Java并发之CyclicBarrier 可重用同步工具类

 1 package com.thread.test.thread;
 2 
 3 import java.util.Random;
 4 import java.util.concurrent.*;
 5 
 6 /**
 7  * CyclicBarrier
 8  * 同步工具：允许一组线程共同等待一个壁垒点
 9  * 适用于固定数量线程的同步
10  * 等待线程释放后可以重复使用
11  * 
12  * Created by windwant on 2016/5/27.
13  */
14 public class MyCyclicBarrier {
15     public static void main(String[] args) {
16         ExecutorService es = Executors.newCachedThreadPool();
17         CyclicBarrier cb = new CyclicBarrier(5, new MainTask());//MainTask可选
18         Random r = new Random();
19         es.execute(new SubTask(cb, r.nextInt(10), "task1"));
20         es.execute(new SubTask(cb, r.nextInt(10), "task2"));
21         es.execute(new SubTask(cb, r.nextInt(10), "task3"));
22         es.execute(new SubTask(cb, r.nextInt(10), "task4"));
23         es.execute(new SubTask(cb, r.nextInt(10), "task5"));
24         es.shutdown();
25     }
26 }
27 
28 class MainTask implements Runnable {
29 
30     public void run() {
31         try {
32             System.out.println("mian task begin");
33             for (int i = 0; i < 5; i++) {
34                 Thread.sleep(1000);
35                 System.out.println("============" + i + "============");
36             }
37             System.out.println("mian task implemented");
38         } catch (Exception e) {
39             e.printStackTrace();
40         }
41 
42     }
43 }
44 
45 class SubTask implements Runnable{
46 
47     private CyclicBarrier cb;
48 
49     private int seconds;
50 
51     private String taskName;
52 
53     SubTask(CyclicBarrier cb, int seconds, String taskName){
54         this.cb = cb;
55         this.seconds = seconds;
56         this.taskName = taskName;
57     }
58 
59     public void run() {
60         try{
61             System.out.println("subtask " + taskName + " begin, need time: " + seconds + "s");
62             long b = System.currentTimeMillis();
63             for (int i = 0; i < seconds; i++) {
64                 Thread.sleep(1000);
65                 System.out.println("subtask: " + taskName + "============" + i + "============");
66             }
67             long d = System.currentTimeMillis() - b;
68             System.out.println("subtask " + taskName + " over, executing time: " + TimeUnit.SECONDS.convert(d, TimeUnit.MILLISECONDS));
69             cb.await();
70         } catch (InterruptedException e) {
71             e.printStackTrace();
72         } catch (BrokenBarrierException e) {
73             e.printStackTrace();
74         }
75     }
76 }