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/*
* 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 junit.framework.*;
import java.util.Arrays;
import java.util.concurrent.atomic.AtomicReferenceArray;
public class AtomicReferenceArrayTest extends JSR166TestCase {
/**
* constructor creates array of given size with all elements null
*/
public void testConstructor() {
AtomicReferenceArray<Integer> aa = new AtomicReferenceArray<Integer>(SIZE);
for (int i = 0; i < SIZE; i++) {
assertNull(aa.get(i));
}
}
/**
* constructor with null array throws NPE
*/
public void testConstructor2NPE() {
try {
Integer[] a = null;
AtomicReferenceArray<Integer> aa = new AtomicReferenceArray<Integer>(a);
shouldThrow();
} catch (NullPointerException success) {}
}
/**
* constructor with array is of same size and has all elements
*/
public void testConstructor2() {
Integer[] a = { two, one, three, four, seven };
AtomicReferenceArray<Integer> aa = new AtomicReferenceArray<Integer>(a);
assertEquals(a.length, aa.length());
for (int i = 0; i < a.length; i++)
assertEquals(a[i], aa.get(i));
}
/**
* Initialize AtomicReferenceArray<Class> with SubClass[]
*/
public void testConstructorSubClassArray() {
Integer[] a = { two, one, three, four, seven };
AtomicReferenceArray<Number> aa = new AtomicReferenceArray<Number>(a);
assertEquals(a.length, aa.length());
for (int i = 0; i < a.length; i++) {
assertSame(a[i], aa.get(i));
Long x = Long.valueOf(i);
aa.set(i, x);
assertSame(x, aa.get(i));
}
}
/**
* get and set for out of bound indices throw IndexOutOfBoundsException
*/
public void testIndexing() {
AtomicReferenceArray<Integer> aa = new AtomicReferenceArray<Integer>(SIZE);
for (int index : new int[] { -1, SIZE }) {
try {
aa.get(index);
shouldThrow();
} catch (IndexOutOfBoundsException success) {}
try {
aa.set(index, null);
shouldThrow();
} catch (IndexOutOfBoundsException success) {}
try {
aa.lazySet(index, null);
shouldThrow();
} catch (IndexOutOfBoundsException success) {}
try {
aa.compareAndSet(index, null, null);
shouldThrow();
} catch (IndexOutOfBoundsException success) {}
try {
aa.weakCompareAndSet(index, null, null);
shouldThrow();
} catch (IndexOutOfBoundsException success) {}
}
}
/**
* get returns the last value set at index
*/
public void testGetSet() {
AtomicReferenceArray aa = new AtomicReferenceArray(SIZE);
for (int i = 0; i < SIZE; i++) {
aa.set(i, one);
assertSame(one, aa.get(i));
aa.set(i, two);
assertSame(two, aa.get(i));
aa.set(i, m3);
assertSame(m3, aa.get(i));
}
}
/**
* get returns the last value lazySet at index by same thread
*/
public void testGetLazySet() {
AtomicReferenceArray aa = new AtomicReferenceArray(SIZE);
for (int i = 0; i < SIZE; i++) {
aa.lazySet(i, one);
assertSame(one, aa.get(i));
aa.lazySet(i, two);
assertSame(two, aa.get(i));
aa.lazySet(i, m3);
assertSame(m3, aa.get(i));
}
}
/**
* compareAndSet succeeds in changing value if equal to expected else fails
*/
public void testCompareAndSet() {
AtomicReferenceArray aa = new AtomicReferenceArray(SIZE);
for (int i = 0; i < SIZE; i++) {
aa.set(i, one);
assertTrue(aa.compareAndSet(i, one, two));
assertTrue(aa.compareAndSet(i, two, m4));
assertSame(m4, aa.get(i));
assertFalse(aa.compareAndSet(i, m5, seven));
assertSame(m4, aa.get(i));
assertTrue(aa.compareAndSet(i, m4, seven));
assertSame(seven, aa.get(i));
}
}
/**
* compareAndSet in one thread enables another waiting for value
* to succeed
*/
public void testCompareAndSetInMultipleThreads() throws InterruptedException {
final AtomicReferenceArray a = new AtomicReferenceArray(1);
a.set(0, one);
Thread t = new Thread(new CheckedRunnable() {
public void realRun() {
while (!a.compareAndSet(0, two, three))
Thread.yield();
}});
t.start();
assertTrue(a.compareAndSet(0, one, two));
t.join(LONG_DELAY_MS);
assertFalse(t.isAlive());
assertSame(three, a.get(0));
}
/**
* repeated weakCompareAndSet succeeds in changing value when equal
* to expected
*/
public void testWeakCompareAndSet() {
AtomicReferenceArray aa = new AtomicReferenceArray(SIZE);
for (int i = 0; i < SIZE; i++) {
aa.set(i, one);
while (!aa.weakCompareAndSet(i, one, two));
while (!aa.weakCompareAndSet(i, two, m4));
assertSame(m4, aa.get(i));
while (!aa.weakCompareAndSet(i, m4, seven));
assertSame(seven, aa.get(i));
}
}
/**
* getAndSet returns previous value and sets to given value at given index
*/
public void testGetAndSet() {
AtomicReferenceArray aa = new AtomicReferenceArray(SIZE);
for (int i = 0; i < SIZE; i++) {
aa.set(i, one);
assertSame(one, aa.getAndSet(i, zero));
assertSame(zero, aa.getAndSet(i, m10));
assertSame(m10, aa.getAndSet(i, one));
}
}
/**
* a deserialized serialized array holds same values
*/
public void testSerialization() throws Exception {
AtomicReferenceArray x = new AtomicReferenceArray(SIZE);
for (int i = 0; i < SIZE; i++) {
x.set(i, new Integer(-i));
}
AtomicReferenceArray y = serialClone(x);
assertNotSame(x, y);
assertEquals(x.length(), y.length());
for (int i = 0; i < SIZE; i++) {
assertEquals(x.get(i), y.get(i));
}
}
/**
* toString returns current value.
*/
public void testToString() {
Integer[] a = { two, one, three, four, seven };
AtomicReferenceArray<Integer> aa = new AtomicReferenceArray<Integer>(a);
assertEquals(Arrays.toString(a), aa.toString());
}
}
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