Delay when unhiding UIButtons after presenting SKScene?

Question

I have encountered a delay/pause that I was not expecting and the reason so far has me scratching my head. I have a simple game setup where the UIViewController

Answer 1

With regards to preloadTextureAtlases:withCompletionHandler: the completionHandler gets called on a background thread, I would assume the same one that was used to preload the atlases. The problem that I was having was that I was using the completion handler to send an NSNotification to my viewController saying "the assets have loaded, start the game" The issue with this is that "Notifications are delivered in the same thread that they are sent from" so my game also started in the background thread. As a consequence the code that set the UIButtons to visible was also running on that same background thread, hence the delay in them reacting to either being made visible or hidden.