Java Locks

lock() locks the Lock instance if possible. If the Lock instance is already locked, the thread calling lock() is blocked until the Lock is unlocked.
lockInterruptibly() locks the Lock unless the thread calling the method has been interrupted.
tryLock() method attempts to lock the Lock instance immediately. It returns true if the locking succeeds, false if Lock is already locked. This method never blocks.
tryLock(long timeout, TimeUnit timeUnit) works like the tryLock() method, except it waits up the given timeout before giving up trying to lock the Lock.
unlock() unlocks the Lock instance. If the Lock is already unlocked, it throws an IllegalMonitorStateException.