并发控制(4) 使用CyclicBarrier来控制多线程的执行流程

并发控制(4) 使用CyclicBarrier来控制多线程的执行流程

简单理解就是，有A,B,C三个线程，主线程需要通过这3个线程加载制定的资源（流程），如果其中任意一个线程（资源）没有准备好，那都没有办法继续执行下去，这就是CyclicBarrier的作用，或者可以形象的理解为运动员比赛之前，需要统一准备好，才可以开始比赛

import java.io.IOException;  
import java.util.Random;  
import java.util.concurrent.BrokenBarrierException;  
import java.util.concurrent.CyclicBarrier;  
import java.util.concurrent.ExecutorService;  
import java.util.concurrent.Executors; 
public class UseCyclicBarrier {

    static class Runner implements Runnable {  
        private CyclicBarrier barrier;  
        private String name;  

        public Runner(CyclicBarrier barrier, String name) {  
            this.barrier = barrier;  
            this.name = name;  
        }  
        @Override  
        public void run() {  
            try {  
                Thread.sleep(1000 * (new Random()).nextInt(5));  
                System.out.println(name + " 准备OK.");  
                barrier.await();  
            } catch (InterruptedException e) {  
                e.printStackTrace();  
            } catch (BrokenBarrierException e) {  
                e.printStackTrace();  
            }  
            System.out.println(name + " Go!!");  
        }  
    } 

    public static void main(String[] args) throws IOException, InterruptedException {  
        CyclicBarrier barrier = new CyclicBarrier(3);  // 3 
        ExecutorService executor = Executors.newFixedThreadPool(3);  

        executor.submit(new Thread(new Runner(barrier, "zhangsan")));  
        executor.submit(new Thread(new Runner(barrier, "lisi")));  
        executor.submit(new Thread(new Runner(barrier, "wangwu")));  

        executor.shutdown();  
    }  

}