj))
-                throw new ClassCastException();
-            return unsafe.getLongVolatile(obj, offset);
-        }
-    }
-
-
-    private static class LockedUpdater<T> extends AtomicLongFieldUpdater<T> {
-        // BEGIN android-changed
-        private static final Unsafe unsafe = UnsafeAccess.THE_ONE;
-        // END android-changed
-        private final long offset;
-        private final Class<T> tclass;
-
-        LockedUpdater(Class<T> tclass, String fieldName) {
-            Field field = null;
-            try {
-                field = tclass.getDeclaredField(fieldName);
-            } catch(Exception ex) {
-                throw new RuntimeException(ex);
-            }
-            
-            Class fieldt = field.getType();
-            if (fieldt != long.class)
-                throw new IllegalArgumentException("Must be long type");
-            
-            if (!Modifier.isVolatile(field.getModifiers()))
-                throw new IllegalArgumentException("Must be volatile type");
-            
-            this.tclass = tclass;
-            offset = unsafe.objectFieldOffset(field);
-        }
-
-        public boolean compareAndSet(T obj, long expect, long update) {
-            if (!tclass.isInstance(obj))
-                throw new ClassCastException();
-            synchronized(this) {
-                long v = unsafe.getLong(obj, offset);
-                if (v != expect) 
-                    return false;
-                unsafe.putLong(obj, offset, update);
-                return true;
-            }
-        }
-
-        public boolean weakCompareAndSet(T obj, long expect, long update) {
-            return compareAndSet(obj, expect, update);
-        }
-
-        public void set(T obj, long newValue) {
-            if (!tclass.isInstance(obj))
-                throw new ClassCastException();
-            synchronized(this) {
-                unsafe.putLong(obj, offset, newValue);
-            }
-        }
-
-        public long get(T obj) {
-            if (!tclass.isInstance(obj))
-                throw new ClassCastException();
-            synchronized(this) {
-                return unsafe.getLong(obj, offset);
-            }
-        }
-    }
-}
-
diff --git a/concurrent/src/main/java/java/util/concurrent/atomic/AtomicMarkableReference.java b/concurrent/src/main/java/java/util/concurrent/atomic/AtomicMarkableReference.java
deleted file mode 100644
index 11c91ba..0000000
--- a/concurrent/src/main/java/java/util/concurrent/atomic/AtomicMarkableReference.java
+++ /dev/null
@@ -1,163 +0,0 @@
-/*
- * Written by Doug Lea with assistance from members of JCP JSR-166
- * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
- */
-
-package java.util.concurrent.atomic;
-
-/**
- * An <tt>AtomicMarkableReference</tt> maintains an object reference
- * along with a mark bit, that can be updated atomically.
- * <p>
- * <p> Implementation note. This implementation maintains markable
- * references by creating internal objects representing "boxed"
- * [reference, boolean] pairs.
- *
- * @since 1.5
- * @author Doug Lea
- * @param <V> The type of object referred to by this reference
- */
-public class AtomicMarkableReference<V>  {
-
-    private static class ReferenceBooleanPair<T> {
-        private final T reference;
-        private final boolean bit;
-        ReferenceBooleanPair(T r, boolean i) {
-            reference = r; bit = i;
-        }
-    }
-
-    private final AtomicReference<ReferenceBooleanPair<V>>  atomicRef;
-
-    /**
-     * Creates a new <tt>AtomicMarkableReference</tt> with the given
-     * initial values.
-     *
-     * @param initialRef the initial reference
-     * @param initialMark the initial mark
-     */
-    public AtomicMarkableReference(V initialRef, boolean initialMark) {
-        atomicRef = new AtomicReference<ReferenceBooleanPair<V>> (new ReferenceBooleanPair<V>(initialRef, initialMark));
-    }
-
-    /**
-     * Returns the current value of the reference.
-     *
-     * @return the current value of the reference
-     */
-    public V getReference() {
-        return atomicRef.get().reference;
-    }
-
-    /**
-     * Returns the current value of the mark.
-     *
-     * @return the current value of the mark
-     */
-    public boolean isMarked() {
-        return atomicRef.get().bit;
-    }
-
-    /**
-     * Returns the current values of both the reference and the mark.
-     * Typical usage is <tt>boolean[1] holder; ref = v.get(holder); </tt>.
-     *
-     * @param markHolder an array of size of at least one. On return,
-     * <tt>markholder[0]</tt> will hold the value of the mark.
-     * @return the current value of the reference
-     */
-    public V get(boolean[] markHolder) {
-        ReferenceBooleanPair<V> p = atomicRef.get();
-        markHolder[0] = p.bit;
-        return p.reference;
-    }
-
-    /**
-     * Atomically sets the value of both the reference and mark
-     * to the given update values if the
-     * current reference is <tt>==</tt> to the expected reference
-     * and the current mark is equal to the expected mark.  Any given
-     * invocation of this operation may fail (return
-     * <tt>false</tt>) spuriously, but repeated invocation when
-     * the current value holds the expected value and no other thread
-     * is also attempting to set the value will eventually succeed.
-     *
-     * @param expectedReference the expected value of the reference
-     * @param newReference the new value for the reference
-     * @param expectedMark the expected value of the mark
-     * @param newMark the new value for the mark
-     * @return true if successful
-     */
-    public boolean weakCompareAndSet(V       expectedReference,
-                                     V       newReference,
-                                     boolean expectedMark,
-                                     boolean newMark) {
-        ReferenceBooleanPair current = atomicRef.get();
-        return  expectedReference == current.reference &&
-            expectedMark == current.bit &&
-            ((newReference == current.reference && newMark == current.bit) ||
-             atomicRef.weakCompareAndSet(current,
-                                     new ReferenceBooleanPair<V>(newReference,
-                                                              newMark)));
-    }
-
-    /**
-     * Atomically sets the value of both the reference and mark
-     * to the given update values if the
-     * current reference is <tt>==</tt> to the expected reference
-     * and the current mark is equal to the expected mark.  
-     *
-     * @param expectedReference the expected value of the reference
-     * @param newReference the new value for the reference
-     * @param expectedMark the expected value of the mark
-     * @param newMark the new value for the mark
-     * @return true if successful
-     */
-    public boolean compareAndSet(V       expectedReference,
-                                 V       newReference,
-                                 boolean expectedMark,
-                                 boolean newMark) {
-        ReferenceBooleanPair current = atomicRef.get();
-        return  expectedReference == current.reference &&
-            expectedMark == current.bit &&
-            ((newReference == current.reference && newMark == current.bit) ||
-             atomicRef.compareAndSet(current,
-                                     new ReferenceBooleanPair<V>(newReference,
-                                                              newMark)));
-    }
-
-    /**
-     * Unconditionally sets the value of both the reference and mark.
-     *
-     * @param newReference the new value for the reference
-     * @param newMark the new value for the mark
-     */
-    public void set(V newReference, boolean newMark) {
-        ReferenceBooleanPair current = atomicRef.get();
-        if (newReference != current.reference || newMark != current.bit)
-            atomicRef.set(new ReferenceBooleanPair<V>(newReference, newMark));
-    }
-
-    /**
-     * Atomically sets the value of the mark to the given update value
-     * if the current reference is <tt>==</tt> to the expected
-     * reference.  Any given invocation of this operation may fail
-     * (return <tt>false</tt>) spuriously, but repeated invocation
-     * when the current value holds the expected value and no other
-     * thread is also attempting to set the value will eventually
-     * succeed.
-     *
-     * @param expectedReference the expected value of the reference
-     * @param newMark the new value for the mark
-     * @return true if successful
-     */
-    public boolean attemptMark(V expectedReference, boolean newMark) {
-        ReferenceBooleanPair current = atomicRef.get();
-        return  expectedReference == current.reference &&
-            (newMark == current.bit ||
-             atomicRef.compareAndSet
-             (current, new ReferenceBooleanPair<V>(expectedReference,
-                                                newMark)));
-    }
-}
diff --git a/concurrent/src/main/java/java/util/concurrent/atomic/AtomicReference.java b/concurrent/src/main/java/java/util/concurrent/atomic/AtomicReference.java
deleted file mode 100644
index 89c050c..0000000
--- a/concurrent/src/main/java/java/util/concurrent/atomic/AtomicReference.java
+++ /dev/null
@@ -1,114 +0,0 @@
-/*
- * Written by Doug Lea with assistance from members of JCP JSR-166
- * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
- */
-
-package java.util.concurrent.atomic;
-import sun.misc.Unsafe;
-
-/**
- * An object reference that may be updated atomically. See the {@link
- * java.util.concurrent.atomic} package specification for description
- * of the properties of atomic variables.
- * @since 1.5
- * @author Doug Lea
- * @param <V> The type of object referred to by this reference
- */
-public class AtomicReference<V>  implements java.io.Serializable { 
-    private static final long serialVersionUID = -1848883965231344442L;
-
-    // BEGIN android-changed
-    private static final Unsafe unsafe = UnsafeAccess.THE_ONE;
-    // END android-changed
-    private static final long valueOffset;
-
-    static {
-      try {
-        valueOffset = unsafe.objectFieldOffset
-            (AtomicReference.class.getDeclaredField("value"));
-      } catch(Exception ex) { throw new Error(ex); }
-    }
-
-    private volatile V value;
-
-    /**
-     * Create a new AtomicReference with the given initial value.
-     *
-     * @param initialValue the initial value
-     */
-    public AtomicReference(V initialValue) {
-        value = initialValue;
-    }
-
-    /**
-     * Create a new AtomicReference with null initial value.
-     */
-    public AtomicReference() {
-    }
-  
-    /**
-     * Get the current value.
-     *
-     * @return the current value
-     */
-    public final V get() {
-        return value;
-    }
-  
-    /**
-     * Set to the given value.
-     *
-     * @param newValue the new value
-     */
-    public final void set(V newValue) {
-        value = newValue;
-    }
-  
-    /**
-     * Atomically set the value to the given updated value
-     * if the current value <tt>==</tt> the expected value.
-     * @param expect the expected value
-     * @param update the new value
-     * @return true if successful. False return indicates that
-     * the actual value was not equal to the expected value.
-     */
-    public final boolean compareAndSet(V expect, V update) {
-      return unsafe.compareAndSwapObject(this, valueOffset, expect, update);
-    }
-
-    /**
-     * Atomically set the value to the given updated value
-     * if the current value <tt>==</tt> the expected value.
-     * May fail spuriously.
-     * @param expect the expected value
-     * @param update the new value
-     * @return true if successful.
-     */
-    public final boolean weakCompareAndSet(V expect, V update) {
-      return unsafe.compareAndSwapObject(this, valueOffset, expect, update);
-    }
-
-    /**
-     * Set to the given value and return the old value.
-     *
-     * @param newValue the new value
-     * @return the previous value
-     */
-    public final V getAndSet(V newValue) {
-        while (true) {
-            V x = get();
-            if (compareAndSet(x, newValue))
-                return x;
-        }
-    }
-
-    /**
-     * Returns the String representation of the current value.
-     * @return the String representation of the current value.
-     */
-    public String toString() {
-        return String.valueOf(get());
-    }
-
-}
diff --git a/concurrent/src/main/java/java/util/concurrent/atomic/AtomicReferenceArray.java b/concurrent/src/main/java/java/util/concurrent/atomic/AtomicReferenceArray.java
deleted file mode 100644
index 9ad800c..0000000
--- a/concurrent/src/main/java/java/util/concurrent/atomic/AtomicReferenceArray.java
+++ /dev/null
@@ -1,151 +0,0 @@
-/*
- * Written by Doug Lea with assistance from members of JCP JSR-166
- * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
- */
-
-package java.util.concurrent.atomic;
-import sun.misc.Unsafe;
-import java.util.*;
-
-/**
- * An array of object references in which elements may be updated
- * atomically.  See the {@link java.util.concurrent.atomic} package
- * specification for description of the properties of atomic
- * variables.
- * @since 1.5
- * @author Doug Lea
- * @param <E> The base class of elements held in this array
- */
-public class AtomicReferenceArray<E> implements java.io.Serializable { 
-    private static final long serialVersionUID = -6209656149925076980L;
-
-    // BEGIN android-changed
-    private static final Unsafe unsafe = UnsafeAccess.THE_ONE;
-    // END android-changed
-    private static final int base = unsafe.arrayBaseOffset(Object[].class);
-    private static final int scale = unsafe.arrayIndexScale(Object[].class);
-    private final Object[] array;
-
-    private long rawIndex(int i) {
-        if (i < 0 || i >= array.length)
-            throw new IndexOutOfBoundsException("index " + i);
-        return base + i * scale;
-    }
-
-    /**
-     * Create a new AtomicReferenceArray of given length.
-     * @param length the length of the array
-     */
-    public AtomicReferenceArray(int length) {
-        array = new Object[length];
-        // must perform at least one volatile write to conform to JMM
-        if (length > 0) 
-            unsafe.putObjectVolatile(array, rawIndex(0), null);
-    }
-
-    /**
-     * Create a new AtomicReferenceArray with the same length as, and
-     * all elements copied from, the given array.
-     *
-     * @param array the array to copy elements from
-     * @throws NullPointerException if array is null
-     */
-    public AtomicReferenceArray(E[] array) {
-        if (array == null) 
-            throw new NullPointerException();
-        int length = array.length;
-        this.array = new Object[length];
-        if (length > 0) {
-            int last = length-1;
-            for (int i = 0; i < last; ++i)
-                this.array[i] = array[i];
-            // Do the last write as volatile
-            E e = array[last];
-            unsafe.putObjectVolatile(this.array, rawIndex(last), e);
-        }
-    }
-
-    /**
-     * Returns the length of the array.
-     *
-     * @return the length of the array
-     */
-    public final int length() {
-        return array.length;
-    }
-
-    /**
-     * Get the current value at position <tt>i</tt>.
-     *
-     * @param i the index
-     * @return the current value
-     */
-    public final E get(int i) {
-        return (E) unsafe.getObjectVolatile(array, rawIndex(i));
-    }
- 
-    /**
-     * Set the element at position <tt>i</tt> to the given value.
-     *
-     * @param i the index
-     * @param newValue the new value
-     */
-    public final void set(int i, E newValue) {
-        unsafe.putObjectVolatile(array, rawIndex(i), newValue);
-    }
-  
-    /**
-     * Set the element at position <tt>i</tt> to the given value and return the
-     * old value.
-     *
-     * @param i the index
-     * @param newValue the new value
-     * @return the previous value
-     */
-    public final E getAndSet(int i, E newValue) {
-        while (true) {
-            E current = get(i);
-            if (compareAndSet(i, current, newValue))
-                return current;
-        }
-    }
-  
-    /**
-     * Atomically set the value to the given updated value
-     * if the current value <tt>==</tt> the expected value.
-     * @param i the index
-     * @param expect the expected value
-     * @param update the new value
-     * @return true if successful. False return indicates that
-     * the actual value was not equal to the expected value.
-     */
-    public final boolean compareAndSet(int i, E expect, E update) {
-        return unsafe.compareAndSwapObject(array, rawIndex(i), 
-                                         expect, update);
-    }
-
-    /**
-     * Atomically set the value to the given updated value
-     * if the current value <tt>==</tt> the expected value.
-     * May fail spuriously.
-     * @param i the index
-     * @param expect the expected value
-     * @param update the new value
-     * @return true if successful.
-     */
-    public final boolean weakCompareAndSet(int i, E expect, E update) {
-        return compareAndSet(i, expect, update);
-    }
-
-    /**
-     * Returns the String representation of the current values of array.
-     * @return the String representation of the current values of array.
-     */
-    public String toString() {
-        if (array.length > 0) // force volatile read
-            get(0);
-        return Arrays.toString(array);
-    }
-
-}
diff --git a/concurrent/src/main/java/java/util/concurrent/atomic/AtomicReferenceFieldUpdater.java b/concurrent/src/main/java/java/util/concurrent/atomic/AtomicReferenceFieldUpdater.java
deleted file mode 100644
index f20661d..0000000
--- a/concurrent/src/main/java/java/util/concurrent/atomic/AtomicReferenceFieldUpdater.java
+++ /dev/null
@@ -1,197 +0,0 @@
-/*
- * Written by Doug Lea with assistance from members of JCP JSR-166
- * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
- */
-
-package java.util.concurrent.atomic;
-import sun.misc.Unsafe;
-import java.lang.reflect.*;
-
-/**
- * A reflection-based utility that enables atomic updates to
- * designated <tt>volatile</tt> reference fields of designated
- * classes.  This class is designed for use in atomic data structures
- * in which several reference fields of the same node are
- * independently subject to atomic updates. For example, a tree node
- * might be declared as
- *
- * <pre>
- * class Node {
- *   private volatile Node left, right;
- *
- *   private static final AtomicReferenceFieldUpdater&lt;Node, Node&gt; leftUpdater =
- *     AtomicReferenceFieldUpdater.newUpdater(Node.class, Node.class, "left");
- *   private static AtomicReferenceFieldUpdater&lt;Node, Node&gt; rightUpdater =
- *     AtomicReferenceFieldUpdater.newUpdater(Node.class, Node.class, "right");
- *
- *   Node getLeft() { return left;  }
- *   boolean compareAndSetLeft(Node expect, Node update) {
- *     return leftUpdater.compareAndSet(this, expect, update);
- *   }
- *   // ... and so on
- * }
- * </pre>
- *
- * <p> Note that the guarantees of the <tt>compareAndSet</tt>
- * method in this class are weaker than in other atomic classes. Because this
- * class cannot ensure that all uses of the field are appropriate for
- * purposes of atomic access, it can guarantee atomicity and volatile
- * semantics only with respect to other invocations of
- * <tt>compareAndSet</tt> and <tt>set</tt>.
- * @since 1.5
- * @author Doug Lea
- * @param <T> The type of the object holding the updatable field
- * @param <V> The type of the field
- */
-public abstract class AtomicReferenceFieldUpdater<T, V>  {
-
-    /**
-     * Creates an updater for objects with the given field.  The Class
-     * arguments are needed to check that reflective types and generic
-     * types match.
-     * @param tclass the class of the objects holding the field.
-     * @param vclass the class of the field
-     * @param fieldName the name of the field to be updated.
-     * @return the updater
-     * @throws IllegalArgumentException if the field is not a volatile reference type.
-     * @throws RuntimeException with a nested reflection-based
-     * exception if the class does not hold field or is the wrong type.
-     */
-    public static <U, W> AtomicReferenceFieldUpdater<U,W> newUpdater(Class<U> tclass, Class<W> vclass, String fieldName) {
-        // Currently rely on standard intrinsics implementation
-        return new AtomicReferenceFieldUpdaterImpl<U,W>(tclass, 
-                                                        vclass, 
-                                                        fieldName);
-    }
-
-    /**
-     * Protected do-nothing constructor for use by subclasses.
-     */
-    protected AtomicReferenceFieldUpdater() {
-    }
-
-    /**
-     * Atomically set the value of the field of the given object managed
-     * by this Updater to the given updated value if the current value
-     * <tt>==</tt> the expected value. This method is guaranteed to be
-     * atomic with respect to other calls to <tt>compareAndSet</tt> and
-     * <tt>set</tt>, but not necessarily with respect to other
-     * changes in the field.
-     * @param obj An object whose field to conditionally set
-     * @param expect the expected value
-     * @param update the new value
-     * @return true if successful.
-     */
-
-    public abstract boolean compareAndSet(T obj, V expect, V update);
-
-    /**
-     * Atomically set the value of the field of the given object managed
-     * by this Updater to the given updated value if the current value
-     * <tt>==</tt> the expected value. This method is guaranteed to be
-     * atomic with respect to other calls to <tt>compareAndSet</tt> and
-     * <tt>set</tt>, but not necessarily with respect to other
-     * changes in the field, and may fail spuriously.
-     * @param obj An object whose field to conditionally set
-     * @param expect the expected value
-     * @param update the new value
-     * @return true if successful.
-     */
-    public abstract boolean weakCompareAndSet(T obj, V expect, V update);
-
-    /**
-     * Set the field of the given object managed by this updater. This
-     * operation is guaranteed to act as a volatile store with respect
-     * to subsequent invocations of <tt>compareAndSet</tt>.
-     * @param obj An object whose field to set
-     * @param newValue the new value
-     */
-    public abstract void set(T obj, V newValue);
-
-    /**
-     * Get the current value held in the field by the given object.
-     * @param obj An object whose field to get
-     * @return the current value
-     */
-    public abstract V get(T obj);
-
-    /**
-     * Set to the given value and return the old value.
-     *
-     * @param obj An object whose field to get and set
-     * @param newValue the new value
-     * @return the previous value
-     */
-    public V getAndSet(T obj, V newValue) {
-        for (;;) {
-            V current = get(obj);
-            if (compareAndSet(obj, current, newValue))
-                return current;
-        }
-    }
-
-    /**
-     * Standard hotspot implementation using intrinsics
-     */
-    private static class AtomicReferenceFieldUpdaterImpl<T,V> extends AtomicReferenceFieldUpdater<T,V> {
-        // BEGIN android-changed
-        private static final Unsafe unsafe = UnsafeAccess.THE_ONE;
-        // END android-changed
-        private final long offset;
-        private final Class<T> tclass;
-        private final Class<V> vclass;
-
-        AtomicReferenceFieldUpdaterImpl(Class<T> tclass, Class<V> vclass, String fieldName) {
-            Field field = null;
-            Class fieldClass = null;
-            try {
-                field = tclass.getDeclaredField(fieldName);
-                fieldClass = field.getType();
-            } catch(Exception ex) {
-                throw new RuntimeException(ex);
-            }
-            
-            if (vclass != fieldClass)
-                throw new ClassCastException();
-            
-            if (!Modifier.isVolatile(field.getModifiers()))
-                throw new IllegalArgumentException("Must be volatile type");
-
-            this.tclass = tclass;
-            this.vclass = vclass;
-            offset = unsafe.objectFieldOffset(field);
-        }
-        
-
-        public boolean compareAndSet(T obj, V expect, V update) {
-            if (!tclass.isInstance(obj) ||
-                (update != null && !vclass.isInstance(update)))
-                throw new ClassCastException();
-            return unsafe.compareAndSwapObject(obj, offset, expect, update);
-        }
-
-        public boolean weakCompareAndSet(T obj, V expect, V update) {
-            // same implementation as strong form for now
-            if (!tclass.isInstance(obj) ||
-                (update != null && !vclass.isInstance(update)))
-                throw new ClassCastException();
-            return unsafe.compareAndSwapObject(obj, offset, expect, update);
-        }
-
-
-        public void set(T obj, V newValue) {
-            if (!tclass.isInstance(obj) ||
-                (newValue != null && !vclass.isInstance(newValue)))
-                throw new ClassCastException();
-            unsafe.putObjectVolatile(obj, offset, newValue);
-        }
-
-        public V get(T obj) {
-            if (!tclass.isInstance(obj))
-                throw new ClassCastException();
-            return (V)unsafe.getObjectVolatile(obj, offset);
-        }
-    }
-}
-
diff --git a/concurrent/src/main/java/java/util/concurrent/atomic/AtomicStampedReference.java b/concurrent/src/main/java/java/util/concurrent/atomic/AtomicStampedReference.java
deleted file mode 100644
index b0a02c2..0000000
--- a/concurrent/src/main/java/java/util/concurrent/atomic/AtomicStampedReference.java
+++ /dev/null
@@ -1,167 +0,0 @@
-/*
- * Written by Doug Lea with assistance from members of JCP JSR-166
- * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
- */
-
-package java.util.concurrent.atomic;
-
-/**
- * An <tt>AtomicStampedReference</tt> maintains an object reference
- * along with an integer "stamp", that can be updated atomically.  
- *
- * <p> Implementation note. This implementation maintains stamped
- * references by creating internal objects representing "boxed"
- * [reference, integer] pairs.
- *
- * @since 1.5
- * @author Doug Lea
- * @param <V> The type of object referred to by this reference
- */
-public class AtomicStampedReference<V>  {
-
-    private static class ReferenceIntegerPair<T> {
-        private final T reference;
-        private final int integer;
-        ReferenceIntegerPair(T r, int i) {
-            reference = r; integer = i;
-        }
-    }
-
-    private final AtomicReference<ReferenceIntegerPair<V>>  atomicRef;
-
-    /**
-     * Creates a new <tt>AtomicStampedReference</tt> with the given
-     * initial values.
-     *
-     * @param initialRef the initial reference
-     * @param initialStamp the initial stamp
-     */
-    public AtomicStampedReference(V initialRef, int initialStamp) {
-        atomicRef = new AtomicReference<ReferenceIntegerPair<V>>
-            (new ReferenceIntegerPair<V>(initialRef, initialStamp));
-    }
-
-    /**
-     * Returns the current value of the reference.
-     *
-     * @return the current value of the reference
-     */
-    public V getReference() {
-        return atomicRef.get().reference;
-    }
-
-    /**
-     * Returns the current value of the stamp.
-     *
-     * @return the current value of the stamp
-     */
-    public int getStamp() {
-        return atomicRef.get().integer;
-    }
-
-    /**
-     * Returns the current values of both the reference and the stamp.
-     * Typical usage is <tt>int[1] holder; ref = v.get(holder); </tt>.
-     *
-     * @param stampHolder an array of size of at least one.  On return,
-     * <tt>stampholder[0]</tt> will hold the value of the stamp.
-     * @return the current value of the reference
-     */
-    public V get(int[] stampHolder) {
-        ReferenceIntegerPair<V> p = atomicRef.get();
-        stampHolder[0] = p.integer;
-        return p.reference;
-    }
-
-    /**
-     * Atomically sets the value of both the reference and stamp
-     * to the given update values if the
-     * current reference is <tt>==</tt> to the expected reference
-     * and the current stamp is equal to the expected stamp.  Any given
-     * invocation of this operation may fail (return
-     * <tt>false</tt>) spuriously, but repeated invocation when
-     * the current value holds the expected value and no other thread
-     * is also attempting to set the value will eventually succeed.
-     *
-     * @param expectedReference the expected value of the reference
-     * @param newReference the new value for the reference
-     * @param expectedStamp the expected value of the stamp
-     * @param newStamp the new value for the stamp
-     * @return true if successful
-     */
-    public boolean weakCompareAndSet(V      expectedReference,
-                                     V      newReference,
-                                     int    expectedStamp,
-                                     int    newStamp) {
-        ReferenceIntegerPair current = atomicRef.get();
-        return  expectedReference == current.reference &&
-            expectedStamp == current.integer &&
-            ((newReference == current.reference &&
-              newStamp == current.integer) ||
-             atomicRef.weakCompareAndSet(current,
-                                     new ReferenceIntegerPair<V>(newReference,
-                                                              newStamp)));
-    }
-
-    /**
-     * Atomically sets the value of both the reference and stamp
-     * to the given update values if the
-     * current reference is <tt>==</tt> to the expected reference
-     * and the current stamp is equal to the expected stamp. 
-     *
-     * @param expectedReference the expected value of the reference
-     * @param newReference the new value for the reference
-     * @param expectedStamp the expected value of the stamp
-     * @param newStamp the new value for the stamp
-     * @return true if successful
-     */
-    public boolean compareAndSet(V      expectedReference,
-                                 V      newReference,
-                                 int    expectedStamp,
-                                 int    newStamp) {
-        ReferenceIntegerPair current = atomicRef.get();
-        return  expectedReference == current.reference &&
-            expectedStamp == current.integer &&
-            ((newReference == current.reference &&
-              newStamp == current.integer) ||
-             atomicRef.compareAndSet(current,
-                                     new ReferenceIntegerPair<V>(newReference,
-                                                              newStamp)));
-    }
-
-
-    /**
-     * Unconditionally sets the value of both the reference and stamp.
