Continuously pass in data to AsyncTask?

Question

In my Android app, I have a snippet of code, similar to Run code for x seconds in Java?

long t= System.currentTimeMillis();
long end = t+15000;
while(System.currentTimeMillis() < end) {
//useful calculation
}

And this code will freeze the UI thread, so I'm wondering if there's a way to continuously pass in data to my AsyncTask that will do the calculation in the background thread to avoid freezing? Or is there a better way, or to keep calling AsyncTask from within my while loop?

Sounds like you want a Thread rather than an AsyncTask. If something should continually process in the background, a Thread is a better fit. AsyncTasks by default operate all on a single thread, so you shouldn't use one to do more than a few seconds worth of processing. Beyond that- what kind of data do you want to pass it, with what frequency? A normal way of doing this would be via a synchronized messaging queue. Passing data to a thread or task is possible, but easy to do wrong. — Gabe Sechan, Feb 27 '16 at 23:57
@GabeSechan I'm reading data (double) from a sensor, not a sensor on the phone, at very high frequency (at least to the eye), I'm not sure what, but it looks like 10Hz ish. Can you point me to a document or something? — Jasmine Rain, Feb 28 '16 at 00:24
A synchronized message queue with the sensor handler writing data to the queue and the thread reading (or waiting for data to be available) sounds about right to me. — Gabe Sechan, Feb 28 '16 at 00:26

score 0 · Answer 1 · answered Feb 28 '16 at 02:09

For this purpose, use a Handler instead.

It goes like this :

Handler timerHandler = new Handler();

Runnable timerRunnable = new Runnable() {

    @Override
    public void run() {
        //READ HERE WHAT YOU NEED FROM THE SENSOR (useful calculation)

        //And then set the next execution of the sensor reading
        timerHandler.postDelayed(this, 1000); //runs 1000 milliseconds
    }
};

//Launch It for the first time
timerHandler.post(timerRunnable);

//Whenever you would like to stop it, use the following commented line
//timerHandler.removeCallbacks(timerRunnable);

Continuously pass in data to AsyncTask?

1 Answers1