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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 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(...);
// }
/**
* 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());
}
}
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