-     *
-     * @param newReference the new value for the reference
-     * @param newStamp the new value for the stamp
-     */
-    public void set(V newReference, int newStamp) {
-        ReferenceIntegerPair current = atomicRef.get();
-        if (newReference != current.reference || newStamp != current.integer)
-            atomicRef.set(new ReferenceIntegerPair<V>(newReference, newStamp));
-    }
-
-    /**
-     * Atomically sets the value of the stamp to the given update value
-     * if the current reference is <tt>==</tt> to the expected
-     * reference.  Any given invocation of this operation may fail
-     * (return <tt>false</tt>) spuriously, but repeated invocation
-     * when the current value holds the expected value and no other
-     * thread is also attempting to set the value will eventually
-     * succeed.
-     *
-     * @param expectedReference the expected value of the reference
-     * @param newStamp the new value for the stamp
-     * @return true if successful
-     */
-    public boolean attemptStamp(V expectedReference, int newStamp) {
-        ReferenceIntegerPair current = atomicRef.get();
-        return  expectedReference == current.reference &&
-            (newStamp == current.integer ||
-             atomicRef.compareAndSet(current,
-                                     new ReferenceIntegerPair<V>(expectedReference,
-                                                              newStamp)));
-    }
-}
diff --git a/concurrent/src/main/java/java/util/concurrent/atomic/UnsafeAccess.java b/concurrent/src/main/java/java/util/concurrent/atomic/UnsafeAccess.java
deleted file mode 100644
index 96fff17..0000000
--- a/concurrent/src/main/java/java/util/concurrent/atomic/UnsafeAccess.java
+++ /dev/null
@@ -1,34 +0,0 @@
-/*
- * Copyright (C) 2008 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package java.util.concurrent.atomic;
-
-import sun.misc.Unsafe;
-
-/**
- * Easy access to {@link Unsafe} for the rest of this package.
- */
-/*package*/ final class UnsafeAccess {
-    /** non-null; unique instance of {@link Unsafe} */
-    /*package*/ static final Unsafe THE_ONE = Unsafe.getUnsafe();
-
-    /**
-     * This class is uninstantiable.
-     */
-    private UnsafeAccess() {
-        // This space intentionally left blank.
-    }
-}
diff --git a/concurrent/src/main/java/java/util/concurrent/atomic/package.html b/concurrent/src/main/java/java/util/concurrent/atomic/package.html
deleted file mode 100644
index bdb15e8..0000000
--- a/concurrent/src/main/java/java/util/concurrent/atomic/package.html
+++ /dev/null
@@ -1,132 +0,0 @@
-<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML//EN">
-<html> <head>
-<title>Atomics</title>
-</head>
-
-<body>
-
-A small toolkit of classes that support lock-free thread-safe
-programming on single variables. In essence, the classes in this
-package extend the notion of <tt>volatile</tt> values, fields, and
-array elements to those that also provide an atomic conditional update
-operation of the form:
-
-<pre>
-  boolean compareAndSet(expectedValue, updateValue);
-</pre>
-
-<p> This method (which varies in argument types across different
-classes) atomically sets a variable to the <tt>updateValue</tt> if it
-currently holds the <tt>expectedValue</tt>, reporting <tt>true</tt> on
-success.  The classes in this package also contain methods to get and
-unconditionally set values, as well as a weaker conditional atomic
-update operation <tt> weakCompareAndSet</tt>.  The weak version may be
-more efficient in the normal case, but differs in that any given
-invocation of <tt>weakCompareAndSet</tt> method may fail, even
-spuriously (that is, for no apparent reason). A <tt>false</tt> return
-means only that the operation may be retried if desired, relying on
-the guarantee that repeated invocation when the variable holds
-<tt>expectedValue</tt> and no other thread is also attempting to set
-the variable will eventually succeed.
-
-<p> The specifications of these methods enable implementations to
-employ efficient machine-level atomic instructions that are available
-on contemporary processors. However on some platforms, support may
-entail some form of internal locking. Thus the methods are not
-strictly guaranteed to be non-blocking --
-a thread may block transiently before performing the operation.
-
-<p> Instances of classes {@link
-java.util.concurrent.atomic.AtomicBoolean}, {@link
-java.util.concurrent.atomic.AtomicInteger}, {@link
-java.util.concurrent.atomic.AtomicLong}, and {@link
-java.util.concurrent.atomic.AtomicReference} each provide access and
-updates to a single variable of the corresponding type.  Each class
-also provides appropriate utility methods for that type.  For example,
-classes <tt>AtomicLong</tt> and <tt>AtomicInteger</tt> provide atomic
-increment methods.  One application is to generate sequence numbers,
-as in:
-
-<pre>
-class Sequencer {
-  private AtomicLong sequenceNumber = new AtomicLong(0);
-  public long next() { return sequenceNumber.getAndIncrement(); }
-}
-</pre>
-
-<p>The memory effects for accesses and updates of atomics generally follow the
-rules for volatiles:
-
-<ul>
-
-  <li> <tt>get</tt> has the memory effects of reading a
-<tt>volatile</tt> variable.
-
-  <li> <tt>set</tt> has the memory effects of writing (assigning) a
-<tt>volatile</tt> variable.
-
-  <li><tt>weakCompareAndSet</tt> atomically reads and conditionally
-  writes a variable, is ordered with respect to other
-  memory operations on that variable, but otherwise acts as an
-  ordinary non-volatile memory operation.
-
-  <li> <tt>compareAndSet</tt>
-  and all other read-and-update operations such as <tt>getAndIncrement</tt>
-  have the memory effects of both reading and
-  writing <tt>volatile</tt> variables.
-</ul> 
-
-<p>In addition to classes representing single values, this package
-contains <em>Updater</em> classes that can be used to obtain
-<tt>compareAndSet</tt> operations on any selected <tt>volatile</tt>
-field of any selected class.  {@link
-java.util.concurrent.atomic.AtomicReferenceFieldUpdater}, {@link
-java.util.concurrent.atomic.AtomicIntegerFieldUpdater}, and {@link
-java.util.concurrent.atomic.AtomicLongFieldUpdater} are
-reflection-based utilities that provide access to the associated field
-types. These are mainly of use in atomic data structures in which
-several <tt>volatile</tt> fields of the same node (for example, the
-links of a tree node) are independently subject to atomic
-updates. These classes enable greater flexibility in how and when to
-use atomic updates, at the expense of more awkward reflection-based
-setup, less convenient usage, and weaker guarantees.
-
-<p>The {@link java.util.concurrent.atomic.AtomicIntegerArray}, {@link
-java.util.concurrent.atomic.AtomicLongArray}, and {@link
-java.util.concurrent.atomic.AtomicReferenceArray} classes further
-extend atomic operation support to arrays of these types. These
-classes are also notable in providing <tt>volatile</tt> access
-semantics for their array elements, which is not supported for
-ordinary arrays.
-
-<p> The {@link java.util.concurrent.atomic.AtomicMarkableReference}
-class associates a single boolean with a reference. For example, this
-bit might be used inside a data structure to mean that the object
-being referenced has logically been deleted. The {@link
-java.util.concurrent.atomic.AtomicStampedReference} class associates
-an integer value with a reference. This may be used for example, to
-represent version numbers corresponding to series of updates.
-
-<p> Atomic classes are designed primarily as building blocks for
-implementing non-blocking data structures and related infrastructure
-classes.  The <tt>compareAndSet</tt> method is not a general
-replacement for locking. It applies only when critical updates for an
-object are confined to a <em>single</em> variable.
-
-<p> Atomic classes are not general purpose replacements for
-<tt>java.lang.Integer</tt> and related classes. They do <em>not</em>
-define methods such as <tt>hashCode</tt> and
-<tt>compareTo</tt>. (Because atomic variables are expected to be
-mutated, they are poor choices for hash table keys.)  Additionally,
-classes are provided only for those types that are commonly useful in
-intended applications. For example, there is no atomic class for
-representing <tt>byte</tt>. In those infrequent cases where you would
-like to do so, you can use an <tt>AtomicInteger</tt> to hold
-<tt>byte</tt> values, and cast appropriately. You can also hold floats
-using <tt>Float.floatToIntBits</tt> and <tt>Float.intBitstoFloat</tt>
-conversions, and doubles using <tt>Double.doubleToLongBits</tt> and
-<tt>Double.longBitsToDouble</tt> conversions.
-
-@since Android 1.0
-
-</body> </html>
diff --git a/concurrent/src/main/java/java/util/concurrent/locks/AbstractQueuedSynchronizer.java b/concurrent/src/main/java/java/util/concurrent/locks/AbstractQueuedSynchronizer.java
deleted file mode 100644
index 29e72b5..0000000
--- a/concurrent/src/main/java/java/util/concurrent/locks/AbstractQueuedSynchronizer.java
+++ /dev/null
@@ -1,2058 +0,0 @@
-/*
- * Written by Doug Lea with assistance from members of JCP JSR-166
- * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
- */
-
-package java.util.concurrent.locks;
-import java.util.*;
-import java.util.concurrent.*;
-import java.util.concurrent.atomic.*;
-import sun.misc.Unsafe;
-
-/**
- * Provides a framework for implementing blocking locks and related
- * synchronizers (semaphores, events, etc) that rely on
- * first-in-first-out (FIFO) wait queues.  This class is designed to
- * be a useful basis for most kinds of synchronizers that rely on a
- * single atomic <tt>int</tt> value to represent state. Subclasses
- * must define the protected methods that change this state, and which
- * define what that state means in terms of this object being acquired
- * or released.  Given these, the other methods in this class carry
- * out all queuing and blocking mechanics. Subclasses can maintain
- * other state fields, but only the atomically updated <tt>int</tt>
- * value manipulated using methods {@link #getState}, {@link
- * #setState} and {@link #compareAndSetState} is tracked with respect
- * to synchronization.
- *
- * <p>Subclasses should be defined as non-public internal helper
- * classes that are used to implement the synchronization properties
- * of their enclosing class.  Class
- * <tt>AbstractQueuedSynchronizer</tt> does not implement any
- * synchronization interface.  Instead it defines methods such as
- * {@link #acquireInterruptibly} that can be invoked as
- * appropriate by concrete locks and related synchronizers to
- * implement their public methods. 
- *
- * <p>This class supports either or both a default <em>exclusive</em>
- * mode and a <em>shared</em> mode. When acquired in exclusive mode,
- * attempted acquires by other threads cannot succeed. Shared mode
- * acquires by multiple threads may (but need not) succeed. This class
- * does not &quot;understand&quot; these differences except in the
- * mechanical sense that when a shared mode acquire succeeds, the next
- * waiting thread (if one exists) must also determine whether it can
- * acquire as well. Threads waiting in the different modes share the
- * same FIFO queue. Usually, implementation subclasses support only
- * one of these modes, but both can come into play for example in a
- * {@link ReadWriteLock}. Subclasses that support only exclusive or
- * only shared modes need not define the methods supporting the unused mode.
- *
- * <p>This class defines a nested {@link ConditionObject} class that
- * can be used as a {@link Condition} implementation by subclasses
- * supporting exclusive mode for which method {@link
- * #isHeldExclusively} reports whether synchronization is exclusively
- * held with respect to the current thread, method {@link #release}
- * invoked with the current {@link #getState} value fully releases
- * this object, and {@link #acquire}, given this saved state value,
- * eventually restores this object to its previous acquired state.  No
- * <tt>AbstractQueuedSynchronizer</tt> method otherwise creates such a
- * condition, so if this constraint cannot be met, do not use it.  The
- * behavior of {@link ConditionObject} depends of course on the
- * semantics of its synchronizer implementation.
- * 
- * <p> This class provides inspection, instrumentation, and monitoring
- * methods for the internal queue, as well as similar methods for
- * condition objects. These can be exported as desired into classes
- * using an <tt>AbstractQueuedSynchronizer</tt> for their
- * synchronization mechanics.
- *
- * <p> Serialization of this class stores only the underlying atomic
- * integer maintaining state, so deserialized objects have empty
- * thread queues. Typical subclasses requiring serializability will
- * define a <tt>readObject</tt> method that restores this to a known
- * initial state upon deserialization.
- *
- * <h3>Usage</h3>
- *
- * <p> To use this class as the basis of a synchronizer, redefine the
- * following methods, as applicable, by inspecting and/or modifying
- * the synchronization state using {@link #getState}, {@link
- * #setState} and/or {@link #compareAndSetState}: 
- *
- * <ul>
- * <li> {@link #tryAcquire}
- * <li> {@link #tryRelease}
- * <li> {@link #tryAcquireShared}
- * <li> {@link #tryReleaseShared}
- * <li> {@link #isHeldExclusively}
- *</ul>
- *
- * Each of these methods by default throws {@link
- * UnsupportedOperationException}.  Implementations of these methods
- * must be internally thread-safe, and should in general be short and
- * not block. Defining these methods is the <em>only</em> supported
- * means of using this class. All other methods are declared
- * <tt>final</tt> because they cannot be independently varied.
- *
- * <p> Even though this class is based on an internal FIFO queue, it
- * does not automatically enforce FIFO acquisition policies.  The core
- * of exclusive synchronization takes the form:
- *
- * <pre>
- * Acquire:
- *     while (!tryAcquire(arg)) {
- *        <em>enqueue thread if it is not already queued</em>;
- *        <em>possibly block current thread</em>;
- *     }
- *
- * Release:
- *     if (tryRelease(arg))
- *        <em>unblock the first queued thread</em>;
- * </pre>
- *
- * (Shared mode is similar but may involve cascading signals.)
- *
- * <p> Because checks in acquire are invoked before enqueuing, a newly
- * acquiring thread may <em>barge</em> ahead of others that are
- * blocked and queued. However, you can, if desired, define
- * <tt>tryAcquire</tt> and/or <tt>tryAcquireShared</tt> to disable
- * barging by internally invoking one or more of the inspection
- * methods. In particular, a strict FIFO lock can define
- * <tt>tryAcquire</tt> to immediately return <tt>false</tt> if {@link
- * #getFirstQueuedThread} does not return the current thread.  A
- * normally preferable non-strict fair version can immediately return
- * <tt>false</tt> only if {@link #hasQueuedThreads} returns
- * <tt>true</tt> and <tt>getFirstQueuedThread</tt> is not the current
- * thread; or equivalently, that <tt>getFirstQueuedThread</tt> is both
- * non-null and not the current thread.  Further variations are
- * possible.
- *
- * <p> Throughput and scalability are generally highest for the
- * default barging (also known as <em>greedy</em>,
- * <em>renouncement</em>, and <em>convoy-avoidance</em>) strategy.
- * While this is not guaranteed to be fair or starvation-free, earlier
- * queued threads are allowed to recontend before later queued
- * threads, and each recontention has an unbiased chance to succeed
- * against incoming threads.  Also, while acquires do not
- * &quot;spin&quot; in the usual sense, they may perform multiple
- * invocations of <tt>tryAcquire</tt> interspersed with other
- * computations before blocking.  This gives most of the benefits of
- * spins when exclusive synchronization is only briefly held, without
- * most of the liabilities when it isn't. If so desired, you can
- * augment this by preceding calls to acquire methods with
- * "fast-path" checks, possibly prechecking {@link #hasContended}
- * and/or {@link #hasQueuedThreads} to only do so if the synchronizer
- * is likely not to be contended.
- *
- * <p> This class provides an efficient and scalable basis for
- * synchronization in part by specializing its range of use to
- * synchronizers that can rely on <tt>int</tt> state, acquire, and
- * release parameters, and an internal FIFO wait queue. When this does
- * not suffice, you can build synchronizers from a lower level using
- * {@link java.util.concurrent.atomic atomic} classes, your own custom
- * {@link java.util.Queue} classes, and {@link LockSupport} blocking
- * support.
- * 
- * <h3>Usage Examples</h3>
- *
- * <p>Here is a non-reentrant mutual exclusion lock class that uses
- * the value zero to represent the unlocked state, and one to
- * represent the locked state. It also supports conditions and exposes
- * one of the instrumentation methods:
- *
- * <pre>
- * class Mutex implements Lock, java.io.Serializable {
- *
- *    // Our internal helper class
- *    private static class Sync extends AbstractQueuedSynchronizer {
- *      // Report whether in locked state
- *      protected boolean isHeldExclusively() { 
- *        return getState() == 1; 
- *      }
- *
- *      // Acquire the lock if state is zero
- *      public boolean tryAcquire(int acquires) {
- *        assert acquires == 1; // Otherwise unused
- *        return compareAndSetState(0, 1);
- *      }
- *
- *      // Release the lock by setting state to zero
- *      protected boolean tryRelease(int releases) {
- *        assert releases == 1; // Otherwise unused
- *        if (getState() == 0) throw new IllegalMonitorStateException();
- *        setState(0);
- *        return true;
- *      }
- *       
- *      // Provide a Condition
- *      Condition newCondition() { return new ConditionObject(); }
- *
- *      // Deserialize properly
- *      private void readObject(ObjectInputStream s) throws IOException, ClassNotFoundException {
- *        s.defaultReadObject();
- *        setState(0); // reset to unlocked state
- *      }
- *    }
- *
- *    // The sync object does all the hard work. We just forward to it.
- *    private final Sync sync = new Sync();
- *
- *    public void lock()                { sync.acquire(1); }
- *    public boolean tryLock()          { return sync.tryAcquire(1); }
- *    public void unlock()              { sync.release(1); }
- *    public Condition newCondition()   { return sync.newCondition(); }
- *    public boolean isLocked()         { return sync.isHeldExclusively(); }
- *    public boolean hasQueuedThreads() { return sync.hasQueuedThreads(); }
- *    public void lockInterruptibly() throws InterruptedException { 
- *      sync.acquireInterruptibly(1);
- *    }
- *    public boolean tryLock(long timeout, TimeUnit unit) throws InterruptedException {
- *      return sync.tryAcquireNanos(1, unit.toNanos(timeout));
- *    }
- * }
- * </pre>
- *
- * <p> Here is a latch class that is like a {@link CountDownLatch}
- * except that it only requires a single <tt>signal</tt> to
- * fire. Because a latch is non-exclusive, it uses the <tt>shared</tt>
- * acquire and release methods.
- *
- * <pre>
- * class BooleanLatch {
- *
- *    private static class Sync extends AbstractQueuedSynchronizer {
- *      boolean isSignalled() { return getState() != 0; }
- *
- *      protected int tryAcquireShared(int ignore) {
- *        return isSignalled()? 1 : -1;
- *      }
- *        
- *      protected boolean tryReleaseShared(int ignore) {
- *        setState(1);
- *        return true;
- *      }
- *    }
- *
- *    private final Sync sync = new Sync();
- *    public boolean isSignalled() { return sync.isSignalled(); }
- *    public void signal()         { sync.releaseShared(1); }
- *    public void await() throws InterruptedException {
- *      sync.acquireSharedInterruptibly(1);
- *    }
- * }
- *
- * </pre>
- *
- * @since 1.5
- * @author Doug Lea
- */
-public abstract class AbstractQueuedSynchronizer implements java.io.Serializable {
-    private static final long serialVersionUID = 7373984972572414691L;
-
-    /**
-     * Creates a new <tt>AbstractQueuedSynchronizer</tt> instance
-     * with initial synchronization state of zero.
-     */
-    protected AbstractQueuedSynchronizer() { }
-
-    /**
-     * Wait queue node class.
-     *
-     * <p> The wait queue is a variant of a "CLH" (Craig, Landin, and
-     * Hagersten) lock queue. CLH locks are normally used for
-     * spinlocks.  We instead use them for blocking synchronizers, but
-     * use the same basic tactic of holding some of the control
-     * information about a thread in the predecessor of its node.  A
-     * "status" field in each node keeps track of whether a thread
-     * should block.  A node is signalled when its predecessor
-     * releases.  Each node of the queue otherwise serves as a
-     * specific-notification-style monitor holding a single waiting
-     * thread. The status field does NOT control whether threads are
-     * granted locks etc though.  A thread may try to acquire if it is
-     * first in the queue. But being first does not guarantee success;
-     * it only gives the right to contend.  So the currently released
-     * contender thread may need to rewait.
-     *
-     * <p>To enqueue into a CLH lock, you atomically splice it in as new
-     * tail. To dequeue, you just set the head field.  
-     * <pre>
-     *      +------+  prev +-----+       +-----+
-     * head |      | <---- |     | <---- |     |  tail
-     *      +------+       +-----+       +-----+
-     * </pre>
-     *
-     * <p>Insertion into a CLH queue requires only a single atomic
-     * operation on "tail", so there is a simple atomic point of
-     * demarcation from unqueued to queued. Similarly, dequeing
-     * involves only updating the "head". However, it takes a bit
-     * more work for nodes to determine who their successors are,
-     * in part to deal with possible cancellation due to timeouts
-     * and interrupts.
-     *
-     * <p>The "prev" links (not used in original CLH locks), are mainly
-     * needed to handle cancellation. If a node is cancelled, its
-     * successor is (normally) relinked to a non-cancelled
-     * predecessor. For explanation of similar mechanics in the case
-     * of spin locks, see the papers by Scott and Scherer at
-     * http://www.cs.rochester.edu/u/scott/synchronization/
-     * 
-     * <p>We also use "next" links to implement blocking mechanics.
-     * The thread id for each node is kept in its own node, so a
-     * predecessor signals the next node to wake up by traversing
-     * next link to determine which thread it is.  Determination of
-     * successor must avoid races with newly queued nodes to set
-     * the "next" fields of their predecessors.  This is solved
-     * when necessary by checking backwards from the atomically
-     * updated "tail" when a node's successor appears to be null.
-     * (Or, said differently, the next-links are an optimization
-     * so that we don't usually need a backward scan.)
-     *
-     * <p>Cancellation introduces some conservatism to the basic
-     * algorithms.  Since we must poll for cancellation of other
-     * nodes, we can miss noticing whether a cancelled node is
-     * ahead or behind us. This is dealt with by always unparking
-     * successors upon cancellation, allowing them to stabilize on
-     * a new predecessor.
-     *
-     * <p>CLH queues need a dummy header node to get started. But
-     * we don't create them on construction, because it would be wasted
-     * effort if there is never contention. Instead, the node
-     * is constructed and head and tail pointers are set upon first
-     * contention.
-     *
-     * <p>Threads waiting on Conditions use the same nodes, but
-     * use an additional link. Conditions only need to link nodes
-     * in simple (non-concurrent) linked queues because they are
-     * only accessed when exclusively held.  Upon await, a node is
-     * inserted into a condition queue.  Upon signal, the node is
-     * transferred to the main queue.  A special value of status
-     * field is used to mark which queue a node is on.
-     *
-     * <p>Thanks go to Dave Dice, Mark Moir, Victor Luchangco, Bill
-     * Scherer and Michael Scott, along with members of JSR-166
-     * expert group, for helpful ideas, discussions, and critiques
-     * on the design of this class.
-     */
-    static final class Node {
-        /** waitStatus value to indicate thread has cancelled */
-        static final int CANCELLED =  1;
-        /** waitStatus value to indicate thread needs unparking */
-        static final int SIGNAL    = -1;
-        /** waitStatus value to indicate thread is waiting on condition */
-        static final int CONDITION = -2;
-        /** Marker to indicate a node is waiting in shared mode */
-        static final Node SHARED = new Node();
-        /** Marker to indicate a node is waiting in exclusive mode */
-        static final Node EXCLUSIVE = null;
-
-        /**
-         * Status field, taking on only the values:
-         *   SIGNAL:     The successor of this node is (or will soon be) 
-         *               blocked (via park), so the current node must 
-         *               unpark its successor when it releases or 
-         *               cancels. To avoid races, acquire methods must
-         *               first indicate they need a signal, 
-         *               then retry the atomic acquire, and then, 
-         *               on failure, block.
-         *   CANCELLED:  Node is cancelled due to timeout or interrupt
-         *               Nodes never leave this state. In particular,
-         *               a thread with cancelled node never again blocks.
-         *   CONDITION:  Node is currently on a condition queue
-         *               It will not be used as a sync queue node until
-         *               transferred. (Use of this value here
-         *               has nothing to do with the other uses
-         *               of the field, but simplifies mechanics.)
-         *   0:          None of the above
-         *
-         * The values are arranged numerically to simplify use.
-         * Non-negative values mean that a node doesn't need to
-         * signal. So, most code doesn't need to check for particular
-         * values, just for sign.
-         *
-         * The field is initialized to 0 for normal sync nodes, and
-         * CONDITION for condition nodes.  It is modified only using
-         * CAS.
-         */
-        volatile int waitStatus;
-
-        /**
-         * Link to predecessor node that current node/thread relies on
-         * for checking waitStatus. Assigned during enqueing, and nulled
-         * out (for sake of GC) only upon dequeuing.  Also, upon
-         * cancellation of a predecessor, we short-circuit while
-         * finding a non-cancelled one, which will always exist
-         * because the head node is never cancelled: A node becomes
-         * head only as a result of successful acquire. A
-         * cancelled thread never succeeds in acquiring, and a thread only
-         * cancels itself, not any other node.
-         */
-        volatile Node prev;
-
-        /**
-         * Link to the successor node that the current node/thread
-         * unparks upon release. Assigned once during enqueuing, and
-         * nulled out (for sake of GC) when no longer needed.  Upon
-         * cancellation, we cannot adjust this field, but can notice
-         * status and bypass the node if cancelled.  The enq operation
-         * does not assign next field of a predecessor until after
-         * attachment, so seeing a null next field does not
-         * necessarily mean that node is at end of queue. However, if
-         * a next field appears to be null, we can scan prev's from
-         * the tail to double-check.
-         */
-        volatile Node next;
-
-        /**
-         * The thread that enqueued this node.  Initialized on
-         * construction and nulled out after use. 
-         */
-        volatile Thread thread;
-
-        /** 
-         * Link to next node waiting on condition, or the special
-         * value SHARED.  Because condition queues are accessed only
-         * when holding in exclusive mode, we just need a simple
-         * linked queue to hold nodes while they are waiting on
-         * conditions. They are then transferred to the queue to
-         * re-acquire. And because conditions can only be exclusive,
-         * we save a field by using special value to indicate shared
-         * mode.
-         */
-        Node nextWaiter;
-
-        /**
-         * Returns true if node is waiting in shared mode
-         */
-        final boolean isShared() {
-            return nextWaiter == SHARED;
-        }
-
-        /**
-         * Returns previous node, or throws NullPointerException if
-         * null.  Use when predecessor cannot be null.
-         * @return the predecessor of this node
-         */
-        final Node predecessor() throws NullPointerException {
-            Node p = prev;
-            if (p == null)
-                throw new NullPointerException(); 
-            else
-                return p;
-        }
-
-        Node() {    // Used to establish initial head or SHARED marker
-        }
-
-        Node(Thread thread, Node mode) {     // Used by addWaiter
-            this.nextWaiter = mode;
-            this.thread = thread;
-        }
-
-        Node(Thread thread, int waitStatus) { // Used by Condition
-            this.waitStatus = waitStatus;
-            this.thread = thread; 
-        }
-    }
-
-    /** 
-     * Head of the wait queue, lazily initialized.  Except for
-     * initialization, it is modified only via method setHead.  Note:
-     * If head exists, its waitStatus is guaranteed not to be
-     * CANCELLED.
-     */
-    private transient volatile Node head;
-
-    /** 
-     * Tail of the wait queue, lazily initialized.  Modified only via
-     * method enq to add new wait node.
-     */
-    private transient volatile Node tail; 
-
-    /**
-     * The synchronization state.
-     */
-    private volatile int state;
-
-    /**
-     * Returns the current value of synchronization state.
-     * This operation has memory semantics of a <tt>volatile</tt> read.
-     * @return current state value
-     */
-    protected final int getState() {
-        return state;
-    }
-
-    /**
-     * Sets the value of synchronization state.
-     * This operation has memory semantics of a <tt>volatile</tt> write.
-     * @param newState the new state value
-     */
-    protected final void setState(int newState) {
-        state = newState;
-    }
-
-    /**
-     * Atomically sets synchronization state to the given updated
-     * value if the current state value equals the expected value.
