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();

			}

		}

	}

}