Asynchronous vs Synchronous vs Threading in an iPhone App

Question

I\'m in the design stage for an app which will utilize a REST web service and sort of have a dilemma in as far as using asynchronous vs synchronous vs threading. Here\'s the sce

Answer 1

I would use dispatch_async with synchronous. This way, you have the advantage of no delegates/NSNotifications and it is non-blocking

- (NSArray *)users {
    if(users == nil) {
        users = do_sync_request();
    }

    return users;
}

// now when calling the users method, do this

- (NSArray *)getUsers {
     dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
           NSArray *users = [self users];
           dispatch_sync(dispatch_get_main_queue(), ^{
                 return users;
           }
     }
}