One-off timer with GCD on high priority thread #concurrency #GCD #objective-c #advanced

gcd_one_off_timer.m

    
    dispatch_source_t _timer;
    
    _timer = dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER, 0, 0, dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0));
    dispatch_source_set_timer(_timer,
                              dispatch_walltime(NULL, <#timeout#> * NSEC_PER_SEC),
                              1 * NSEC_PER_SEC, // this doenst really matter
                              <# 0.01 (tolerance) #> * NSEC_PER_SEC); 
    dispatch_source_set_event_handler(_timer, ^{
        dispatch_source_cancel(_timer);  // cancel the repeat
        
        // YOUR STUFF
        
    });
    
    dispatch_resume(_timer);