如何中断从方法内部创建的线程? [英] How can I interrupt a thread created from within a method?

问题描述

我知道您可以中断从一个可运行类创建的线程，但是如何中断从方法创建的该线程呢?使用易失的布尔值对我不起作用，因此我认为有更好的方法可以做到这一点，或者我需要以某种方式打断它.我不想中断所有线程，仅此一个.

I know that you can interrupt a thread created from say a runnable class, but how can I interrupt this thread I created from a method? Using a volatile boolean isn't working for me, so I assume either there is a better way to do this, or I need to somehow interrupt it. I don't want to interrupt all threads, just this one.

我创建了一个启动像这样的线程的方法:

I created a method that kicks off a Thread like this:

public static void StartSyncThread() {
        new Thread() {
            public void run() {
                    isRunning = true;  // Set to true so while loop will start

                    while (isRunning) {
                        ...
                        }

            } // Close run()
        }.start();

    }

....

public static void KillSyncThread() {
    isRunning = false;
}

推荐答案

如果您保留对该线程的引用:

If you keep a reference to the thread:

private static Thread myThread;

public static void StartSyncThread() {
    myThread = new Thread() {
        public void run() {    
            while (!Thread.currentThread().isInterrupted()) {
                        ...
            }

        } // Close run()
    }
    myThread.start();
}

然后您可以致电

public static void killSyncThread() {
    if (myThread != null && myThread.isAlive()) {
        myThread.interrupt();
    }
}

取消.这样，您就可以摆脱静态的isRunning标志，interrupt()设置与之等效的内置标志，另外它将唤醒线程从睡眠或等待状态.

to cancel it. This way you can get rid of the static isRunning flag, interrupt() sets a built-in flag that's equivalent to that, plus it will wake the thread up from sleeping or waiting.

如果您确实确实将变量声明为volatile，则其更新值应该在线程之间可见.如果您正在测试的标志与您设置的标志不同，这可能是一个范围界定问题吗?在全局可变状态下，它似乎很快就会变得令人费解.举一个小例子，并亲自验证设置标志​​或中断线程是否有效，然后充满信心地寻找真正的问题.

If you really did declare the variable as volatile then its updated value should be visible across threads. Could be this is a scoping problem where the flag you're testing isn't the same as what you're setting? With global mutable state it seems likely it could get convoluted fast. Make a small example and verify for yourself that setting the flag or interrupting the thread works, then with that confidence you can look for the real problem.

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