Java™ How To Program (Early Objects), Tenth Edition

Methods wait, notify and notifyAll

Object methods wait, notify and notifyAll can be used with conditions to make threads wait when they cannot perform their tasks. If a thread obtains the monitor lock on an object, then determines that it cannot continue with its task on that object until some condition is satisfied, the thread can call Object method wait on the synchronized object; this releases the monitor lock on the object, and the thread waits in the waiting state while the other threads try to enter the object’s synchronized statement(s) or method(s). When a thread executing a synchronized statement (or method) completes or satisfies the condition on which another thread may be waiting, it can call Object method notify on the synchronized ...