CountDownLatch 使用 示例

public class TestCountDownLatch {

    public static void main(String[] args) throws InterruptedException {
        long start = System.currentTimeMillis();
        CountDownLatch countDownLatch = new CountDownLatch(10);
        CountDownLatchDemo latch = new CountDownLatchDemo(countDownLatch);
        for (int i = 0; i < 10 ; i++) {
           new Thread(latch).start();
        }
        // 等待其他線程
        countDownLatch.await();
        long end = System.currentTimeMillis();

        System.out.println("耗費時間爲：" + (end - start));
    }

}

class  CountDownLatchDemo implements  Runnable {

    private CountDownLatch countDownLatch;

    public CountDownLatchDemo(CountDownLatch countDownLatch) {
        this.countDownLatch = countDownLatch;
    }

    @Override
    public void run() {
        synchronized (this) {
            try {
                for (int i = 0; i < 100000 ; i++) {
                    System.out.println(i);
                }
            } finally {
                // 對應線程數量減一
                countDownLatch.countDown();
            }
        }
    }
}