import java.util.concurrent.CountDownLatch;
/**
* 作用于单个线程或几个线程,,在其他线程执行完之前,一直等待(await)知道countDown为零
* @author Administrator
*
*/
public class CountDownlatchTest {
public static void main(String[] args) throws InterruptedException {
CountDownLatch countDownLatch = new CountDownLatch(5);
for(int i=0;i<5;i++){
new Thread(new readNum(i,countDownLatch)).start();
}
countDownLatch.await();
System.out.println("线程执行结束。。。。");
}
static class readNum implements Runnable{
private int id;
private CountDownLatch latch;
public readNum(int id,CountDownLatch latch){
this.id = id;
this.latch = latch;
}
@Override
public void run() {
synchronized (this){
System.out.println("id:"+id);
latch.countDown();
System.out.println("线程组任务"+id+"结束,其他任务继续");
}
}
}
}
/**
* 作用于多个线程
* 可以通过CyclicBarrier实现没有先后顺序的同时执行任意的线程(假设cpu也是任意个)
* 多个线程一直阻塞,直到await数量达到CyclicBarrier的参数时,唤醒阻塞的线程
* 可重用
* @author Administrator
*
*/
public class CyclicBarrierTest {
public static void main(String[] args) throws InterruptedException {
CyclicBarrier cyclicBarrier = new CyclicBarrier(5, new Runnable() {
@Override
public void run() {
System.out.println("线程组执行结束");
}
});
for (int i = 0; i < 5; i++) {
new Thread(new readNum(i,cyclicBarrier)).start();
}
//CyclicBarrier 可以重复利用,
// 这个是CountDownLatch做不到的
// for (int i = 11; i < 16; i++) {
// new Thread(new readNum(i,cyclicBarrier)).start();
// }
}
static class readNum implements Runnable{
private int id;
private CyclicBarrier cyc;
public readNum(int id,CyclicBarrier cyc){
this.id = id;
this.cyc = cyc;
}
@Override
public void run() {
synchronized (this){
System.out.println("id:"+id);
try {
cyc.await();
System.out.println("线程组任务" + id + "结束,其他任务继续");
} catch (Exception e) {
e.printStackTrace();
}
}
}
}
}