学习多线程6---栅栏

CyclicBarrier用于模拟所有线程都到达一个临界条件后在进行下一步，CyclicBarrier使用在run函数里面

下面是一个使用例子

package com.condition;

import java.util.concurrent.BrokenBarrierException;
import java.util.concurrent.CyclicBarrier;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class CyclicBarrierTest {

	public static void main(String[] args) {
		ExecutorService threadPool = Executors.newCachedThreadPool();
		final CyclicBarrier cb = new CyclicBarrier(3);
		for(int i = 0; i < 3;i++){
			Runnable runnable = new Runnable(){
				@Override
				public void run() {
					try {
						Thread.sleep((long) (Math.random()*10000));
					} catch (InterruptedException e) {
						// TODO Auto-generated catch block
						e.printStackTrace();
					}
					System.out.println(1+Thread.currentThread().getName()
						+" 当前已有 "+cb.getNumberWaiting());
					try {
						cb.await();
					} catch (InterruptedException e) {
						// TODO Auto-generated catch block
						e.printStackTrace();
					} catch (BrokenBarrierException e) {
						// TODO Auto-generated catch block
						e.printStackTrace();
					}
					try {
						Thread.sleep((long) (Math.random()*10000));
					} catch (InterruptedException e) {
						// TODO Auto-generated catch block
						e.printStackTrace();
					}
					System.out.println(2+Thread.currentThread().getName()
						+" 当前已有 "+cb.getNumberWaiting());
					try {
						cb.await();
					} catch (InterruptedException e) {
						// TODO Auto-generated catch block
						e.printStackTrace();
					} catch (BrokenBarrierException e) {
						// TODO Auto-generated catch block
						e.printStackTrace();
					}
				}
			};
			 threadPool.execute(runnable);
		}
	}

}