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Thread: Thread runs only once and not again

  1. #1
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    Question Thread runs only once and not again

    I have something like the following:

    class t_thread extends Thread {
     
            public t_thread() {
                new Thread(this).start();
            }
     
            @Override
            public void run() {
                // change some variables
                try {
                    Thread.sleep(1000);
                } catch (InterruptedException e) {}
            }
    }

    And I call it like:

    t_thread t = new t_thread();

    The problem is that, it runs once when it is created, sleeps, and never runs again. If I add a run() after sleep(1000), it works fine but eventually causes a Stack Overflow.

    Does anyone know why it does not continue to run until I stop it?


  2. #2
    Super Moderator Norm's Avatar
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    Default Re: Thread runs only once and not again

    why it does not continue to run
    Threads "run" until they exit the run() method. Your code exits immediately after sleeping.
    Why not use a loop in the run method if you want that thread to "run" again.

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    Super Moderator Json's Avatar
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    Default Re: Thread runs only once and not again

    Something like

            @Override
            public void run() {
                while(true) {
                    // change some variables
                    try {
                        Thread.sleep(1000);
                    } catch (InterruptedException e) {}
                }
            }

    You might want to think of a way you can interrupt this though, but it gives you a clue on how to do it.

    // Json

  5. #4
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    Default Re: Thread runs only once and not again

    Probably a better way so that it can get interrupted

    @Override
            public void run() {
                try {
                    while(true) {
                         // change some variables
                         Thread.sleep(1000);
                    } catch (InterruptedException e) {}
                }
            }

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