-     * This operation has memory semantics of a <tt>volatile</tt> read
-     * and write.
-     * @param expect the expected value
-     * @param update the new value
-     * @return true if successful. False return indicates that
-     * the actual value was not equal to the expected value.
-     */
-    protected final boolean compareAndSetState(int expect, int update) {
-        // See below for intrinsics setup to support this
-        return unsafe.compareAndSwapInt(this, stateOffset, expect, update);
-    }
-
-    // Queuing utilities
-
-    /**
-     * Insert node into queue, initializing if necessary. See picture above.
-     * @param node the node to insert
-     * @return node's predecessor
-     */
-    private Node enq(final Node node) {
-        for (;;) {
-            Node t = tail;
-            if (t == null) { // Must initialize
-                Node h = new Node(); // Dummy header
-                h.next = node;
-                node.prev = h;
-                if (compareAndSetHead(h)) {
-                    tail = node;
-                    return h;
-                }
-            }
-            else {
-                node.prev = t;     
-                if (compareAndSetTail(t, node)) {
-                    t.next = node; 
-                    return t; 
-                }
-            }
-        }
-    }
-
-    /**
-     * Create and enq node for given thread and mode
-     * @param current the thread
-     * @param mode Node.EXCLUSIVE for exclusive, Node.SHARED for shared
-     * @return the new node
-     */
-    private Node addWaiter(Node mode) {
-        Node node = new Node(Thread.currentThread(), mode);
-        // Try the fast path of enq; backup to full enq on failure
-        Node pred = tail;
-        if (pred != null) {
-            node.prev = pred;     
-            if (compareAndSetTail(pred, node)) {
-                pred.next = node; 
-                return node;
-            }
-        }
-        enq(node);
-        return node;
-    }
-
-    /**
-     * Set head of queue to be node, thus dequeuing. Called only by
-     * acquire methods.  Also nulls out unused fields for sake of GC
-     * and to suppress unnecessary signals and traversals.
-     * @param node the node 
-     */
-    private void setHead(Node node) {
-        head = node;
-        node.thread = null;
-        node.prev = null; 
-    }
-
-    /**
-     * Wake up node's successor, if one exists.
-     * @param node the node
-     */
-    private void unparkSuccessor(Node node) {
-        /*
-         * Try to clear status in anticipation of signalling.  It is
-         * OK if this fails or if status is changed by waiting thread.
-         */
-        compareAndSetWaitStatus(node, Node.SIGNAL, 0);
-        
-        /*
-         * Thread to unpark is held in successor, which is normally
-         * just the next node.  But if cancelled or apparently null,
-         * traverse backwards from tail to find the actual
-         * non-cancelled successor.
-         */
-        Thread thread;
-        Node s = node.next;
-        if (s != null && s.waitStatus <= 0)
-            thread = s.thread;
-        else {
-            thread = null;
-            for (s = tail; s != null && s != node; s = s.prev) 
-                if (s.waitStatus <= 0)
-                    thread = s.thread;
-        }
-        LockSupport.unpark(thread);
-    }
-
-    /**
-     * Set head of queue, and check if successor may be waiting
-     * in shared mode, if so propagating if propagate > 0.
-     * @param pred the node holding waitStatus for node
-     * @param node the node 
-     * @param propagate the return value from a tryAcquireShared
-     */
-    private void setHeadAndPropagate(Node node, int propagate) {
-        setHead(node);
-        if (propagate > 0 && node.waitStatus != 0) {
-            /*
-             * Don't bother fully figuring out successor.  If it
-             * looks null, call unparkSuccessor anyway to be safe.
-             */
-            Node s = node.next; 
-            if (s == null || s.isShared())
-                unparkSuccessor(node);
-        }
-    }
-
-    // Utilities for various versions of acquire
-
-    /**
-     * Cancel an ongoing attempt to acquire.
-     * @param node the node
-     */
-    private void cancelAcquire(Node node) {
-        if (node != null) { // Ignore if node doesn't exist
-            node.thread = null;
-            // Can use unconditional write instead of CAS here
-            node.waitStatus = Node.CANCELLED;
-            unparkSuccessor(node);
-        }
-    }
-
-    /**
-     * Checks and updates status for a node that failed to acquire.
-     * Returns true if thread should block. This is the main signal
-     * control in all acquire loops.  Requires that pred == node.prev
-     * @param pred node's predecessor holding status
-     * @param node the node 
-     * @return true if thread should block
-     */
-    private static boolean shouldParkAfterFailedAcquire(Node pred, Node node) {
-        int s = pred.waitStatus;
-        if (s < 0)
-            /*
-             * This node has already set status asking a release
-             * to signal it, so it can safely park
-             */
-            return true;
-        if (s > 0) 
-            /*
-             * Predecessor was cancelled. Move up to its predecessor
-             * and indicate retry.
-             */
-            node.prev = pred.prev;
-        else
-            /*
-             * Indicate that we need a signal, but don't park yet. Caller
-             * will need to retry to make sure it cannot acquire before
-             * parking.
-             */
-            compareAndSetWaitStatus(pred, 0, Node.SIGNAL);
-        return false;
-    }
-
-    /**
-     * Convenience method to interrupt current thread.
-     */
-    private static void selfInterrupt() {
-        Thread.currentThread().interrupt();
-    }
-
-    /**
-     * Convenience method to park and then check if interrupted
-     * @return true if interrupted
-     */
-    private static boolean parkAndCheckInterrupt() {
-        LockSupport.park();
-        return Thread.interrupted();
-    }
-
-    /*
-     * Various flavors of acquire, varying in exclusive/shared and
-     * control modes.  Each is mostly the same, but annoyingly
-     * different.  Only a little bit of factoring is possible due to
-     * interactions of exception mechanics (including ensuring that we
-     * cancel if tryAcquire throws exception) and other control, at
-     * least not without hurting performance too much. 
-     */
-
-    /**
-     * Acquire in exclusive uninterruptible mode for thread already in
-     * queue. Used by condition wait methods as well as acquire.
-     * @param node the node
-     * @param arg the acquire argument
-     * @return true if interrupted while waiting
-     */
-    final boolean acquireQueued(final Node node, int arg) {
-        try {
-            boolean interrupted = false;
-            for (;;) {
-                final Node p = node.predecessor();
-                if (p == head && tryAcquire(arg)) {
-                    setHead(node);
-                    p.next = null; // help GC
-                    return interrupted;
-                }
-                if (shouldParkAfterFailedAcquire(p, node) && 
-                    parkAndCheckInterrupt()) 
-                    interrupted = true;
-            }
-        } catch (RuntimeException ex) {
-            cancelAcquire(node);
-            throw ex;
-        }
-    }
-
-    /** 
-     * Acquire in exclusive interruptible mode
-     * @param arg the acquire argument
-     */
-    private void doAcquireInterruptibly(int arg) 
-        throws InterruptedException {
-        final Node node = addWaiter(Node.EXCLUSIVE);
-        try {
-            for (;;) {
-                final Node p = node.predecessor();
-                if (p == head && tryAcquire(arg)) {
-                    setHead(node);
-                    p.next = null; // help GC
-                    return;
-                }
-                if (shouldParkAfterFailedAcquire(p, node) && 
-                    parkAndCheckInterrupt()) 
-                    break;
-            }
-        } catch (RuntimeException ex) {
-            cancelAcquire(node);
-            throw ex;
-        }
-        // Arrive here only if interrupted
-        cancelAcquire(node);
-        throw new InterruptedException();
-    }
-
-    /** 
-     * Acquire in exclusive timed mode
-     * @param arg the acquire argument
-     * @param nanosTimeout max wait time
-     * @return true if acquired
-     */
-    private boolean doAcquireNanos(int arg, long nanosTimeout) 
-        throws InterruptedException {
-        long lastTime = System.nanoTime();
-        final Node node = addWaiter(Node.EXCLUSIVE);
-        try {
-            for (;;) {
-                final Node p = node.predecessor();
-                if (p == head && tryAcquire(arg)) {
-                    setHead(node);
-                    p.next = null; // help GC
-                    return true;
-                }
-                if (nanosTimeout <= 0) {
-                    cancelAcquire(node);
-                    return false;
-                }
-                if (shouldParkAfterFailedAcquire(p, node)) {
-                    LockSupport.parkNanos(nanosTimeout);
-                    if (Thread.interrupted()) 
-                        break;
-                    long now = System.nanoTime();
-                    nanosTimeout -= now - lastTime;
-                    lastTime = now;
-                }
-            }
-        } catch (RuntimeException ex) {
-            cancelAcquire(node);
-            throw ex;
-        }
-        // Arrive here only if interrupted
-        cancelAcquire(node);
-        throw new InterruptedException();
-    }
-
-    /** 
-     * Acquire in shared uninterruptible mode
-     * @param arg the acquire argument
-     */
-    private void doAcquireShared(int arg) {
-        final Node node = addWaiter(Node.SHARED);
-        try {
-            boolean interrupted = false;
-            for (;;) {
-                final Node p = node.predecessor();
-                if (p == head) {
-                    int r = tryAcquireShared(arg);
-                    if (r >= 0) {
-                        setHeadAndPropagate(node, r);
-                        p.next = null; // help GC
-                        if (interrupted)
-                            selfInterrupt();
-                        return;
-                    }
-                }
-                if (shouldParkAfterFailedAcquire(p, node) && 
-                    parkAndCheckInterrupt()) 
-                    interrupted = true;
-            }
-        } catch (RuntimeException ex) {
-            cancelAcquire(node);
-            throw ex;
-        }
-    }
-
-    /** 
-     * Acquire in shared interruptible mode
-     * @param arg the acquire argument
-     */
-    private void doAcquireSharedInterruptibly(int arg) 
-        throws InterruptedException {
-        final Node node = addWaiter(Node.SHARED);
-        try {
-            for (;;) {
-                final Node p = node.predecessor();
-                if (p == head) {
-                    int r = tryAcquireShared(arg);
-                    if (r >= 0) {
-                        setHeadAndPropagate(node, r);
-                        p.next = null; // help GC
-                        return;
-                    }
-                }
-                if (shouldParkAfterFailedAcquire(p, node) && 
-                    parkAndCheckInterrupt()) 
-                    break;
-            }
-        } catch (RuntimeException ex) {
-            cancelAcquire(node);
-            throw ex;
-        }
-        // Arrive here only if interrupted
-        cancelAcquire(node);
-        throw new InterruptedException();
-    }
-
-    /** 
-     * Acquire in shared timed mode
-     * @param arg the acquire argument
-     * @param nanosTimeout max wait time
-     * @return true if acquired
-     */
-    private boolean doAcquireSharedNanos(int arg, long nanosTimeout) 
-        throws InterruptedException {
-
-        long lastTime = System.nanoTime();
-        final Node node = addWaiter(Node.SHARED);
-        try {
-            for (;;) {
-                final Node p = node.predecessor();
-                if (p == head) {
-                    int r = tryAcquireShared(arg);
-                    if (r >= 0) {
-                        setHeadAndPropagate(node, r);
-                        p.next = null; // help GC
-                        return true;
-                    }
-                }
-                if (nanosTimeout <= 0) {
-                    cancelAcquire(node);
-                    return false;
-                }
-                if (shouldParkAfterFailedAcquire(p, node)) {
-                    LockSupport.parkNanos(nanosTimeout);
-                    if (Thread.interrupted()) 
-                        break;
-                    long now = System.nanoTime();
-                    nanosTimeout -= now - lastTime;
-                    lastTime = now;
-                }
-            }
-        } catch (RuntimeException ex) {
-            cancelAcquire(node);
-            throw ex;
-        }
-        // Arrive here only if interrupted
-        cancelAcquire(node);
-        throw new InterruptedException();
-    }
-
-    // Main exported methods 
-
-    /**
-     * Attempts to acquire in exclusive mode. This method should query
-     * if the state of the object permits it to be acquired in the
-     * exclusive mode, and if so to acquire it.
-     *
-     * <p>This method is always invoked by the thread performing
-     * acquire.  If this method reports failure, the acquire method
-     * may queue the thread, if it is not already queued, until it is
-     * signalled by a release from some other thread. This can be used
-     * to implement method {@link Lock#tryLock()}. 
-     *
-     * <p>The default
-     * implementation throws {@link UnsupportedOperationException}
-     *
-     * @param arg the acquire argument. This value
-     * is always the one passed to an acquire method,
-     * or is the value saved on entry to a condition wait.
-     * The value is otherwise uninterpreted and can represent anything
-     * you like.
-     * @return true if successful. Upon success, this object has been
-     * acquired.
-     * @throws IllegalMonitorStateException if acquiring would place
-     * this synchronizer in an illegal state. This exception must be
-     * thrown in a consistent fashion for synchronization to work
-     * correctly.
-     * @throws UnsupportedOperationException if exclusive mode is not supported
-     */
-    protected boolean tryAcquire(int arg) {
-        throw new UnsupportedOperationException();
-    }
-
-    /**
-     * Attempts to set the state to reflect a release in exclusive
-     * mode.  <p>This method is always invoked by the thread
-     * performing release.  
-     *
-     * <p>The default implementation throws
-     * {@link UnsupportedOperationException}
-     * @param arg the release argument. This value
-     * is always the one passed to a release method,
-     * or the current state value upon entry to a condition wait.
-     * The value is otherwise uninterpreted and can represent anything
-     * you like.
-     * @return <tt>true</tt> if this object is now in a fully released state, 
-     * so that any waiting threads may attempt to acquire; and <tt>false</tt>
-     * otherwise.
-     * @throws IllegalMonitorStateException if releasing would place
-     * this synchronizer in an illegal state. This exception must be
-     * thrown in a consistent fashion for synchronization to work
-     * correctly.
-     * @throws UnsupportedOperationException if exclusive mode is not supported
-     */
-    protected boolean tryRelease(int arg) {
-        throw new UnsupportedOperationException();
-    }
-
-    /**
-     * Attempts to acquire in shared mode. This method should query if
-     * the state of the object permits it to be acquired in the shared
-     * mode, and if so to acquire it.  
-     *
-     * <p>This method is always invoked by the thread performing
-     * acquire.  If this method reports failure, the acquire method
-     * may queue the thread, if it is not already queued, until it is
-     * signalled by a release from some other thread.
-     *
-     * <p>The default implementation throws {@link
-     * UnsupportedOperationException}
-     *
-     * @param arg the acquire argument. This value
-     * is always the one passed to an acquire method,
-     * or is the value saved on entry to a condition wait.
-     * The value is otherwise uninterpreted and can represent anything
-     * you like.
-     * @return a negative value on failure, zero on exclusive success,
-     * and a positive value if non-exclusively successful, in which
-     * case a subsequent waiting thread must check
-     * availability. (Support for three different return values
-     * enables this method to be used in contexts where acquires only
-     * sometimes act exclusively.)  Upon success, this object has been
-     * acquired.
-     * @throws IllegalMonitorStateException if acquiring would place
-     * this synchronizer in an illegal state. This exception must be
-     * thrown in a consistent fashion for synchronization to work
-     * correctly.
-     * @throws UnsupportedOperationException if shared mode is not supported
-     */
-    protected int tryAcquireShared(int arg) {
-        throw new UnsupportedOperationException();
-    }
-
-    /**
-     * Attempts to set the state to reflect a release in shared mode.
-     * <p>This method is always invoked by the thread performing release.
-     * <p> The default implementation throws 
-     * {@link UnsupportedOperationException}
-     * @param arg the release argument. This value
-     * is always the one passed to a release method,
-     * or the current state value upon entry to a condition wait.
-     * The value is otherwise uninterpreted and can represent anything
-     * you like.
-     * @return <tt>true</tt> if this object is now in a fully released state, 
-     * so that any waiting threads may attempt to acquire; and <tt>false</tt>
-     * otherwise.
-     * @throws IllegalMonitorStateException if releasing would place
-     * this synchronizer in an illegal state. This exception must be
-     * thrown in a consistent fashion for synchronization to work
-     * correctly.
-     * @throws UnsupportedOperationException if shared mode is not supported
-     */
-    protected boolean tryReleaseShared(int arg) {
-        throw new UnsupportedOperationException();
-    }
-
-    /**
-     * Returns true if synchronization is held exclusively with respect
-     * to the current (calling) thread.  This method is invoked
-     * upon each call to a non-waiting {@link ConditionObject} method.
-     * (Waiting methods instead invoke {@link #release}.)
-     * <p>The default implementation throws {@link
-     * UnsupportedOperationException}. This method is invoked
-     * internally only within {@link ConditionObject} methods, so need
-     * not be defined if conditions are not used.
-     *
-     * @return true if synchronization is held exclusively;
-     * else false
-     * @throws UnsupportedOperationException if conditions are not supported
-     */
-    protected boolean isHeldExclusively() {
-        throw new UnsupportedOperationException();
-    }
-
-    /**
-     * Acquires in exclusive mode, ignoring interrupts.  Implemented
-     * by invoking at least once {@link #tryAcquire},
-     * returning on success.  Otherwise the thread is queued, possibly
-     * repeatedly blocking and unblocking, invoking {@link
-     * #tryAcquire} until success.  This method can be used
-     * to implement method {@link Lock#lock}
-     * @param arg the acquire argument.
-     * This value is conveyed to {@link #tryAcquire} but is
-     * otherwise uninterpreted and can represent anything
-     * you like.
-     */ 
-    public final void acquire(int arg) {
-        if (!tryAcquire(arg) &&
-            acquireQueued(addWaiter(Node.EXCLUSIVE), arg))
-            selfInterrupt();
-    }
-
-    /**
-     * Acquires in exclusive mode, aborting if interrupted.
-     * Implemented by first checking interrupt status, then invoking
-     * at least once {@link #tryAcquire}, returning on
-     * success.  Otherwise the thread is queued, possibly repeatedly
-     * blocking and unblocking, invoking {@link #tryAcquire}
-     * until success or the thread is interrupted.  This method can be
-     * used to implement method {@link Lock#lockInterruptibly}
-     * @param arg the acquire argument.
-     * This value is conveyed to {@link #tryAcquire} but is
-     * otherwise uninterpreted and can represent anything
-     * you like.
-     * @throws InterruptedException if the current thread is interrupted
-     */
-    public final void acquireInterruptibly(int arg) throws InterruptedException {
-        if (Thread.interrupted())
-            throw new InterruptedException();
-        if (!tryAcquire(arg))
-            doAcquireInterruptibly(arg);
-    }
-
-    /**
-     * Attempts to acquire in exclusive mode, aborting if interrupted,
-     * and failing if the given timeout elapses.  Implemented by first
-     * checking interrupt status, then invoking at least once {@link
-     * #tryAcquire}, returning on success.  Otherwise, the thread is
-     * queued, possibly repeatedly blocking and unblocking, invoking
-     * {@link #tryAcquire} until success or the thread is interrupted
-     * or the timeout elapses.  This method can be used to implement
-     * method {@link Lock#tryLock(long, TimeUnit)}.
-     * @param arg the acquire argument.
-     * This value is conveyed to {@link #tryAcquire} but is
-     * otherwise uninterpreted and can represent anything
-     * you like.
-     * @param nanosTimeout the maximum number of nanoseconds to wait
-     * @return true if acquired; false if timed out
-     * @throws InterruptedException if the current thread is interrupted
-     */
-   public final boolean tryAcquireNanos(int arg, long nanosTimeout) throws InterruptedException {
-       if (Thread.interrupted())
-           throw new InterruptedException();
-       return tryAcquire(arg) ||
-           doAcquireNanos(arg, nanosTimeout);
-   }
-
-    /**
-     * Releases in exclusive mode.  Implemented by unblocking one or
-     * more threads if {@link #tryRelease} returns true.
-     * This method can be used to implement method {@link Lock#unlock}
-     * @param arg the release argument.
-     * This value is conveyed to {@link #tryRelease} but is
-     * otherwise uninterpreted and can represent anything
-     * you like.
-     * @return the value returned from {@link #tryRelease} 
-     */
-    public final boolean release(int arg) {
-        if (tryRelease(arg)) {
-            Node h = head;
-            if (h != null && h.waitStatus != 0) 
-                unparkSuccessor(h);
-            return true;
-        }
-        return false;
-    }
-
-    /**
-     * Acquires in shared mode, ignoring interrupts.  Implemented by
-     * first invoking at least once {@link #tryAcquireShared},
-     * returning on success.  Otherwise the thread is queued, possibly
-     * repeatedly blocking and unblocking, invoking {@link
-     * #tryAcquireShared} until success.  
-     * @param arg the acquire argument.
-     * This value is conveyed to {@link #tryAcquireShared} but is
-     * otherwise uninterpreted and can represent anything
-     * you like.
-     */
-    public final void acquireShared(int arg) {
-        if (tryAcquireShared(arg) < 0)
-            doAcquireShared(arg);
-    }
-
-    /**
-     * Acquires in shared mode, aborting if interrupted.  Implemented
-     * by first checking interrupt status, then invoking at least once
-     * {@link #tryAcquireShared}, returning on success.  Otherwise the
-     * thread is queued, possibly repeatedly blocking and unblocking,
-     * invoking {@link #tryAcquireShared} until success or the thread
-     * is interrupted.  
-     * @param arg the acquire argument.
-     * This value is conveyed to {@link #tryAcquireShared} but is
-     * otherwise uninterpreted and can represent anything
-     * you like.
-     * @throws InterruptedException if the current thread is interrupted
-     */
-    public final void acquireSharedInterruptibly(int arg) throws InterruptedException {
-        if (Thread.interrupted())
-            throw new InterruptedException();
-        if (tryAcquireShared(arg) < 0)
-            doAcquireSharedInterruptibly(arg);
-   }
-
-    /**
-     * Attempts to acquire in shared mode, aborting if interrupted, and
-     * failing if the given timeout elapses.  Implemented by first
-     * checking interrupt status, then invoking at least once {@link
-     * #tryAcquireShared}, returning on success.  Otherwise, the
-     * thread is queued, possibly repeatedly blocking and unblocking,
-     * invoking {@link #tryAcquireShared} until success or the thread
-     * is interrupted or the timeout elapses.
-     * @param arg the acquire argument.
-     * This value is conveyed to {@link #tryAcquireShared} but is
-     * otherwise uninterpreted and can represent anything
-     * you like.
-     * @param nanosTimeout the maximum number of nanoseconds to wait
-     * @return true if acquired; false if timed out
-     * @throws InterruptedException if the current thread is interrupted
-     */
-   public final boolean tryAcquireSharedNanos(int arg, long nanosTimeout) throws InterruptedException {
-       if (Thread.interrupted())
-           throw new InterruptedException();
-       return tryAcquireShared(arg) >= 0 ||
-           doAcquireSharedNanos(arg, nanosTimeout);
-   }
-
-    /**
-     * Releases in shared mode.  Implemented by unblocking one or more
-     * threads if {@link #tryReleaseShared} returns true. 
-     * @param arg the release argument.
-     * This value is conveyed to {@link #tryReleaseShared} but is
-     * otherwise uninterpreted and can represent anything
-     * you like.
-     * @return the value returned from {@link #tryReleaseShared} 
-     */
-    public final boolean releaseShared(int arg) {
-        if (tryReleaseShared(arg)) {
-            Node h = head;
-            if (h != null && h.waitStatus != 0) 
-                unparkSuccessor(h);
-            return true;
-        }
-        return false;
-    }
-
-    // Queue inspection methods
-
-    /**
-     * Queries whether any threads are waiting to acquire. Note that
-     * because cancellations due to interrupts and timeouts may occur
-     * at any time, a <tt>true</tt> return does not guarantee that any
-     * other thread will ever acquire.
-     *
-     * <p> In this implementation, this operation returns in
-     * constant time.
-     *
-     * @return true if there may be other threads waiting to acquire
-     * the lock.
-     */
-    public final boolean hasQueuedThreads() { 
-        return head != tail;
-    }
-
-    /**
-     * Queries whether any threads have ever contended to acquire this
-     * synchronizer; that is if an acquire method has ever blocked.
-     *
-     * <p> In this implementation, this operation returns in
-     * constant time.
-     *
-     * @return true if there has ever been contention
-     */
-    public final boolean hasContended() {
-        return head != null;
-    }
-
-    /**
-     * Returns the first (longest-waiting) thread in the queue, or
-     * <tt>null</tt> if no threads are currently queued.
-     *
-     * <p> In this implementation, this operation normally returns in
-     * constant time, but may iterate upon contention if other threads are
-     * concurrently modifying the queue.
-     *
-     * @return the first (longest-waiting) thread in the queue, or
-     * <tt>null</tt> if no threads are currently queued.
-     */
-    public final Thread getFirstQueuedThread() {
-        // handle only fast path, else relay
-        return (head == tail)? null : fullGetFirstQueuedThread();
-    }
-
-    /**
-     * Version of getFirstQueuedThread called when fastpath fails
-     */
-    private Thread fullGetFirstQueuedThread() {
-        /*
-         * This loops only if the queue changes while we read sets of
-         * fields.
-         */
-        for (;;) {
-            Node h = head;
-            if (h == null)                    // No queue
-                return null;
-
-            /*
-             * The first node is normally h.next. Try to get its
-             * thread field, ensuring consistent reads: If thread
-             * field is nulled out or s.prev is no longer head, then
-             * some other thread(s) concurrently performed setHead in
-             * between some of our reads, so we must reread.
-             */
-            Node s = h.next;
-            if (s != null) {
-                Thread st = s.thread;
-                Node sp = s.prev;
-                if (st != null && sp == head)
-                    return st;
-            }
-
-            /*
-             * Head's next field might not have been set yet, or may
-             * have been unset after setHead. So we must check to see
-             * if tail is actually first node, in almost the same way
-             * as above.
-             */
-            Node t = tail; 
-            if (t == h)                       // Empty queue
-                return null;
-
-            if (t != null) {
-                Thread tt = t.thread;
-                Node tp = t.prev;
-                if (tt != null && tp == head)
-                    return tt;
-            }
-        }
-    }
-
-    /**
-     * Returns true if the given thread is currently queued. 
-     *
-     * <p> This implementation traverses the queue to determine
-     * presence of the given thread.
-     *
-     * @param thread the thread
-     * @return true if the given thread in on the queue
-     * @throws NullPointerException if thread null
-     */
-    public final boolean isQueued(Thread thread) {
-        if (thread == null)
-            throw new NullPointerException();
-        for (Node p = tail; p != null; p = p.prev)
-            if (p.thread == thread)
-                return true;
-        return false;
-    }
-
-    // Instrumentation and monitoring methods
-
-    /**
-     * Returns an estimate of the number of threads waiting to
-     * acquire.  The value is only an estimate because the number of
-     * threads may change dynamically while this method traverses
-     * internal data structures.  This method is designed for use in
-     * monitoring system state, not for synchronization
-     * control.
-     *
-     * @return the estimated number of threads waiting for this lock
-     */
-    public final int getQueueLength() {
-        int n = 0;
-        for (Node p = tail; p != null; p = p.prev) {
-            if (p.thread != null)
-                ++n;
-        }
-        return n;
-    }
-
-    /**
-     * Returns a collection containing threads that may be waiting to
-     * acquire.  Because the actual set of threads may change
-     * dynamically while constructing this result, the returned
-     * collection is only a best-effort estimate.  The elements of the
-     * returned collection are in no particular order.  This method is
-     * designed to facilitate construction of subclasses that provide
-     * more extensive monitoring facilities.
-     * @return the collection of threads
-     */
-    public final Collection<Thread> getQueuedThreads() {
-        ArrayList<Thread> list = new ArrayList<Thread>();
-        for (Node p = tail; p != null; p = p.prev) {
-            Thread t = p.thread;
-            if (t != null)
-                list.add(t);
-        }
-        return list;
-    }
-
-    /**
-     * Returns a collection containing threads that may be waiting to
-     * acquire in exclusive mode. This has the same properties
-     * as {@link #getQueuedThreads} except that it only returns
-     * those threads waiting due to an exclusive acquire.
