Premature exit from dispatch_asycn , Grand Central Dispatch

Question

Lets say i am running some code in dispatch async. .. is there a way to terminate the thread it creates before it completes? like when the user clicks cancel

dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{

    //start doing something here.. break bofore it finishes? 


    dispatch_async(dispatch_get_main_queue(), ^{

    //main thread stuff..   

    });



});

possible duplicate of [Dispatch queues: How to tell if they're running and how to stop them.](http://stackoverflow.com/questions/1550658/dispatch-queues-how-to-tell-if-theyre-running-and-how-to-stop-them) — David Gelhar, Oct 26 '10 at 03:04
Yep, set a flag to request cancellation, and have your async operation check the cancellation status at designated points where it's safe to cancel (making sure to do any necessary cleanup). — David Gelhar, Oct 26 '10 at 03:23
Click here for a full discussion .. http://stackoverflow.com/questions/5449469/can-you-use-cancel-iscancelled-with-gcd-dispatch-async — Fattie, Mar 27 '11 at 20:53

Ryan · Accepted Answer · 2012-06-21T19:01:32.730

3

David is right. GCD has no built-in method of cancellation. It is up to the client (you).

edited Jun 21 '12 at 19:01

answered Nov 06 '10 at 07:03

Ryan

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Premature exit from dispatch_asycn , Grand Central Dispatch

1 Answers1