java的CyclicBarrier使用

 

假设有一个场景：每个线程代表一个跑步运动员，当运动员都准备好后，才一起出发，只要有一个人没有准备好，大家都等待。

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();  
    }  
  
}