Java Code Examples for java.util.concurrent.atomic.AtomicIntegerFieldUpdater#compareAndSet()

The following examples show how to use java.util.concurrent.atomic.AtomicIntegerFieldUpdater#compareAndSet() . You can vote up the ones you like or vote down the ones you don't like, and go to the original project or source file by following the links above each example. You may check out the related API usage on the sidebar.
Example 1
Source File: AtomicIntegerFieldUpdaterTest.java    From openjdk-jdk9 with GNU General Public License v2.0 6 votes vote down vote up 
/**
 * compareAndSet in one thread enables another waiting for value
 * to succeed
 */
public void testCompareAndSetInMultipleThreads() throws Exception {
    x = 1;
    final AtomicIntegerFieldUpdater<AtomicIntegerFieldUpdaterTest> a;
    a = updaterFor("x");

    Thread t = new Thread(new CheckedRunnable() {
        public void realRun() {
            while (!a.compareAndSet(AtomicIntegerFieldUpdaterTest.this, 2, 3))
                Thread.yield();
        }});

    t.start();
    assertTrue(a.compareAndSet(this, 1, 2));
    t.join(LONG_DELAY_MS);
    assertFalse(t.isAlive());
    assertEquals(3, a.get(this));
}
Example 2
Source File: AtomicIntegerFieldUpdaterTest.java    From j2objc with Apache License 2.0 6 votes vote down vote up 
/**
 * compareAndSet in one thread enables another waiting for value
 * to succeed
 */
public void testCompareAndSetInMultipleThreads() throws Exception {
    x = 1;
    final AtomicIntegerFieldUpdater<AtomicIntegerFieldUpdaterTest> a;
    a = updaterFor("x");

    Thread t = new Thread(new CheckedRunnable() {
        public void realRun() {
            while (!a.compareAndSet(AtomicIntegerFieldUpdaterTest.this, 2, 3))
                Thread.yield();
        }});

    t.start();
    assertTrue(a.compareAndSet(this, 1, 2));
    t.join(LONG_DELAY_MS);
    assertFalse(t.isAlive());
    assertEquals(3, a.get(this));
}
Example 3
Source File: ConcurrentUtils.java    From servicetalk with Apache License 2.0 5 votes vote down vote up 
/**
 * Acquire a lock that is exclusively held with no re-entry, but attempts to acquire the lock while it is
 * held can be detected by {@link #releaseLock(AtomicIntegerFieldUpdater, Object)}.
 * @param lockUpdater The {@link AtomicIntegerFieldUpdater} used to control the lock state.
 * @param owner The owner of the lock object.
 * @param <T> The type of object that owns the lock.
 * @return {@code true} if the lock was acquired, {@code false} otherwise.
 */
public static <T> boolean tryAcquireLock(AtomicIntegerFieldUpdater<T> lockUpdater, T owner) {
    for (;;) {
        final int prevEmitting = lockUpdater.get(owner);
        if (prevEmitting == CONCURRENT_IDLE) {
            if (lockUpdater.compareAndSet(owner, CONCURRENT_IDLE, CONCURRENT_EMITTING)) {
                return true;
            }
        } else if (lockUpdater.compareAndSet(owner, prevEmitting, CONCURRENT_PENDING)) {
            return false;
        }
    }
}
Example 4
Source File: Atomic8Test.java    From openjdk-jdk9 with GNU General Public License v2.0 5 votes vote down vote up 
/**
 * Object arguments for parameters of type T that are not
 * instances of the class passed to the newUpdater call will
 * result in a ClassCastException being thrown.
 */
public void testFieldUpdaters_ClassCastException() {
    // Use raw types to allow passing wrong object type, provoking CCE
    final AtomicLongFieldUpdater longUpdater = aLongFieldUpdater();
    final AtomicIntegerFieldUpdater intUpdater = anIntFieldUpdater();
    final AtomicReferenceFieldUpdater refUpdater = anIntegerFieldUpdater();
    final Object obj = new Object();
    for (Object x : new Object[]{ new Object(), null }) {
        Runnable[] throwingActions = {
            () -> longUpdater.get(x),
            () -> intUpdater.get(x),
            () -> refUpdater.get(x),

            () -> longUpdater.set(x, 17L),
            () -> intUpdater.set(x, 17),
            () -> refUpdater.set(x, (Integer) 17),

            () -> longUpdater.addAndGet(x, 17L),
            () -> intUpdater.addAndGet(x, 17),

            () -> longUpdater.getAndUpdate(x, y -> y),
            () -> intUpdater.getAndUpdate(x, y -> y),
            () -> refUpdater.getAndUpdate(x, y -> y),

            () -> longUpdater.compareAndSet(x, 17L, 42L),
            () -> intUpdater.compareAndSet(x, 17, 42),
            () -> refUpdater.compareAndSet(x, (Integer) 17, (Integer) 42),
        };
        assertThrows(ClassCastException.class, throwingActions);
    }
}