Java - 在特定点上同步线程

Question

我需要在某个检查点同步一些线程，只有所有线程都到达这个点后，它们才应该继续。有什么简单的构造方法吗？

for (int v = 0; v < 10; v++) {
    new Thread(new Runnable() {
        @Override
        public void run() {
            try {

                doFirst();

                //checkpoint

                doSecond();

            } catch (Throwable e) {
                    e.printStackTrace();
            }
        }
    }).start();
}

Answer 1

import java.util.concurrent.CountDownLatch;
private CountDownLatch countDownLatch = new CountDownLatch(10)
...
public void run() {
    doFirst();
    countDownLatch.countDown();
    countDownLatch.await();
    doSecond();
}

---- 或(少 1 行代码)----

import java.util.concurrent.CyclicBarrier;
private CyclicBarrier cyclicBarrier= new CyclicBarrier(10)
...
public void run() {
    doFirst();
    cyclicBarrier.await();
    doSecond();
}