CyclicBarrier用法

1.简介

    通俗点讲就是一组线程相互等待，直到临界点。具体可查官方文档
    注意:CountDownLatch是一组线程或一个线程等待另一组线程

2.小栗子

public class CyclicBarrierDemo {

    private static final int CYCLIC_BARRIER_COUNT = 2;
    private static final int THREAD_COUNT = 4;

    public static void main(String[] args) {
        CyclicBarrier cyclicBarrier = new CyclicBarrier(CYCLIC_BARRIER_COUNT, ()->{
            System.out.println("达到临界点");
        });

        ExecutorService executorService = Executors.newFixedThreadPool(THREAD_COUNT);
        for (int index = 0; index < THREAD_COUNT; index ++) {
            executorService.execute(()->{
                try {
                    System.out.println("ThreadId:" + Thread.currentThread().getId());
                    Thread.sleep(2000);
                    int await = cyclicBarrier.await();
                    System.out.println("await:" + await);
                    System.out.println("ThreadId:" + Thread.currentThread().getId());
                } catch (Exception e) {
                    e.printStackTrace();
                }
            });
        }
        executorService.shutdown();
    }
}