How do I terminate HandlerThreads?

Question

Following Googles examples for using a Service, I created a couple of threads like this. I can't use IntentService, because I'm doing something that involves waiting for callbacks.

However, I don't know how to terminate a Thread started in this manner. As I understand it, Threads automatically terminate when the run() method returns. However, this kind of thread doesn't have a run method. My Threads are leaking--they stay alive after stopSelf().

@Override
public void onCreate() {

    HandlerThread thread = new HandlerThread("ServiceStartArguments",
            android.os.Process.THREAD_PRIORITY_BACKGROUND);
    thread.start();
    HandlerThread thread2 = new HandlerThread("CallbackHandling",
            android.os.Process.THREAD_PRIORITY_BACKGROUND);
    thread2.start();

    mServiceLooper = thread.getLooper();
    mCallbackLooper = thread2.getLooper();
    mServiceHandler = new MyHandler(mServiceLooper);
    mCallbackHandler = new Handler(mCallbackLooper);
}

@Override
public int onStartCommand(Intent intent, int flags, int startId) {
    Toast.makeText(this, "service starting", Toast.LENGTH_SHORT).show();

    // For each start request, send a message to start a job and deliver the
    // start ID so we know which request we're stopping when we finish the job
    Message msg = mServiceHandler.obtainMessage();
    msg.arg1 = startId;
    mServiceHandler.sendMessage(msg);
    mMainThreadHandler=new Handler();
    // If we get killed, after returning from here, restart
    return START_STICKY;
}

private final class MyHandler extends Handler {
    public MyHandler(Looper looper) {
        super(looper);
    }
    @Override
    public void handleMessage(Message msg) {
        cycle();


        // Stop the service using the startId, so that we don't stop
        // the service in the middle of handling another job
        stopSelf(msg.arg1);
    }
}

protected void cycle() {
    ...
    mCallbackHandler.post(new Runnable(){
        public void run(){
            goAskForSomeCallbacks();
        }
    });

    try {
        Thread.sleep(GIVE_UP_TIME);
    } catch (InterruptedException e){
        //The callback will interrupt this thread to stop it from waiting
        Log.d(TAG,"Got early callback, stop waiting.");
    }
    Thread.interrupted(); //clear the interrupt
    doStuff(); 

}

Answer 1

You can also use the following recommended approach:

but be careful before using it because it cancels all pending jobs

handler.quitSafely();

Answer 2

Try calling the quit method on the corresponding Loopers.