Example usage for java.util.concurrent.locks Lock tryLock

Introduction

In this page you can find the example usage for java.util.concurrent.locks Lock tryLock.

Prototype

boolean tryLock(long time, TimeUnit unit) throws InterruptedException;

Source Link

Document

Acquires the lock if it is free within the given waiting time and the current thread has not been Thread#interrupt interrupted .

Usage

From source file:org.rhq.core.pc.PluginContainer.java

private Lock obtainReadLock() {
    // try to obtain the lock, but if we can't get the lock in 60 seconds,
    // keep going. The PC is usually fine within seconds after its initializes,
    // so not getting this lock within 60 seconds probably isn't detrimental.
    // But if there is a deadlock, blocking forever here would be detrimental,
    // so we do not do it. We'll just log a warning and let the thread keep going.
    Lock readLock = rwLock.readLock();
    try {//from w  w  w .j  a v  a 2  s .co  m
        if (!readLock.tryLock(60L, TimeUnit.SECONDS)) {
            String msg = "There may be a deadlock in the plugin container.";
            //noinspection ThrowableInstanceNeverThrown
            log.warn(msg, new Throwable(msg));
            readLock = null;
        }
    } catch (InterruptedException e) {
        readLock = null;
    }
    return readLock;
}

From source file:org.rhq.core.pc.PluginContainer.java

private Lock obtainWriteLock() {
    // try to obtain the lock, but if we can't get the lock in 60 seconds,
    // keep going. The PC is usually fine within seconds after its initializes,
    // so not getting this lock within 60 seconds probably isn't detrimental.
    // But if there is a deadlock, blocking forever here would be detrimental,
    // so we do not do it. We'll just log a warning and let the thread keep going.
    Lock writeLock = rwLock.writeLock();
    try {//from  w ww .  j ava  2 s .  co m
        if (!writeLock.tryLock(60L, TimeUnit.SECONDS)) {
            String msg = "There may be a deadlock in the plugin container.";
            //noinspection ThrowableInstanceNeverThrown
            log.warn(msg, new Throwable(msg));
            writeLock = null;
        }
    } catch (InterruptedException e) {
        writeLock = null;
    }
    return writeLock;
}

From source file:org.springframework.integration.redis.util.RedisLockRegistryTests.java

@Test
@RedisAvailable/*from   w  w  w. j  av a2 s .co m*/
public void testTwoThreadsSecondFailsToGetLock() throws Exception {
    final RedisLockRegistry registry = new RedisLockRegistry(this.getConnectionFactoryForTest(),
            this.registryKey);
    final Lock lock1 = registry.obtain("foo");
    lock1.lockInterruptibly();
    final AtomicBoolean locked = new AtomicBoolean();
    final CountDownLatch latch = new CountDownLatch(1);
    Future<Object> result = Executors.newSingleThreadExecutor().submit(() -> {
        Lock lock2 = registry.obtain("foo");
        locked.set(lock2.tryLock(200, TimeUnit.MILLISECONDS));
        latch.countDown();
        try {
            lock2.unlock();
        } catch (IllegalStateException ise) {
            return ise;
        }
        return null;
    });
    assertTrue(latch.await(10, TimeUnit.SECONDS));
    assertFalse(locked.get());
    lock1.unlock();
    Object ise = result.get(10, TimeUnit.SECONDS);
    assertThat(ise, instanceOf(IllegalStateException.class));
    assertThat(((Exception) ise).getMessage(), containsString("Lock is not locked"));
    assertNull(TestUtils.getPropertyValue(registry, "hardThreadLocks", ThreadLocal.class).get());
}