-     * @return the collection of threads
-     */
-    public final Collection<Thread> getExclusiveQueuedThreads() {
-        ArrayList<Thread> list = new ArrayList<Thread>();
-        for (Node p = tail; p != null; p = p.prev) {
-            if (!p.isShared()) {
-                Thread t = p.thread;
-                if (t != null)
-                    list.add(t);
-            }
-        }
-        return list;
-    }
-
-    /**
-     * Returns a collection containing threads that may be waiting to
-     * acquire in shared mode. This has the same properties
-     * as {@link #getQueuedThreads} except that it only returns
-     * those threads waiting due to a shared acquire.
-     * @return the collection of threads
-     */
-    public final Collection<Thread> getSharedQueuedThreads() {
-        ArrayList<Thread> list = new ArrayList<Thread>();
-        for (Node p = tail; p != null; p = p.prev) {
-            if (p.isShared()) {
-                Thread t = p.thread;
-                if (t != null)
-                    list.add(t);
-            }
-        }
-        return list;
-    }
-
-    /**
-     * Returns a string identifying this synchronizer, as well as its
-     * state.  The state, in brackets, includes the String &quot;State
-     * =&quot; followed by the current value of {@link #getState}, and
-     * either &quot;nonempty&quot; or &quot;empty&quot; depending on
-     * whether the queue is empty.
-     *
-     * @return a string identifying this synchronizer, as well as its state.
-     */
-    public String toString() {
-        int s = getState();
-        String q  = hasQueuedThreads()? "non" : "";
-        return super.toString() + 
-            "[State = " + s + ", " + q + "empty queue]";
-    }
-
-
-    // Internal support methods for Conditions
-
-    /**
-     * Returns true if a node, always one that was initially placed on
-     * a condition queue, is now waiting to reacquire on sync queue.
-     * @param node the node
-     * @return true if is reacquiring
-     */
-    final boolean isOnSyncQueue(Node node) {
-        if (node.waitStatus == Node.CONDITION || node.prev == null)
-            return false;
-        if (node.next != null) // If has successor, it must be on queue
-            return true;
-        /*
-         * node.prev can be non-null, but not yet on queue because
-         * the CAS to place it on queue can fail. So we have to
-         * traverse from tail to make sure it actually made it.  It
-         * will always be near the tail in calls to this method, and
-         * unless the CAS failed (which is unlikely), it will be
-         * there, so we hardly ever traverse much.
-         */
-        return findNodeFromTail(node);
-    } 
-
-    /**
-     * Returns true if node is on sync queue by searching backwards from tail.
-     * Called only when needed by isOnSyncQueue.
-     * @return true if present
-     */
-    private boolean findNodeFromTail(Node node) {
-        Node t = tail; 
-        for (;;) {
-            if (t == node)
-                return true;
-            if (t == null)
-                return false;
-            t = t.prev;
-        }
-    }
-
-    /**
-     * Transfers a node from a condition queue onto sync queue. 
-     * Returns true if successful.
-     * @param node the node
-     * @return true if successfully transferred (else the node was
-     * cancelled before signal).
-     */
-    final boolean transferForSignal(Node node) {
-        /*
-         * If cannot change waitStatus, the node has been cancelled.
-         */
-        if (!compareAndSetWaitStatus(node, Node.CONDITION, 0))
-            return false;
-
-        /*
-         * Splice onto queue and try to set waitStatus of predecessor to
-         * indicate that thread is (probably) waiting. If cancelled or
-         * attempt to set waitStatus fails, wake up to resync (in which
-         * case the waitStatus can be transiently and harmlessly wrong).
-         */
-        Node p = enq(node);
-        int c = p.waitStatus;
-        if (c > 0 || !compareAndSetWaitStatus(p, c, Node.SIGNAL)) 
-            LockSupport.unpark(node.thread);
-        return true;
-    }
-
-    /**
-     * Transfers node, if necessary, to sync queue after a cancelled
-     * wait. Returns true if thread was cancelled before being
-     * signalled.
-     * @param current the waiting thread
-     * @param node its node
-     * @return true if cancelled before the node was signalled.
-     */
-    final boolean transferAfterCancelledWait(Node node) {
-        if (compareAndSetWaitStatus(node, Node.CONDITION, 0)) {
-            enq(node);
-            return true;
-        }
-        /*
-         * If we lost out to a signal(), then we can't proceed
-         * until it finishes its enq().  Cancelling during an
-         * incomplete transfer is both rare and transient, so just
-         * spin.
-         */
-        while (!isOnSyncQueue(node)) 
-            Thread.yield();
-        return false;
-    }
-
-    /**
-     * Invoke release with current state value; return saved state.
-     * Cancel node and throw exception on failure.
-     * @param node the condition node for this wait
-     * @return previous sync state
-     */
-    final int fullyRelease(Node node) {
-        try {
-            int savedState = getState();
-            if (release(savedState))
-                return savedState;
-        } catch(RuntimeException ex) {
-            node.waitStatus = Node.CANCELLED;
-            throw ex;
-        }
-        // reach here if release fails
-        node.waitStatus = Node.CANCELLED;
-        throw new IllegalMonitorStateException();
-    }
-
-    // Instrumentation methods for conditions
-
-    /**
-     * Queries whether the given ConditionObject 
-     * uses this synchronizer as its lock.
-     * @param condition the condition
-     * @return <tt>true</tt> if owned
-     * @throws NullPointerException if condition null
-     */
-    public final boolean owns(ConditionObject condition) {
-        if (condition == null)
-            throw new NullPointerException();
-        return condition.isOwnedBy(this);
-    }
-
-    /**
-     * Queries whether any threads are waiting on the given condition
-     * associated with this synchronizer. Note that because timeouts
-     * and interrupts may occur at any time, a <tt>true</tt> return
-     * does not guarantee that a future <tt>signal</tt> will awaken
-     * any threads.  This method is designed primarily for use in
-     * monitoring of the system state.
-     * @param condition the condition
-     * @return <tt>true</tt> if there are any waiting threads.
-     * @throws IllegalMonitorStateException if exclusive synchronization 
-     * is not held
-     * @throws IllegalArgumentException if the given condition is
-     * not associated with this synchronizer
-     * @throws NullPointerException if condition null
-     */ 
-    public final boolean hasWaiters(ConditionObject condition) {
-        if (!owns(condition))
-            throw new IllegalArgumentException("Not owner");
-        return condition.hasWaiters();
-    }
-
-    /**
-     * Returns an estimate of the number of threads waiting on the
-     * given condition associated with this synchronizer. Note that
-     * because timeouts and interrupts may occur at any time, the
-     * estimate serves only as an upper bound on the actual number of
-     * waiters.  This method is designed for use in monitoring of the
-     * system state, not for synchronization control.
-     * @param condition the condition
-     * @return the estimated number of waiting threads.
-     * @throws IllegalMonitorStateException if exclusive synchronization 
-     * is not held
-     * @throws IllegalArgumentException if the given condition is
-     * not associated with this synchronizer
-     * @throws NullPointerException if condition null
-     */ 
-    public final int getWaitQueueLength(ConditionObject condition) {
-        if (!owns(condition))
-            throw new IllegalArgumentException("Not owner");
-        return condition.getWaitQueueLength();
-    }
-
-    /**
-     * Returns a collection containing those threads that may be
-     * waiting on the given condition associated with this
-     * synchronizer.  Because the actual set of threads may change
-     * dynamically while constructing this result, the returned
-     * collection is only a best-effort estimate. The elements of the
-     * returned collection are in no particular order.  
-     * @param condition the condition
-     * @return the collection of threads
-     * @throws IllegalMonitorStateException if exclusive synchronization 
-     * is not held
-     * @throws IllegalArgumentException if the given condition is
-     * not associated with this synchronizer
-     * @throws NullPointerException if condition null
-     */
-    public final Collection<Thread> getWaitingThreads(ConditionObject condition) {
-        if (!owns(condition))
-            throw new IllegalArgumentException("Not owner");
-        return condition.getWaitingThreads();
-    }
-
-    /**
-     * Condition implementation for a {@link
-     * AbstractQueuedSynchronizer} serving as the basis of a {@link
-     * Lock} implementation.
-     *
-     * <p> Method documentation for this class describes mechanics,
-     * not behavioral specifications from the point of view of Lock
-     * and Condition users. Exported versions of this class will in
-     * general need to be accompanied by documentation describing
-     * condition semantics that rely on those of the associated
-     * <tt>AbstractQueuedSynchronizer</tt>.
-     * 
-     * <p> This class is Serializable, but all fields are transient,
-     * so deserialized conditions have no waiters.
-     */
-    public class ConditionObject implements Condition, java.io.Serializable {
-        private static final long serialVersionUID = 1173984872572414699L;
-        /** First node of condition queue. */
-        private transient Node firstWaiter;
-        /** Last node of condition queue. */
-        private transient Node lastWaiter;
-
-        /**
-         * Creates a new <tt>ConditionObject</tt> instance.
-         */
-        public ConditionObject() { }
-
-        // Internal methods
-
-        /**
-         * Add a new waiter to wait queue
-         * @return its new wait node
-         */
-        private Node addConditionWaiter() {
-            Node node = new Node(Thread.currentThread(), Node.CONDITION);
-            Node t = lastWaiter;
-            if (t == null) 
-                firstWaiter = node;
-            else 
-                t.nextWaiter = node;
-            lastWaiter = node;
-            return node;
-        }
-
-        /**
-         * Remove and transfer nodes until hit non-cancelled one or
-         * null. Split out from signal in part to encourage compilers
-         * to inline the case of no waiters.
-         * @param first (non-null) the first node on condition queue
-         */
-        private void doSignal(Node first) {
-            do {
-                if ( (firstWaiter = first.nextWaiter) == null) 
-                    lastWaiter = null;
-                first.nextWaiter = null;
-            } while (!transferForSignal(first) &&
-                     (first = firstWaiter) != null);
-        }
-
-        /**
-         * Remove and transfer all nodes.
-         * @param first (non-null) the first node on condition queue
-         */
-        private void doSignalAll(Node first) {
-            lastWaiter = firstWaiter  = null;
-            do {
-                Node next = first.nextWaiter;
-                first.nextWaiter = null;
-                transferForSignal(first);
-                first = next;
-            } while (first != null);
-        }
-
-        // public methods
-
-        /**
-         * Moves the longest-waiting thread, if one exists, from the
-         * wait queue for this condition to the wait queue for the
-         * owning lock.
-         * @throws IllegalMonitorStateException if {@link #isHeldExclusively}
-         * returns false
-         */
-        public final void signal() {
-            if (!isHeldExclusively()) 
-                throw new IllegalMonitorStateException();
-            Node first = firstWaiter;
-            if (first != null)
-                doSignal(first);
-        }
-         
-        /**
-         * Moves all threads from the wait queue for this condition to
-         * the wait queue for the owning lock.
-         * @throws IllegalMonitorStateException if {@link #isHeldExclusively}
-         * returns false
-         */
-        public final void signalAll() {
-            if (!isHeldExclusively()) 
-                throw new IllegalMonitorStateException();
-            Node first = firstWaiter;
-            if (first != null) 
-                doSignalAll(first);
-        }
-
-        /**
-         * Implements uninterruptible condition wait.
-         * <ol>
-         * <li> Save lock state returned by {@link #getState} 
-         * <li> Invoke {@link #release} with 
-         *      saved state as argument, throwing 
-         *      IllegalMonitorStateException  if it fails.
-         * <li> Block until signalled
-         * <li> Reacquire by invoking specialized version of
-         *      {@link #acquire} with saved state as argument.
-         * </ol>
-         */
-        public final void awaitUninterruptibly() {
-            Node node = addConditionWaiter();
-            int savedState = fullyRelease(node);
-            boolean interrupted = false;
-            while (!isOnSyncQueue(node)) {
-                LockSupport.park();
-                if (Thread.interrupted()) 
-                    interrupted = true;
-            }
-            if (acquireQueued(node, savedState) || interrupted)
-                selfInterrupt();
-        }
-
-        /*
-         * For interruptible waits, we need to track whether to throw
-         * InterruptedException, if interrupted while blocked on
-         * condition, versus reinterrupt current thread, if
-         * interrupted while blocked waiting to re-acquire.
-         */
-
-        /** Mode meaning to reinterrupt on exit from wait */
-        private static final int REINTERRUPT =  1;
-        /** Mode meaning to throw InterruptedException on exit from wait */
-        private static final int THROW_IE    = -1;
-
-        /**
-         * Check for interrupt, returning THROW_IE if interrupted
-         * before signalled, REINTERRUPT if after signalled, or
-         * 0 if not interrupted.
-         */
-        private int checkInterruptWhileWaiting(Node node) {
-            return (Thread.interrupted()) ?
-                ((transferAfterCancelledWait(node))? THROW_IE : REINTERRUPT) :
-                0;
-        }
-
-        /**
-         * Throw InterruptedException, reinterrupt current thread, or
-         * do nothing, depending on mode.
-         */
-        private void reportInterruptAfterWait(int interruptMode) 
-            throws InterruptedException {
-            if (interruptMode == THROW_IE)
-                throw new InterruptedException();
-            else if (interruptMode == REINTERRUPT)
-                Thread.currentThread().interrupt();
-        }
-
-        /**
-         * Implements interruptible condition wait.
-         * <ol>
-         * <li> If current thread is interrupted, throw InterruptedException
-         * <li> Save lock state returned by {@link #getState} 
-         * <li> Invoke {@link #release} with 
-         *      saved state as argument, throwing 
-         *      IllegalMonitorStateException  if it fails.
-         * <li> Block until signalled or interrupted
-         * <li> Reacquire by invoking specialized version of
-         *      {@link #acquire} with saved state as argument.
-         * <li> If interrupted while blocked in step 4, throw exception
-         * </ol>
-         * 
-         * @throws InterruptedException if the current thread is interrupted (and
-         * interruption of thread suspension is supported).
-         */
-        public final void await() throws InterruptedException {
-            if (Thread.interrupted()) 
-                throw new InterruptedException();
-            Node node = addConditionWaiter();
-            int savedState = fullyRelease(node);
-            int interruptMode = 0;
-            while (!isOnSyncQueue(node)) {
-                LockSupport.park();
-                if ((interruptMode = checkInterruptWhileWaiting(node)) != 0)
-                    break;
-            }
-            if (acquireQueued(node, savedState) && interruptMode != THROW_IE)
-                interruptMode = REINTERRUPT;
-            if (interruptMode != 0)
-                reportInterruptAfterWait(interruptMode);
-        }
-
-        /**
-         * Implements timed condition wait.
-         * <ol>
-         * <li> If current thread is interrupted, throw InterruptedException
-         * <li> Save lock state returned by {@link #getState} 
-         * <li> Invoke {@link #release} with 
-         *      saved state as argument, throwing 
-         *      IllegalMonitorStateException  if it fails.
-         * <li> Block until signalled, interrupted, or timed out
-         * <li> Reacquire by invoking specialized version of
-         *      {@link #acquire} with saved state as argument.
-         * <li> If interrupted while blocked in step 4, throw InterruptedException
-         * </ol>
-         * 
-         * @param nanosTimeout the maximum time to wait, in nanoseconds
-         * @return A value less than or equal to zero if the wait has
-         * timed out; otherwise an estimate, that
-         * is strictly less than the <tt>nanosTimeout</tt> argument,
-         * of the time still remaining when this method returned.
-         *
-         * @throws InterruptedException if the current thread is interrupted (and
-         * interruption of thread suspension is supported).
-         */
-        public final long awaitNanos(long nanosTimeout) throws InterruptedException {
-            if (Thread.interrupted()) 
-                throw new InterruptedException();
-            Node node = addConditionWaiter();
-            int savedState = fullyRelease(node);
-            long lastTime = System.nanoTime();
-            int interruptMode = 0;
-            while (!isOnSyncQueue(node)) {
-                if (nanosTimeout <= 0L) {
-                    transferAfterCancelledWait(node); 
-                    break;
-                }
-                LockSupport.parkNanos(nanosTimeout);
-                if ((interruptMode = checkInterruptWhileWaiting(node)) != 0)
-                    break;
-                long now = System.nanoTime();
-                nanosTimeout -= now - lastTime;
-                lastTime = now;
-            }
-            if (acquireQueued(node, savedState) && interruptMode != THROW_IE)
-                interruptMode = REINTERRUPT;
-            if (interruptMode != 0)
-                reportInterruptAfterWait(interruptMode);
-            return nanosTimeout - (System.nanoTime() - lastTime);
-        }
-
-        /**
-         * Implements absolute timed condition wait.
-         * <ol>
-         * <li> If current thread is interrupted, throw InterruptedException
-         * <li> Save lock state returned by {@link #getState} 
-         * <li> Invoke {@link #release} with 
-         *      saved state as argument, throwing 
-         *      IllegalMonitorStateException  if it fails.
-         * <li> Block until signalled, interrupted, or timed out
-         * <li> Reacquire by invoking specialized version of
-         *      {@link #acquire} with saved state as argument.
-         * <li> If interrupted while blocked in step 4, throw InterruptedException
-         * <li> If timed out while blocked in step 4, return false, else true
-         * </ol>
-         * 
-         * @param deadline the absolute time to wait until
-         * @return <tt>false</tt> if the deadline has
-         * elapsed upon return, else <tt>true</tt>.
-         *
-         * @throws InterruptedException if the current thread is interrupted (and
-         * interruption of thread suspension is supported).
-         */
-        public final boolean awaitUntil(Date deadline) throws InterruptedException {
-            if (deadline == null)
-                throw new NullPointerException();
-            long abstime = deadline.getTime();
-            if (Thread.interrupted()) 
-                throw new InterruptedException();
-            Node node = addConditionWaiter();
-            int savedState = fullyRelease(node);
-            boolean timedout = false;
-            int interruptMode = 0;
-            while (!isOnSyncQueue(node)) {
-                if (System.currentTimeMillis() > abstime) {
-                    timedout = transferAfterCancelledWait(node); 
-                    break;
-                }
-                LockSupport.parkUntil(abstime);
-                if ((interruptMode = checkInterruptWhileWaiting(node)) != 0)
-                    break;
-            }
-            if (acquireQueued(node, savedState) && interruptMode != THROW_IE)
-                interruptMode = REINTERRUPT;
-            if (interruptMode != 0)
-                reportInterruptAfterWait(interruptMode);
-            return !timedout;
-        }
-        
-        /**
-         * Implements timed condition wait. 
-         * <ol>
-         * <li> If current thread is interrupted, throw InterruptedException
-         * <li> Save lock state returned by {@link #getState} 
-         * <li> Invoke {@link #release} with 
-         *      saved state as argument, throwing 
-         *      IllegalMonitorStateException  if it fails.
-         * <li> Block until signalled, interrupted, or timed out
-         * <li> Reacquire by invoking specialized version of
-         *      {@link #acquire} with saved state as argument.
-         * <li> If interrupted while blocked in step 4, throw InterruptedException
-         * <li> If timed out while blocked in step 4, return false, else true
-         * </ol>
-         * 
-         * @param time the maximum time to wait
-         * @param unit the time unit of the <tt>time</tt> argument.
-         * @return <tt>false</tt> if the waiting time detectably elapsed
-         * before return from the method, else <tt>true</tt>.
-         * @throws InterruptedException if the current thread is interrupted (and
-         * interruption of thread suspension is supported).
-         */
-        public final boolean await(long time, TimeUnit unit) throws InterruptedException {
-            if (unit == null)
-                throw new NullPointerException();
-            long nanosTimeout = unit.toNanos(time);
-            if (Thread.interrupted()) 
-                throw new InterruptedException();
-            Node node = addConditionWaiter();
-            int savedState = fullyRelease(node);
-            long lastTime = System.nanoTime();
-            boolean timedout = false;
-            int interruptMode = 0;
-            while (!isOnSyncQueue(node)) {
-                if (nanosTimeout <= 0L) {
-                    timedout = transferAfterCancelledWait(node); 
-                    break;
-                }
-                LockSupport.parkNanos(nanosTimeout);
-                if ((interruptMode = checkInterruptWhileWaiting(node)) != 0)
-                    break;
-                long now = System.nanoTime();
-                nanosTimeout -= now - lastTime;
-                lastTime = now;
-            }
-            if (acquireQueued(node, savedState) && interruptMode != THROW_IE)
-                interruptMode = REINTERRUPT;
-            if (interruptMode != 0)
-                reportInterruptAfterWait(interruptMode);
-            return !timedout;
-        }
-
-        //  support for instrumentation
-
-        /**
-         * Returns true if this condition was created by the given
-         * synchronization object
-         * @return true if owned
-         */
-        final boolean isOwnedBy(AbstractQueuedSynchronizer sync) {
-            return sync == AbstractQueuedSynchronizer.this;
-        }
-
-        /**
-         * Queries whether any threads are waiting on this condition.
-         * Implements {@link AbstractQueuedSynchronizer#hasWaiters}
-         * @return <tt>true</tt> if there are any waiting threads.
-         * @throws IllegalMonitorStateException if {@link #isHeldExclusively}
-         * returns false
-         */ 
-        protected final boolean hasWaiters() {
-            if (!isHeldExclusively()) 
-                throw new IllegalMonitorStateException();
-            for (Node w = firstWaiter; w != null; w = w.nextWaiter) {
-                if (w.waitStatus == Node.CONDITION)
-                    return true;
-            }
-            return false;
-        }
-
-        /**
-         * Returns an estimate of the number of threads waiting on
-         * this condition. 
-         * Implements {@link AbstractQueuedSynchronizer#getWaitQueueLength}
-         * @return the estimated number of waiting threads.
-         * @throws IllegalMonitorStateException if {@link #isHeldExclusively}
-         * returns false
-         */ 
-        protected final int getWaitQueueLength() {
-            if (!isHeldExclusively()) 
-                throw new IllegalMonitorStateException();
-            int n = 0;
-            for (Node w = firstWaiter; w != null; w = w.nextWaiter) {
-                if (w.waitStatus == Node.CONDITION)
-                    ++n;
-            }
-            return n;
-        }
-
-        /**
-         * Returns a collection containing those threads that may be
-         * waiting on this Condition.  
-         * Implements {@link AbstractQueuedSynchronizer#getWaitingThreads}
-         * @return the collection of threads
-         * @throws IllegalMonitorStateException if {@link #isHeldExclusively}
-         * returns false
-         */
-        protected final Collection<Thread> getWaitingThreads() {
-            if (!isHeldExclusively()) 
-                throw new IllegalMonitorStateException();
-            ArrayList<Thread> list = new ArrayList<Thread>();
-            for (Node w = firstWaiter; w != null; w = w.nextWaiter) {
-                if (w.waitStatus == Node.CONDITION) {
-                    Thread t = w.thread;
-                    if (t != null)
-                        list.add(t);
-                }
-            }
-            return list;
-        }
-    }
-
-    /**
-     * Setup to support compareAndSet. We need to natively implement
-     * this here: For the sake of permitting future enhancements, we
-     * cannot explicitly subclass AtomicInteger, which would be
-     * efficient and useful otherwise. So, as the lesser of evils, we
-     * natively implement using hotspot intrinsics API. And while we
-     * are at it, we do the same for other CASable fields (which could
-     * otherwise be done with atomic field updaters).
-     */
-    // BEGIN android-changed
-    private static final Unsafe unsafe = UnsafeAccess.THE_ONE;
-    // END android-changed
-    private static final long stateOffset;
-    private static final long headOffset;
-    private static final long tailOffset;
-    private static final long waitStatusOffset;
-
-    static {
-        try {
-            stateOffset = unsafe.objectFieldOffset
-                (AbstractQueuedSynchronizer.class.getDeclaredField("state"));
-            headOffset = unsafe.objectFieldOffset
-                (AbstractQueuedSynchronizer.class.getDeclaredField("head"));
-            tailOffset = unsafe.objectFieldOffset
-                (AbstractQueuedSynchronizer.class.getDeclaredField("tail"));
-            waitStatusOffset = unsafe.objectFieldOffset
-                (Node.class.getDeclaredField("waitStatus"));
-            
-        } catch(Exception ex) { throw new Error(ex); }
-    }
-
-    /**
-     * CAS head field. Used only by enq
-     */
-    private final boolean compareAndSetHead(Node update) {
-        return unsafe.compareAndSwapObject(this, headOffset, null, update);
-    }
-    
-    /**
-     * CAS tail field. Used only by enq
-     */
-    private final boolean compareAndSetTail(Node expect, Node update) {
-        return unsafe.compareAndSwapObject(this, tailOffset, expect, update);
-    }
-
-    /**
-     * CAS waitStatus field of a node.
-     */
-    private final static boolean compareAndSetWaitStatus(Node node, 
-                                                         int expect, 
-                                                         int update) {
-        return unsafe.compareAndSwapInt(node, waitStatusOffset, 
-                                        expect, update);
-    }
-
-}
diff --git a/concurrent/src/main/java/java/util/concurrent/locks/Condition.java b/concurrent/src/main/java/java/util/concurrent/locks/Condition.java
deleted file mode 100644
index 7a8ca5b..0000000
--- a/concurrent/src/main/java/java/util/concurrent/locks/Condition.java
+++ /dev/null
@@ -1,439 +0,0 @@
-/*
- * Written by Doug Lea with assistance from members of JCP JSR-166
- * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
- */
-
-package java.util.concurrent.locks;
-import java.util.concurrent.*;
-import java.util.Date;
-
-/**
- * <tt>Condition</tt> factors out the <tt>Object</tt> monitor
- * methods ({@link Object#wait() wait}, {@link Object#notify notify}
- * and {@link Object#notifyAll notifyAll}) into distinct objects to
- * give the effect of having multiple wait-sets per object, by
- * combining them with the use of arbitrary {@link Lock} implementations.
- * Where a <tt>Lock</tt> replaces the use of <tt>synchronized</tt> methods
- * and statements, a <tt>Condition</tt> replaces the use of the Object
- * monitor methods.
- *
- * <p>Conditions (also known as <em>condition queues</em> or
- * <em>condition variables</em>) provide a means for one thread to
- * suspend execution (to &quot;wait&quot;) until notified by another
- * thread that some state condition may now be true.  Because access
- * to this shared state information occurs in different threads, it
- * must be protected, so a lock of some form is associated with the
- * condition. The key property that waiting for a condition provides
- * is that it <em>atomically</em> releases the associated lock and
- * suspends the current thread, just like <tt>Object.wait</tt>.
- *
- * <p>A <tt>Condition</tt> instance is intrinsically bound to a lock.
- * To obtain a <tt>Condition</tt> instance for a particular {@link Lock} 
- * instance use its {@link Lock#newCondition newCondition()} method.
- *
- * <p>As an example, suppose we have a bounded buffer which supports
- * <tt>put</tt> and <tt>take</tt> methods.  If a
- * <tt>take</tt> is attempted on an empty buffer, then the thread will block
- * until an item becomes available; if a <tt>put</tt> is attempted on a
- * full buffer, then the thread will block until a space becomes available.
- * We would like to keep waiting <tt>put</tt> threads and <tt>take</tt>
- * threads in separate wait-sets so that we can use the optimization of
- * only notifying a single thread at a time when items or spaces become
- * available in the buffer. This can be achieved using two 
- * {@link Condition} instances.
