performSelectorInBackground called method slowing down main thread - can that be fixed?

Question

The client wrote a REST API for their website before ever starting on an app. it's a nice API, but it was designed to interact with a service that's running on the same network. The client didn't account for the fact that interaction over cellular data would take an exponentially longer amount of time than interaction on the same network, or even the same physical computer. Due to the fact that the client didn't account for this during server design, I am now left with an API that requires I transfer an entire object back and forth every single time the user changes 1 option. At first, it was slowing my main thread down by a ridiculous amount. So, I attempted to fix the problem by putting the API interaction on a background thread with a call to

[self performSelectorInBackground:]

This helped a great deal. However, the graphics are still a little bit choppy. The speed at which the data is transferred and returned isn't overly important, as long as it happens. I was wondering if there's a method of lowering the background thread's priority so that the graphics on the main thread aren't affected at all, or at least, very little. Is that possible?

Answer 1

By default, running a method on the background thread is lowering the priority below the main thread, so it should not be slowing the main (UI) thread. I would guess there is something else going on. I would venture that you are doing something else on the main thread that you are not aware of that is slowing down your "graphics". To check, try stubbing out your server calls, because there is almost no way that a download / parsing of data on the background thread would slow things to the point where the main thread would get hung and cause animations to stutter. The other possibility is that your animations are not done efficiently and are just choppy themselves.

You will need to be more specific with what you mean by the graphics being choppy to get a better answer, though.