--- jsr166/src/test/tck/AtomicIntegerArrayTest.java 2003/09/14 20:42:40 1.3 +++ jsr166/src/test/tck/AtomicIntegerArrayTest.java 2016/06/17 01:38:28 1.35 @@ -1,164 +1,340 @@ /* - * Written by members of JCP JSR-166 Expert Group and released to the - * public domain. Use, modify, and redistribute this code in any way - * without acknowledgement. Other contributors include Andrew Wright, - * Jeffrey Hayes, Pat Fischer, Mike Judd. + * 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. */ -import junit.framework.*; -import java.util.concurrent.atomic.*; -import java.io.*; +import java.util.Arrays; +import java.util.concurrent.atomic.AtomicIntegerArray; + +import junit.framework.Test; +import junit.framework.TestSuite; public class AtomicIntegerArrayTest extends JSR166TestCase { - public static void main (String[] args) { - junit.textui.TestRunner.run (suite()); + public static void main(String[] args) { + main(suite(), args); } public static Test suite() { return new TestSuite(AtomicIntegerArrayTest.class); } - - public void testConstructor(){ - AtomicIntegerArray ai = new AtomicIntegerArray(SIZE); - for (int i = 0; i < SIZE; ++i) - assertEquals(0,ai.get(i)); - } - - public void testGetSet(){ - AtomicIntegerArray ai = new AtomicIntegerArray(SIZE); - for (int i = 0; i < SIZE; ++i) { - ai.set(i, 1); - assertEquals(1,ai.get(i)); - ai.set(i, 2); - assertEquals(2,ai.get(i)); - ai.set(i, -3); - assertEquals(-3,ai.get(i)); - } - } - - public void testCompareAndSet(){ - AtomicIntegerArray ai = new AtomicIntegerArray(SIZE); - for (int i = 0; i < SIZE; ++i) { - ai.set(i, 1); - assertTrue(ai.compareAndSet(i, 1,2)); - assertTrue(ai.compareAndSet(i, 2,-4)); - assertEquals(-4,ai.get(i)); - assertFalse(ai.compareAndSet(i, -5,7)); - assertFalse((7 == ai.get(i))); - assertTrue(ai.compareAndSet(i, -4,7)); - assertEquals(7,ai.get(i)); - } - } - - public void testWeakCompareAndSet(){ - AtomicIntegerArray ai = new AtomicIntegerArray(SIZE); - for (int i = 0; i < SIZE; ++i) { - ai.set(i, 1); - while(!ai.weakCompareAndSet(i, 1,2)); - while(!ai.weakCompareAndSet(i, 2,-4)); - assertEquals(-4,ai.get(i)); - while(!ai.weakCompareAndSet(i, -4,7)); - assertEquals(7,ai.get(i)); - } - } - - public void testGetAndSet(){ - AtomicIntegerArray ai = new AtomicIntegerArray(SIZE); - for (int i = 0; i < SIZE; ++i) { - ai.set(i, 1); - assertEquals(1,ai.getAndSet(i,0)); - assertEquals(0,ai.getAndSet(i,-10)); - assertEquals(-10,ai.getAndSet(i,1)); - } - } - - public void testGetAndAdd(){ - AtomicIntegerArray ai = new AtomicIntegerArray(SIZE); - for (int i = 0; i < SIZE; ++i) { - ai.set(i, 1); - assertEquals(1,ai.getAndAdd(i,2)); - assertEquals(3,ai.get(i)); - assertEquals(3,ai.getAndAdd(i,-4)); - assertEquals(-1,ai.get(i)); - } - } - - public void testGetAndDecrement(){ - AtomicIntegerArray ai = new AtomicIntegerArray(SIZE); - for (int i = 0; i < SIZE; ++i) { - ai.set(i, 1); - assertEquals(1,ai.getAndDecrement(i)); - assertEquals(0,ai.getAndDecrement(i)); - assertEquals(-1,ai.getAndDecrement(i)); - } - } - - public void testGetAndIncrement(){ - AtomicIntegerArray ai = new AtomicIntegerArray(SIZE); - for (int i = 0; i < SIZE; ++i) { - ai.set(i, 1); - assertEquals(1,ai.getAndIncrement(i)); - assertEquals(2,ai.get(i)); - ai.set(i,-2); - assertEquals(-2,ai.getAndIncrement(i)); - assertEquals(-1,ai.getAndIncrement(i)); - assertEquals(0,ai.getAndIncrement(i)); - assertEquals(1,ai.get(i)); - } + /** + * constructor