How can I replace deprecated method dispatch_get_current_queue()? [duplicate]

Answer 1

How about using NSOperationQueue?

-(void) doSomeThing:(void (^)(BOOL success)) completionHandler
{
    NSOperationQueue* callbackQueue = [NSOperationQueue currentQueue];
    if(!callbackQueue) {
        callbackQueue = [NSOperationQueue mainQueue];
    }
    dispatch_async(...,^{
         // do heavyweight stuff here
         // then call completionHandler
         if(completionHandler) {
             [callbackQueue addOperationWithBlock:^{
                 completionHandler(...);
             }];
         }
    });