Running and managing NSTimer in different NSThread/NSRunLoop
- by mips
I'm writing a Cocoa application, with a GUI designed in Interface Builder. I need to schedule background activity (at regular intervals) without blocking the UI, so I run it in a separate thread, like this:
- (void)applicationDidFinishLaunching:(NSNotification *)aNotification {
[self performSelectorInBackground:@selector(schedule) withObject:nil];
}
- (void) schedule {
NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
NSRunLoop* runLoop = [NSRunLoop currentRunLoop];
timer = [[NSTimer scheduledTimerWithTimeInterval:FEED_UPDATE_INTERVAL
target:activityObj
selector:@selector(run:)
userInfo:nil
repeats:YES]
retain];
[runLoop run];
[pool release];
}
I retain the timer, so I can easily invalidate and reschedule.
Problem: I must also fire the run: method in response to GUI events, so it is synchronous (i.e. a "perform activity" button). Like this:
[timer fire];
I could do this with performSelectorInBackground too, and of course it doesn't block the UI. But this synchronous firings run in another runloop! So I have no guarantee that they won't overlap. How can I queue all of my firings on the same runloop?
