Multiple AsyncTask vs multiple requests within one AsyncTask

Question

I'm following this tutorial to create an XML reader with options to download multiple feeds at once. Are there any downsides to executing multiple AsyncTasks (max 3) simultaneously? I'm going to add a timer to check if they finished.

Answer 1

They won't be run simultaneously, but serially. See here:

When first introduced, AsyncTasks were executed serially on a single background thread. Starting with DONUT, this was changed to a pool of threads allowing multiple tasks to operate in parallel. Starting with HONEYCOMB, tasks are executed on a single thread to avoid common application errors caused by parallel execution.

If you truly want parallel execution, you can invoke executeOnExecutor(java.util.concurrent.Executor, Object[]) with THREAD_POOL_EXECUTOR

Answer 2

Running multiple AsyncTasks at the same time -- not possible? It is possible. However it could be, that due to the cpu depending on each device, one is faster than the other. But as @Alex already answered, you wont get "real" multitasking. Haven't it tried yet I would assume, that doing it all in one AsyncTask is faster. And you could reuse the connection you established to the server.

Answer 3

For better architecture I'll choose 1 AsyncTask per request. It is easier to manage actual request. Also it would be easier to modify (add/remove request).

Downsides of executing multiple AsyncTasks depend on your knowledge of AsyncTask lifecycle. You need to execute it correctly (depends on android version).

Good article about the dark side of Async tasks http://bon-app-etit.blogspot.com.by/2013/04/the-dark-side-of-asynctask.html