javaCountDownLatch闭锁

package com.java.concurrent;import java.util.concurrent.CountDownLatch;
/**
 * CountDownLatch: 闭锁，在完成某些运算的时候，只有其它所有线程的运算全部完成后，当前运算才会执行
 * @author fliay
 *
 */
public class TestCountDownLatch {public static void main(String[] args) {
final CountDownLatch latch = new CountDownLatch(10);
LactchDemo Ld = new LactchDemo(latch);
long start = System.currentTimeMillis();
for (int i = 0; i < 5; i++) {
new Thread(Ld).start();
new Thread(Ld).start();
}try {
latch.await();//执行等待
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
long end = System.currentTimeMillis();
System.out.println("消耗时间为：" + (end - start));}}class LactchDemo implements Runnable {private CountDownLatch latch;public LactchDemo(CountDownLatch latch) {
this.latch = latch;
}public void run() {
synchronized (this) {
try {
for (int i = 0; i < 10; i++) {
if (i % 2 == 0) {
System.out.println(i);
}
}
} finally {
// 启动闭锁
latch.countDown();
}
}}}