title: asynctask doInBackgound() not running if there's a asynctask already running
body: <p>When the user logs in into my app. I am starting an <code>asynctask</code> to maintain the user session. And that async task is running indefinitely till the user logs out. My problem is that when I try to start other <code>asynctasks</code>, their <code>doInBackground()</code> method is never executed. </p>
  
  <p>I read somewhere that if an async task is already running, we cannot start new <code>async task</code>. I can confirm this because when i removed the user session async task, it worked properly. Is there a workaround?</p>
  
  <p>P.S.: I have already used <code>executeOnExecutor()</code> method. but it didn't help.</p>