/* * 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/publicdomain/zero/1.0/ * Other contributors include Andrew Wright, Jeffrey Hayes, * Pat Fisher, Mike Judd. */ package jsr166; import java.util.Arrays; import java.util.Collection; import java.util.Iterator; import java.util.NoSuchElementException; import java.util.Queue; import java.util.concurrent.ConcurrentLinkedQueue; import junit.framework.Test; import junit.framework.TestSuite; public class ConcurrentLinkedQueueTest extends JSR166TestCase { // android-note: Removed because the CTS runner does a bad job of // retrying tests that have suite() declarations. // // public static void main(String[] args) { // main(suite(), args); // } // public static Test suite() { // return new TestSuite(...); // } /** * Returns a new queue of given size containing consecutive * Integers 0 ... n. */ private ConcurrentLinkedQueue populatedQueue(int n) { ConcurrentLinkedQueue q = new ConcurrentLinkedQueue(); assertTrue(q.isEmpty()); for (int i = 0; i < n; ++i) assertTrue(q.offer(new Integer(i))); assertFalse(q.isEmpty()); assertEquals(n, q.size()); return q; } /** * new queue is empty */ public void testConstructor1() { assertEquals(0, new ConcurrentLinkedQueue().size()); } /** * Initializing from null Collection throws NPE */ public void testConstructor3() { try { new ConcurrentLinkedQueue((Collection)null); shouldThrow(); } catch (NullPointerException success) {} } /** * Initializing from Collection of null elements throws NPE */ public void testConstructor4() { try { Integer[] ints = new Integer[SIZE]; new ConcurrentLinkedQueue(Arrays.asList(ints)); shouldThrow(); } catch (NullPointerException success) {} } /** * Initializing from Collection with some null elements throws NPE */ public void testConstructor5() { try { Integer[] ints = new Integer[SIZE]; for (int i = 0; i < SIZE-1; ++i) ints[i] = new Integer(i); new ConcurrentLinkedQueue(Arrays.asList(ints)); shouldThrow(); } catch (NullPointerException success) {} } /** * Queue contains all elements of collection used to initialize */ public void testConstructor6() { Integer[] ints = new Integer[SIZE]; for (int i = 0; i < SIZE; ++i) ints[i] = new Integer(i); ConcurrentLinkedQueue q = new ConcurrentLinkedQueue(Arrays.asList(ints)); for (int i = 0; i < SIZE; ++i) assertEquals(ints[i], q.poll()); } /** * isEmpty is true before add, false after */ public void testEmpty() { ConcurrentLinkedQueue q = new ConcurrentLinkedQueue(); assertTrue(q.isEmpty()); q.add(one); assertFalse(q.isEmpty()); q.add(two); q.remove(); q.remove(); assertTrue(q.isEmpty()); } /** * size changes when elements added and removed */ public void testSize() { ConcurrentLinkedQueue q = populatedQueue(SIZE); for (int i = 0; i < SIZE; ++i) { assertEquals(SIZE-i, q.size()); q.remove(); } for (int i = 0; i < SIZE; ++i) { assertEquals(i, q.size()); q.add(new Integer(i)); } } /** * offer(null) throws NPE */ public void testOfferNull() { try { ConcurrentLinkedQueue q = new ConcurrentLinkedQueue(); q.offer(null); shouldThrow(); } catch (NullPointerException success) {} } /** * add(null) throws NPE */ public void testAddNull() { try { ConcurrentLinkedQueue q = new ConcurrentLinkedQueue(); q.add(null); shouldThrow(); } catch (NullPointerException success) {} } /** * Offer returns true */ public void testOffer() { ConcurrentLinkedQueue q = new ConcurrentLinkedQueue(); assertTrue(q.offer(zero)); assertTrue(q.offer(one)); } /** * add returns true */ public void testAdd() { ConcurrentLinkedQueue q = new ConcurrentLinkedQueue(); for (int i = 0; i < SIZE; ++i) { assertEquals(i, q.size()); assertTrue(q.add(new Integer(i))); } } /** * addAll(null) throws NPE */ public void testAddAll1() { try { ConcurrentLinkedQueue q = new ConcurrentLinkedQueue(); q.addAll(null); shouldThrow(); } catch (NullPointerException success) {} } /** * addAll(this) throws IAE */ public void testAddAllSelf() { try { ConcurrentLinkedQueue q = populatedQueue(SIZE); q.addAll(q); shouldThrow(); } catch (IllegalArgumentException success) {} } /** * addAll of a collection with null elements throws NPE */ public void testAddAll2() { try { ConcurrentLinkedQueue q = new ConcurrentLinkedQueue(); Integer[] ints = new Integer[SIZE]; q.addAll(Arrays.asList(ints)); shouldThrow(); } catch (NullPointerException success) {} } /** * addAll of a collection with any null elements throws NPE after * possibly adding some elements */ public void testAddAll3() { try { ConcurrentLinkedQueue q = new ConcurrentLinkedQueue(); Integer[] ints = new Integer[SIZE]; for (int i = 0; i < SIZE-1; ++i) ints[i] = new Integer(i); q.addAll(Arrays.asList(ints)); shouldThrow(); } catch (NullPointerException success) {} } /** * Queue contains all elements, in traversal order, of successful addAll */ public void testAddAll5() { Integer[] empty = new Integer[0]; Integer[] ints = new Integer[SIZE]; for (int i = 0; i < SIZE; ++i) ints[i] = new Integer(i); ConcurrentLinkedQueue q = new ConcurrentLinkedQueue(); assertFalse(q.addAll(Arrays.asList(empty))); assertTrue(q.addAll(Arrays.asList(ints))); for (int i = 0; i < SIZE; ++i) assertEquals(ints[i], q.poll()); } /** * poll succeeds unless empty */ public void testPoll() { ConcurrentLinkedQueue q = populatedQueue(SIZE); for (int i = 0; i < SIZE; ++i) { assertEquals(i, q.poll()); } assertNull(q.poll()); } /** * peek returns next element, or null if empty */ public void testPeek() { ConcurrentLinkedQueue q = populatedQueue(SIZE); for (int i = 0; i < SIZE; ++i) { assertEquals(i, q.peek()); assertEquals(i, q.poll()); assertTrue(q.peek() == null || !q.peek().equals(i)); } assertNull(q.peek()); } /** * element returns next element, or throws NSEE if empty */ public void testElement() { ConcurrentLinkedQueue q = populatedQueue(SIZE); for (int i = 0; i < SIZE; ++i) { assertEquals(i, q.element()); assertEquals(i, q.poll()); } try { q.element(); shouldThrow(); } catch (NoSuchElementException success) {} } /** * remove removes next element, or throws NSEE if empty */ public void testRemove() { ConcurrentLinkedQueue q = populatedQueue(SIZE); for (int i = 0; i < SIZE; ++i) { assertEquals(i, q.remove()); } try { q.remove(); shouldThrow(); } catch (NoSuchElementException success) {} } /** * remove(x) removes x and returns true if present */ public void testRemoveElement() { ConcurrentLinkedQueue q = populatedQueue(SIZE); for (int i = 1; i < SIZE; i += 2) { assertTrue(q.contains(i)); assertTrue(q.remove(i)); assertFalse(q.contains(i)); assertTrue(q.contains(i-1)); } for (int i = 0; i < SIZE; i += 2) { assertTrue(q.contains(i)); assertTrue(q.remove(i)); assertFalse(q.contains(i)); assertFalse(q.remove(i+1)); assertFalse(q.contains(i+1)); } assertTrue(q.isEmpty()); } /** * contains(x) reports true when elements added but not yet removed */ public void testContains() { ConcurrentLinkedQueue q = populatedQueue(SIZE); for (int i = 0; i < SIZE; ++i) { assertTrue(q.contains(new Integer(i))); q.poll(); assertFalse(q.contains(new Integer(i))); } } /** * clear removes all elements */ public void testClear() { ConcurrentLinkedQueue q = populatedQueue(SIZE); q.clear(); assertTrue(q.isEmpty()); assertEquals(0, q.size()); q.add(one); assertFalse(q.isEmpty()); q.clear(); assertTrue(q.isEmpty()); } /** * containsAll(c) is true when c contains a subset of elements */ public void testContainsAll() { ConcurrentLinkedQueue q = populatedQueue(SIZE); ConcurrentLinkedQueue p = new ConcurrentLinkedQueue(); for (int i = 0; i < SIZE; ++i) { assertTrue(q.containsAll(p)); assertFalse(p.containsAll(q)); p.add(new Integer(i)); } assertTrue(p.containsAll(q)); } /** * retainAll(c) retains only those elements of c and reports true if change */ public void testRetainAll() { ConcurrentLinkedQueue q = populatedQueue(SIZE); ConcurrentLinkedQueue p = populatedQueue(SIZE); for (int i = 0; i < SIZE; ++i) { boolean changed = q.retainAll(p); if (i == 0) assertFalse(changed); else assertTrue(changed); assertTrue(q.containsAll(p)); assertEquals(SIZE-i, q.size()); p.remove(); } } /** * removeAll(c) removes only those elements of c and reports true if changed */ public void testRemoveAll() { for (int i = 1; i < SIZE; ++i) { ConcurrentLinkedQueue q = populatedQueue(SIZE); ConcurrentLinkedQueue p = populatedQueue(i); assertTrue(q.removeAll(p)); assertEquals(SIZE-i, q.size()); for (int j = 0; j < i; ++j) { Integer x = (Integer)(p.remove()); assertFalse(q.contains(x)); } } } /** * toArray contains all elements in FIFO order */ public void testToArray() { ConcurrentLinkedQueue q = populatedQueue(SIZE); Object[] o = q.toArray(); for (int i = 0; i < o.length; i++) assertSame(o[i], q.poll()); } /** * toArray(a) contains all elements in FIFO order */ public void testToArray2() { ConcurrentLinkedQueue q = populatedQueue(SIZE); Integer[] ints = new Integer[SIZE]; Integer[] array = q.toArray(ints); assertSame(ints, array); for (int i = 0; i < ints.length; i++) assertSame(ints[i], q.poll()); } /** * toArray(null) throws NullPointerException */ public void testToArray_NullArg() { ConcurrentLinkedQueue q = populatedQueue(SIZE); try { q.toArray(null); shouldThrow(); } catch (NullPointerException success) {} } /** * toArray(incompatible array type) throws ArrayStoreException */ public void testToArray1_BadArg() { ConcurrentLinkedQueue q = populatedQueue(SIZE); try { q.toArray(new String[10]); shouldThrow(); } catch (ArrayStoreException success) {} } /** * iterator iterates through all elements */ public void testIterator() { ConcurrentLinkedQueue q = populatedQueue(SIZE); Iterator it = q.iterator(); int i; for (i = 0; it.hasNext(); i++) assertTrue(q.contains(it.next())); assertEquals(i, SIZE); assertIteratorExhausted(it); } /** * iterator of empty collection has no elements */ public void testEmptyIterator() { assertIteratorExhausted(new ConcurrentLinkedQueue().iterator()); } /** * iterator ordering is FIFO */ public void testIteratorOrdering() { final ConcurrentLinkedQueue q = new ConcurrentLinkedQueue(); q.add(one); q.add(two); q.add(three); int k = 0; for (Iterator it = q.iterator(); it.hasNext();) { assertEquals(++k, it.next()); } assertEquals(3, k); } /** * Modifications do not cause iterators to fail */ public void testWeaklyConsistentIteration() { final ConcurrentLinkedQueue q = new ConcurrentLinkedQueue(); q.add(one); q.add(two); q.add(three); for (Iterator it = q.iterator(); it.hasNext();) { q.remove(); it.next(); } assertEquals("queue should be empty again", 0, q.size()); } /** * iterator.remove removes current element */ public void testIteratorRemove() { final ConcurrentLinkedQueue q = new ConcurrentLinkedQueue(); q.add(one); q.add(two); q.add(three); Iterator it = q.iterator(); it.next(); it.remove(); it = q.iterator(); assertSame(it.next(), two); assertSame(it.next(), three); assertFalse(it.hasNext()); } /** * toString contains toStrings of elements */ public void testToString() { ConcurrentLinkedQueue q = populatedQueue(SIZE); String s = q.toString(); for (int i = 0; i < SIZE; ++i) { assertTrue(s.contains(String.valueOf(i))); } } /** * A deserialized serialized queue has same elements in same order */ public void testSerialization() throws Exception { Queue x = populatedQueue(SIZE); Queue y = serialClone(x); assertNotSame(x, y); assertEquals(x.size(), y.size()); assertEquals(x.toString(), y.toString()); assertTrue(Arrays.equals(x.toArray(), y.toArray())); while (!x.isEmpty()) { assertFalse(y.isEmpty()); assertEquals(x.remove(), y.remove()); } assertTrue(y.isEmpty()); } /** * remove(null), contains(null) always return false */ public void testNeverContainsNull() { Collection[] qs = { new ConcurrentLinkedQueue(), populatedQueue(2), }; for (Collection q : qs) { assertFalse(q.contains(null)); assertFalse(q.remove(null)); } } }