Question

Are fragments running on a separate thread than the activity they were created on?

So let’s say I have a fragment that calls a web-service synchronously, does it also block my main activity while retrieving data from the server?

Answer 1

I would assume they’re on the UI thread, since Android makes such a big deal keeping UI actions on the UI thread. When calling commit(), those transactions are definitely performed on the UI thread, as stated in the documentation.

Seems like you could test it pretty easily with

Log.d("Fragment", "thread = " + Thread.currentThread().getName());

If it’s on thread ‘main’, then it’s on the UI thread.