Countdownlatch

个人感觉countdownlatch功能么有CyclicBarrier强大，demo如下：

package com.jerry.concurrency;
import java.util.Random;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
public class TestCountdownlatch {
	
	 public static void main(String[] args) throws Exception{
		    final  int count = 10;
		    final CountDownLatch latch = new CountDownLatch(count);
		    ExecutorService exec = Executors.newCachedThreadPool();
		    exec.submit(new Runnable() {
				@Override
				public void run() {
						try {
							latch.await();    
				            System.out.println("全部任务都完成了");  
						} catch (InterruptedException e) {
							e.printStackTrace();
						}
				}
			});
		    for(int i=0;i<count;i++){
		    	exec.submit(new Runnable() {
					@Override
					public void run() {
							try {
								int second = new Random().nextInt(2000);
								Thread.sleep(second);
								System.out.println(Thread.currentThread().getName() + " 线程完成完成，耗时:" + second); 
								latch.countDown();
							} catch (InterruptedException e) {
								e.printStackTrace();
							} 
							}
				});
		    }
		    exec.shutdown();
		  }
}