| /* |
| * 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.concurrent.atomic.AtomicStampedReference; |
| |
| import junit.framework.Test; |
| import junit.framework.TestSuite; |
| |
| public class AtomicStampedReferenceTest 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(...); |
| // } |
| |
| /** |
| * constructor initializes to given reference and stamp |
| */ |
| public void testConstructor() { |
| AtomicStampedReference ai = new AtomicStampedReference(one, 0); |
| assertSame(one, ai.getReference()); |
| assertEquals(0, ai.getStamp()); |
| AtomicStampedReference a2 = new AtomicStampedReference(null, 1); |
| assertNull(a2.getReference()); |
| assertEquals(1, a2.getStamp()); |
| } |
| |
| /** |
| * get returns the last values of reference and stamp set |
| */ |
| public void testGetSet() { |
| int[] mark = new int[1]; |
| AtomicStampedReference ai = new AtomicStampedReference(one, 0); |
| assertSame(one, ai.getReference()); |
| assertEquals(0, ai.getStamp()); |
| assertSame(one, ai.get(mark)); |
| assertEquals(0, mark[0]); |
| ai.set(two, 0); |
| assertSame(two, ai.getReference()); |
| assertEquals(0, ai.getStamp()); |
| assertSame(two, ai.get(mark)); |
| assertEquals(0, mark[0]); |
| ai.set(one, 1); |
| assertSame(one, ai.getReference()); |
| assertEquals(1, ai.getStamp()); |
| assertSame(one, ai.get(mark)); |
| assertEquals(1, mark[0]); |
| } |
| |
| /** |
| * attemptStamp succeeds in single thread |
| */ |
| public void testAttemptStamp() { |
| int[] mark = new int[1]; |
| AtomicStampedReference ai = new AtomicStampedReference(one, 0); |
| assertEquals(0, ai.getStamp()); |
| assertTrue(ai.attemptStamp(one, 1)); |
| assertEquals(1, ai.getStamp()); |
| assertSame(one, ai.get(mark)); |
| assertEquals(1, mark[0]); |
| } |
| |
| /** |
| * compareAndSet succeeds in changing values if equal to expected reference |
| * and stamp else fails |
| */ |
| public void testCompareAndSet() { |
| int[] mark = new int[1]; |
| AtomicStampedReference ai = new AtomicStampedReference(one, 0); |
| assertSame(one, ai.get(mark)); |
| assertEquals(0, ai.getStamp()); |
| assertEquals(0, mark[0]); |
| |
| assertTrue(ai.compareAndSet(one, two, 0, 0)); |
| assertSame(two, ai.get(mark)); |
| assertEquals(0, mark[0]); |
| |
| assertTrue(ai.compareAndSet(two, m3, 0, 1)); |
| assertSame(m3, ai.get(mark)); |
| assertEquals(1, mark[0]); |
| |
| assertFalse(ai.compareAndSet(two, m3, 1, 1)); |
| assertSame(m3, ai.get(mark)); |
| assertEquals(1, mark[0]); |
| } |
| |
| /** |
| * compareAndSet in one thread enables another waiting for reference value |
| * to succeed |
| */ |
| public void testCompareAndSetInMultipleThreads() throws Exception { |
| final AtomicStampedReference ai = new AtomicStampedReference(one, 0); |
| Thread t = new Thread(new CheckedRunnable() { |
| public void realRun() { |
| while (!ai.compareAndSet(two, three, 0, 0)) |
| Thread.yield(); |
| }}); |
| |
| t.start(); |
| assertTrue(ai.compareAndSet(one, two, 0, 0)); |
| t.join(LONG_DELAY_MS); |
| assertFalse(t.isAlive()); |
| assertSame(three, ai.getReference()); |
| assertEquals(0, ai.getStamp()); |
| } |
| |
| /** |
| * compareAndSet in one thread enables another waiting for stamp value |
| * to succeed |
| */ |
| public void testCompareAndSetInMultipleThreads2() throws Exception { |
| final AtomicStampedReference ai = new AtomicStampedReference(one, 0); |
| Thread t = new Thread(new CheckedRunnable() { |
| public void realRun() { |
| while (!ai.compareAndSet(one, one, 1, 2)) |
| Thread.yield(); |
| }}); |
| |
| t.start(); |
| assertTrue(ai.compareAndSet(one, one, 0, 1)); |
| t.join(LONG_DELAY_MS); |
| assertFalse(t.isAlive()); |
| assertSame(one, ai.getReference()); |
| assertEquals(2, ai.getStamp()); |
| } |
| |
| /** |
| * repeated weakCompareAndSet succeeds in changing values when equal |
| * to expected |
| */ |
| public void testWeakCompareAndSet() { |
| int[] mark = new int[1]; |
| AtomicStampedReference ai = new AtomicStampedReference(one, 0); |
| assertSame(one, ai.get(mark)); |
| assertEquals(0, ai.getStamp()); |
| assertEquals(0, mark[0]); |
| |
| do {} while (!ai.weakCompareAndSet(one, two, 0, 0)); |
| assertSame(two, ai.get(mark)); |
| assertEquals(0, mark[0]); |
| |
| do {} while (!ai.weakCompareAndSet(two, m3, 0, 1)); |
| assertSame(m3, ai.get(mark)); |
| assertEquals(1, mark[0]); |
| } |
| |
| } |