AsyncTask – Order of Execution / Versions

Order of execution

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[]) withTHREAD_POOL_EXECUTOR.