执行interrupted()后park()失效的问题

[GechangLiu]

先执行interrupted()方法可以得到预期结果，线程的中断标记被清空，park()可以正常阻塞线程

    private static void test4() {
        Thread t1 = new Thread(() -> {
            for (int i = 0; i < 5; i++) {
                log.debug("park...");
                LockSupport.park();
                log.debug("打断状态：{}", Thread.interrupted());
                log.debug("打断状态：{}", Thread.currentThread().isInterrupted());
            }
        });
        t1.start();


        sleep(1);
        t1.interrupt();
    }

运行结果

14:59:59.983 c.TestInterrupt [Thread-0] - park...
15:00:00.982 c.TestInterrupt [Thread-0] - 打断状态：true
15:00:00.983 c.TestInterrupt [Thread-0] - 打断状态：false
15:00:00.983 c.TestInterrupt [Thread-0] - park...

如果是先运行isInterrupted()方法，那么park()需要到下次interrupted()的时候才会阻塞线程

    private static void test4() {
        Thread t1 = new Thread(() -> {
            for (int i = 0; i < 5; i++) {
                log.debug("park...");
                LockSupport.park();
                log.debug("打断状态：{}", Thread.currentThread().isInterrupted());
                log.debug("打断状态：{}", Thread.interrupted());
            }
        });
        t1.start();


        sleep(1);
        t1.interrupt();
    }

运行结果

15:05:34.855 c.TestInterrupt [Thread-0] - park...
15:05:35.853 c.TestInterrupt [Thread-0] - 打断状态：true
15:05:35.854 c.TestInterrupt [Thread-0] - 打断状态：true
15:05:35.855 c.TestInterrupt [Thread-0] - park...
15:05:35.855 c.TestInterrupt [Thread-0] - 打断状态：false
15:05:35.855 c.TestInterrupt [Thread-0] - 打断状态：false
15:05:35.855 c.TestInterrupt [Thread-0] - park...

[编程菜农]

interrupt() 改变了标志位，Thread.interrupted()静态方法会得到标志位同时置标志位为false，而成员方法的interrupted（）并不会置回false；park在中断标志位为true的时候是失效的