Question

I work for my license project, and one part consist in an android client. All was ok, until I upgraded my phone to Android 4.0.4.

So, I have one AsyncTask. It looks like this:

public class TestTask extends AsyncTask<Context, Integer, Long> {

@Override
protected Long doInBackground(Context... params) {
    for (int i = 0; i < 10; i++) {
        System.out.println("nothing-" + i);
        if (i == 5) {
            TestTask2 testTask2 = new TestTask2();
            testTask2.execute(null);
        }
        try {
            Thread.sleep(1000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
    return null;
}

}

This task wait 5 seconds, than it calls another async task, TestTask2.

public class TestTask2 extends AsyncTask<Context, Integer, Long> {

@Override
protected Long doInBackground(Context... params) {
    System.out.println("task 2 in action");
    return null;
}

}

In android 4.0.3 or lower, the output is:

nothing-0 nothing-1 nothing-2 nothing-3 nothing-4 nothing-5

task 2 in action

nothing-6 nothing-7 nothing-8 nothing-9

When I upgraded to 4.0.4, the second task doesn’t start until the first finished its job.

nothing-0 nothing-1 nothing-2 nothing-3 nothing-4 nothing-5 nothing-6 nothing-7 nothing-8 nothing-9
task 2 in action

Is there any thread policy in android 4.0.4, or something else? what could be the problem?

Answer 1

Thanks for the question. Apparently the default behavior has changed:
https://groups.google.com/d/msg/android-developers/8M0RTFfO7-M/JZSHiOz9bPgJ

You can get the old behavior by changing this:

testTask2.execute(null);

to this:

testTask2.executeOnExecutor(THREAD_POOL_EXECUTOR, null);