package com.demo.test3;import java.util.concurrent.CountDownLatch;/** * @author QQ: 1236897 * *///闭锁//nThread - 线程数目//startGate -确保所有线程就绪-》countDown->所有线程工作//endGate - 等待所有线程完成工作后才返回timeTask方法public class CountDownLockTest {    /**     * @param args     */    public static void main(String[] args) {        // TODO Auto-generated method stub        Caller caller = new Caller();        MyTask task = new MyTask();        try {            System.out.println(caller.timeTask(5, task));        } catch (InterruptedException e) {            // TODO Auto-generated catch block            e.printStackTrace();        }    }}class Caller {    public long timeTask(int nThreads, final Runnable task)            throws InterruptedException {        final CountDownLatch startGate = new CountDownLatch(1);        final CountDownLatch endGate = new CountDownLatch(nThreads);        for (int i = 0; i < nThreads; i++) {            Thread t = new Thread() {                public void run() {                    try {                        System.out.println("startGate await");                        startGate.await();                        try {                            task.run();                        } finally {                            endGate.countDown();                        }                    } catch (InterruptedException e) {                    }                }            };            t.start();        }        long start = System.nanoTime();        System.out.println("startGate countDown");        startGate.countDown();        endGate.await();        long end = System.nanoTime();        System.out.println("return");        return end - start;    }}class MyTask implements Runnable {    /*     * (non-Javadoc)     *      * @see java.lang.Runnable#run()     */    @Override    public void run() {        // TODO Auto-generated method stub        System.out.println("id sleep: - " + Thread.currentThread().getId());        try {            Thread.sleep(5000);            System.out.println("Sleep done: - "                    + Thread.currentThread().getId());        } catch (InterruptedException e) {            // TODO Auto-generated catch block            Thread.currentThread().interrupt();        }    }}