Java多线程系列--“JUC锁”10之 CyclicBarrier原理和示例(三)
erException e) {
28 e.printStackTrace();
29 } catch (InterruptedException e) {
30 e.printStackTrace();
31 }
32 }
33 }
34 }
复制代码
运行结果：
复制代码
Thread-1 wait for CyclicBarrier.
Thread-2 wait for CyclicBarrier.
Thread-3 wait for CyclicBarrier.
Thread-4 wait for CyclicBarrier.
Thread-0 wait for CyclicBarrier.
Thread-0 continued.
Thread-4 continued.
Thread-2 continued.
Thread-3 continued.
Thread-1 continued.
复制代码
结果说明：主线程中新建了5个线程，所有的这些线程都调用cb.await()等待。所有这些线程一直等待，直到cb中所有线程都达到barrier时，这些线程才继续运行！
示例2
新建5个线程，当这5个线程达到一定的条件时，执行某项任务。
复制代码
1 import java.util.concurrent.CyclicBarrier;
2 import java.util.concurrent.BrokenBarrierException;
3
4 public class CyclicBarrierTest2 {
5
6 private static int SIZE = 5;
7 private static CyclicBarrier cb;
8 public static void main(String[] args) {
9
10 cb = new CyclicBarrier(SIZE, new Runnable () {
11 public void run() {
12 System.out.println("CyclicBarrier's parties is: "+ cb.getParties());
13 }
14 });
15
16 // 新建5个任务
17 for(int i=0; i
18 new InnerThread().start();
19 }
20
21 static class InnerThread extends Thread{
22 public void run() {
23 try {
24 System.out.println(Thread.currentThread().getName() + " wait for CyclicBarrier.");
25
26 // 将cb的参与者数量加1
27 cb.await();
28
29 // cb的参与者数量等于5时，才继续往后执行
30 System.out.println(Thread.currentThread().getName() + " continued.");
31 } catch (BrokenBarrierException e) {
32 e.printStackTrace();
33 } catch (InterruptedException e) {
34 e.printStackTrace();
35 }
36 }
37 }
38 }
复制代码
运行结果：
复制代码
Thread-1 wait for CyclicBarrier.
Thread-2 wait for CyclicBarrier.
Thread-3 wait for CyclicBarrier.
Thread-4 wait for CyclicBarrier.
Thread-0 wait for CyclicBarrier.
CyclicBarrier's parties is: 5
Thread-0 continued.
Thread-4 continued.
Thread-2 continued.
Thread-3 continued.
Thread-1 continued.
复制代码
结果说明：主线程中新建了5个线程，所有的这些线程都调用cb.await()等待。所有这些线程一直等待，直到cb中所有线程都达到barrier时，执行新建cb时注册的Runnable任务。