| /* |
| * 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.AtomicReference; |
| |
| import junit.framework.Test; |
| import junit.framework.TestSuite; |
| |
| public class AtomicReferenceTest 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(AtomicReferenceTest.class); |
| // } |
| |
| /** |
| * constructor initializes to given value |
| */ |
| public void testConstructor() { |
| AtomicReference ai = new AtomicReference(one); |
| assertSame(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); |
| assertSame(one, ai.get()); |
| ai.set(two); |
| assertSame(two, ai.get()); |
| ai.set(m3); |
| assertSame(m3, ai.get()); |
| } |
| |
| /** |
| * get returns the last value lazySet in same thread |
| */ |
| public void testGetLazySet() { |
| AtomicReference ai = new AtomicReference(one); |
| assertSame(one, ai.get()); |
| ai.lazySet(two); |
| assertSame(two, ai.get()); |
| ai.lazySet(m3); |
| assertSame(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)); |
| assertTrue(ai.compareAndSet(two, m4)); |
| assertSame(m4, ai.get()); |
| assertFalse(ai.compareAndSet(m5, seven)); |
| assertSame(m4, ai.get()); |
| assertTrue(ai.compareAndSet(m4, seven)); |
| assertSame(seven, ai.get()); |
| } |
| |
| /** |
| * compareAndSet in one thread enables another waiting for value |
| * to succeed |
| */ |
| public void testCompareAndSetInMultipleThreads() throws Exception { |
| final AtomicReference ai = new AtomicReference(one); |
| Thread t = new Thread(new CheckedRunnable() { |
| public void realRun() { |
| while (!ai.compareAndSet(two, three)) |
| Thread.yield(); |
| }}); |
| |
| t.start(); |
| assertTrue(ai.compareAndSet(one, two)); |
| t.join(LONG_DELAY_MS); |
| assertFalse(t.isAlive()); |
| assertSame(three, ai.get()); |
| } |
| |
| /** |
| * repeated weakCompareAndSet succeeds in changing value when equal |
| * to expected |
| */ |
| public void testWeakCompareAndSet() { |
| AtomicReference ai = new AtomicReference(one); |
| do {} while (!ai.weakCompareAndSet(one, two)); |
| do {} while (!ai.weakCompareAndSet(two, m4)); |
| assertSame(m4, ai.get()); |
| do {} while (!ai.weakCompareAndSet(m4, seven)); |
| assertSame(seven, ai.get()); |
| } |
| |
| /** |
| * getAndSet returns previous value and sets to given value |
| */ |
| public void testGetAndSet() { |
| AtomicReference ai = new AtomicReference(one); |
| assertSame(one, ai.getAndSet(zero)); |
| assertSame(zero, ai.getAndSet(m10)); |
| assertSame(m10, ai.getAndSet(one)); |
| } |
| |
| /** |
| * a deserialized serialized atomic holds same value |
| */ |
| public void testSerialization() throws Exception { |
| AtomicReference x = new AtomicReference(); |
| AtomicReference y = serialClone(x); |
| assertNotSame(x, y); |
| x.set(one); |
| AtomicReference z = serialClone(x); |
| assertNotSame(y, z); |
| assertEquals(one, x.get()); |
| assertEquals(null, y.get()); |
| assertEquals(one, z.get()); |
| } |
| |
| /** |
| * toString returns current value. |
| */ |
| public void testToString() { |
| AtomicReference<Integer> ai = new AtomicReference<Integer>(one); |
| assertEquals(one.toString(), ai.toString()); |
| ai.set(two); |
| assertEquals(two.toString(), ai.toString()); |
| } |
| |
| } |