/** compareAndSet in one thread enables another waiting for value to succeed */
public void testCompareAndSetInMultipleThreads() throws Exception {
x = one;
final AtomicReferenceFieldUpdater<AtomicReferenceFieldUpdaterTest, Integer> a;
try {
a =
AtomicReferenceFieldUpdater.newUpdater(
AtomicReferenceFieldUpdaterTest.class, Integer.class, "x");
} catch (RuntimeException ok) {
return;
}
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(a.get(this), three);
}
/** Checks that the threads do not terminate within the given millisecond delay. */
void assertThreadsStayAlive(long millis, Thread... threads) {
try {
// No need to optimize the failing case via Thread.join.
delay(millis);
for (Thread thread : threads) assertTrue(thread.isAlive());
} catch (InterruptedException ie) {
fail("Unexpected InterruptedException");
}
}
/** Spin-waits until sync.isQueued(t) becomes true. */
void waitForQueuedThread(AbstractQueuedLongSynchronizer sync, Thread t) {
long startTime = System.nanoTime();
while (!sync.isQueued(t)) {
if (millisElapsedSince(startTime) > LONG_DELAY_MS)
throw new AssertionFailedError("timed out");
Thread.yield();
}
assertTrue(t.isAlive());
}
/**
* Spin-waits up to the specified number of milliseconds for the given thread to enter a wait
* state: BLOCKED, WAITING, or TIMED_WAITING.
*/
void waitForThreadToEnterWaitState(Thread thread, long timeoutMillis) {
long startTime = System.nanoTime();
for (; ; ) {
Thread.State s = thread.getState();
if (s == Thread.State.BLOCKED || s == Thread.State.WAITING || s == Thread.State.TIMED_WAITING)
return;
else if (s == Thread.State.TERMINATED) fail("Unexpected thread termination");
else if (millisElapsedSince(startTime) > timeoutMillis) {
threadAssertTrue(thread.isAlive());
return;
}
Thread.yield();
}
}
/** compareAndSet in one thread enables another waiting for value to succeed */
public void testCompareAndSetInMultipleThreads() {
final AtomicLong ai = new AtomicLong(1);
Thread t =
new Thread(
new Runnable() {
public void run() {
while (!ai.compareAndSet(2, 3)) Thread.yield();
}
});
try {
t.start();
assertTrue(ai.compareAndSet(1, 2));
t.join(LONG_DELAY_MS);
assertFalse(t.isAlive());
assertEquals(ai.get(), 3);
} catch (Exception e) {
unexpectedException();
}
}