Java并发之CyclicBarrier 可重用同步工具类

 package com.thread.test.thread;

 import java.util.Random;
 import java.util.concurrent.*;

 /**
  * CyclicBarrier
  * 同步工具：允许一组线程共同等待一个壁垒点
  * 适用于固定数量线程的同步
  * 等待线程释放后可以重复使用
  *
  * Created by windwant on 2016/5/27.
  */
 public class MyCyclicBarrier {
     public static void main(String[] args) {
         ExecutorService es = Executors.newCachedThreadPool();
         CyclicBarrier cb = new CyclicBarrier(5, new MainTask());//MainTask可选
         Random r = new Random();
         es.execute(new SubTask(cb, r.nextInt(10), "task1"));
         es.execute(new SubTask(cb, r.nextInt(10), "task2"));
         es.execute(new SubTask(cb, r.nextInt(10), "task3"));
         es.execute(new SubTask(cb, r.nextInt(10), "task4"));
         es.execute(new SubTask(cb, r.nextInt(10), "task5"));
         es.shutdown();
     }
 }

 class MainTask implements Runnable {

     public void run() {
         try {
             System.out.println("mian task begin");
             for (int i = 0; i < 5; i++) {
                 Thread.sleep(1000);
                 System.out.println("============" + i + "============");
             }
             System.out.println("mian task implemented");
         } catch (Exception e) {
             e.printStackTrace();
         }

     }
 }

 class SubTask implements Runnable{

     private CyclicBarrier cb;

     private int seconds;

     private String taskName;

     SubTask(CyclicBarrier cb, int seconds, String taskName){
         this.cb = cb;
         this.seconds = seconds;
         this.taskName = taskName;
     }

     public void run() {
         try{
             System.out.println("subtask " + taskName + " begin, need time: " + seconds + "s");
             long b = System.currentTimeMillis();
             for (int i = 0; i < seconds; i++) {
                 Thread.sleep(1000);
                 System.out.println("subtask: " + taskName + "============" + i + "============");
             }
             long d = System.currentTimeMillis() - b;
             System.out.println("subtask " + taskName + " over, executing time: " + TimeUnit.SECONDS.convert(d, TimeUnit.MILLISECONDS));
             cb.await();
         } catch (InterruptedException e) {
             e.printStackTrace();
         } catch (BrokenBarrierException e) {
             e.printStackTrace();
         }
     }
 }

项目地址：https://github.com/windwant/windwant-demo/tree/master/thread-demo