AsyncTask not running asynchronously

Question

The following were supposed to be the same if I am not mistaking.
Using AsyncTask:

private class GetDataTask extends AsyncTask<String, Void, String>{

    @Override
    protected void onPreExecute() {

    }

    @Override
    protected String doInBackground(String... params) {
        return NetConnection.getRecordData(mUserId, mUserPassword);
    }

    @Override
    protected void onPostExecute(String result) {
        parseJson(result);
    }
}

Using a Thread:

    new Thread( new Runnable() {

        @Override
        public void run() {
            String res = NetConnection. getRecordData(mUserId, mUserPassword);
            parseJson(res);

        }
    }).start();

But when uploading a file, the AsyncTask runs synchronously while the Thread run asynchronously(in parallel).
Why is so? Why AsyncTask behaves like this? Isn't AsyncTask supposed to run asynchronously?
I am little confused so I need your help.
This is how I invoke the GetDataTask:

new GetDataTask().execute()

I prefer using AsyncTask but it is not doing the job for me. Please refer to my early question for more details

Answer 1

As of 4.x calling 2 AsyncTasks will cause them to be executed serially.

One way to fix this is using the following code

if (Build.VERSION.SDK_INT>=Build.VERSION_CODES.HONEYCOMB) {
  myTask.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
}
else {
  myTask.execute();
}

You can read more at: http://commonsware.com/blog/2012/04/20/asynctask-threading-regression-confirmed.html