- * <pre>
- * class BoundedBuffer {
- *   <b>Lock lock = new ReentrantLock();</b>
- *   final Condition notFull  = <b>lock.newCondition(); </b>
- *   final Condition notEmpty = <b>lock.newCondition(); </b>
- *
- *   Object[] items = new Object[100];
- *   int putptr, takeptr, count;
- *
- *   public void put(Object x) throws InterruptedException {
- *     <b>lock.lock();
- *     try {</b>
- *       while (count == items.length) 
- *         <b>notFull.await();</b>
- *       items[putptr] = x; 
- *       if (++putptr == items.length) putptr = 0;
- *       ++count;
- *       <b>notEmpty.signal();</b>
- *     <b>} finally {
- *       lock.unlock();
- *     }</b>
- *   }
- *
- *   public Object take() throws InterruptedException {
- *     <b>lock.lock();
- *     try {</b>
- *       while (count == 0) 
- *         <b>notEmpty.await();</b>
- *       Object x = items[takeptr]; 
- *       if (++takeptr == items.length) takeptr = 0;
- *       --count;
- *       <b>notFull.signal();</b>
- *       return x;
- *     <b>} finally {
- *       lock.unlock();
- *     }</b>
- *   } 
- * }
- * </pre>
- *
- * (The {@link java.util.concurrent.ArrayBlockingQueue} class provides
- * this functionality, so there is no reason to implement this
- * sample usage class.)
- *
- * <p>A <tt>Condition</tt> implementation can provide behavior and semantics 
- * that is 
- * different from that of the <tt>Object</tt> monitor methods, such as 
- * guaranteed ordering for notifications, or not requiring a lock to be held 
- * when performing notifications.
- * If an implementation provides such specialized semantics then the 
- * implementation must document those semantics.
- *
- * <p>Note that <tt>Condition</tt> instances are just normal objects and can 
- * themselves be used as the target in a <tt>synchronized</tt> statement,
- * and can have their own monitor {@link Object#wait wait} and
- * {@link Object#notify notification} methods invoked.
- * Acquiring the monitor lock of a <tt>Condition</tt> instance, or using its
- * monitor methods, has no specified relationship with acquiring the
- * {@link Lock} associated with that <tt>Condition</tt> or the use of its
- * {@link #await waiting} and {@link #signal signalling} methods.
- * It is recommended that to avoid confusion you never use <tt>Condition</tt>
- * instances in this way, except perhaps within their own implementation.
- *
- * <p>Except where noted, passing a <tt>null</tt> value for any parameter 
- * will result in a {@link NullPointerException} being thrown.
- *
- * <h3>Implementation Considerations</h3>
- *
- * <p>When waiting upon a <tt>Condition</tt>, a &quot;<em>spurious
- * wakeup</em>&quot; is permitted to occur, in 
- * general, as a concession to the underlying platform semantics.
- * This has little practical impact on most application programs as a
- * <tt>Condition</tt> should always be waited upon in a loop, testing
- * the state predicate that is being waited for.  An implementation is
- * free to remove the possibility of spurious wakeups but it is 
- * recommended that applications programmers always assume that they can
- * occur and so always wait in a loop.
- *
- * <p>The three forms of condition waiting 
- * (interruptible, non-interruptible, and timed) may differ in their ease of 
- * implementation on some platforms and in their performance characteristics.
- * In particular, it may be difficult to provide these features and maintain 
- * specific semantics such as ordering guarantees. 
- * Further, the ability to interrupt the actual suspension of the thread may 
- * not always be feasible to implement on all platforms.
- * <p>Consequently, an implementation is not required to define exactly the 
- * same guarantees or semantics for all three forms of waiting, nor is it 
- * required to support interruption of the actual suspension of the thread.
- * <p>An implementation is required to
- * clearly document the semantics and guarantees provided by each of the 
- * waiting methods, and when an implementation does support interruption of 
- * thread suspension then it must obey the interruption semantics as defined 
- * in this interface.
- * <p>As interruption generally implies cancellation, and checks for 
- * interruption are often infrequent, an implementation can favor responding
- * to an interrupt over normal method return. This is true even if it can be
- * shown that the interrupt occurred after another action may have unblocked
- * the thread. An implementation should document this behavior. 
- *
- *
- * @since 1.5
- * @author Doug Lea
- */
-public interface Condition {
-
-    /**
-     * Causes the current thread to wait until it is signalled or 
-     * {@link Thread#interrupt interrupted}.
-     *
-     * <p>The lock associated with this <tt>Condition</tt> is atomically 
-     * released and the current thread becomes disabled for thread scheduling 
-     * purposes and lies dormant until <em>one</em> of four things happens:
-     * <ul>
-     * <li>Some other thread invokes the {@link #signal} method for this 
-     * <tt>Condition</tt> and the current thread happens to be chosen as the 
-     * thread to be awakened; or
-     * <li>Some other thread invokes the {@link #signalAll} method for this 
-     * <tt>Condition</tt>; or
-     * <li>Some other thread {@link Thread#interrupt interrupts} the current
-     * thread, and interruption of thread suspension is supported; or
-     * <li>A &quot;<em>spurious wakeup</em>&quot; occurs
-     * </ul>
-     *
-     * <p>In all cases, before this method can return the current thread must
-     * re-acquire the lock associated with this condition. When the
-     * thread returns it is <em>guaranteed</em> to hold this lock.
-     *
-     * <p>If the current thread:
-     * <ul>
-     * <li>has its interrupted status set on entry to this method; or 
-     * <li>is {@link Thread#interrupt interrupted} while waiting 
-     * and interruption of thread suspension is supported, 
-     * </ul>
-     * then {@link InterruptedException} is thrown and the current thread's 
-     * interrupted status is cleared. It is not specified, in the first
-     * case, whether or not the test for interruption occurs before the lock
-     * is released.
-     * 
-     * <p><b>Implementation Considerations</b>
-     * <p>The current thread is assumed to hold the lock associated with this
-     * <tt>Condition</tt> when this method is called.
-     * It is up to the implementation to determine if this is
-     * the case and if not, how to respond. Typically, an exception will be 
-     * thrown (such as {@link IllegalMonitorStateException}) and the
-     * implementation must document that fact.
-     *
-     * <p>An implementation can favor responding to an interrupt over normal
-     * method return in response to a signal. In that case the implementation
-     * must ensure that the signal is redirected to another waiting thread, if
-     * there is one.
-     *
-     * @throws InterruptedException if the current thread is interrupted (and
-     * interruption of thread suspension is supported).
-     **/
-    void await() throws InterruptedException;
-
-    /**
-     * Causes the current thread to wait until it is signalled.
-     *
-     * <p>The lock associated with this condition is atomically 
-     * released and the current thread becomes disabled for thread scheduling 
-     * purposes and lies dormant until <em>one</em> of three things happens:
-     * <ul>
-     * <li>Some other thread invokes the {@link #signal} method for this 
-     * <tt>Condition</tt> and the current thread happens to be chosen as the 
-     * thread to be awakened; or
-     * <li>Some other thread invokes the {@link #signalAll} method for this 
-     * <tt>Condition</tt>; or
-     * <li>A &quot;<em>spurious wakeup</em>&quot; occurs
-     * </ul>
-     *
-     * <p>In all cases, before this method can return the current thread must
-     * re-acquire the lock associated with this condition. When the
-     * thread returns it is <em>guaranteed</em> to hold this lock.
-     *
-     * <p>If the current thread's interrupt status is set when it enters
-     * this method, or it is {@link Thread#interrupt interrupted} 
-     * while waiting, it will continue to wait until signalled. When it finally
-     * returns from this method its <em>interrupted status</em> will still
-     * be set.
-     * 
-     * <p><b>Implementation Considerations</b>
-     * <p>The current thread is assumed to hold the lock associated with this
-     * <tt>Condition</tt> when this method is called.
-     * It is up to the implementation to determine if this is
-     * the case and if not, how to respond. Typically, an exception will be 
-     * thrown (such as {@link IllegalMonitorStateException}) and the
-     * implementation must document that fact.
-     *
-     **/
-    void awaitUninterruptibly();
-
-    /**
-     * Causes the current thread to wait until it is signalled or interrupted,
-     * or the specified waiting time elapses.
-     *
-     * <p>The lock associated with this condition is atomically 
-     * released and the current thread becomes disabled for thread scheduling 
-     * purposes and lies dormant until <em>one</em> of five things happens:
-     * <ul>
-     * <li>Some other thread invokes the {@link #signal} method for this 
-     * <tt>Condition</tt> and the current thread happens to be chosen as the 
-     * thread to be awakened; or 
-     * <li>Some other thread invokes the {@link #signalAll} method for this 
-     * <tt>Condition</tt>; or
-     * <li>Some other thread {@link Thread#interrupt interrupts} the current
-     * thread, and interruption of thread suspension is supported; or
-     * <li>The specified waiting time elapses; or
-     * <li>A &quot;<em>spurious wakeup</em>&quot; occurs.
-     * </ul>
-     *
-     * <p>In all cases, before this method can return the current thread must
-     * re-acquire the lock associated with this condition. When the
-     * thread returns it is <em>guaranteed</em> to hold this lock.
-     *
-     * <p>If the current thread:
-     * <ul>
-     * <li>has its interrupted status set on entry to this method; or 
-     * <li>is {@link Thread#interrupt interrupted} while waiting 
-     * and interruption of thread suspension is supported, 
-     * </ul>
-     * then {@link InterruptedException} is thrown and the current thread's 
-     * interrupted status is cleared. It is not specified, in the first
-     * case, whether or not the test for interruption occurs before the lock
-     * is released.
-     *
-     * <p>The method returns an estimate of the number of nanoseconds
-     * remaining to wait given the supplied <tt>nanosTimeout</tt>
-     * value upon return, or a value less than or equal to zero if it
-     * timed out. This value can be used to determine whether and how
-     * long to re-wait in cases where the wait returns but an awaited
-     * condition still does not hold. Typical uses of this method take
-     * the following form:
-     *
-     * <pre>
-     * synchronized boolean aMethod(long timeout, TimeUnit unit) {
-     *   long nanosTimeout = unit.toNanos(timeout);
-     *   while (!conditionBeingWaitedFor) {
-     *     if (nanosTimeout &gt; 0)
-     *         nanosTimeout = theCondition.awaitNanos(nanosTimeout);
-     *      else
-     *        return false;
-     *   }
-     *   // ... 
-     * }
-     * </pre>
-     *
-     * <p> Design note: This method requires a nanosecond argument so
-     * as to avoid truncation errors in reporting remaining times.
-     * Such precision loss would make it difficult for programmers to
-     * ensure that total waiting times are not systematically shorter
-     * than specified when re-waits occur.
-     *
-     * <p><b>Implementation Considerations</b>
-     * <p>The current thread is assumed to hold the lock associated with this
-     * <tt>Condition</tt> when this method is called.
-     * It is up to the implementation to determine if this is
-     * the case and if not, how to respond. Typically, an exception will be 
-     * thrown (such as {@link IllegalMonitorStateException}) and the
-     * implementation must document that fact.
-     *
-     * <p>An implementation can favor responding to an interrupt over normal
-     * method return in response to a signal, or over indicating the elapse
-     * of the specified waiting time. In either case the implementation
-     * must ensure that the signal is redirected to another waiting thread, if
-     * there is one.
-     *
-     * @param nanosTimeout the maximum time to wait, in nanoseconds
-     * @return A value less than or equal to zero if the wait has
-     * timed out; otherwise an estimate, that
-     * is strictly less than the <tt>nanosTimeout</tt> argument,
-     * of the time still remaining when this method returned.
-     *
-     * @throws InterruptedException if the current thread is interrupted (and
-     * interruption of thread suspension is supported).
-     */
-    long awaitNanos(long nanosTimeout) throws InterruptedException;
-
-    /**
-     * Causes the current thread to wait until it is signalled or interrupted,
-     * or the specified waiting time elapses. This method is behaviorally
-     * equivalent to:<br>
-     * <pre>
-     *   awaitNanos(unit.toNanos(time)) &gt; 0
-     * </pre>
-     * @param time the maximum time to wait
-     * @param unit the time unit of the <tt>time</tt> argument.
-     * @return <tt>false</tt> if the waiting time detectably elapsed
-     * before return from the method, else <tt>true</tt>.
-     * @throws InterruptedException if the current thread is interrupted (and
-     * interruption of thread suspension is supported).
-     */
-    boolean await(long time, TimeUnit unit) throws InterruptedException;
-    
-    /**
-     * Causes the current thread to wait until it is signalled or interrupted,
-     * or the specified deadline elapses.
-     *
-     * <p>The lock associated with this condition is atomically 
-     * released and the current thread becomes disabled for thread scheduling 
-     * purposes and lies dormant until <em>one</em> of five things happens:
-     * <ul>
-     * <li>Some other thread invokes the {@link #signal} method for this 
-     * <tt>Condition</tt> and the current thread happens to be chosen as the 
-     * thread to be awakened; or 
-     * <li>Some other thread invokes the {@link #signalAll} method for this 
-     * <tt>Condition</tt>; or
-     * <li>Some other thread {@link Thread#interrupt interrupts} the current
-     * thread, and interruption of thread suspension is supported; or
-     * <li>The specified deadline elapses; or
-     * <li>A &quot;<em>spurious wakeup</em>&quot; occurs.
-     * </ul>
-     *
-     * <p>In all cases, before this method can return the current thread must
-     * re-acquire the lock associated with this condition. When the
-     * thread returns it is <em>guaranteed</em> to hold this lock.
-     *
-     *
-     * <p>If the current thread:
-     * <ul>
-     * <li>has its interrupted status set on entry to this method; or 
-     * <li>is {@link Thread#interrupt interrupted} while waiting 
-     * and interruption of thread suspension is supported, 
-     * </ul>
-     * then {@link InterruptedException} is thrown and the current thread's 
-     * interrupted status is cleared. It is not specified, in the first
-     * case, whether or not the test for interruption occurs before the lock
-     * is released.
-     *
-     *
-     * <p>The return value indicates whether the deadline has elapsed,
-     * which can be used as follows:
-     * <pre>
-     * synchronized boolean aMethod(Date deadline) {
-     *   boolean stillWaiting = true;
-     *   while (!conditionBeingWaitedFor) {
-     *     if (stillwaiting)
-     *         stillWaiting = theCondition.awaitUntil(deadline);
-     *      else
-     *        return false;
-     *   }
-     *   // ... 
-     * }
-     * </pre>
-     *
-     * <p><b>Implementation Considerations</b>
-     * <p>The current thread is assumed to hold the lock associated with this
-     * <tt>Condition</tt> when this method is called.
-     * It is up to the implementation to determine if this is
-     * the case and if not, how to respond. Typically, an exception will be 
-     * thrown (such as {@link IllegalMonitorStateException}) and the
-     * implementation must document that fact.
-     *
-     * <p>An implementation can favor responding to an interrupt over normal
-     * method return in response to a signal, or over indicating the passing
-     * of the specified deadline. In either case the implementation
-     * must ensure that the signal is redirected to another waiting thread, if
-     * there is one.
-     *
-     *
-     * @param deadline the absolute time to wait until
-     * @return <tt>false</tt> if the deadline has
-     * elapsed upon return, else <tt>true</tt>.
-     *
-     * @throws InterruptedException if the current thread is interrupted (and
-     * interruption of thread suspension is supported).
-     */
-    boolean awaitUntil(Date deadline) throws InterruptedException;
-
-    /**
-     * Wakes up one waiting thread.
-     *
-     * <p>If any threads are waiting on this condition then one
-     * is selected for waking up. That thread must then re-acquire the
-     * lock before returning from <tt>await</tt>.
-     **/
-    void signal();
-
-    /**
-     * Wakes up all waiting threads.
-     *
-     * <p>If any threads are waiting on this condition then they are
-     * all woken up. Each thread must re-acquire the lock before it can
-     * return from <tt>await</tt>.
-     **/
-    void signalAll();
-
-}
-
-
-
-
-
-
-
diff --git a/concurrent/src/main/java/java/util/concurrent/locks/Lock.java b/concurrent/src/main/java/java/util/concurrent/locks/Lock.java
deleted file mode 100644
index f07b72e..0000000
--- a/concurrent/src/main/java/java/util/concurrent/locks/Lock.java
+++ /dev/null
@@ -1,329 +0,0 @@
-/*
- * Written by Doug Lea with assistance from members of JCP JSR-166
- * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
- */
-
-package java.util.concurrent.locks;
-import java.util.concurrent.TimeUnit;
-
-/**
- * <tt>Lock</tt> implementations provide more extensive locking
- * operations than can be obtained using <tt>synchronized</tt> methods
- * and statements.  They allow more flexible structuring, may have
- * quite different properties, and may support multiple associated
- * {@link Condition} objects.
- *
- * <p>A lock is a tool for controlling access to a shared resource by
- * multiple threads. Commonly, a lock provides exclusive access to a
- * shared resource: only one thread at a time can acquire the lock and
- * all access to the shared resource requires that the lock be
- * acquired first. However, some locks may allow concurrent access to
- * a shared resource, such as the read lock of a {@link
- * ReadWriteLock}.
- *
- * <p>The use of <tt>synchronized</tt> methods or statements provides 
- * access to the implicit monitor lock associated with every object, but
- * forces all lock acquisition and release to occur in a block-structured way:
- * when multiple locks are acquired they must be released in the opposite
- * order, and all locks must be released in the same lexical scope in which
- * they were acquired.
- *
- * <p>While the scoping mechanism for <tt>synchronized</tt> methods
- * and statements makes it much easier to program with monitor locks,
- * and helps avoid many common programming errors involving locks,
- * there are occasions where you need to work with locks in a more
- * flexible way. For example, some algorithms for traversing
- * concurrently accessed data structures require the use of
- * &quot;hand-over-hand&quot; or &quot;chain locking&quot;: you
- * acquire the lock of node A, then node B, then release A and acquire
- * C, then release B and acquire D and so on.  Implementations of the
- * <tt>Lock</tt> interface enable the use of such techniques by
- * allowing a lock to be acquired and released in different scopes,
- * and allowing multiple locks to be acquired and released in any
- * order.
- *
- * <p>With this increased flexibility comes additional
- * responsibility. The absence of block-structured locking removes the
- * automatic release of locks that occurs with <tt>synchronized</tt>
- * methods and statements. In most cases, the following idiom
- * should be used:
- *
- * <pre><tt>     Lock l = ...; 
- *     l.lock();
- *     try {
- *         // access the resource protected by this lock
- *     } finally {
- *         l.unlock();
- *     }
- * </tt></pre>
- *
- * When locking and unlocking occur in different scopes, care must be
- * taken to ensure that all code that is executed while the lock is
- * held is protected by try-finally or try-catch to ensure that the
- * lock is released when necessary.
- *
- * <p><tt>Lock</tt> implementations provide additional functionality
- * over the use of <tt>synchronized</tt> methods and statements by
- * providing a non-blocking attempt to acquire a lock ({@link
- * #tryLock()}), an attempt to acquire the lock that can be
- * interrupted ({@link #lockInterruptibly}, and an attempt to acquire
- * the lock that can timeout ({@link #tryLock(long, TimeUnit)}).
- *
- * <p>A <tt>Lock</tt> class can also provide behavior and semantics
- * that is quite different from that of the implicit monitor lock,
- * such as guaranteed ordering, non-reentrant usage, or deadlock
- * detection. If an implementation provides such specialized semantics
- * then the implementation must document those semantics.
- *
- * <p>Note that <tt>Lock</tt> instances are just normal objects and can 
- * themselves be used as the target in a <tt>synchronized</tt> statement.
- * Acquiring the
- * monitor lock of a <tt>Lock</tt> instance has no specified relationship
- * with invoking any of the {@link #lock} methods of that instance. 
- * It is recommended that to avoid confusion you never use <tt>Lock</tt>
- * instances in this way, except within their own implementation.
- *
- * <p>Except where noted, passing a <tt>null</tt> value for any
- * parameter will result in a {@link NullPointerException} being
- * thrown.
- *
- * <h3>Memory Synchronization</h3>
- * <p>All <tt>Lock</tt> implementations <em>must</em> enforce the same
- * memory synchronization semantics as provided by the built-in monitor lock:
- * <ul>
- * <li>A successful lock operation acts like a successful 
- * <tt>monitorEnter</tt> action
- * <li>A successful <tt>unlock</tt> operation acts like a successful
- * <tt>monitorExit</tt> action
- * </ul>
- *
- * Unsuccessful locking and unlocking operations, and reentrant
- * locking/unlocking operations, do not require any memory
- * synchronization effects.
- *
- * <h3>Implementation Considerations</h3>
- *
- * <p> The three forms of lock acquisition (interruptible,
- * non-interruptible, and timed) may differ in their performance
- * characteristics, ordering guarantees, or other implementation
- * qualities.  Further, the ability to interrupt the <em>ongoing</em>
- * acquisition of a lock may not be available in a given <tt>Lock</tt>
- * class.  Consequently, an implementation is not required to define
- * exactly the same guarantees or semantics for all three forms of
- * lock acquisition, nor is it required to support interruption of an
- * ongoing lock acquisition.  An implementation is required to clearly
- * document the semantics and guarantees provided by each of the
- * locking methods. It must also obey the interruption semantics as
- * defined in this interface, to the extent that interruption of lock
- * acquisition is supported: which is either totally, or only on
- * method entry.
- *
- * <p>As interruption generally implies cancellation, and checks for 
- * interruption are often infrequent, an implementation can favor responding
- * to an interrupt over normal method return. This is true even if it can be
- * shown that the interrupt occurred after another action may have unblocked
- * the thread. An implementation should document this behavior. 
- *
- *
- * @see ReentrantLock
- * @see Condition
- * @see ReadWriteLock
- *
- * @since 1.5
- * @author Doug Lea
- *
- **/
-public interface Lock {
-
-    /**
-     * Acquires the lock.
-     * <p>If the lock is not available then
-     * the current thread becomes disabled for thread scheduling 
-     * purposes and lies dormant until the lock has been acquired.
-     * <p><b>Implementation Considerations</b>
-     * <p>A <tt>Lock</tt> implementation may be able to detect 
-     * erroneous use of the lock, such as an invocation that would cause 
-     * deadlock, and may throw an (unchecked) exception in such circumstances. 
-     * The circumstances and the exception type must be documented by that 
-     * <tt>Lock</tt> implementation.
-     *
-     **/
-    void lock();
-
-    /**
-     * Acquires the lock unless the current thread is  
-     * {@link Thread#interrupt interrupted}. 
-     * <p>Acquires the lock if it is available and returns immediately.
-     * <p>If the lock is not available then
-     * the current thread becomes disabled for thread scheduling 
-     * purposes and lies dormant until one of two things happens:
-     * <ul>
-     * <li>The lock is acquired by the current thread; or
-     * <li>Some other thread {@link Thread#interrupt interrupts} the current
-     * thread, and interruption of lock acquisition is supported.
-     * </ul>
-     * <p>If the current thread:
-     * <ul>
-     * <li>has its interrupted status set on entry to this method; or 
-     * <li>is {@link Thread#interrupt interrupted} while acquiring 
-     * the lock, and interruption of lock acquisition is supported, 
-     * </ul>
-     * then {@link InterruptedException} is thrown and the current thread's 
-     * interrupted status is cleared. 
-     *
-     * <p><b>Implementation Considerations</b>
-     *
-     * <p>The ability to interrupt a lock acquisition in some
-     * implementations may not be possible, and if possible may be an
-     * expensive operation.  The programmer should be aware that this
-     * may be the case. An implementation should document when this is
-     * the case.
-     *
-     * <p>An implementation can favor responding to an interrupt over
-     * normal method return.
-     *
-     * <p>A <tt>Lock</tt> implementation may be able to detect
-     * erroneous use of the lock, such as an invocation that would
-     * cause deadlock, and may throw an (unchecked) exception in such
-     * circumstances.  The circumstances and the exception type must
-     * be documented by that <tt>Lock</tt> implementation.
-     *
-     * @throws InterruptedException if the current thread is interrupted
-     * while acquiring the lock (and interruption of lock acquisition is 
-     * supported).
-     *
-     * @see Thread#interrupt
-     *
-     **/
-    void lockInterruptibly() throws InterruptedException;
-
-
-    /**
-     * Acquires the lock only if it is free at the time of invocation.
-     * <p>Acquires the lock if it is available and returns immediately
-     * with the value <tt>true</tt>.
-     * If the lock is not available then this method will return 
-     * immediately with the value <tt>false</tt>.
-     * <p>A typical usage idiom for this method would be:
-     * <pre>
-     *      Lock lock = ...;
-     *      if (lock.tryLock()) {
-     *          try {
-     *              // manipulate protected state
-     *          } finally {
-     *              lock.unlock();
-     *          }
-     *      } else {
-     *          // perform alternative actions
-     *      }
-     * </pre>
-     * This usage ensures that the lock is unlocked if it was acquired, and
-     * doesn't try to unlock if the lock was not acquired.
-     *
-     * @return <tt>true</tt> if the lock was acquired and <tt>false</tt>
-     * otherwise.
-     **/
-    boolean tryLock();
-
-    /**
-     * Acquires the lock if it is free within the given waiting time and the
-     * current thread has not been {@link Thread#interrupt interrupted}.
-     *
-     * <p>If the lock is available this method returns immediately
-     * with the value <tt>true</tt>.
-     * If the lock is not available then
-     * the current thread becomes disabled for thread scheduling 
-     * purposes and lies dormant until one of three things happens:
-     * <ul>
-     * <li>The lock is acquired by the current thread; or
-     * <li>Some other thread {@link Thread#interrupt interrupts} the current
-     * thread, and interruption of lock acquisition is supported; or
-     * <li>The specified waiting time elapses
-     * </ul>
-     * <p>If the lock is acquired then the value <tt>true</tt> is returned.
-     * <p>If the current thread:
-     * <ul>
-     * <li>has its interrupted status set on entry to this method; or 
-     * <li>is {@link Thread#interrupt interrupted} while acquiring 
-     * the lock, and interruption of lock acquisition is supported, 
-     * </ul>
-     * then {@link InterruptedException} is thrown and the current thread's 
-     * interrupted status is cleared. 
-     * <p>If the specified waiting time elapses then the value <tt>false</tt>
-     * is returned.
-     * If the time is 
-     * less than or equal to zero, the method will not wait at all.
-     *
-     * <p><b>Implementation Considerations</b>
-     * <p>The ability to interrupt a lock acquisition in some implementations
-     * may not be possible, and if possible may 
-     * be an expensive operation. 
-     * The programmer should be aware that this may be the case. An
-     * implementation should document when this is the case.
-     * <p>An implementation can favor responding to an interrupt over normal 
-     * method return, or reporting a timeout.
-     * <p>A <tt>Lock</tt> implementation may be able to detect 
-     * erroneous use of the lock, such as an invocation that would cause 
-     * deadlock, and may throw an (unchecked) exception in such circumstances. 
-     * The circumstances and the exception type must be documented by that 
-     * <tt>Lock</tt> implementation.
-     *
-     * @param time the maximum time to wait for the lock
-     * @param unit the time unit of the <tt>time</tt> argument.
-     * @return <tt>true</tt> if the lock was acquired and <tt>false</tt>
-     * if the waiting time elapsed before the lock was acquired.
-     *
-     * @throws InterruptedException if the current thread is interrupted
-     * while acquiring the lock (and interruption of lock acquisition is 
-     * supported).
-     *
-     * @see Thread#interrupt
-     *
-     **/
-    boolean tryLock(long time, TimeUnit unit) throws InterruptedException;
-
-    /**
-     * Releases the lock.
-     * <p><b>Implementation Considerations</b>
-     * <p>A <tt>Lock</tt> implementation will usually impose
-     * restrictions on which thread can release a lock (typically only the
-     * holder of the lock can release it) and may throw
-     * an (unchecked) exception if the restriction is violated.
-     * Any restrictions and the exception
-     * type must be documented by that <tt>Lock</tt> implementation.
-     **/
-    void unlock();
-
-    /**
-     * Returns a new {@link Condition} instance that is bound to this 
-     * <tt>Lock</tt> instance.
-     * <p>Before waiting on the condition the lock must be held by the 
-     * current thread. 
-     * A call to {@link Condition#await()} will atomically release the lock 
-     * before waiting and re-acquire the lock before the wait returns.
