Android running on UI thread even when using worker thread

Question

I am using a worker thread, as described here but still the code is blocking the UI. If I sleep at the beginning of the run() method, it doesn't block the UI. The thing is, it's a heavy code that runs from the onCreate method, but no matter what I do, I can't make it not block the UI. What am I doing wrong?

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    new Thread(new Runnable() {
        @Override
        public void run() {
            for (int i = 0; i < 1000000; i++) {
                Log.d("asdf", "asdf");
            }
        }
    }).start();
}

Can we see some of the code you're expressing has a problem? — Justin Jasmann, Jan 21 '13 at 22:15
what makes you think that it is blocking the UI thread as is? — FoamyGuy, Jan 21 '13 at 22:20
@A--C, have you ever seen a thread in android? [here](http://android-developers.blogspot.de/2009/05/painless-threading.html) — vault, Jan 21 '13 at 22:26
hey, you're right... it's something else! back to the drawing board... thanks for your time — Kalisky, Jan 21 '13 at 22:28
@vault You're right, I have never seen a Thread in Android. Ty for the link! — A--C, Jan 21 '13 at 22:29
Thread is taking a new Runnable because that is one of the ways you create an anonymous thread in Java. I think the reason you are seeing degraded performance is that your thread is very CPU/storage intensive. Try placing a sleep in there to slow the loop down and I would think the UI would become more responsive. — Erik Nedwidek, Jan 21 '13 at 22:31
code seems to me correct..not sure why It is blocking UI in main thread. You should check other code too. — Jambaaz, Jan 22 '13 at 05:34

score 0 · Answer 1 · edited May 23 '17 at 12:12

0

You are not using an AsyncTask - which is the control Android uses to do long running processes off the UI thread.

Bottom line, use this and you will have much more success.

AsyncTask Android example

edited May 23 '17 at 12:12

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answered Jan 21 '13 at 22:16

Booger

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score 0 · Answer 2 · answered Jan 22 '13 at 02:14

Use Handler to or .runOnUiThread(runnable) to call your UI thread. You can execute your thread without the Runnable as well, like this:

new Thread(){
        @Override
        public void run() {
            for (int i = 0; i < 1000000; i++) {
                Log.d("asdf", "asdf");
            }
        }
    }).start();

Android running on UI thread even when using worker thread

2 Answers2