t.interrupt() 问题

Question

本帖最后由 jn0115 于 2014-05-30 22:59:38 编辑

Answer 1

刚对线程有些研究，Thread2没有自己中断的可能无法释放锁所以应该是死锁了，只能强制终止。调用thread1的interrupt方法可以改变线程的中断状态，但是由于没有获得锁无法抛出InterruptedException异常。就像notify一样，只有退出同步块放弃了锁才能唤醒一个等待的线程。个人观点，可能有误。
测试的代码：public class Interrupt {
    Object lock = new Object();    public static void main(String[] args) throws InterruptedException {
        new Interrupt().foo();
    }    Thread thread1;
    Thread thread2;    private void foo() throws InterruptedException {
        thread1 = new Thread1();
        thread2 = new Thread2();
        thread1.start();
        thread2.start();
        new Thread() {
            {
                setDaemon(true);
            }            @Override
            public void run() {
                boolean b1 = false;
                boolean b2 = false;
                while (true) {
                    if (b1 != (b1 = thread1.isInterrupted()))
                        System.out.println("thread1.isInterrupted()" + thread1.isInterrupted());                    if (b2 != (b2 = thread2.isInterrupted()))
                        System.out.println("thread2.isInterrupted()" + thread2.isInterrupted());
                    try {
                        Thread.sleep(10);
                    } catch (InterruptedException e) {}
                }
            }
        }.start();        try {
            Thread.sleep(5000);
        } catch (InterruptedException e) {}
        thread2.interrupt();
        // thread2.stop();
    }
    class Thread1 extends Thread {
        @Override
        public void run() {
            boolean once = true;
            synchronized (lock) {
                for (int i = 0; i < 10; i++) {
                    System.out.println("Thread1 running.");
                    if (once) {
                        once = false;
                        try {
                            lock.wait();
                        } catch (InterruptedException e) {
                            System.out.println("wait interrupted,isInterrupted=false");
                        }
                    }
                    try {
                        Thread.sleep(500);
                    } catch (InterruptedException e) {}
                }
            }
        }
    }
    class Thread2 extends Thread {
        @Override
        public void run() {
            boolean once = true;
            synchronized (lock) {
                while (true) {
                    System.out.println("Thread2 running");
                    try {
                        Thread.sleep(500);
                        if (once) {
                            once = false;
                            System.out.println("Interrupt Thread1.");
                            thread1.interrupt();
                            // lock.notify();
                        }
                    } catch (InterruptedException e) {
                        System.out.println("Thread2 end.");
                        return;
                    }
                }
            }
        }
    }
}

Answer 2

Thread1 running.
Thread2 running
Interrupt Thread1.
Thread2 running
thread1.isInterrupted()true
Thread2 running
Thread2 running
Thread2 running
Thread2 running
Thread2 running
Thread2 running
Thread2 running
Thread2 running
Thread2 end.
wait interrupted,isInterrupted=false
thread1.isInterrupted()false
Thread1 running.
Thread1 running.
Thread1 running.
Thread1 running.
Thread1 running.
Thread1 running.
Thread1 running.
Thread1 running.
Thread1 running.