--- jsr166/src/test/tck/AtomicReferenceTest.java 2003/09/14 20:42:40 1.3 +++ jsr166/src/test/tck/AtomicReferenceTest.java 2009/11/16 04:57:10 1.10 @@ -1,8 +1,9 @@ /* - * 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/licenses/publicdomain + * Other contributors include Andrew Wright, Jeffrey Hayes, + * Pat Fisher, Mike Judd. */ import junit.framework.*; @@ -17,16 +18,25 @@ public class AtomicReferenceTest extends return new TestSuite(AtomicReferenceTest.class); } + /** + * constructor initializes to given value + */ public void testConstructor(){ AtomicReference ai = new AtomicReference(one); assertEquals(one,ai.get()); } + /** + * default constructed initializes to null + */ public void testConstructor2(){ AtomicReference ai = new AtomicReference(); assertNull(ai.get()); } + /** + * get returns the last value set + */ public void testGetSet(){ AtomicReference ai = new AtomicReference(one); assertEquals(one,ai.get()); @@ -34,8 +44,23 @@ public class AtomicReferenceTest extends assertEquals(two,ai.get()); ai.set(m3); assertEquals(m3,ai.get()); - } + + /** + * get returns the last value lazySet in same thread + */ + public void testGetLazySet(){ + AtomicReference ai = new AtomicReference(one); + assertEquals(one,ai.get()); + ai.lazySet(two); + assertEquals(two,ai.get()); + ai.lazySet(m3); + assertEquals(m3,ai.get()); + } + + /** + * compareAndSet succeeds in changing value if equal to expected else fails + */ public void testCompareAndSet(){ AtomicReference ai = new AtomicReference(one); assertTrue(ai.compareAndSet(one,two)); @@ -47,15 +72,44 @@ public class AtomicReferenceTest extends assertEquals(seven,ai.get()); } + /** + * compareAndSet in one thread enables another waiting for value + * to succeed + */ + public void testCompareAndSetInMultipleThreads() { + final AtomicReference ai = new AtomicReference(one); + Thread t = new Thread(new Runnable() { + public void run() { + while (!ai.compareAndSet(two, three)) Thread.yield(); + }}); + try { + t.start(); + assertTrue(ai.compareAndSet(one, two)); + t.join(LONG_DELAY_MS); + assertFalse(t.isAlive()); + assertEquals(ai.get(), three); + } + catch (Exception e) { + unexpectedException(); + } + } + + /** + * repeated weakCompareAndSet succeeds in changing value when equal + * to expected + */ public void testWeakCompareAndSet(){ AtomicReference ai = new AtomicReference(one); - while(!ai.weakCompareAndSet(one,two)); - while(!ai.weakCompareAndSet(two,m4)); + while (!ai.weakCompareAndSet(one,two)); + while (!ai.weakCompareAndSet(two,m4)); assertEquals(m4,ai.get()); - while(!ai.weakCompareAndSet(m4,seven)); + while (!ai.weakCompareAndSet(m4,seven)); assertEquals(seven,ai.get()); } + /** + * getAndSet returns previous value and sets to given value + */ public void testGetAndSet(){ AtomicReference ai = new AtomicReference(one); assertEquals(one,ai.getAndSet(zero)); @@ -63,6 +117,9 @@ public class AtomicReferenceTest extends assertEquals(m10,ai.getAndSet(one)); } + /** + * a deserialized serialized atomic holds same value + */ public void testSerialization() { AtomicReference l = new AtomicReference(); @@ -77,11 +134,19 @@ public class AtomicReferenceTest extends ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(bin)); AtomicReference r = (AtomicReference) in.readObject(); assertEquals(l.get(), r.get()); - } catch(Exception e){ - e.printStackTrace(); - fail("unexpected exception"); + } catch (Exception e){ + unexpectedException(); } } -} + /** + * toString returns current value. + */ + public void testToString() { + AtomicReference ai = new AtomicReference(one); + assertEquals(ai.toString(), one.toString()); + ai.set(two); + assertEquals(ai.toString(), two.toString()); + } +}