-     * <p><b>Implementation Considerations</b>
-     * <p>The exact operation of the {@link Condition} instance depends on the
-     * <tt>Lock</tt> implementation and must be documented by that
-     * implementation.
-     * 
-     * @return A new {@link Condition} instance for this <tt>Lock</tt> 
-     * instance.
-     * @throws UnsupportedOperationException if this <tt>Lock</tt> 
-     * implementation does not support conditions.
-     **/
-    Condition newCondition();
-
-}
-
-
-
-
-
-
-
-
-
-
-
-
diff --git a/concurrent/src/main/java/java/util/concurrent/locks/LockSupport.java b/concurrent/src/main/java/java/util/concurrent/locks/LockSupport.java
deleted file mode 100644
index 8603785..0000000
--- a/concurrent/src/main/java/java/util/concurrent/locks/LockSupport.java
+++ /dev/null
@@ -1,178 +0,0 @@
-/*
- * Written by Doug Lea with assistance from members of JCP JSR-166
- * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
- */
-
-package java.util.concurrent.locks;
-import java.util.concurrent.*;
-import sun.misc.Unsafe;
-
-
-/**
- * Basic thread blocking primitives for creating locks and other
- * synchronization classes.
- *
- * <p>This class associates with each thread that uses it, a permit
- * (in the sense of the {@link java.util.concurrent.Semaphore
- * Semaphore} class). A call to <tt>park</tt> will return immediately
- * if the permit is available, consuming it in the process; otherwise
- * it <em>may</em> block.  A call to <tt>unpark</tt> makes the permit
- * available, if it was not already available. (Unlike with Semaphores
- * though, permits do not accumulate. There is at most one.)
- *
- * <p>Methods <tt>park</tt> and <tt>unpark</tt> provide efficient
- * means of blocking and unblocking threads that do not encounter the
- * problems that cause the deprecated methods <tt>Thread.suspend</tt>
- * and <tt>Thread.resume</tt> to be unusable for such purposes: Races
- * between one thread invoking <tt>park</tt> and another thread trying
- * to <tt>unpark</tt> it will preserve liveness, due to the
- * permit. Additionally, <tt>park</tt> will return if the caller's
- * thread was interrupted, and timeout versions are supported. The
- * <tt>park</tt> method may also return at any other time, for "no
- * reason", so in general must be invoked within a loop that rechecks
- * conditions upon return. In this sense <tt>park</tt> serves as an
- * optimization of a "busy wait" that does not waste as much time
- * spinning, but must be paired with an <tt>unpark</tt> to be
- * effective.
- *
- * <p>These methods are designed to be used as tools for creating
- * higher-level synchronization utilities, and are not in themselves
- * useful for most concurrency control applications.
- *
- * <p><b>Sample Usage.</b> Here is a sketch of a First-in-first-out
- * non-reentrant lock class.
- * <pre>
- *   private AtomicBoolean locked = new AtomicBoolean(false);
- *   private Queue&lt;Thread&gt; waiters = new ConcurrentLinkedQueue&lt;Thread&gt;();
- *
- *   public void lock() { 
- *     boolean wasInterrupted = false;
- *     Thread current = Thread.currentThread();
- *     waiters.add(current);
- *
- *     // Block while not first in queue or cannot acquire lock
- *     while (waiters.peek() != current || 
- *            !locked.compareAndSet(false, true)) { 
- *        LockSupport.park();
- *        if (Thread.interrupted()) // ignore interrupts while waiting
- *          wasInterrupted = true;
- *     }
- *
- *     waiters.remove();
- *     if (wasInterrupted)          // reassert interrupt status on exit
- *        current.interrupt();
- *   }
- *
- *   public void unlock() {
- *     locked.set(false);
- *     LockSupport.unpark(waiters.peek());
- *   } 
- * }
- * </pre>
- */
-@SuppressWarnings("all")
-public class LockSupport {
-    private LockSupport() {} // Cannot be instantiated.
-
-    // BEGIN android-changed
-    private static final Unsafe unsafe = UnsafeAccess.THE_ONE;
-    // END android-changed
-
-    /**
-     * Make available the permit for the given thread, if it
-     * was not already available.  If the thread was blocked on
-     * <tt>park</tt> then it will unblock.  Otherwise, its next call
-     * to <tt>park</tt> is guaranteed not to block. This operation
-     * is not guaranteed to have any effect at all if the given
-     * thread has not been started.
-     * @param thread the thread to unpark, or <tt>null</tt>, in which case
-     * this operation has no effect. 
-     */
-    public static void unpark(Thread thread) {
-        if (thread != null)
-            unsafe.unpark(thread);
-    }
-
-    /**
-     * Disables the current thread for thread scheduling purposes unless the
-     * permit is available.
-     * <p>If the permit is available then it is consumed and the call returns
-     * immediately; otherwise 
-     * the current thread becomes disabled for thread scheduling 
-     * purposes and lies dormant until one of three things happens:
-     * <ul>
-     * <li>Some other thread invokes <tt>unpark</tt> with the current thread 
-     * as the target; or
-     * <li>Some other thread {@link Thread#interrupt interrupts} the current
-     * thread; or
-     * <li>The call spuriously (that is, for no reason) returns.
-     * </ul>
-     * <p>This method does <em>not</em> report which of these caused the 
-     * method to return. Callers should re-check the conditions which caused 
-     * the thread to park in the first place. Callers may also determine, 
-     * for example, the interrupt status of the thread upon return.
-     */
-    public static void park() {
-        unsafe.park(false, 0L);
-    }
-
-    /**
-     * Disables the current thread for thread scheduling purposes, for up to
-     * the specified waiting time, unless the permit is available.
-     * <p>If the permit is available then it is consumed and the call returns
-     * immediately; otherwise 
-     * the current thread becomes disabled for thread scheduling 
-     * purposes and lies dormant until one of four things happens:
-     * <ul>
-     * <li>Some other thread invokes <tt>unpark</tt> with the current thread 
-     * as the target; or
-     * <li>Some other thread {@link Thread#interrupt interrupts} the current
-     * thread; or
-     * <li>The specified waiting time elapses; or
-     * <li>The call spuriously (that is, for no reason) returns.
-     * </ul>
-     * <p>This method does <em>not</em> report which of these caused the 
-     * method to return. Callers should re-check the conditions which caused 
-     * the thread to park in the first place. Callers may also determine, 
-     * for example, the interrupt status of the thread, or the elapsed time
-     * upon return.
-     *
-     * @param nanos the maximum number of nanoseconds to wait
-     */
-    public static void parkNanos(long nanos) {
-        if (nanos > 0)
-            unsafe.park(false, nanos);   
-    }
-
-    /**
-     * Disables the current thread for thread scheduling purposes, until
-     * the specified deadline, unless the permit is available.
-     * <p>If the permit is available then it is consumed and the call returns
-     * immediately; otherwise 
-     * the current thread becomes disabled for thread scheduling 
-     * purposes and lies dormant until one of four things happens:
-     * <ul>
-     * <li>Some other thread invokes <tt>unpark</tt> with the current thread 
-     * as the target; or
-     * <li>Some other thread {@link Thread#interrupt interrupts} the current
-     * thread; or
-     * <li>The specified deadline passes; or
-     * <li>The call spuriously (that is, for no reason) returns.
-     * </ul>
-     * <p>This method does <em>not</em> report which of these caused the 
-     * method to return. Callers should re-check the conditions which caused 
-     * the thread to park in the first place. Callers may also determine, 
-     * for example, the interrupt status of the thread, or the current time
-     * upon return.
-     *
-     * @param deadline the absolute time, in milliseconds from the Epoch, to
-     * wait until
-     */
-    public static void parkUntil(long deadline) {
-        unsafe.park(true, deadline);   
-    }
-
-}
-
-
diff --git a/concurrent/src/main/java/java/util/concurrent/locks/ReadWriteLock.java b/concurrent/src/main/java/java/util/concurrent/locks/ReadWriteLock.java
deleted file mode 100644
index c7116d5..0000000
--- a/concurrent/src/main/java/java/util/concurrent/locks/ReadWriteLock.java
+++ /dev/null
@@ -1,97 +0,0 @@
-/*
- * Written by Doug Lea with assistance from members of JCP JSR-166
- * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
- */
-
-package java.util.concurrent.locks;
-
-/**
- * A <tt>ReadWriteLock</tt> maintains a pair of associated {@link
- * Lock locks}, one for read-only operations and one for writing.
- * The {@link #readLock read lock} may be held simultaneously by
- * multiple reader threads, so long as there are no writers.  The
- * {@link #writeLock write lock} is exclusive.
- * 
- * <p>A read-write lock allows for a greater level of concurrency in
- * accessing shared data, than that permitted by a mutual exclusion lock.
- * It exploits the fact that while only a single thread at a time (a
- * <em>writer</em> thread) can modify the shared data, in many cases any 
- * number of threads can concurrently read the data (hence <em>reader</em>
- * threads).
- * In theory, the increase in concurrency permitted by the use of a read-write
- * lock will lead to performance improvements over the use of a mutual
- * exclusion lock. In practice this increase in concurrency will only be fully
- * realized on a multi-processor, and then only if the access patterns for
- * the shared data are suitable.
- *
- * <p>Whether or not a read-write lock will improve performance over the use
- * of a mutual exclusion lock depends on the frequency that the data is
- * read compared to being modified, the duration of the read and write 
- * operations, and the contention for the data - that is, the number of
- * threads that will try to read or write the data at the same time.
- * For example, a collection that is initially populated with data and
- * thereafter infrequently modified, while being frequently searched
- * (such as a directory of some kind) is an ideal candidate for the use of
- * a read-write lock. However, if updates become frequent then the data
- * spends most of its time being exclusively locked and there is little, if any
- * increase in concurrency. Further, if the read operations are too short
- * the overhead of the read-write lock implementation (which is inherently
- * more complex than a mutual exclusion lock) can dominate the execution
- * cost, particularly as many read-write lock implementations still serialize
- * all threads through a small section of code. Ultimately, only profiling
- * and measurement will establish whether the use of a read-write lock is
- * suitable for your application.
- *
- *
- * <p>Although the basic operation of a read-write lock is straight-forward,
- * there are many policy decisions that an implementation must make, which
- * may affect the effectiveness of the read-write lock in a given application.
- * Examples of these policies include:
- * <ul>
- * <li>Determining whether to grant the read lock or the write lock, when
- * both readers and writers are waiting, at the time that a writer releases
- * the write lock. Writer preference is common, as writes are expected to be
- * short and infrequent. Reader preference is less common as it can lead to
- * lengthy delays for a write if the readers are frequent and long-lived as
- * expected. Fair, or &quot;in-order&quot; implementations are also possible.
- *
- * <li>Determining whether readers that request the read lock while a 
- * reader is active and a writer is waiting, are granted the read lock.
- * Preference to the reader can delay the writer indefinitely, while
- * preference to the write can reduce the potential for concurrency.
- *
- * <li>Determining whether the locks are reentrant: can a thread with the
- * write lock reacquire it? can it acquire a read lock while holding the
- * write lock? is the read lock itself reentrant?
- *
- * <li>Can the write lock be downgraded to a read lock without allowing
- * an intervening writer? Can a read lock be upgraded to a write lock,
- * in preference to other waiting readers or writers?
- *
- * </ul>
- * You should consider all of these things when evaluating the suitability
- * of a given implementation for your application.
- *
- * @see ReentrantReadWriteLock
- * @see Lock
- * @see ReentrantLock
- *
- * @since 1.5
- * @author Doug Lea
- */
-public interface ReadWriteLock {
-    /**
-     * Returns the lock used for reading.
-     *
-     * @return the lock used for reading.
-     */
-    Lock readLock();
-
-    /**
-     * Returns the lock used for writing.
-     *
-     * @return the lock used for writing.
-     */
-    Lock writeLock();
-}
diff --git a/concurrent/src/main/java/java/util/concurrent/locks/ReentrantLock.java b/concurrent/src/main/java/java/util/concurrent/locks/ReentrantLock.java
deleted file mode 100644
index bf3d653..0000000
--- a/concurrent/src/main/java/java/util/concurrent/locks/ReentrantLock.java
+++ /dev/null
@@ -1,727 +0,0 @@
-/*
- * Written by Doug Lea with assistance from members of JCP JSR-166
- * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
- */
-
-package java.util.concurrent.locks;
-import java.util.*;
-import java.util.concurrent.*;
-import java.util.concurrent.atomic.*;
-
-/**
- * A reentrant mutual exclusion {@link Lock} with the same basic
- * behavior and semantics as the implicit monitor lock accessed using
- * <tt>synchronized</tt> methods and statements, but with extended
- * capabilities.
- *
- * <p> A <tt>ReentrantLock</tt> is <em>owned</em> by the thread last
- * successfully locking, but not yet unlocking it. A thread invoking
- * <tt>lock</tt> will return, successfully acquiring the lock, when
- * the lock is not owned by another thread. The method will return
- * immediately if the current thread already owns the lock. This can
- * be checked using methods {@link #isHeldByCurrentThread}, and {@link
- * #getHoldCount}.  
- *
- * <p> The constructor for this class accepts an optional
- * <em>fairness</em> parameter.  When set <tt>true</tt>, under
- * contention, locks favor granting access to the longest-waiting
- * thread.  Otherwise this lock does not guarantee any particular
- * access order.  Programs using fair locks accessed by many threads
- * may display lower overall throughput (i.e., are slower; often much
- * slower) than those using the default setting, but have smaller
- * variances in times to obtain locks and guarantee lack of
- * starvation. Note however, that fairness of locks does not guarantee
- * fairness of thread scheduling. Thus, one of many threads using a
- * fair lock may obtain it multiple times in succession while other
- * active threads are not progressing and not currently holding the
- * lock.
- *
- * <p> It is recommended practice to <em>always</em> immediately
- * follow a call to <tt>lock</tt> with a <tt>try</tt> block, most
- * typically in a before/after construction such as:
- *
- * <pre>
- * class X {
- *   private final ReentrantLock lock = new ReentrantLock();
- *   // ...
- *
- *   public void m() { 
- *     lock.lock();  // block until condition holds
- *     try {
- *       // ... method body
- *     } finally {
- *       lock.unlock()
- *     }
- *   }
- * }
- * </pre>
- *
- * <p>In addition to implementing the {@link Lock} interface, this
- * class defines methods <tt>isLocked</tt> and
- * <tt>getLockQueueLength</tt>, as well as some associated
- * <tt>protected</tt> access methods that may be useful for
- * instrumentation and monitoring.
- *
- * <p> Serialization of this class behaves in the same way as built-in
- * locks: a deserialized lock is in the unlocked state, regardless of
- * its state when serialized.
- *
- * <p> This lock supports a maximum of 2147483648 recursive locks by
- * the same thread. 
- *
- * @since 1.5
- * @author Doug Lea
- * 
- */
-public class ReentrantLock implements Lock, java.io.Serializable {
-    private static final long serialVersionUID = 7373984872572414699L;
-    /** Synchronizer providing all implementation mechanics */
-    private final Sync sync;
-
-    /**
-     * Base of synchronization control for this lock. Subclassed
-     * into fair and nonfair versions below. Uses AQS state to
-     * represent the number of holds on the lock.
-     */
-    static abstract class Sync  extends AbstractQueuedSynchronizer {
-        /** Current owner thread */
-        transient Thread owner;
-
-        /**
-         * Perform {@link Lock#lock}. The main reason for subclassing
-         * is to allow fast path for nonfair version.
-         */
-        abstract void lock();
-
-        /** 
-         * Perform non-fair tryLock.  tryAcquire is
-         * implemented in subclasses, but both need nonfair
-         * try for trylock method
-         */
-        final boolean nonfairTryAcquire(int acquires) { 
-            final Thread current = Thread.currentThread();
-            int c = getState();
-            if (c == 0) {
-                if (compareAndSetState(0, acquires)) {
-                    owner = current;
-                    return true;
-                }
-            }
-            else if (current == owner) {
-                setState(c+acquires);
-                return true;
-            }
-            return false;
-        }
-
-        protected final boolean tryRelease(int releases) {
-            int c = getState() - releases;
-            if (Thread.currentThread() != owner)
-                throw new IllegalMonitorStateException();
-            boolean free = false;
-            if (c == 0) {
-                free = true;
-                owner = null;
-            }
-            setState(c);
-            return free;
-        }
-
-        protected final boolean isHeldExclusively() {
-            return getState() != 0 && owner == Thread.currentThread();
-        }
-
-        final ConditionObject newCondition() {
-            return new ConditionObject();
-        }
-
-        // Methods relayed from outer class
-
-        final Thread getOwner() {
-            int c = getState();
-            Thread o = owner;
-            return (c == 0)? null : o;
-        }
-        
-        final int getHoldCount() {
-            int c = getState();
-            Thread o = owner;
-            return (o == Thread.currentThread())? c : 0;
-        }
-        
-        final boolean isLocked() {
-            return getState() != 0;
-        }
-
-        /**
-         * Reconstitute this lock instance from a stream
-         * @param s the stream
-         */
-        private void readObject(java.io.ObjectInputStream s)
-            throws java.io.IOException, ClassNotFoundException {
-            s.defaultReadObject();
-            setState(0); // reset to unlocked state
-        }
-    }
-
-    /**
-     * Sync object for non-fair locks
-     */
-    final static class NonfairSync extends Sync {
-        /**
-         * Perform lock.  Try immediate barge, backing up to normal
-         * acquire on failure.
-         */
-        final void lock() {
-            if (compareAndSetState(0, 1))
-                owner = Thread.currentThread();
-            else
-                acquire(1);
-        }
-
-        protected final boolean tryAcquire(int acquires) { 
-            return nonfairTryAcquire(acquires);
-        }
-    }
-
-    /**
-     * Sync object for fair locks
-     */
-    final static class FairSync  extends Sync {
-        final void lock() { 
-            acquire(1); 
-        }
-
-        /**
-         * Fair version of tryAcquire.  Don't grant access unless
-         * recursive call or no waiters or is first.
-         */
-        protected final boolean tryAcquire(int acquires) { 
-            final Thread current = Thread.currentThread();
-            int c = getState();
-            if (c == 0) {
-                Thread first = getFirstQueuedThread();
-                if ((first == null || first == current) && 
-                    compareAndSetState(0, acquires)) {
-                    owner = current;
-                    return true;
-                }
-            }
-            else if (current == owner) {
-                setState(c+acquires);
-                return true;
-            }
-            return false;
-        }
-    }
-
-    /**
-     * Creates an instance of <tt>ReentrantLock</tt>.
-     * This is equivalent to using <tt>ReentrantLock(false)</tt>.
-     */
-    public ReentrantLock() { 
-        sync = new NonfairSync();
-    }
-
-    /**
-     * Creates an instance of <tt>ReentrantLock</tt> with the
-     * given fairness policy.
-     * @param fair true if this lock will be fair; else false
-     */
-    public ReentrantLock(boolean fair) { 
-        sync = (fair)? new FairSync() : new NonfairSync();
-    }
-
-    /**
-     * Acquires the lock. 
-     *
-     * <p>Acquires the lock if it is not held by another thread and returns 
-     * immediately, setting the lock hold count to one.
-     *
-     * <p>If the current thread
-     * already holds the lock then the hold count is incremented by one and
-     * the method returns immediately.
-     *
-     * <p>If the lock is held by another thread then the
-     * current thread becomes disabled for thread scheduling 
-     * purposes and lies dormant until the lock has been acquired,
-     * at which time the lock hold count is set to one. 
-     */
-    public void lock() {
-        sync.lock();
-    }
-
-    /**
-     * Acquires the lock unless the current thread is 
-     * {@link Thread#interrupt interrupted}.
-     *
-     * <p>Acquires the lock if it is not held by another thread and returns 
-     * immediately, setting the lock hold count to one.
-     *
-     * <p>If the current thread already holds this lock then the hold count 
-     * is incremented by one and the method returns immediately.
-     *
-     * <p>If the lock is held by another thread then the
-     * current thread becomes disabled for thread scheduling 
-     * purposes and lies dormant until one of two things happens:
-     *
-     * <ul>
-     *
-     * <li>The lock is acquired by the current thread; or
-     *
-     * <li>Some other thread {@link Thread#interrupt interrupts} the current
-     * thread.
-     *
-     * </ul>
-     *
-     * <p>If the lock is acquired by the current thread then the lock hold 
-     * count is set to one.
-     *
-     * <p>If the current thread:
-     *
-     * <ul>
-     *
-     * <li>has its interrupted status set on entry to this method; or 
-     *
-     * <li>is {@link Thread#interrupt interrupted} while acquiring 
-     * the lock,
-     *
-     * </ul>
-     *
-     * then {@link InterruptedException} is thrown and the current thread's 
-     * interrupted status is cleared. 
-     *
-     * <p>In this implementation, as this method is an explicit interruption 
-     * point, preference is 
-     * given to responding to the interrupt over normal or reentrant 
-     * acquisition of the lock.
-     *
-     * @throws InterruptedException if the current thread is interrupted
-     */
-    public void lockInterruptibly() throws InterruptedException { 
-        sync.acquireInterruptibly(1);
-    }
-
-    /**
-     * Acquires the lock only if it is not held by another thread at the time
-     * of invocation.
-     *
-     * <p>Acquires the lock if it is not held by another thread and
-     * returns immediately with the value <tt>true</tt>, setting the
-     * lock hold count to one. Even when this lock has been set to use a
-     * fair ordering policy, a call to <tt>tryLock()</tt> <em>will</em>
-     * immediately acquire the lock if it is available, whether or not
-     * other threads are currently waiting for the lock. 
-     * This &quot;barging&quot; behavior can be useful in certain 
-     * circumstances, even though it breaks fairness. If you want to honor
-     * the fairness setting for this lock, then use 
-     * {@link #tryLock(long, TimeUnit) tryLock(0, TimeUnit.SECONDS) }
-     * which is almost equivalent (it also detects interruption).
-     *
-     * <p> If the current thread
-     * already holds this lock then the hold count is incremented by one and
-     * the method returns <tt>true</tt>.
-     *
-     * <p>If the lock is held by another thread then this method will return 
-     * immediately with the value <tt>false</tt>.  
-     *
-     * @return <tt>true</tt> if the lock was free and was acquired by the
-     * current thread, or the lock was already held by the current thread; and
-     * <tt>false</tt> otherwise.
-     */
-    public boolean tryLock() {
-        return sync.nonfairTryAcquire(1);
-    }
-
-    /**
-     * Acquires the lock if it is not held by another thread within the given 
-     * waiting time and the current thread has not been 
-     * {@link Thread#interrupt interrupted}.
-     *
-     * <p>Acquires the lock if it is not held by another thread and returns 
-     * immediately with the value <tt>true</tt>, setting the lock hold count 
-     * to one. If this lock has been set to use a fair ordering policy then
-     * an available lock <em>will not</em> be acquired if any other threads
-     * are waiting for the lock. This is in contrast to the {@link #tryLock()}
-     * method. If you want a timed <tt>tryLock</tt> that does permit barging on
-     * a fair lock then combine the timed and un-timed forms together:
-     *
-     * <pre>if (lock.tryLock() || lock.tryLock(timeout, unit) ) { ... }
-     * </pre>
-     *
-     * <p>If the current thread
-     * already holds this lock then the hold count is incremented by one and
-     * the method returns <tt>true</tt>.
-     *
-     * <p>If the lock is held by another thread then the
-     * current thread becomes disabled for thread scheduling 
-     * purposes and lies dormant until one of three things happens:
-     *
-     * <ul>
-     *
-     * <li>The lock is acquired by the current thread; or
-     *
-     * <li>Some other thread {@link Thread#interrupt interrupts} the current
-     * thread; or
-     *
-     * <li>The specified waiting time elapses
-     *
-     * </ul>
-     *
-     * <p>If the lock is acquired then the value <tt>true</tt> is returned and
-     * the lock hold count is set to one.
-     *
-     * <p>If the current thread:
-     *
-     * <ul>
-     *
-     * <li>has its interrupted status set on entry to this method; or 
-     *
-     * <li>is {@link Thread#interrupt interrupted} while acquiring
-     * the lock,
-     *
-     * </ul>
-     * then {@link InterruptedException} is thrown and the current thread's 
-     * interrupted status is cleared. 
-     *
-     * <p>If the specified waiting time elapses then the value <tt>false</tt>
-     * is returned.
-     * If the time is 
-     * less than or equal to zero, the method will not wait at all.
-     *
-     * <p>In this implementation, as this method is an explicit interruption 
-     * point, preference is 
-     * given to responding to the interrupt over normal or reentrant 
-     * acquisition of the lock, and over reporting the elapse of the waiting
-     * time.
-     *
-     * @param timeout the time to wait for the lock
-     * @param unit the time unit of the timeout argument
-     *
-     * @return <tt>true</tt> if the lock was free and was acquired by the
-     * current thread, or the lock was already held by the current thread; and
-     * <tt>false</tt> if the waiting time elapsed before the lock could be 
-     * acquired.
-     *
-     * @throws InterruptedException if the current thread is interrupted
-     * @throws NullPointerException if unit is null
-     *
-     */
-    public boolean tryLock(long timeout, TimeUnit unit) throws InterruptedException {
-        return sync.tryAcquireNanos(1, unit.toNanos(timeout));
-    }
-
-    /**
-     * Attempts to release this lock.  
-     *
-     * <p>If the current thread is the
-     * holder of this lock then the hold count is decremented. If the
-     * hold count is now zero then the lock is released.  If the
-     * current thread is not the holder of this lock then {@link
-     * IllegalMonitorStateException} is thrown.
-     * @throws IllegalMonitorStateException if the current thread does not
-     * hold this lock.
-     */
-    public void unlock() {
-        sync.release(1);
-    }
-
-    /**
-     * Returns a {@link Condition} instance for use with this 
-     * {@link Lock} instance.
-     *
-     * <p>The returned {@link Condition} instance supports the same
-     * usages as do the {@link Object} monitor methods ({@link
-     * Object#wait() wait}, {@link Object#notify notify}, and {@link
-     * Object#notifyAll notifyAll}) when used with the built-in
-     * monitor lock.
-     *
-     * <ul>
-     *
-     * <li>If this lock is not held when any of the {@link Condition}
-     * {@link Condition#await() waiting} or {@link Condition#signal
-     * signalling} methods are called, then an {@link
-     * IllegalMonitorStateException} is thrown.
-     *
-     * <li>When the condition {@link Condition#await() waiting}
-     * methods are called the lock is released and, before they
-     * return, the lock is reacquired and the lock hold count restored
-     * to what it was when the method was called.
-     *
-     * <li>If a thread is {@link Thread#interrupt interrupted} while
-     * waiting then the wait will terminate, an {@link
-     * InterruptedException} will be thrown, and the thread's
-     * interrupted status will be cleared.
-     *
-     * <li> Waiting threads are signalled in FIFO order
-     *
-     * <li>The ordering of lock reacquisition for threads returning
-     * from waiting methods is the same as for threads initially
-     * acquiring the lock, which is in the default case not specified,
-     * but for <em>fair</em> locks favors those threads that have been
-     * waiting the longest.
-     * 
-     * </ul>
-     *
-     * @return the Condition object
-     */
-    public Condition newCondition() {
-        return sync.newCondition();
-    }
-
-    /**
-     * Queries the number of holds on this lock by the current thread.
-     *
-     * <p>A thread has a hold on a lock for each lock action that is not 
-     * matched by an unlock action.
-     *
-     * <p>The hold count information is typically only used for testing and
-     * debugging purposes. For example, if a certain section of code should
-     * not be entered with the lock already held then we can assert that
-     * fact:
-     *
-     * <pre>
-     * class X {
-     *   ReentrantLock lock = new ReentrantLock();
-     *   // ...     
-     *   public void m() { 
-     *     assert lock.getHoldCount() == 0;
-     *     lock.lock();
-     *     try {
-     *       // ... method body
-     *     } finally {
-     *       lock.unlock();
-     *     }
-     *   }
-     * }
-     * </pre>
-     *
-     * @return the number of holds on this lock by the current thread,
-     * or zero if this lock is not held by the current thread.
