java.util.concurrent.locks · java.base · since Java 1.5

ReentrantLock

declaration

public class ReentrantLock implements Lock, Serializable

Explicit mutual-exclusion lock with the powers synchronized lacks: tryLock, timed and interruptible acquisition, fairness, and multiple Conditions.

Key methods

`void lock() / void unlock()`	unlock() in finally, always.
`boolean tryLock() / tryLock(long, TimeUnit)`	Deadlock-avoiding acquisition.
`void lockInterruptibly()`	Cancellable waiting.
`Condition newCondition()`	await/signal wait-sets, multiple per lock.