creates array of given size with all elements zero + */ + public void testConstructor() { + AtomicIntegerArray aa = new AtomicIntegerArray(SIZE); + for (int i = 0; i < SIZE; i++) + assertEquals(0, aa.get(i)); } + /** + * constructor with null array throws NPE + */ + public void testConstructor2NPE() { + try { + int[] a = null; + new AtomicIntegerArray(a); + shouldThrow(); + } catch (NullPointerException success) {} + } + + /** + * constructor with array is of same size and has all elements + */ + public void testConstructor2() { + int[] a = { 17, 3, -42, 99, -7 }; + AtomicIntegerArray aa = new AtomicIntegerArray(a); + assertEquals(a.length, aa.length()); + for (int i = 0; i < a.length; i++) + assertEquals(a[i], aa.get(i)); + } + + /** + * get and set for out of bound indices throw IndexOutOfBoundsException + */ + public void testIndexing() { + AtomicIntegerArray aa = new AtomicIntegerArray(SIZE); + for (int index : new int[] { -1, SIZE }) { + try { + aa.get(index); + shouldThrow(); + } catch (IndexOutOfBoundsException success) {} + try { + aa.set(index, 1); + shouldThrow(); + } catch (IndexOutOfBoundsException success) {} + try { + aa.lazySet(index, 1); + shouldThrow(); + } catch (IndexOutOfBoundsException success) {} + try { + aa.compareAndSet(index, 1, 2); + shouldThrow(); + } catch (IndexOutOfBoundsException success) {} + try { + aa.weakCompareAndSet(index, 1, 2); + shouldThrow(); + } catch (IndexOutOfBoundsException success) {} + try { + aa.getAndAdd(index, 1); + shouldThrow(); + } catch (IndexOutOfBoundsException success) {} + try { + aa.addAndGet(index, 1); + shouldThrow(); + } catch (IndexOutOfBoundsException success) {} + try { + aa.getPlain(index); + shouldThrow(); + } catch (IndexOutOfBoundsException success) {} + try { + aa.getOpaque(index); + shouldThrow(); + } catch (IndexOutOfBoundsException success) {} + try { + aa.getAcquire(index); + shouldThrow(); + } catch (IndexOutOfBoundsException success) {} + try { + aa.setPlain(index, 1); + shouldThrow(); + } catch (IndexOutOfBoundsException success) {} + try { + aa.setOpaque(index, 1); + shouldThrow(); + } catch (IndexOutOfBoundsException success) {} + try { + aa.setRelease(index, 1); + shouldThrow(); + } catch (IndexOutOfBoundsException success) {} + try { + aa.compareAndExchange(index, 1, 2); + shouldThrow(); + } catch (IndexOutOfBoundsException success) {} + try { + aa.compareAndExchangeAcquire(index, 1, 2); + shouldThrow(); + } catch (IndexOutOfBoundsException success) {} + try { + aa.compareAndExchangeRelease(index, 1, 2); + shouldThrow(); + } catch (IndexOutOfBoundsException success) {} + try { + aa.weakCompareAndSetVolatile(index, 1, 2); + shouldThrow(); + } catch (IndexOutOfBoundsException success) {} + try { + aa.weakCompareAndSetAcquire(index, 1, 2); + shouldThrow(); + } catch (IndexOutOfBoundsException success) {} + try { + aa.weakCompareAndSetRelease(index, 1, 2); + shouldThrow(); + } catch (IndexOutOfBoundsException success) {} + } + } + + /** + * get returns the last value set at index + */ + public void testGetSet() { + AtomicIntegerArray aa = new AtomicIntegerArray(SIZE); + for (int i = 0; i < SIZE; i++) { + aa.set(i, 1); + assertEquals(1, aa.get(i)); + aa.set(i, 2); + assertEquals(2, aa.get(i)); + aa.set(i, -3); + assertEquals(-3, aa.get(i)); + } + } + + /** + * get returns the last value lazySet at index by same thread + */ + public void