-     */
-    public int getHoldCount() {
-        return sync.getHoldCount();
-    }
-
-    /**
-     * Queries if this lock is held by the current thread.
-     *
-     * <p>Analogous to the {@link Thread#holdsLock} method for built-in
-     * monitor locks, this method is typically used for debugging and
-     * testing. For example, a method that should only be called while
-     * a lock is held can assert that this is the case:
-     *
-     * <pre>
-     * class X {
-     *   ReentrantLock lock = new ReentrantLock();
-     *   // ...
-     *
-     *   public void m() { 
-     *       assert lock.isHeldByCurrentThread();
-     *       // ... method body
-     *   }
-     * }
-     * </pre>
-     *
-     * <p>It can also be used to ensure that a reentrant lock is used
-     * in a non-reentrant manner, for example:
-     *
-     * <pre>
-     * class X {
-     *   ReentrantLock lock = new ReentrantLock();
-     *   // ...
-     *
-     *   public void m() { 
-     *       assert !lock.isHeldByCurrentThread();
-     *       lock.lock();
-     *       try {
-     *           // ... method body
-     *       } finally {
-     *           lock.unlock();
-     *       }
-     *   }
-     * }
-     * </pre>
-     * @return <tt>true</tt> if current thread holds this lock and 
-     * <tt>false</tt> otherwise.
-     */
-    public boolean isHeldByCurrentThread() {
-        return sync.isHeldExclusively();
-    }
-
-    /**
-     * Queries if this lock is held by any thread. This method is
-     * designed for use in monitoring of the system state, 
-     * not for synchronization control.
-     * @return <tt>true</tt> if any thread holds this lock and 
-     * <tt>false</tt> otherwise.
-     */
-    public boolean isLocked() {
-        return sync.isLocked();
-    }
-
-    /**
-     * Returns true if this lock has fairness set true.
-     * @return true if this lock has fairness set true.
-     */
-    public final boolean isFair() {
-        return sync instanceof FairSync;
-    }
-
-    /**
-     * Returns the thread that currently owns the exclusive lock, or
-     * <tt>null</tt> if not owned. Note that the owner may be
-     * momentarily <tt>null</tt> even if there are threads trying to
-     * acquire the lock but have not yet done so.  This method is
-     * designed to facilitate construction of subclasses that provide
-     * more extensive lock monitoring facilities.
-     * @return the owner, or <tt>null</tt> if not owned.
-     */
-    protected Thread getOwner() {
-        return sync.getOwner();
-    }
-
-    /**
-     * Queries whether any threads are waiting to acquire. Note that
-     * because cancellations may occur at any time, a <tt>true</tt>
-     * return does not guarantee that any other thread will ever
-     * acquire.  This method is designed primarily for use in
-     * monitoring of the system state.
-     *
-     * @return true if there may be other threads waiting to acquire
-     * the lock.
-     */
-    public final boolean hasQueuedThreads() { 
-        return sync.hasQueuedThreads();
-    }
-
-
-    /**
-     * Queries whether the given thread is waiting to acquire this
-     * lock. Note that because cancellations may occur at any time, a
-     * <tt>true</tt> return does not guarantee that this thread
-     * will ever acquire.  This method is designed primarily for use
-     * in monitoring of the system state.
-     *
-     * @param thread the thread
-     * @return true if the given thread is queued waiting for this lock.
-     * @throws NullPointerException if thread is null
-     */
-    public final boolean hasQueuedThread(Thread thread) { 
-        return sync.isQueued(thread);
-    }
-
-
-    /**
-     * Returns an estimate of the number of threads waiting to
-     * acquire.  The value is only an estimate because the number of
-     * threads may change dynamically while this method traverses
-     * internal data structures.  This method is designed for use in
-     * monitoring of the system state, not for synchronization
-     * control.
-     * @return the estimated number of threads waiting for this lock
-     */
-    public final int getQueueLength() {
-        return sync.getQueueLength();
-    }
-
-    /**
-     * Returns a collection containing threads that may be waiting to
-     * acquire.  Because the actual set of threads may change
-     * dynamically while constructing this result, the returned
-     * collection is only a best-effort estimate.  The elements of the
-     * returned collection are in no particular order.  This method is
-     * designed to facilitate construction of subclasses that provide
-     * more extensive monitoring facilities.
-     * @return the collection of threads
-     */
-    protected Collection<Thread> getQueuedThreads() {
-        return sync.getQueuedThreads();
-    }
-
-    /**
-     * Queries whether any threads are waiting on the given condition
-     * associated with this lock. Note that because timeouts and
-     * interrupts may occur at any time, a <tt>true</tt> return does
-     * not guarantee that a future <tt>signal</tt> will awaken any
-     * threads.  This method is designed primarily for use in
-     * monitoring of the system state.
-     * @param condition the condition
-     * @return <tt>true</tt> if there are any waiting threads.
-     * @throws IllegalMonitorStateException if this lock 
-     * is not held
-     * @throws IllegalArgumentException if the given condition is
-     * not associated with this lock
-     * @throws NullPointerException if condition null
-     */ 
-    public boolean hasWaiters(Condition condition) {
-        if (condition == null)
-            throw new NullPointerException();
-        if (!(condition instanceof AbstractQueuedSynchronizer.ConditionObject))
-            throw new IllegalArgumentException("not owner");
-        return sync.hasWaiters((AbstractQueuedSynchronizer.ConditionObject)condition);
-    }
-
-    /**
-     * Returns an estimate of the number of threads waiting on the
-     * given condition associated with this lock. Note that because
-     * timeouts and interrupts may occur at any time, the estimate
-     * serves only as an upper bound on the actual number of waiters.
-     * This method is designed for use in monitoring of the system
-     * state, not for synchronization control.
-     * @param condition the condition
-     * @return the estimated number of waiting threads.
-     * @throws IllegalMonitorStateException if this lock 
-     * is not held
-     * @throws IllegalArgumentException if the given condition is
-     * not associated with this lock
-     * @throws NullPointerException if condition null
-     */ 
-    public int getWaitQueueLength(Condition condition) {
-        if (condition == null)
-            throw new NullPointerException();
-        if (!(condition instanceof AbstractQueuedSynchronizer.ConditionObject))
-            throw new IllegalArgumentException("not owner");
-        return sync.getWaitQueueLength((AbstractQueuedSynchronizer.ConditionObject)condition);
-    }
-
-    /**
-     * Returns a collection containing those threads that may be
-     * waiting on the given condition associated with this lock.
-     * Because the actual set of threads may change dynamically while
-     * constructing this result, the returned collection is only a
-     * best-effort estimate. The elements of the returned collection
-     * are in no particular order.  This method is designed to
-     * facilitate construction of subclasses that provide more
-     * extensive condition monitoring facilities.
-     * @param condition the condition
-     * @return the collection of threads
-     * @throws IllegalMonitorStateException if this lock 
-     * is not held
-     * @throws IllegalArgumentException if the given condition is
-     * not associated with this lock
-     * @throws NullPointerException if condition null
-     */
-    protected Collection<Thread> getWaitingThreads(Condition condition) {
-        if (condition == null)
-            throw new NullPointerException();
-        if (!(condition instanceof AbstractQueuedSynchronizer.ConditionObject))
-            throw new IllegalArgumentException("not owner");
-        return sync.getWaitingThreads((AbstractQueuedSynchronizer.ConditionObject)condition);
-    }
-
-    /**
-     * Returns a string identifying this lock, as well as its lock
-     * state.  The state, in brackets, includes either the String
-     * &quot;Unlocked&quot; or the String &quot;Locked by&quot;
-     * followed by the {@link Thread#getName} of the owning thread.
-     * @return a string identifying this lock, as well as its lock state.
-     */
-    public String toString() {
-        Thread owner = sync.getOwner();
-        return super.toString() + ((owner == null) ?
-                                   "[Unlocked]" :
-                                   "[Locked by thread " + owner.getName() + "]");
-    }
-}
diff --git a/concurrent/src/main/java/java/util/concurrent/locks/ReentrantReadWriteLock.java b/concurrent/src/main/java/java/util/concurrent/locks/ReentrantReadWriteLock.java
deleted file mode 100644
index 95fc7af..0000000
--- a/concurrent/src/main/java/java/util/concurrent/locks/ReentrantReadWriteLock.java
+++ /dev/null
@@ -1,1119 +0,0 @@
-/*
- * Written by Doug Lea with assistance from members of JCP JSR-166
- * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
- */
-
-package java.util.concurrent.locks;
-import java.util.concurrent.*;
-import java.util.concurrent.atomic.*;
-import java.util.*;
-
-/**
- * An implementation of {@link ReadWriteLock} supporting similar
- * semantics to {@link ReentrantLock}.
- * <p>This class has the following properties:
- *
- * <ul>
- * <li><b>Acquisition order</b>
- *
- * <p> This class does not impose a reader or writer preference
- * ordering for lock access.  However, it does support an optional
- * <em>fairness</em> policy.  When constructed as fair, threads
- * contend for entry using an approximately arrival-order policy. When
- * the write lock is released either the longest-waiting single writer
- * will be assigned the write lock, or if there is a reader waiting
- * longer than any writer, the set of readers will be assigned the
- * read lock.  When constructed as non-fair, the order of entry to the
- * lock need not be in arrival order.  In either case, if readers are
- * active and a writer enters the lock then no subsequent readers will
- * be granted the read lock until after that writer has acquired and
- * released the write lock.
- * 
- * <li><b>Reentrancy</b>
- * <p>This lock allows both readers and writers to reacquire read or
- * write locks in the style of a {@link ReentrantLock}. Readers are not
- * allowed until all write locks held by the writing thread have been
- * released.  
- * <p>Additionally, a writer can acquire the read lock - but not vice-versa.
- * Among other applications, reentrancy can be useful when
- * write locks are held during calls or callbacks to methods that
- * perform reads under read locks. 
- * If a reader tries to acquire the write lock it will never succeed.
- * 
- * <li><b>Lock downgrading</b>
- * <p>Reentrancy also allows downgrading from the write lock to a read lock,
- * by acquiring the write lock, then the read lock and then releasing the
- * write lock. However, upgrading from a read lock to the write lock, is
- * <b>not</b> possible.
- *
- * <li><b>Interruption of lock acquisition</b>
- * <p>The read lock and write lock both support interruption during lock
- * acquisition.
- *
- * <li><b>{@link Condition} support</b>
- * <p>The write lock provides a {@link Condition} implementation that
- * behaves in the same way, with respect to the write lock, as the 
- * {@link Condition} implementation provided by
- * {@link ReentrantLock#newCondition} does for {@link ReentrantLock}.
- * This {@link Condition} can, of course, only be used with the write lock.
- * <p>The read lock does not support a {@link Condition} and
- * <tt>readLock().newCondition()</tt> throws 
- * <tt>UnsupportedOperationException</tt>.
- *
- * <li><b>Instrumentation</b>
- * <P> This class supports methods to determine whether locks
- * are held or contended. These methods are designed for monitoring
- * system state, not for synchronization control.
- * </ul>
- *
- * <p> Serialization of this class behaves in the same way as built-in
- * locks: a deserialized lock is in the unlocked state, regardless of
- * its state when serialized.
- *
- * <p><b>Sample usages</b>. Here is a code sketch showing how to exploit
- * reentrancy to perform lock downgrading after updating a cache (exception
- * handling is elided for simplicity):
- * <pre>
- * class CachedData {
- *   Object data;
- *   volatile boolean cacheValid;
- *   ReentrantReadWriteLock rwl = new ReentrantReadWriteLock();
- *
- *   void processCachedData() {
- *     rwl.readLock().lock();
- *     if (!cacheValid) {
- *        // upgrade lock manually
- *        rwl.readLock().unlock();   // must unlock first to obtain writelock
- *        rwl.writeLock().lock();
- *        if (!cacheValid) { // recheck
- *          data = ...
- *          cacheValid = true;
- *        }
- *        // downgrade lock
- *        rwl.readLock().lock();  // reacquire read without giving up write lock
- *        rwl.writeLock().unlock(); // unlock write, still hold read
- *     }
- *
- *     use(data);
- *     rwl.readLock().unlock();
- *   }
- * }
- * </pre>
- *
- * ReentrantReadWriteLocks can be used to improve concurrency in some
- * uses of some kinds of Collections. This is typically worthwhile
- * only when the collections are expected to be large, accessed by
- * more reader threads than writer threads, and entail operations with
- * overhead that outweighs synchronization overhead. For example, here
- * is a class using a TreeMap that is expected to be large and 
- * concurrently accessed.
- *
- * <pre>
- * class RWDictionary {
- *    private final Map&lt;String, Data&gt;  m = new TreeMap&lt;String, Data&gt;();
- *    private final ReentrantReadWriteLock rwl = new ReentrantReadWriteLock();
- *    private final Lock r = rwl.readLock();
- *    private final Lock w = rwl.writeLock();
- *
- *    public Data get(String key) {
- *        r.lock(); try { return m.get(key); } finally { r.unlock(); }
- *    }
- *    public String[] allKeys() {
- *        r.lock(); try { return m.keySet().toArray(); } finally { r.unlock(); }
- *    }
- *    public Data put(String key, Data value) {
- *        w.lock(); try { return m.put(key, value); } finally { w.unlock(); }
- *    }
- *    public void clear() {
- *        w.lock(); try { m.clear(); } finally { w.unlock(); }
- *    }
- * }
- * </pre>
- * 
- *
- * <h3>Implementation Notes</h3>
- *
- * <p>A reentrant write lock intrinsically defines an owner and can
- * only be released by the thread that acquired it.  In contrast, in
- * this implementation, the read lock has no concept of ownership, and
- * there is no requirement that the thread releasing a read lock is
- * the same as the one that acquired it.  However, this property is
- * not guaranteed to hold in future implementations of this class.
- *
- * <p> This lock supports a maximum of 65536 recursive write locks
- * and 65536 read locks. Attempts to exceed these limits result in
- * {@link Error} throws from locking methods.
- *
- * @since 1.5
- * @author Doug Lea
- *
- */
-public class ReentrantReadWriteLock implements ReadWriteLock, java.io.Serializable  {
-    private static final long serialVersionUID = -6992448646407690164L;
-    /** Inner class providing readlock */
-    private final ReentrantReadWriteLock.ReadLock readerLock;
-    /** Inner class providing writelock */
-    private final ReentrantReadWriteLock.WriteLock writerLock;
-    /** Performs all synchronization mechanics */
-    private final Sync sync;
-
-    /**
-     * Creates a new <tt>ReentrantReadWriteLock</tt> with
-     * default ordering properties.
-     */
-    public ReentrantReadWriteLock() {
-        sync = new NonfairSync();
-        readerLock = new ReadLock(this);
-        writerLock = new WriteLock(this);
-    }
-
-    /**
-     * Creates a new <tt>ReentrantReadWriteLock</tt> with
-     * the given fairness policy.
-     *
-     * @param fair true if this lock should use a fair ordering policy
-     */
-    public ReentrantReadWriteLock(boolean fair) {
-        sync = (fair)? new FairSync() : new NonfairSync();
-        readerLock = new ReadLock(this);
-        writerLock = new WriteLock(this);
-    }
-
-    public ReentrantReadWriteLock.WriteLock writeLock() { return writerLock; }
-    public ReentrantReadWriteLock.ReadLock  readLock()  { return readerLock; }
-
-    /* 
-     * Read vs write count extraction constants and functions.
-     * Lock state is logically divided into two shorts: The lower
-     * one representing the exclusive (writer) lock hold count,
-     * and the upper the shared (reader) hold count.
-     */
-    
-    static final int SHARED_SHIFT   = 16;
-    static final int SHARED_UNIT    = (1 << SHARED_SHIFT);
-    static final int EXCLUSIVE_MASK = (1 << SHARED_SHIFT) - 1;
-    
-    /** Returns the number of shared holds represented in count  */
-    static int sharedCount(int c)    { return c >>> SHARED_SHIFT; }
-    /** Returns the number of exclusive holds represented in count  */
-    static int exclusiveCount(int c) { return c & EXCLUSIVE_MASK; }
-
-    /** 
-     * Synchronization implementation for ReentrantReadWriteLock.
-     * Subclassed into fair and nonfair versions.
-     */
-    abstract static class Sync extends AbstractQueuedSynchronizer {
-        /** Current (exclusive) owner thread */
-        transient Thread owner;
-
-        /**
-         * Perform write lock. Allows fast path in non-fair version.
-         */
-        abstract void wlock();
-
-        /** 
-         * Perform non-fair tryLock for write.  tryAcquire is
-         * implemented in subclasses, but both versions need nonfair
-         * try for trylock method
-         */
-        final boolean nonfairTryAcquire(int acquires) {
-            // mask out readlocks if called from condition methods
-            acquires = exclusiveCount(acquires);
-            Thread current = Thread.currentThread();
-            int c = getState();
-            int w = exclusiveCount(c);
-            if (w + acquires >= SHARED_UNIT)
-                throw new Error("Maximum lock count exceeded");
-            if (c != 0 && (w == 0 || current != owner))
-                return false;
-            if (!compareAndSetState(c, c + acquires)) 
-                return false;
-            owner = current;
-            return true;
-        }
-
-        /** 
-         * Perform nonfair tryLock for read. 
-         */
-        final int nonfairTryAcquireShared(int acquires) {
-            for (;;) {
-                int c = getState();
-                int nextc = c + (acquires << SHARED_SHIFT);
-                if (nextc < c)
-                    throw new Error("Maximum lock count exceeded");
-                if (exclusiveCount(c) != 0 && 
-                    owner != Thread.currentThread())
-                    return -1;
-                if (compareAndSetState(c, nextc)) 
-                    return 1;
-                // Recheck count if lost CAS
-            }
-        }
-
-        protected final boolean tryRelease(int releases) {
-            Thread current = Thread.currentThread();
-            int c = getState();
-            if (owner != current)
-                throw new IllegalMonitorStateException();
-            int nextc = c - releases;
-            boolean free = false;
-            if (exclusiveCount(c) == releases) {
-                free = true;
-                owner = null;
-            }
-            setState(nextc);
-            return free;
-        }
-
-        protected final boolean tryReleaseShared(int releases) {
-            for (;;) {
-                int c = getState();
-                int nextc = c - (releases << SHARED_SHIFT);
-                if (nextc < 0)
-                    throw new IllegalMonitorStateException();
-                if (compareAndSetState(c, nextc)) 
-                    return nextc == 0;
-            }
-        }
-    
-        protected final boolean isHeldExclusively() {
-            return exclusiveCount(getState()) != 0 && 
-                owner == Thread.currentThread();
-        }
-
-        // Methods relayed to outer class
-        
-        final ConditionObject newCondition() { 
-            return new ConditionObject(); 
-        }
-
-        final Thread getOwner() {
-            int c = exclusiveCount(getState());
-            Thread o = owner;
-            return (c == 0)? null : o;
-        }
-        
-        final int getReadLockCount() {
-            return sharedCount(getState());
-        }
-        
-        final boolean isWriteLocked() {
-            return exclusiveCount(getState()) != 0;
-        }
-
-        final int getWriteHoldCount() {
-            int c = exclusiveCount(getState());
-            Thread o = owner;
-            return (o == Thread.currentThread())? c : 0;
-        }
-
-        /**
-         * Reconstitute this lock instance from a stream
-         * @param s the stream
-         */
-        private void readObject(java.io.ObjectInputStream s)
-            throws java.io.IOException, ClassNotFoundException {
-            s.defaultReadObject();
-            setState(0); // reset to unlocked state
-        }
-
-        final int getCount() { return getState(); }
-    }
-
-    /** 
-     * Nonfair version of Sync
-     */
-    final static class NonfairSync extends Sync {
-        protected final boolean tryAcquire(int acquires) { 
-            return nonfairTryAcquire(acquires);
-        }
-
-        protected final int tryAcquireShared(int acquires) {
-            return nonfairTryAcquireShared(acquires);
-        }
-
-        // Use fastpath for main write lock method
-        final void wlock() {
-            if (compareAndSetState(0, 1))
-                owner = Thread.currentThread();
-            else
-                acquire(1);
-        }
-    }
-
-    /** 
-     * Fair version of Sync
-     */
-    final static class FairSync extends Sync {
-        protected final boolean tryAcquire(int acquires) { 
-            // mask out readlocks if called from condition methods
-            acquires = exclusiveCount(acquires);
-            Thread current = Thread.currentThread();
-            Thread first;
-            int c = getState();
-            int w = exclusiveCount(c);
-            if (w + acquires >= SHARED_UNIT)
-                throw new Error("Maximum lock count exceeded");
-            if ((w == 0 || current != owner) &&
-                (c != 0 || 
-                 ((first = getFirstQueuedThread()) != null && 
-                  first != current)))
-                return false;
-            if (!compareAndSetState(c, c + acquires)) 
-                return false;
-            owner = current;
-            return true;
-        }
-
-        protected final int tryAcquireShared(int acquires) {
-            Thread current = Thread.currentThread();
-            for (;;) {
-                Thread first = getFirstQueuedThread();
-                if (first != null && first != current)
-                    return -1;
-                int c = getState();
-                int nextc = c + (acquires << SHARED_SHIFT);
-                if (nextc < c)
-                    throw new Error("Maximum lock count exceeded");
-                if (exclusiveCount(c) != 0 && 
-                    owner != Thread.currentThread())
-                    return -1;
-                if (compareAndSetState(c, nextc)) 
-                    return 1;
-                // Recheck count if lost CAS
-            }
-        }
-
-        final void wlock() { // no fast path
-            acquire(1);
-        }
-    }
-
-    /**
-     * The lock returned by method {@link ReentrantReadWriteLock#readLock}.
-     */
-    public static class ReadLock implements Lock, java.io.Serializable  {
-        private static final long serialVersionUID = -5992448646407690164L;
-        private final Sync sync;
-        
-        /** 
-         * Constructor for use by subclasses.
-         * @param lock the outer lock object
-         * @throws NullPointerException if lock null
-         */
-        protected ReadLock(ReentrantReadWriteLock lock) {
-            sync = lock.sync;
-        }
-
-        /**
-         * Acquires the shared lock. 
-         *
-         * <p>Acquires the lock if it is not held exclusively by
-         * another thread and returns immediately.
-         *
-         * <p>If the lock is held exclusively by another thread then
-         * the current thread becomes disabled for thread scheduling
-         * purposes and lies dormant until the lock has been acquired.
-         */
-        public void lock() { 
-            sync.acquireShared(1);
-        }
-
-        /**
-         * Acquires the shared lock unless the current thread is 
-         * {@link Thread#interrupt interrupted}.
-         *
-         * <p>Acquires the shared lock if it is not held exclusively
-         * by another thread and returns immediately.
-         *
-         * <p>If the lock is held by another thread then the
-         * current thread becomes disabled for thread scheduling 
-         * purposes and lies dormant until one of two things happens:
-         *
-         * <ul>
-         *
-         * <li>The lock is acquired by the current thread; or
-         *
-         * <li>Some other thread {@link Thread#interrupt interrupts}
-         * the current thread.
-         *
-         * </ul>
-         *
-         * <p>If the current thread:
-         *
-         * <ul>
-         *
-         * <li>has its interrupted status set on entry to this method; or 
-         *
-         * <li>is {@link Thread#interrupt interrupted} while acquiring 
-         * the lock,
-         *
-         * </ul>
-         *
-         * then {@link InterruptedException} is thrown and the current
-         * thread's interrupted status is cleared.
-         *
-         * <p>In this implementation, as this method is an explicit
-         * interruption point, preference is given to responding to
-         * the interrupt over normal or reentrant acquisition of the
-         * lock.
-         *
-         * @throws InterruptedException if the current thread is interrupted
-         */
-        public void lockInterruptibly() throws InterruptedException {
-            sync.acquireSharedInterruptibly(1);
-        }
-
-        /**
-         * Acquires the shared lock only if it is not held exclusively by
-         * another thread at the time of invocation.
-         *
-         * <p>Acquires the lock if it is not held exclusively by
-         * another thread and returns immediately with the value
-         * <tt>true</tt>. Even when this lock has been set to use a
-         * fair ordering policy, a call to <tt>tryLock()</tt>
-         * <em>will</em> immediately acquire the lock if it is
-         * available, whether or not other threads are currently
-         * waiting for the lock.  This &quot;barging&quot; behavior
-         * can be useful in certain circumstances, even though it
-         * breaks fairness. If you want to honor the fairness setting
-         * for this lock, then use {@link #tryLock(long, TimeUnit)
-         * tryLock(0, TimeUnit.SECONDS) } which is almost equivalent
-         * (it also detects interruption).
-         *
-         * <p>If the lock is held exclusively by another thread then
-         * this method will return immediately with the value
-         * <tt>false</tt>.
-         *
-         * @return <tt>true</tt> if the lock was acquired.
-         */
-        public  boolean tryLock() {
-            return sync.nonfairTryAcquireShared(1) >= 0;
-        }
-
-        /**
-         * Acquires the shared lock if it is not held exclusively by
-         * another thread within the given waiting time and the
-         * current thread has not been {@link Thread#interrupt
-         * interrupted}.
-         *
-         * <p>Acquires the lock if it is not held exclusively by
-         * another thread and returns immediately with the value
-         * <tt>true</tt>. If this lock has been set to use a fair
-         * ordering policy then an available lock <em>will not</em> be
-         * acquired if any other threads are waiting for the
-         * lock. This is in contrast to the {@link #tryLock()}
-         * method. If you want a timed <tt>tryLock</tt> that does
-         * permit barging on a fair lock then combine the timed and
-         * un-timed forms together:
-         *
-         * <pre>if (lock.tryLock() || lock.tryLock(timeout, unit) ) { ... }
-         * </pre>
-         *
-         * <p>If the lock is held exclusively by another thread then the
-         * current thread becomes disabled for thread scheduling 
-         * purposes and lies dormant until one of three things happens:
-         *
-         * <ul>
-         *
-         * <li>The lock is acquired by the current thread; or
-         *
-         * <li>Some other thread {@link Thread#interrupt interrupts} the current
-         * thread; or
-         *
-         * <li>The specified waiting time elapses
-         *
-         * </ul>
-         *
-         * <p>If the lock is acquired then the value <tt>true</tt> is
-         * returned.
-         *
-         * <p>If the current thread:
-         *
-         * <ul>
-         *
-         * <li>has its interrupted status set on entry to this method; or 
-         *
-         * <li>is {@link Thread#interrupt interrupted} while acquiring
-         * the lock,
-         *
-         * </ul> then {@link InterruptedException} is thrown and the
-         * current thread's interrupted status is cleared.
-         *
-         * <p>If the specified waiting time elapses then the value
-         * <tt>false</tt> is returned.  If the time is less than or
-         * equal to zero, the method will not wait at all.
-         *
-         * <p>In this implementation, as this method is an explicit
-         * interruption point, preference is given to responding to
-         * the interrupt over normal or reentrant acquisition of the
-         * lock, and over reporting the elapse of the waiting time.
-         *
-         * @param timeout the time to wait for the lock
-         * @param unit the time unit of the timeout argument
-         *
-         * @return <tt>true</tt> if the lock was acquired.
-         *
-         * @throws InterruptedException if the current thread is interrupted
-         * @throws NullPointerException if unit is null
-         *
-         */
-        public boolean tryLock(long timeout, TimeUnit unit) throws InterruptedException {
-            return sync.tryAcquireSharedNanos(1, unit.toNanos(timeout));
-        }
-
-        /**
-         * Attempts to release this lock.  
-         *
-         * <p> If the number of readers is now zero then the lock
-         * is made available for other lock attempts.
-         */
-        public  void unlock() {
-            sync.releaseShared(1);
-        }
-
-        /**
-         * Throws UnsupportedOperationException because ReadLocks
-         * do not support conditions.
