objective c - iPhone SDK Background threads calling other methods -

i seemingly straightforward question can't seem find answer (and hindering app).

i have background thread running paricular method:

-(void)processimage:(uiimage *)image {    nsautoreleasepool * pool = [[nsautoreleasepool alloc] init];    //process image here in background here    [pool drain]; } 

this works great, question comes when want call method inside already-background method. call stay in background? need add nsautoreleasepool * pool = [[nsautoreleasepool alloc] init]; , [pool drain]; new method make run in background well?

any advice helpful. bit confused this.

many thanks, brett

it stay in background, on same thread called from.

some threading notes consider this:

• it may not obvious, if call timer background thread, , thread exits before timer supposed go off, timer not called. recommended setup timers main thread
• you dont need autorelease pool unless spawn thread.
• any ui updates should done on main thread