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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.AtomicReferenceFieldUpdater;
import junit.framework.Test;
import junit.framework.TestSuite;
public class AtomicReferenceFieldUpdaterTest extends JSR166TestCase {
volatile Integer x = null;
Object z;
Integer w;
volatile int i;
// 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(...);
// }
AtomicReferenceFieldUpdater<AtomicReferenceFieldUpdaterTest, Integer> updaterFor(String fieldName) {
return AtomicReferenceFieldUpdater.newUpdater
(AtomicReferenceFieldUpdaterTest.class, Integer.class, fieldName);
}
/**
* Construction with non-existent field throws RuntimeException
*/
public void testConstructor() {
try {
updaterFor("y");
shouldThrow();
} catch (RuntimeException success) {
assertNotNull(success.getCause());
}
}
/**
* construction with field not of given type throws ClassCastException
*/
public void testConstructor2() {
try {
updaterFor("z");
shouldThrow();
} catch (ClassCastException success) {}
}
/**
* Constructor with non-volatile field throws IllegalArgumentException
*/
public void testConstructor3() {
try {
updaterFor("w");
shouldThrow();
} catch (IllegalArgumentException success) {}
}
/**
* Constructor with non-reference field throws ClassCastException
*/
public void testConstructor4() {
try {
updaterFor("i");
shouldThrow();
} catch (ClassCastException success) {}
}
/**
* get returns the last value set or assigned
*/
public void testGetSet() {
AtomicReferenceFieldUpdater<AtomicReferenceFieldUpdaterTest, Integer> a;
a = updaterFor("x");
x = one;
assertSame(one, a.get(this));
a.set(this, two);
assertSame(two, a.get(this));
a.set(this, m3);
assertSame(m3, a.get(this));
}
/**
* get returns the last value lazySet by same thread
*/
public void testGetLazySet() {
AtomicReferenceFieldUpdater<AtomicReferenceFieldUpdaterTest, Integer> a;
a = updaterFor("x");
x = one;
assertSame(one, a.get(this));
a.lazySet(this, two);
assertSame(two, a.get(this));
a.lazySet(this, m3);
assertSame(m3, a.get(this));
}
/**
* compareAndSet succeeds in changing value if equal to expected else fails
*/
public void testCompareAndSet() {
AtomicReferenceFieldUpdater<AtomicReferenceFieldUpdaterTest, Integer> a;
a = updaterFor("x");
x = one;
assertTrue(a.compareAndSet(this, one, two));
assertTrue(a.compareAndSet(this, two, m4));
assertSame(m4, a.get(this));
assertFalse(a.compareAndSet(this, m5, seven));
assertFalse(seven == a.get(this));
assertTrue(a.compareAndSet(this, m4, seven));
assertSame(seven, a.get(this));
}
/**
* compareAndSet in one thread enables another waiting for value
* to succeed
*/
public void testCompareAndSetInMultipleThreads() throws Exception {
x = one;
final AtomicReferenceFieldUpdater<AtomicReferenceFieldUpdaterTest, Integer> a;
a = updaterFor("x");
Thread t = new Thread(new CheckedRunnable() {
public void realRun() {
while (!a.compareAndSet(AtomicReferenceFieldUpdaterTest.this, two, three))
Thread.yield();
}});
t.start();
assertTrue(a.compareAndSet(this, one, two));
t.join(LONG_DELAY_MS);
assertFalse(t.isAlive());
assertSame(three, a.get(this));
}
/**
* repeated weakCompareAndSet succeeds in changing value when equal
* to expected
*/
public void testWeakCompareAndSet() {
AtomicReferenceFieldUpdater<AtomicReferenceFieldUpdaterTest, Integer> a;
a = updaterFor("x");
x = one;
do {} while (!a.weakCompareAndSet(this, one, two));
do {} while (!a.weakCompareAndSet(this, two, m4));
assertSame(m4, a.get(this));
do {} while (!a.weakCompareAndSet(this, m4, seven));
assertSame(seven, a.get(this));
}
/**
* getAndSet returns previous value and sets to given value
*/
public void testGetAndSet() {
AtomicReferenceFieldUpdater<AtomicReferenceFieldUpdaterTest, Integer> a;
a = updaterFor("x");
x = one;
assertSame(one, a.getAndSet(this, zero));
assertSame(zero, a.getAndSet(this, m10));
assertSame(m10, a.getAndSet(this, 1));
}
}
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