testGetLazySet() { + AtomicIntegerArray aa = new AtomicIntegerArray(SIZE); + for (int i = 0; i < SIZE; i++) { + aa.lazySet(i, 1); + assertEquals(1, aa.get(i)); + aa.lazySet(i, 2); + assertEquals(2, aa.get(i)); + aa.lazySet(i, -3); + assertEquals(-3, aa.get(i)); + } + } + + /** + * compareAndSet succeeds in changing value if equal to expected else fails + */ + public void testCompareAndSet() { + AtomicIntegerArray aa = new AtomicIntegerArray(SIZE); + for (int i = 0; i < SIZE; i++) { + aa.set(i, 1); + assertTrue(aa.compareAndSet(i, 1, 2)); + assertTrue(aa.compareAndSet(i, 2, -4)); + assertEquals(-4, aa.get(i)); + assertFalse(aa.compareAndSet(i, -5, 7)); + assertEquals(-4, aa.get(i)); + assertTrue(aa.compareAndSet(i, -4, 7)); + assertEquals(7, aa.get(i)); + } + } + + /** + * compareAndSet in one thread enables another waiting for value + * to succeed + */ + public void testCompareAndSetInMultipleThreads() throws Exception { + final AtomicIntegerArray a = new AtomicIntegerArray(1); + a.set(0, 1); + Thread t = new Thread(new CheckedRunnable() { + public void realRun() { + while (!a.compareAndSet(0, 2, 3)) + Thread.yield(); + }}); + + t.start(); + assertTrue(a.compareAndSet(0, 1, 2)); + t.join(LONG_DELAY_MS); + assertFalse(t.isAlive()); + assertEquals(3, a.get(0)); + } + + /** + * repeated weakCompareAndSet succeeds in changing value when equal + * to expected + */ + public void testWeakCompareAndSet() { + AtomicIntegerArray aa = new AtomicIntegerArray(SIZE); + for (int i = 0; i < SIZE; i++) { + aa.set(i, 1); + do {} while (!aa.weakCompareAndSet(i, 1, 2)); + do {} while (!aa.weakCompareAndSet(i, 2, -4)); + assertEquals(-4, aa.get(i)); + do {} while (!aa.weakCompareAndSet(i, -4, 7)); + assertEquals(7, aa.get(i)); + } + } + + /** + * getAndSet returns previous value and sets to given value at given index + */ + public void testGetAndSet() { + AtomicIntegerArray aa = new AtomicIntegerArray(SIZE); + for (int i = 0; i < SIZE; i++) { + aa.set(i, 1); + assertEquals(1, aa.getAndSet(i, 0)); + assertEquals(0, aa.getAndSet(i, -10)); + assertEquals(-10, aa.getAndSet(i, 1)); + } + } + + /** + * getAndAdd returns previous value and adds given value + */ + public void testGetAndAdd() { + AtomicIntegerArray aa = new AtomicIntegerArray(SIZE); + for (int i = 0; i < SIZE; i++) { + aa.set(i, 1); + assertEquals(1, aa.getAndAdd(i, 2)); + assertEquals(3, aa.get(i)); + assertEquals(3, aa.getAndAdd(i, -4)); + assertEquals(-1, aa.get(i)); + } + } + + /** + * getAndDecrement returns previous value and decrements + */ + public void testGetAndDecrement() { + AtomicIntegerArray aa = new AtomicIntegerArray(SIZE); + for (int i = 0; i < SIZE; i++) { + aa.set(i, 1); + assertEquals(1, aa.getAndDecrement(i)); + assertEquals(0, aa.getAndDecrement(i)); + assertEquals(-1, aa.getAndDecrement(i)); + } + } + + /** + * getAndIncrement returns previous value and increments + */ + public void testGetAndIncrement() { + AtomicIntegerArray aa = new AtomicIntegerArray(SIZE); + for (int i = 0; i < SIZE; i++) { + aa.set(i, 1); + assertEquals(1, aa.getAndIncrement(i)); + assertEquals(2, aa.get(i)); + aa.set(i, -2); + assertEquals(-2, aa.getAndIncrement(i)); + assertEquals(-1, aa.getAndIncrement(i)); + assertEquals(0, aa.getAndIncrement(i)); + assertEquals(1, aa.get(i)); + } + } + + /** + * addAndGet adds given value to current, and returns current value + */ public void testAddAndGet() { - AtomicIntegerArray