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

Condition Objects and Interface Condition

If a thread that owns a Lock determines that it cannot continue with its task until some condition is satisfied, the thread can wait on a condition object. Using Lock objects allows you to explicitly declare the condition objects on which a thread may need to wait. For example, in the producer/consumer relationship, producers can wait on one object and consumers can wait on another. This is not possible when using the synchronized keywords and an object’s built-in monitor lock. Condition objects are associated with a specific Lock and are created by calling a Lock’s newCondition method, which returns an object that implements the Condition interface (of package java.util.concurrent.locks). To wait on ...