Calling another method from within a GCD queue

Question

If I do this:

dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0), ^{
[self someMethod];
 });

And someMethod is this:

-(void)someMethod{
  //doing stuff with no mention of GCD
 }

Will someMethod run inside the dispatch queue, or will that queue wait for someMethod to run on the main thread, since someMethod does not itself dispatch anything to other queues?

someMethod won't run on the main thread, and won't wait for anything on the main thread to finish either. It will run in a different thread which has a high priority. — Anurag
– Anurag, Commented Aug 20, 2012 at 4:03

Moshe · Accepted Answer · 2012-08-20 04:03:17Z

4

Methods are executed on the thread or queue from which they are invoked. So, if you wanted to update UI after processing data on a background queue, you'd need to explicitly execute your UI update on the main thread.

For example:

dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0), ^{
   [self someMethod];
});

- (void) someMethod{
    dispatch_async(dispatch_get_main_queue(), ^{
        // Update UI here
    });
}

answered Aug 20, 2012 at 4:03

Moshe

58.2k81 gold badges278 silver badges432 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Calling another method from within a GCD queue

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related