ai = new AtomicIntegerArray(SIZE); - for (int i = 0; i < SIZE; ++i) { - ai.set(i, 1); - assertEquals(3,ai.addAndGet(i,2)); - assertEquals(3,ai.get(i)); - assertEquals(-1,ai.addAndGet(i,-4)); - assertEquals(-1,ai.get(i)); + AtomicIntegerArray aa = new AtomicIntegerArray(SIZE); + for (int i = 0; i < SIZE; i++) { + aa.set(i, 1); + assertEquals(3, aa.addAndGet(i, 2)); + assertEquals(3, aa.get(i)); + assertEquals(-1, aa.addAndGet(i, -4)); + assertEquals(-1, aa.get(i)); } } - public void testDecrementAndGet(){ - AtomicIntegerArray ai = new AtomicIntegerArray(SIZE); - for (int i = 0; i < SIZE; ++i) { - ai.set(i, 1); - assertEquals(0,ai.decrementAndGet(i)); - assertEquals(-1,ai.decrementAndGet(i)); - assertEquals(-2,ai.decrementAndGet(i)); - assertEquals(-2,ai.get(i)); + /** + * decrementAndGet decrements and returns current value + */ + public void testDecrementAndGet() { + AtomicIntegerArray aa = new AtomicIntegerArray(SIZE); + for (int i = 0; i < SIZE; i++) { + aa.set(i, 1); + assertEquals(0, aa.decrementAndGet(i)); + assertEquals(-1, aa.decrementAndGet(i)); + assertEquals(-2, aa.decrementAndGet(i)); + assertEquals(-2, aa.get(i)); } } + /** + * incrementAndGet increments and returns current value + */ public void testIncrementAndGet() { - AtomicIntegerArray ai = new AtomicIntegerArray(SIZE); - for (int i = 0; i < SIZE; ++i) { - ai.set(i, 1); - assertEquals(2,ai.incrementAndGet(i)); - assertEquals(2,ai.get(i)); - ai.set(i, -2); - assertEquals(-1,ai.incrementAndGet(i)); - assertEquals(0,ai.incrementAndGet(i)); - assertEquals(1,ai.incrementAndGet(i)); - assertEquals(1,ai.get(i)); + AtomicIntegerArray aa = new AtomicIntegerArray(SIZE); + for (int i = 0; i < SIZE; i++) { + aa.set(i, 1); + assertEquals(2, aa.incrementAndGet(i)); + assertEquals(2, aa.get(i)); + aa.set(i, -2); + assertEquals(-1, aa.incrementAndGet(i)); + assertEquals(0, aa.incrementAndGet(i)); + assertEquals(1, aa.incrementAndGet(i)); + assertEquals(1, aa.get(i)); } } - static final int COUNTDOWN = 100000; - - class Counter implements Runnable { - final AtomicIntegerArray ai; + class Counter extends CheckedRunnable { + final AtomicIntegerArray aa; volatile int counts; - Counter(AtomicIntegerArray a) { ai = a; } - public void run() { + Counter(AtomicIntegerArray a) { aa = a; } + public void realRun() { for (;;) { boolean done = true; - for (int i = 0; i < ai.length(); ++i) { - int v = ai.get(i); - threadAssertTrue(v >= 0); + for (int i = 0; i < aa.length(); i++) { + int v = aa.get(i); + assertTrue(v >= 0); if (v != 0) { done = false; - if (ai.compareAndSet(i, v, v-1)) + if (aa.compareAndSet(i, v, v - 1)) ++counts; } } @@ -168,47 +344,241 @@ public class AtomicIntegerArrayTest exte } } - public void testCountingInMultipleThreads() { - try { - final AtomicIntegerArray ai = new AtomicIntegerArray(SIZE); - for (int i = 0; i < SIZE; ++i) - ai.set(i, COUNTDOWN); - Counter c1 = new Counter(ai); - Counter c2 = new Counter(ai); - Thread t1 = new Thread(c1); - Thread t2 = new Thread(c2); - t1.start(); - t2.start(); - t1.join(); - t2.join(); - assertEquals(c1.counts+c2.counts, SIZE * COUNTDOWN); - } - catch(InterruptedException ie) { - fail("unexpected exception"); - } - } - - - public void testSerialization() { - AtomicIntegerArray l = new AtomicIntegerArray(SIZE); - for (int i = 0; i < SIZE; ++i) - l.set(i, -i); - - try { - ByteArrayOutputStream bout = new ByteArrayOutputStream(10000); - ObjectOutputStream