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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 junit.framework.*;
import java.util.concurrent.atomic.AtomicBoolean;
public class AtomicBooleanTest extends JSR166TestCase {
/**
* constructor initializes to given value
*/
public void testConstructor() {
assertTrue(new AtomicBoolean(true).get());
assertFalse(new AtomicBoolean(false).get());
}
/**
* default constructed initializes to false
*/
public void testConstructor2() {
AtomicBoolean ai = new AtomicBoolean();
assertFalse(ai.get());
}
/**
* get returns the last value set
*/
public void testGetSet() {
AtomicBoolean ai = new AtomicBoolean(true);
assertTrue(ai.get());
ai.set(false);
assertFalse(ai.get());
ai.set(true);
assertTrue(ai.get());
}
/**
* get returns the last value lazySet in same thread
*/
public void testGetLazySet() {
AtomicBoolean ai = new AtomicBoolean(true);
assertTrue(ai.get());
ai.lazySet(false);
assertFalse(ai.get());
ai.lazySet(true);
assertTrue(ai.get());
}
/**
* compareAndSet succeeds in changing value if equal to expected else fails
*/
public void testCompareAndSet() {
AtomicBoolean ai = new AtomicBoolean(true);
assertTrue(ai.compareAndSet(true, false));
assertFalse(ai.get());
assertTrue(ai.compareAndSet(false, false));
assertFalse(ai.get());
assertFalse(ai.compareAndSet(true, false));
assertFalse(ai.get());
assertTrue(ai.compareAndSet(false, true));
assertTrue(ai.get());
}
/**
* compareAndSet in one thread enables another waiting for value
* to succeed
*/
public void testCompareAndSetInMultipleThreads() throws Exception {
final AtomicBoolean ai = new AtomicBoolean(true);
Thread t = new Thread(new CheckedRunnable() {
public void realRun() {
while (!ai.compareAndSet(false, true)) Thread.yield();
}});
t.start();
assertTrue(ai.compareAndSet(true, false));
t.join(LONG_DELAY_MS);
assertFalse(t.isAlive());
}
/**
* repeated weakCompareAndSet succeeds in changing value when equal
* to expected
*/
public void testWeakCompareAndSet() {
AtomicBoolean ai = new AtomicBoolean(true);
while (!ai.weakCompareAndSet(true, false));
assertFalse(ai.get());
while (!ai.weakCompareAndSet(false, false));
assertFalse(ai.get());
while (!ai.weakCompareAndSet(false, true));
assertTrue(ai.get());
}
/**
* getAndSet returns previous value and sets to given value
*/
public void testGetAndSet() {
AtomicBoolean ai = new AtomicBoolean(true);
assertEquals(true, ai.getAndSet(false));
assertEquals(false, ai.getAndSet(false));
assertEquals(false, ai.getAndSet(true));
assertTrue(ai.get());
}
/**
* a deserialized serialized atomic holds same value
*/
public void testSerialization() throws Exception {
AtomicBoolean x = new AtomicBoolean();
AtomicBoolean y = serialClone(x);
x.set(true);
AtomicBoolean z = serialClone(x);
assertTrue(x.get());
assertFalse(y.get());
assertTrue(z.get());
}
/**
* toString returns current value.
*/
public void testToString() {
AtomicBoolean ai = new AtomicBoolean();
assertEquals(Boolean.toString(false), ai.toString());
ai.set(true);
assertEquals(Boolean.toString(true), ai.toString());
}
}
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