Java CountDownLatch无法解锁?为什么最后一行不打印?
发布时间:2020-12-15 08:25:59 所属栏目:Java 来源:网络整理
导读:在countDown()之后,countDownLatch将不会等待到零.但该程序已被锁定.最后一次打印永不输出. public static void main(String[] args) throws Exception{ CountDownLatch countDownLatch = new CountDownLatch(1); countDownLatch.await(); new Thread(new Ru
在countDown()之后,countDownLatch将不会等待到零.但该程序已被锁定.最后一次打印永不输出.
public static void main(String[] args) throws Exception{ CountDownLatch countDownLatch = new CountDownLatch(1); countDownLatch.await(); new Thread(new Runnable() { @Override public void run() { countDownLatch.countDown(); countDownLatch.countDown(); } }).start(); System.out.println("------should print-------"); } 如果await方法在一个线程(不是主线程)中,它就可以工作.为什么? public static void main(String[] args) throws Exception { CountDownLatch countDownLatch = new CountDownLatch(1); new Thread(new Runnable() { @Override public void run() { try { countDownLatch.await(); } catch (InterruptedException e) { e.printStackTrace(); } } }).start(); new Thread(new Runnable() { @Override public void run() { countDownLatch.countDown(); countDownLatch.countDown(); } }).start(); System.out.println("------should print-------"); } 解决方法
在启动子线程之前,您正在调用await(并停止线程):
public static void main(String[] args) throws Exception{ CountDownLatch countDownLatch = new CountDownLatch(1); new Thread(new Runnable() { @Override public void run() { countDownLatch.countDown(); countDownLatch.countDown(); } }).start(); countDownLatch.await(); System.out.println("------should print-------"); } (编辑:李大同) 【声明】本站内容均来自网络,其相关言论仅代表作者个人观点,不代表本站立场。若无意侵犯到您的权利,请及时与联系站长删除相关内容! |