package com.lyq.jsoup.MyQueue;
/**
* Created by mike on 2016/12/19.
*/
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;
/**
* 示例:CountDownLatch的使用举例
* 构造方法参数指定了计数的次数
* countDown方法,当前线程调用此方法,则计数减一
* await方法,调用此方法会一直阻塞当前线程,直到计时器的值为0
*/
public class TestCountDownLatch {
private static final int N = 5;
public static void main(String[] args) throws InterruptedException {
CountDownLatch startSignal = new CountDownLatch(1);//控制每一个线程是否开始
CountDownLatch doneSignal = new CountDownLatch(N);
for (int i = 1; i <= N; i++) {
new Thread(new Worker(doneSignal, startSignal), "t" + i).start();//所有线程启动,都处于等待状态
}
System.out.println("begin------------");
startSignal.countDown();//2:所有线程都执行
doneSignal.await();//3:等待所有的线程执行完毕
System.out.println("Ok");
}
static class Worker implements Runnable {
private final CountDownLatch doneSignal;
private final CountDownLatch startSignal;
Worker(CountDownLatch doneSignal,
CountDownLatch startSignal) {
this.startSignal = startSignal;
this.doneSignal = doneSignal;
}
public void run() {
try {
startSignal.await(); //1:等待开始执行信号的发布
System.out.println("thread name:" + Thread.currentThread().getName());
} catch (InterruptedException e) {
e.printStackTrace();
} finally {
doneSignal.countDown();//4:每个线程一行完成,都会减一,知道doneSignal.count = 0
}
}
}
}
CountDownLatch 自己的一点理解
發表評論
所有評論
還沒有人評論,想成為第一個評論的人麼? 請在上方評論欄輸入並且點擊發布.