AsyncTask execute() or executeOnExecutor()?

Question

What's the difference between using execute() and executeOnExecuter()?

• How does execute() execute tasks by default? (in serial or in parallel?)

• What should be used for new SDKs >16?

• Is it a good practice to use parallel execution (THREAD_POOL_EXECUTOR) for tasks rather than serial even if it doesn't matter for the application or does that depends on the number of AsyncTasks that will be executed?

Answer 1

.execute() - this function schedules the task on a queue for a single background thread. Means that if you are calling two AsyncTasks and using .execute() method to call them, they will execute in a queue(first then second).

.executeOnExecutor() - If you want parallel execution of both AsyncTasks, you can use this method for execution of AsyncTask. Means both asyncTasks will execute simultaneously.

In simple words: .execute() method creates a single thread for execution of asyncTasks, and .executeOnExecuter() method creates separate thread for each ayncTask.

.execute executes tasks by default in serial order.

EDITED: If you want to use executeOnExecutor() you can use this code:

if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB)
     task.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
 else
     task.execute();

Before HONEYCOMB execute() method run AsynkTask in parallel.