out = new ObjectOutputStream(new BufferedOutputStream(bout)); - out.writeObject(l); - out.close(); - - ByteArrayInputStream bin = new ByteArrayInputStream(bout.toByteArray()); - ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(bin)); - AtomicIntegerArray r = (AtomicIntegerArray) in.readObject(); - for (int i = 0; i < SIZE; ++i) { - assertEquals(l.get(i), r.get(i)); - } - } catch(Exception e){ - e.printStackTrace(); - fail("unexpected exception"); + /** + * Multiple threads using same array of counters successfully + * update a number of times equal to total count + */ + public void testCountingInMultipleThreads() throws InterruptedException { + final AtomicIntegerArray aa = new AtomicIntegerArray(SIZE); + int countdown = 10000; + for (int i = 0; i < SIZE; i++) + aa.set(i, countdown); + Counter c1 = new Counter(aa); + Counter c2 = new Counter(aa); + Thread t1 = new Thread(c1); + Thread t2 = new Thread(c2); + t1.start(); + t2.start(); + t1.join(); + t2.join(); + assertEquals(c1.counts+c2.counts, SIZE * countdown); + } + + /** + * a deserialized serialized array holds same values + */ + public void testSerialization() throws Exception { + AtomicIntegerArray x = new AtomicIntegerArray(SIZE); + for (int i = 0; i < SIZE; i++) + x.set(i, -i); + AtomicIntegerArray 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() { + int[] a = { 17, 3, -42, 99, -7 }; + AtomicIntegerArray aa = new AtomicIntegerArray(a); + assertEquals(Arrays.toString(a), aa.toString()); + } + + // jdk9 + + /** + * getPlain returns the last value set + */ + public void testGetPlainSet() { + AtomicIntegerArray aa = new AtomicIntegerArray(SIZE); + for (int i = 0; i < SIZE; i++) { + aa.set(i, 1); + assertEquals(1, aa.getPlain(i)); + aa.set(i, 2); + assertEquals(2, aa.getPlain(i)); + aa.set(i, -3); + assertEquals(-3, aa.getPlain(i)); + } + } + + /** + * getOpaque returns the last value set + */ + public void testGetOpaqueSet() { + AtomicIntegerArray aa = new AtomicIntegerArray(SIZE); + for (int i = 0; i < SIZE; i++) { + aa.set(i, 1); + assertEquals(1, aa.getOpaque(i)); + aa.set(i, 2); + assertEquals(2, aa.getOpaque(i)); + aa.set(i, -3); + assertEquals(-3, aa.getOpaque(i)); + } + } + + /** + * getAcquire returns the last value set + */ + public void testGetAcquireSet() { + AtomicIntegerArray aa = new AtomicIntegerArray(SIZE); + for (int i = 0; i < SIZE; i++) { + aa.set(i, 1); + assertEquals(1, aa.getAcquire(i)); + aa.set(i, 2); + assertEquals(2, aa.getAcquire(i)); + aa.set(i, -3); + assertEquals(-3, aa.getAcquire(i)); + } + } + + /** + * get returns the last value setPlain + */ + public void testGetSetPlain() { + AtomicIntegerArray aa = new AtomicIntegerArray(SIZE); + for (int i = 0; i < SIZE; i++) { + aa.setPlain(i, 1); + assertEquals(1, aa.get(i)); + aa.setPlain(i, 2); + assertEquals(2, aa.get(i)); + aa.setPlain(i, -3); + assertEquals(-3, aa.get(i)); + } + } + + /** + * get returns the last value setOpaque + */ + public void testGetSetOpaque() { + AtomicIntegerArray aa = new AtomicIntegerArray(SIZE); + for (int i = 0; i < SIZE; i++) { + aa.setOpaque(i, 1); + assertEquals(1, aa.get(i)); + aa.setOpaque(i, 2); + assertEquals(2, aa.get(i)); + aa.setOpaque(i, -3); + assertEquals(-3, aa.get(i)); + } + } + + /** + * get returns the last value setRelease + */ + public void testGetSetRelease() { + AtomicIntegerArray aa = new AtomicIntegerArray(SIZE); + for (int i = 0; i < SIZE; i++) { + aa.setRelease(i, 1); + assertEquals(1, aa.get(i)); + aa.setRelease(i, 2); + assertEquals(2, aa.get(i)); + aa.setRelease(i, -3); + assertEquals(-3, aa.get(i)); + } + } + + /** + * compareAndExchange succeeds in changing value if equal to + * expected else fails + */ + public void testCompareAndExchange() { + AtomicIntegerArray aa = new AtomicIntegerArray(SIZE); + for (int i = 0; i < SIZE; i++) { + aa.set(i, 1); + assertEquals(1, aa.compareAndExchange(i, 1, 2)); + assertEquals(2, aa.compareAndExchange(i, 2, -4)); + assertEquals(-4, aa.get(i)); + assertEquals(-4, aa.compareAndExchange(i,-5, 7)); + assertEquals(-4, aa.get(i)); + assertEquals(-4, aa.compareAndExchange(i, -4, 7)); + assertEquals(7, aa.get(i)); + } + } + + /** + * compareAndExchangeAcquire succeeds in changing value if equal to + * expected else fails + */ + public void testCompareAndExchangeAcquire() { + AtomicIntegerArray aa = new AtomicIntegerArray(SIZE); + for (int i = 0; i < SIZE; i++) { + aa.set(i, 1); + assertEquals(1, aa.compareAndExchangeAcquire(i, 1, 2)); + assertEquals(2, aa.compareAndExchangeAcquire(i, 2, -4)); + assertEquals(-4, aa.get(i)); + assertEquals(-4, aa.compareAndExchangeAcquire(i,-5, 7)); + assertEquals(-4, aa.get(i)); + assertEquals(-4, aa.compareAndExchangeAcquire(i, -4, 7)); + assertEquals(7, aa.get(i)); + } + } + + /** + * compareAndExchangeRelease succeeds in changing value if equal to + * expected else fails + */ + public void testCompareAndExchangeRelease() { + AtomicIntegerArray aa = new AtomicIntegerArray(SIZE); + for (int i = 0; i < SIZE; i++) { + aa.set(i, 1); + assertEquals(1, aa.compareAndExchangeRelease(i, 1, 2)); + assertEquals(2, aa.compareAndExchangeRelease(i, 2, -4)); + assertEquals(-4, aa.get(i)); + assertEquals(-4, aa.compareAndExchangeRelease(i,-5, 7)); + assertEquals(-4, aa.get(i)); + assertEquals(-4, aa.compareAndExchangeRelease(i, -4, 7)); + assertEquals(7, aa.get(i)); + } + } + + /** + * repeated weakCompareAndSetVolatile succeeds in changing value when equal + * to expected + */ + public void testWeakCompareAndSetVolatile() { + AtomicIntegerArray aa = new AtomicIntegerArray(SIZE); + for (int i = 0; i < SIZE; i++) { + aa.set(i, 1); + do {} while (!aa.weakCompareAndSetVolatile(i, 1, 2)); + do {} while (!aa.weakCompareAndSetVolatile(i, 2, -4)); + assertEquals(-4, aa.get(i)); + do {} while (!aa.weakCompareAndSetVolatile(i, -4, 7)); + assertEquals(7, aa.get(i)); + } + } + + /** + * repeated weakCompareAndSetAcquire succeeds in changing value when equal + * to expected + */ + public void testWeakCompareAndSetAcquire() { + AtomicIntegerArray aa = new AtomicIntegerArray(SIZE); + for (int i = 0; i < SIZE; i++) { + aa.set(i, 1); + do {} while (!aa.weakCompareAndSetAcquire(i, 1, 2)); + do {} while (!aa.weakCompareAndSetAcquire(i, 2, -4)); + assertEquals(-4, aa.get(i)); + do {} while (!aa.weakCompareAndSetAcquire(i, -4, 7)); + assertEquals(7, aa.get(i)); + } + } + + /** + * repeated weakCompareAndSetRelease succeeds in changing value when equal + * to expected + */ + public void testWeakCompareAndSetRelease() { + AtomicIntegerArray aa = new AtomicIntegerArray(SIZE); + for (int i = 0; i < SIZE; i++) { + aa.set(i, 1); + do {} while (!aa.weakCompareAndSetRelease(i, 1, 2)); + do {} while (!aa.weakCompareAndSetRelease(i, 2, -4)); + assertEquals(-4, aa.get(i)); + do {} while (!aa.weakCompareAndSetRelease(i, -4, 7)); + assertEquals(7, aa.get(i)); } }