Java 8 - juc - CyclicBarrier

待我称王封你为后i 2023-10-11 22:42 37阅读 0赞

import java.util.concurrent.BrokenBarrierException;
    import java.util.concurrent.CyclicBarrier;
    
    /**
     * 当使用CyclicBarrier时，需要指定等待的线程数量。
     * 每个线程在到达屏障点后，调用await()方法通知CyclicBarrier已到达，并等待其他线程。
     * 当所有线程都到达屏障点后，屏障将被打破，所有线程可以同时继续执行。
     *
     * CyclicBarrier是可重用的，一旦所有线程到达屏障点并继续执行，CyclicBarrier会被重置，可以再次使用。
     */
    public class MyCyclicBarrierExample {
        
        public static void main(String[] args) {
        
            // 指定等待的线程数量为3
            CyclicBarrier barrier = new CyclicBarrier(3, () -> {
        
                System.out.println("All threads have reached the barrier. They can now proceed.");
            });
    
            // 创建并启动三个线程
            Thread thread1 = new Thread(new Worker2(barrier, "Worker 1"));
            Thread thread2 = new Thread(new Worker2(barrier, "Worker 2"));
            Thread thread3 = new Thread(new Worker2(barrier, "Worker 3"));
    
            thread1.start();
            thread2.start();
            thread3.start();
        }
    }
    
    class Worker2 implements Runnable {
        
        private final CyclicBarrier barrier;
        private final String name;
    
        public Worker2(CyclicBarrier barrier, String name) {
        
            this.barrier = barrier;
            this.name = name;
        }
    
        @Override
        public void run() {
        
            System.out.println(name + " has started.");
            // 模拟工作
            try {
        
                Thread.sleep(2000);
            } catch (InterruptedException e) {
        
                e.printStackTrace();
            }
            System.out.println(name + " has reached the barrier.");
            try {
        
                // 等待其他线程到达屏障点
                barrier.await();
                System.out.println(name + " continues execution.");
            } catch (InterruptedException | BrokenBarrierException e) {
        
                e.printStackTrace();
            }
        }
    }