Hi,
It's a bug and your workaround is correct. I'll fix this right away.
On Fri, Jun 26, 2009 at 9:27 AM, Jayesh Salvi<jayeshsa...@gmail.com> wrote:
> Hi,
>
> I am replacing the multithreaded code in my app with the AsyncTask from 1.5.
> I found that two AsyncTasks do not work concurrently. I investigated a bit
> and found a workaround; I would like second opinion if my solution is right.
> OR if there is a better solution.
>
> AsyncTask allows the app to do a task on a thread other than the UI thread.
> But IIUC, it only provides a single thread on which a queue of tasks is
> performed. Therefore, if one of the task is to wait on some event (n/w or
> sleep) then all other tasks will wait for it to finish.
>
> To elaborate with the coding example:
> <code>
>
> public class MyTask extends AsyncTask<...>
> { ... }
>
> // On the UI thread execute two tasks
> MyTask mt1 = new MyTask().execute(args);
>
> MyTask mt2 = new MyTask().execute(args);
>
> </code>
>
> In the above code both the execute calls will return immediately and free up
> the UI thread; however mt1 will be executed first and mt2 will have to wait
> until mt1 finishes.
>
> Thanks to the android's open source, we can see implementation of AsyncTask.
> http://google.com/codesearch/p?hl=en&sa=N&cd=2&ct=rc#uX1GffpyOZk/core/java/android/os/AsyncTask.java&q=lang:java%20AsyncTask
>
> I copied AsyncTask.java as UserTask.java in my project and changed the value
> of CORE_POOL_SIZE to 5. This makes the thread pool to use 5 threads to
> multiplex the queued AsyncTasks. This indeed solved my problem. Now if mt1
> blocks on a sleep; mt2 goes ahead and finishes its job.
>
> Here are some questions for those who know more about AsyncTask
> implementation:
>
> Is this work-around right?
> If yes, can the CORE_POOL_SIZE be made configurable in future, via an API
> call?
> Is there a solution by which multiple thread pools can be used?
>
> Let me add that, I am aware that this is a phone and not a web server - I am
> not using 10s of threads to do network I/O. However a single thread is not
> sufficient for my app either.
>
> Please let me know. Thanks in advance.
>
> Jayesh
>
> >
>
--
Romain Guy
Android framework engineer
romain...@android.com
Note: please don't send private questions to me, as I don't have time
to provide private support. All such questions should be posted on
public forums, where I and others can see and answer them
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