并发包同步工具CyclicBarrier

Posted 2020-09-19

/**
 * 
 * @描述: 同步工具
 * 表示大家彼此等待，大家集合好后才开始出发，分散活动后又在指点地点集合碰合 .
 * @作者: Wnj .
 * @创建时间: 2017年5月16日 .
 * @版本: 1.0 .
 */
public class CyclicBarrierTest {
    
    public static void main(String[] args) {
        ExecutorService service = Executors.newCachedThreadPool();
        //要有三个线程到了才走
        final CyclicBarrier cb = new CyclicBarrier(3);
        for (int i = 0; i < 3; i++) {
            Runnable runnable = new Runnable() {
                public void run() {
                    try {
                        Thread.sleep((long)(Math.random() * 10000));
                        
                        
                        System.out.println("线程" + Thread.currentThread().getName() + "即将到达集合地点1，当前已有" 
                        + (cb.getNumberWaiting() + 1) + "个已经到达，" + (cb.getNumberWaiting() == 2 ? "都到齐了，继续走啊" : "正在等候"));
                        //三个线程的第N个线程等待
                        cb.await();
                        
                        Thread.sleep((long)(Math.random() * 10000));
                        System.out.println("线程" + Thread.currentThread().getName() + "即将到达集合地点2，当前已有" 
                        + (cb.getNumberWaiting() + 1)
                            + "个已经到达，" + (cb.getNumberWaiting() == 2 ? "都到齐了，继续走啊" : "正在等候"));
                        
                        //三个线程的第N个线程等待
                        cb.await();
                        Thread.sleep((long)(Math.random() * 10000));
                        System.out.println("线程" + Thread.currentThread().getName() + "即将到达集合地点3，当前已有"
                        + (cb.getNumberWaiting() + 1)
                            + "个已经到达，" + (cb.getNumberWaiting() == 2 ? "都到齐了，继续走啊" : "正在等候"));
                        
                        //三个线程的第N个线程等待
                        cb.await();
                    }
                    catch (Exception e) {
                        e.printStackTrace();
                    }
                }
            };
            service.execute(runnable);
        }
        service.shutdown();
    }
}