-         * @return A new {@link Condition} instance for this <tt>Lock</tt> 
-         * instance.
-         * @throws UnsupportedOperationException always
-         */
-        public Condition newCondition() {
-            throw new UnsupportedOperationException();
-        }
-
-        /**
-         * Returns a string identifying this lock, as well as its lock state.
-         * The state, in brackets, includes the String 
-         * &quot;Read locks =&quot; followed by the number of held
-         * read locks.
-         * @return a string identifying this lock, as well as its lock state.
-         */
-        public String toString() {
-            int r = sync.getReadLockCount();
-            return super.toString() + 
-                "[Read locks = " + r + "]";
-        }
-
-    }
-
-    /**
-     * The lock returned by method {@link ReentrantReadWriteLock#writeLock}.
-     */
-    public static class WriteLock implements Lock, java.io.Serializable  {
-        private static final long serialVersionUID = -4992448646407690164L;
-        private final Sync sync;
-        
-        /** 
-         * Constructor for use by subclasses.
-         * @param lock the outer lock object
-         * @throws NullPointerException if lock null
-         */
-        protected WriteLock(ReentrantReadWriteLock lock) {
-            sync = lock.sync;
-        }
-
-        /**
-         * Acquire the lock. 
-         *
-         * <p>Acquires the lock if it is not held by another thread
-         * and returns immediately, setting the lock hold count to
-         * one.
-         *
-         * <p>If the current thread already holds the lock then the
-         * hold count is incremented by one and the method returns
-         * immediately.
-         *
-         * <p>If the lock is held by another thread then the current
-         * thread becomes disabled for thread scheduling purposes and
-         * lies dormant until the lock has been acquired, at which
-         * time the lock hold count is set to one.
-         */
-        public void lock() {
-            sync.wlock();
-        }
-
-        /**
-         * Acquires the lock unless the current thread is {@link
-         * Thread#interrupt interrupted}.
-         *
-         * <p>Acquires the lock if it is not held by another thread
-         * and returns immediately, setting the lock hold count to
-         * one.
-         *
-         * <p>If the current thread already holds this lock then the
-         * hold count is incremented by one and the method returns
-         * immediately.
-         *
-         * <p>If the lock is held by another thread then the current
-         * thread becomes disabled for thread scheduling purposes and
-         * lies dormant until one of two things happens:
-         *
-         * <ul>
-         *
-         * <li>The lock is acquired by the current thread; or
-         *
-         * <li>Some other thread {@link Thread#interrupt interrupts}
-         * the current thread.
-         *
-         * </ul>
-         *
-         * <p>If the lock is acquired by the current thread then the
-         * lock hold count is set to one.
-         *
-         * <p>If the current thread:
-         *
-         * <ul>
-         *
-         * <li>has its interrupted status set on entry to this method;
-         * or
-         *
-         * <li>is {@link Thread#interrupt interrupted} while acquiring
-         * the lock,
-         *
-         * </ul>
-         *
-         * then {@link InterruptedException} is thrown and the current
-         * thread's interrupted status is cleared.
-         *
-         * <p>In this implementation, as this method is an explicit
-         * interruption point, preference is given to responding to
-         * the interrupt over normal or reentrant acquisition of the
-         * lock.
-         *
-         * @throws InterruptedException if the current thread is interrupted
-         */
-        public void lockInterruptibly() throws InterruptedException {
-            sync.acquireInterruptibly(1);
-        }
-
-        /**
-         * Acquires the lock only if it is not held by another thread
-         * at the time of invocation.
-         *
-         * <p>Acquires the lock if it is not held by another thread
-         * and returns immediately with the value <tt>true</tt>,
-         * setting the lock hold count to one. Even when this lock has
-         * been set to use a fair ordering policy, a call to
-         * <tt>tryLock()</tt> <em>will</em> immediately acquire the
-         * lock if it is available, whether or not other threads are
-         * currently waiting for the lock.  This &quot;barging&quot;
-         * behavior can be useful in certain circumstances, even
-         * though it breaks fairness. If you want to honor the
-         * fairness setting for this lock, then use {@link
-         * #tryLock(long, TimeUnit) tryLock(0, TimeUnit.SECONDS) }
-         * which is almost equivalent (it also detects interruption).
-         *
-         * <p> If the current thread already holds this lock then the
-         * hold count is incremented by one and the method returns
-         * <tt>true</tt>.
-         *
-         * <p>If the lock is held by another thread then this method
-         * will return immediately with the value <tt>false</tt>.
-         *
-         * @return <tt>true</tt> if the lock was free and was acquired by the
-         * current thread, or the lock was already held by the current thread; and
-         * <tt>false</tt> otherwise.
-         */
-        public boolean tryLock( ) {
-            return sync.nonfairTryAcquire(1);
-        }
-
-        /**
-         * Acquires the lock if it is not held by another thread
-         * within the given waiting time and the current thread has
-         * not been {@link Thread#interrupt interrupted}.
-         *
-         * <p>Acquires the lock if it is not held by another thread
-         * and returns immediately with the value <tt>true</tt>,
-         * setting the lock hold count to one. If this lock has been
-         * set to use a fair ordering policy then an available lock
-         * <em>will not</em> be acquired if any other threads are
-         * waiting for the lock. This is in contrast to the {@link
-         * #tryLock()} method. If you want a timed <tt>tryLock</tt>
-         * that does permit barging on a fair lock then combine the
-         * timed and un-timed forms together:
-         *
-         * <pre>if (lock.tryLock() || lock.tryLock(timeout, unit) ) { ... }
-         * </pre>
-         *
-         * <p>If the current thread already holds this lock then the
-         * hold count is incremented by one and the method returns
-         * <tt>true</tt>.
-         *
-         * <p>If the lock is held by another thread then the current
-         * thread becomes disabled for thread scheduling purposes and
-         * lies dormant until one of three things happens:
-         *
-         * <ul>
-         *
-         * <li>The lock is acquired by the current thread; or
-         *
-         * <li>Some other thread {@link Thread#interrupt interrupts}
-         * the current thread; or
-         *
-         * <li>The specified waiting time elapses
-         *
-         * </ul>
-         *
-         * <p>If the lock is acquired then the value <tt>true</tt> is
-         * returned and the lock hold count is set to one.
-         *
-         * <p>If the current thread:
-         *
-         * <ul>
-         *
-         * <li>has its interrupted status set on entry to this method;
-         * or
-         *
-         * <li>is {@link Thread#interrupt interrupted} while acquiring
-         * the lock,
-         *
-         * </ul> 
-         *
-         * then {@link InterruptedException} is thrown and the current
-         * thread's interrupted status is cleared.
-         *
-         * <p>If the specified waiting time elapses then the value
-         * <tt>false</tt> is returned.  If the time is less than or
-         * equal to zero, the method will not wait at all.
-         *
-         * <p>In this implementation, as this method is an explicit
-         * interruption point, preference is given to responding to
-         * the interrupt over normal or reentrant acquisition of the
-         * lock, and over reporting the elapse of the waiting time.
-         *
-         * @param timeout the time to wait for the lock
-         * @param unit the time unit of the timeout argument
-         *
-         * @return <tt>true</tt> if the lock was free and was acquired
-         * by the current thread, or the lock was already held by the
-         * current thread; and <tt>false</tt> if the waiting time
-         * elapsed before the lock could be acquired.
-         *
-         * @throws InterruptedException if the current thread is interrupted
-         * @throws NullPointerException if unit is null
-         *
-         */
-        public boolean tryLock(long timeout, TimeUnit unit) throws InterruptedException {
-            return sync.tryAcquireNanos(1, unit.toNanos(timeout));
-        }
-        
-        /**
-         * Attempts to release this lock.  
-         *
-         * <p>If the current thread is the holder of this lock then
-         * the hold count is decremented. If the hold count is now
-         * zero then the lock is released.  If the current thread is
-         * not the holder of this lock then {@link
-         * IllegalMonitorStateException} is thrown.
-         * @throws IllegalMonitorStateException if the current thread does not
-         * hold this lock.
-         */
-        public void unlock() {
-            sync.release(1);
-        }
-
-        /**
-         * Returns a {@link Condition} instance for use with this
-         * {@link Lock} instance. 
-         * <p>The returned {@link Condition} instance supports the same
-         * usages as do the {@link Object} monitor methods ({@link
-         * Object#wait() wait}, {@link Object#notify notify}, and {@link
-         * Object#notifyAll notifyAll}) when used with the built-in
-         * monitor lock.
-         *
-         * <ul>
-         *
-         * <li>If this write lock is not held when any {@link
-         * Condition} method is called then an {@link
-         * IllegalMonitorStateException} is thrown.  (Read locks are
-         * held independently of write locks, so are not checked or
-         * affected. However it is essentially always an error to
-         * invoke a condition waiting method when the current thread
-         * has also acquired read locks, since other threads that
-         * could unblock it will not be able to access the write
-         * lock.)
-         *
-         * <li>When the condition {@link Condition#await() waiting}
-         * methods are called the write lock is released and, before
-         * they return, the write lock is reacquired and the lock hold
-         * count restored to what it was when the method was called.
-         *
-         * <li>If a thread is {@link Thread#interrupt interrupted} while
-         * waiting then the wait will terminate, an {@link
-         * InterruptedException} will be thrown, and the thread's
-         * interrupted status will be cleared.
-         *
-         * <li> Waiting threads are signalled in FIFO order
-         *
-         * <li>The ordering of lock reacquisition for threads returning
-         * from waiting methods is the same as for threads initially
-         * acquiring the lock, which is in the default case not specified,
-         * but for <em>fair</em> locks favors those threads that have been
-         * waiting the longest.
-         * 
-         * </ul>
-         * @return the Condition object
-         */
-        public Condition newCondition() { 
-            return sync.newCondition();
-        }
-
-        /**
-         * Returns a string identifying this lock, as well as its lock
-         * state.  The state, in brackets includes either the String
-         * &quot;Unlocked&quot; or the String &quot;Locked by&quot;
-         * followed by the {@link Thread#getName} of the owning thread.
-         * @return a string identifying this lock, as well as its lock state.
-         */
-        public String toString() {
-            Thread owner = sync.getOwner();
-            return super.toString() + ((owner == null) ?
-                                       "[Unlocked]" :
-                                       "[Locked by thread " + owner.getName() + "]");
-        }
-
-    }
-
-
-    // Instrumentation and status
-
-    /**
-     * Returns true if this lock has fairness set true.
-     * @return true if this lock has fairness set true.
-     */
-    public final boolean isFair() {
-        return sync instanceof FairSync;
-    }
-
-    /**
-     * Returns the thread that currently owns the exclusive lock, or
-     * <tt>null</tt> if not owned. Note that the owner may be
-     * momentarily <tt>null</tt> even if there are threads trying to
-     * acquire the lock but have not yet done so.  This method is
-     * designed to facilitate construction of subclasses that provide
-     * more extensive lock monitoring facilities.
-     * @return the owner, or <tt>null</tt> if not owned.
-     */
-    protected Thread getOwner() {
-        return sync.getOwner();
-    }
-    
-    /**
-     * Queries the number of read locks held for this lock. This
-     * method is designed for use in monitoring system state, not for
-     * synchronization control.
-     * @return the number of read locks held.
-     */
-    public int getReadLockCount() {
-        return sync.getReadLockCount();
-    }
-
-    /**
-     * Queries if the write lock is held by any thread. This method is
-     * designed for use in monitoring system state, not for
-     * synchronization control.
-     * @return <tt>true</tt> if any thread holds write lock and 
-     * <tt>false</tt> otherwise.
-     */
-    public boolean isWriteLocked() {
-        return sync.isWriteLocked();
-    }
-
-    /**
-     * Queries if the write lock is held by the current thread. 
-     * @return <tt>true</tt> if current thread holds this lock and 
-     * <tt>false</tt> otherwise.
-     */
-    public boolean isWriteLockedByCurrentThread() {
-        return sync.isHeldExclusively();
-    }
-
-    /**
-     * Queries the number of reentrant write holds on this lock by the
-     * current thread.  A writer thread has a hold on a lock for
-     * each lock action that is not matched by an unlock action.
-     *
-     * @return the number of holds on this lock by the current thread,
-     * or zero if this lock is not held by the current thread.
-     */
-    public int getWriteHoldCount() {
-        return sync.getWriteHoldCount();
-    }
-
-    /**
-     * Returns a collection containing threads that may be waiting to
-     * acquire the write lock.  Because the actual set of threads may
-     * change dynamically while constructing this result, the returned
-     * collection is only a best-effort estimate.  The elements of the
-     * returned collection are in no particular order.  This method is
-     * designed to facilitate construction of subclasses that provide
-     * more extensive lock monitoring facilities.
-     * @return the collection of threads
-     */
-    protected Collection<Thread> getQueuedWriterThreads() {
-        return sync.getExclusiveQueuedThreads();
-    }
-
-    /**
-     * Returns a collection containing threads that may be waiting to
-     * acquire the read lock.  Because the actual set of threads may
-     * change dynamically while constructing this result, the returned
-     * collection is only a best-effort estimate.  The elements of the
-     * returned collection are in no particular order.  This method is
-     * designed to facilitate construction of subclasses that provide
-     * more extensive lock monitoring facilities.
-     * @return the collection of threads
-     */
-    protected Collection<Thread> getQueuedReaderThreads() {
-        return sync.getSharedQueuedThreads();
-    }
-
-    /**
-     * Queries whether any threads are waiting to acquire. Note that
-     * because cancellations may occur at any time, a <tt>true</tt>
-     * return does not guarantee that any other thread will ever
-     * acquire.  This method is designed primarily for use in
-     * monitoring of the system state.
-     *
-     * @return true if there may be other threads waiting to acquire
-     * the lock.
-     */
-    public final boolean hasQueuedThreads() { 
-        return sync.hasQueuedThreads();
-    }
-
-    /**
-     * Queries whether the given thread is waiting to acquire this
-     * lock. Note that because cancellations may occur at any time, a
-     * <tt>true</tt> return does not guarantee that this thread
-     * will ever acquire.  This method is designed primarily for use
-     * in monitoring of the system state.
-     *
-     * @param thread the thread
-     * @return true if the given thread is queued waiting for this lock.
-     * @throws NullPointerException if thread is null
-     */
-    public final boolean hasQueuedThread(Thread thread) { 
-        return sync.isQueued(thread);
-    }
-
-    /**
-     * Returns an estimate of the number of threads waiting to
-     * acquire.  The value is only an estimate because the number of
-     * threads may change dynamically while this method traverses
-     * internal data structures.  This method is designed for use in
-     * monitoring of the system state, not for synchronization
-     * control.
-     * @return the estimated number of threads waiting for this lock
-     */
-    public final int getQueueLength() {
-        return sync.getQueueLength();
-    }
-
-    /**
-     * Returns a collection containing threads that may be waiting to
-     * acquire.  Because the actual set of threads may change
-     * dynamically while constructing this result, the returned
-     * collection is only a best-effort estimate.  The elements of the
-     * returned collection are in no particular order.  This method is
-     * designed to facilitate construction of subclasses that provide
-     * more extensive monitoring facilities.
-     * @return the collection of threads
-     */
-    protected Collection<Thread> getQueuedThreads() {
-        return sync.getQueuedThreads();
-    }
-
-    /**
-     * Queries whether any threads are waiting on the given condition
-     * associated with the write lock. Note that because timeouts and
-     * interrupts may occur at any time, a <tt>true</tt> return does
-     * not guarantee that a future <tt>signal</tt> will awaken any
-     * threads.  This method is designed primarily for use in
-     * monitoring of the system state.
-     * @param condition the condition
-     * @return <tt>true</tt> if there are any waiting threads.
-     * @throws IllegalMonitorStateException if this lock 
-     * is not held
-     * @throws IllegalArgumentException if the given condition is
-     * not associated with this lock
-     * @throws NullPointerException if condition null
-     */ 
-    public boolean hasWaiters(Condition condition) {
-        if (condition == null)
-            throw new NullPointerException();
-        if (!(condition instanceof AbstractQueuedSynchronizer.ConditionObject))
-            throw new IllegalArgumentException("not owner");
-        return sync.hasWaiters((AbstractQueuedSynchronizer.ConditionObject)condition);
-    }
-
-    /**
-     * Returns an estimate of the number of threads waiting on the
-     * given condition associated with the write lock. Note that because
-     * timeouts and interrupts may occur at any time, the estimate
-     * serves only as an upper bound on the actual number of waiters.
-     * This method is designed for use in monitoring of the system
-     * state, not for synchronization control.
-     * @param condition the condition
-     * @return the estimated number of waiting threads.
-     * @throws IllegalMonitorStateException if this lock 
-     * is not held
-     * @throws IllegalArgumentException if the given condition is
-     * not associated with this lock
-     * @throws NullPointerException if condition null
-     */ 
-    public int getWaitQueueLength(Condition condition) {
-        if (condition == null)
-            throw new NullPointerException();
-        if (!(condition instanceof AbstractQueuedSynchronizer.ConditionObject))
-            throw new IllegalArgumentException("not owner");
-        return sync.getWaitQueueLength((AbstractQueuedSynchronizer.ConditionObject)condition);
-    }
-
-    /**
-     * Returns a collection containing those threads that may be
-     * waiting on the given condition associated with the write lock.
-     * Because the actual set of threads may change dynamically while
-     * constructing this result, the returned collection is only a
-     * best-effort estimate. The elements of the returned collection
-     * are in no particular order.  This method is designed to
-     * facilitate construction of subclasses that provide more
-     * extensive condition monitoring facilities.
-     * @param condition the condition
-     * @return the collection of threads
-     * @throws IllegalMonitorStateException if this lock 
-     * is not held
-     * @throws IllegalArgumentException if the given condition is
-     * not associated with this lock
-     * @throws NullPointerException if condition null
-     */
-    protected Collection<Thread> getWaitingThreads(Condition condition) {
-        if (condition == null)
-            throw new NullPointerException();
-        if (!(condition instanceof AbstractQueuedSynchronizer.ConditionObject))
-            throw new IllegalArgumentException("not owner");
-        return sync.getWaitingThreads((AbstractQueuedSynchronizer.ConditionObject)condition);
-    }
-
-    /**
-     * Returns a string identifying this lock, as well as its lock state.
-     * The state, in brackets, includes the String &quot;Write locks =&quot;
-     * follwed by the number of reentrantly held write locks, and the
-     * String &quot;Read locks =&quot; followed by the number of held
-     * read locks.
-     * @return a string identifying this lock, as well as its lock state.
-     */
-    public String toString() {
-        int c = sync.getCount();
-        int w = exclusiveCount(c);
-        int r = sharedCount(c);
-        
-        return super.toString() + 
-            "[Write locks = " + w + ", Read locks = " + r + "]";
-    }
-
-}
diff --git a/concurrent/src/main/java/java/util/concurrent/locks/UnsafeAccess.java b/concurrent/src/main/java/java/util/concurrent/locks/UnsafeAccess.java
deleted file mode 100644
index 07f64e4..0000000
--- a/concurrent/src/main/java/java/util/concurrent/locks/UnsafeAccess.java
+++ /dev/null
@@ -1,34 +0,0 @@
-/*
- * Copyright (C) 2008 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package java.util.concurrent.locks;
-
-import sun.misc.Unsafe;
-
-/**
- * Easy access to {@link Unsafe} for the rest of this package.
- */
-/*package*/ final class UnsafeAccess {
-    /** non-null; unique instance of {@link Unsafe} */
-    /*package*/ static final Unsafe THE_ONE = Unsafe.getUnsafe();
-
-    /**
-     * This class is uninstantiable.
-     */
-    private UnsafeAccess() {
-        // This space intentionally left blank.
-    }
-}
diff --git a/concurrent/src/main/java/java/util/concurrent/locks/package.html b/concurrent/src/main/java/java/util/concurrent/locks/package.html
deleted file mode 100644
index 1cc156f..0000000
--- a/concurrent/src/main/java/java/util/concurrent/locks/package.html
+++ /dev/null
@@ -1,44 +0,0 @@
-<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML//EN">
-<html> <head>
-<title>Locks</title>
-</head>
-
-<body>
-
-Interfaces and classes providing a framework for locking and waiting
-for conditions that is distinct from built-in synchronization and
-monitors. The framework permits much greater flexibility in the use of
-locks and conditions, at the expense of more awkward syntax.
-
-<p> The {@link java.util.concurrent.locks.Lock} interface supports
-locking disciplines that differ in semantics (reentrant, fair, etc),
-and that can be used in non-block-structured contexts including
-hand-over-hand and lock reordering algorithms. The main implementation
-is {@link java.util.concurrent.locks.ReentrantLock}. 
-
-<p> The {@link java.util.concurrent.locks.ReadWriteLock} interface
-similarly defines locks that may be shared among readers but are
-exclusive to writers.  Only a single implementation, {@link
-java.util.concurrent.locks.ReentrantReadWriteLock}, is provided, since
-it covers most standard usage contexts. But programmers may create
-their own implementations to cover nonstandard requirements.
-
-<p> The {@link java.util.concurrent.locks.Condition} interface
-describes condition variables that may be associated with Locks.
-These are similar in usage to the implicit monitors accessed using
-<tt>Object.wait</tt>, but offer extended capabilities.  In particular,
-multiple <tt>Condition</tt> objects may be associated with a single
-<tt>Lock</tt>.  To avoid compatibility issues, the names of
-<tt>Condition</tt> methods are different than the corresponding
-<tt>Object</tt> versions.
-
-<p> The {@link java.util.concurrent.locks.AbstractQueuedSynchronizer}
-class serves as a useful superclass for defining locks and other
-synchronizers that rely on queuing blocked threads.  The {@link
-java.util.concurrent.locks.LockSupport} class provides lower-level
-blocking and unblocking support that is useful for those developers
-implementing their own customized lock classes.
-
-@since Android 1.0
-
-</body> </html>
diff --git a/concurrent/src/main/java/java/util/concurrent/package.html b/concurrent/src/main/java/java/util/concurrent/package.html
deleted file mode 100644
index a5bb8d2..0000000
--- a/concurrent/src/main/java/java/util/concurrent/package.html
+++ /dev/null
@@ -1,125 +0,0 @@
-<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML//EN">
-<html> <head>
-<title>Concurrency Utilities</title>
-</head>
-
-<body>
-
-<p> Utility classes commonly useful in concurrent programming.  This
-package includes a few small standardized extensible frameworks, as
-well as some classes that provide useful functionality and are
-otherwise tedious or difficult to implement.  Here are brief
-descriptions of the main components. See also the <tt>locks</tt> and
-<tt>atomic</tt> packages.
-
-<h2>Executors</h2>
-
-<b>Interfaces.</b> {@link java.util.concurrent.Executor} is a simple
-standardized interface for defining custom thread-like subsystems,
-including thread pools, asynchronous IO, and lightweight task
-frameworks.  Depending on which concrete Executor class is being used,
-tasks may execute in a newly created thread, an existing
-task-execution thread, or the thread calling <tt>execute()</tt>, and
-may execute sequentially or concurrently.  {@link
-java.util.concurrent.ExecutorService} provides a more complete
-asynchronous task execution framework.  An ExecutorService manages
-queuing and scheduling of tasks, and allows controlled shutdown.  The
-{@link java.util.concurrent.ScheduledExecutorService} subinterface
-adds support for delayed and periodic task execution.
-ExecutorServices provide methods arranging asynchronous execution of
-any function expressed as {@link java.util.concurrent.Callable}, the
-result-bearing analog of {@link java.lang.Runnable}.  A {@link
-java.util.concurrent.Future} returns the results of a function, allows
-determination of whether execution has completed, and provides a means to
-cancel execution.
-
-<p>
-
-<b>Implementations.</b> Classes {@link
-java.util.concurrent.ThreadPoolExecutor} and {@link
-java.util.concurrent.ScheduledThreadPoolExecutor} provide tunable,
-flexible thread pools. The {@link java.util.concurrent.Executors}
-class provides factory methods for the most common kinds and
-configurations of Executors, as well as a few utility methods for
-using them. Other utilities based on Executors include the concrete
-class {@link java.util.concurrent.FutureTask} providing a common
-extensible implementation of Futures, and {@link
-java.util.concurrent.ExecutorCompletionService}, that assists in
-coordinating the processing of groups of asynchronous tasks.
-
-<h2>Queues</h2>
-
-The java.util.concurrent {@link
-java.util.concurrent.ConcurrentLinkedQueue} class supplies an
-efficient scalable thread-safe non-blocking FIFO queue.  Five
-implementations in java.util.concurrent support the extended {@link
-java.util.concurrent.BlockingQueue} interface, that defines blocking
-versions of put and take: {@link
-java.util.concurrent.LinkedBlockingQueue}, {@link
-java.util.concurrent.ArrayBlockingQueue}, {@link
-java.util.concurrent.SynchronousQueue}, {@link
-java.util.concurrent.PriorityBlockingQueue}, and {@link
-java.util.concurrent.DelayQueue}. The different classes cover the most
-common usage contexts for producer-consumer, messaging, parallel
-tasking, and related concurrent designs.
-
-
-<h2>Timing</h2>
-
-The {@link java.util.concurrent.TimeUnit} class provides multiple
-granularities (including nanoseconds) for specifying and controlling
-time-out based operations. Most classes in the package contain
-operations based on time-outs in addition to indefinite waits.  In all
-cases that time-outs are used, the time-out specifies the minimum time
-that the method should wait before indicating that it
-timed-out. Implementations make a &quot;best effort&quot; to detect
-time-outs as soon as possible after they occur. However, an indefinite
-amount of time may elapse between a time-out being detected and a
-thread actually executing again after that time-out.
-
-<h2>Synchronizers</h2>
-
-Four classes aid common special-purpose synchronization idioms.
-{@link java.util.concurrent.Semaphore} is a classic concurrency tool.
-{@link java.util.concurrent.CountDownLatch} is a very simple yet very
-common utility for blocking until a given number of signals, events,
-or conditions hold.  A {@link java.util.concurrent.CyclicBarrier} is a
-resettable multiway synchronization point useful in some styles of
-parallel programming. An {@link java.util.concurrent.Exchanger} allows
-two threads to exchange objects at a rendezvous point, and is useful
-in several pipeline designs.
-
-<h2>Concurrent Collections</h2>
-
-Besides Queues, this package supplies a few Collection implementations
-designed for use in multithreaded contexts: {@link
-java.util.concurrent.ConcurrentHashMap}, {@link
-java.util.concurrent.CopyOnWriteArrayList}, and {@link
-java.util.concurrent.CopyOnWriteArraySet}.
-
-<p>The "Concurrent" prefix used with some classes in this package is a
-shorthand indicating several differences from similar "synchronized"
-classes. For example <tt>java.util.Hashtable</tt> and
-<tt>Collections.synchronizedMap(new HashMap())</tt> are
-synchronized. But {@link java.util.concurrent.ConcurrentHashMap} is
-"concurrent".  A concurrent collection is thread-safe, but not
-governed by a single exclusion lock. In the particular case of
-ConcurrentHashMap, it safely permits any number of concurrent reads as
-well as a tunable number of concurrent writes.  "Synchronized" classes
-can be useful when you need to prevent all access to a collection via
-a single lock, at the expense of poorer scalability. In other cases in
-which multiple threads are expected to access a common collection,
-"concurrent" versions are normally preferable. And unsynchronized
-collections are preferable when either collections are unshared, or
-are accessible only when holding other locks.
-
-<p> Most concurrent Collection implementations (including most Queues)
-also differ from the usual java.util conventions in that their Iterators
-provide <em>weakly consistent</em> rather than fast-fail traversal. A
-weakly consistent iterator is thread-safe, but does not necessarily
-freeze the collection while iterating, so it may (or may not) reflect
-any updates since the iterator was created.
-
-@since Android 1.0
-
-</body> </html>