new]; ! ! ! // main printf(“1,"); ! [queue addOperationWithBlock:^{ printf("3"); }]; printf(“2,”); ! // results => 1,2,3 // prepare dispatch_queue_priority_t priority; dispatch_queue_t queue; ! priority = DISPATCH_QUEUE_PRIORITY_DEFAULT; queue = dispatch_get_global_queue(priority,0); ! // main printf(“1,"); ! dispatch_async(queue, ^{ printf("3"); }); printf(“2,”); ! // results => 1,2,3