/** getWaitQueueLength returns number of waiting threads */
public void testGetWaitQueueLength() {
final Mutex sync = new Mutex();
final ConditionObject c = sync.newCondition();
final BooleanLatch acquired1 = new BooleanLatch();
final BooleanLatch acquired2 = new BooleanLatch();
final Thread t1 =
newStartedThread(
new CheckedRunnable() {
public void realRun() throws InterruptedException {
sync.acquire();
assertHasWaitersLocked(sync, c, NO_THREADS);
assertEquals(0, sync.getWaitQueueLength(c));
assertTrue(acquired1.releaseShared(0));
c.await();
sync.release();
}
});
acquired1.acquireShared(0);
sync.acquire();
assertHasWaitersLocked(sync, c, t1);
assertEquals(1, sync.getWaitQueueLength(c));
sync.release();
final Thread t2 =
newStartedThread(
new CheckedRunnable() {
public void realRun() throws InterruptedException {
sync.acquire();
assertHasWaitersLocked(sync, c, t1);
assertEquals(1, sync.getWaitQueueLength(c));
assertTrue(acquired2.releaseShared(0));
c.await();
sync.release();
}
});
acquired2.acquireShared(0);
sync.acquire();
assertHasWaitersLocked(sync, c, t1, t2);
assertHasExclusiveQueuedThreads(sync, NO_THREADS);
assertEquals(2, sync.getWaitQueueLength(c));
c.signalAll();
assertHasWaitersLocked(sync, c, NO_THREADS);
assertHasExclusiveQueuedThreads(sync, t1, t2);
assertEquals(0, sync.getWaitQueueLength(c));
sync.release();
awaitTermination(t1);
awaitTermination(t2);
assertHasWaitersUnlocked(sync, c, NO_THREADS);
}
/** getWaitQueueLength(null) throws NullPointerException */
public void testGetWaitQueueLengthNPE() {
final Mutex sync = new Mutex();
try {
sync.getWaitQueueLength(null);
shouldThrow();
} catch (NullPointerException success) {
}
}
/** Checks that condition c has exactly the given waiter threads. */
void assertHasWaitersLocked(Mutex sync, ConditionObject c, Thread... threads) {
assertEquals(threads.length > 0, sync.hasWaiters(c));
assertEquals(threads.length, sync.getWaitQueueLength(c));
assertEquals(threads.length == 0, sync.getWaitingThreads(c).isEmpty());
assertEquals(threads.length, sync.getWaitingThreads(c).size());
assertEquals(
new HashSet<Thread>(sync.getWaitingThreads(c)),
new HashSet<Thread>(Arrays.asList(threads)));
}
/** getWaitQueueLength throws IllegalMonitorStateException if not synced */
public void testGetWaitQueueLengthIMSE() {
final Mutex sync = new Mutex();
final ConditionObject c = sync.newCondition();
try {
sync.getWaitQueueLength(c);
shouldThrow();
} catch (IllegalMonitorStateException success) {
}
assertHasWaitersUnlocked(sync, c, NO_THREADS);
}