title: AsyncTask threads never die
body: <p>I'm using <code>AsyncTask</code>s to fetch data in response to the user pressing a button. This works well and keeps the interface responsive while fetching the data, but when I checked out what was going on in the Eclipse debugger, I found out that every time a new <code>AsyncTask</code> was created (which is quite often, because they can only be used once), a new thread was being created but never terminated. </p>
  
  <p>The result is a large number of <code>AsyncTask</code> threads just sitting there. I'm not sure if this is a problem in practice or not, but I'd really like to get rid of those extra threads. </p>
  
  <p>How can I kill these threads?</p>