ReentrantLock

特性

可重入 interview
- 加锁 AbstractQueuedSynchronizer state +1, 解锁 -1
公平/非公平, 默认非公平, ReentrantLock(boolean fair)
支持超时, tryLock(long timeout, TimeUnit unit)
等待可中断, lockInterruptibly() throws InterruptedException
- lock() 会忽略异常继续等待获取锁

public class Counter {
	private final Lock lock = new ReentrantLock();
	private int count;
	public void add(int n) {
		lock.lock();
		try {
			count += n;
		} finally {
			lock.unlock();
		}
	}
}

See Also