NSViewController not released

Question

I have a question on the ownership of windows vs view controllers and when they're released. I created a test project, and only added one line of code to the NSViewController:

deinit { print("ViewController Dismissed.") }

Why isn't this called when I close the window? I profiled it in Instruments and there aren't any memory leaks, but there is a reference to the ViewController still.

Also, I tried the "Release when closed" option on the NSWindow, still no dice. Can anyone help with understanding this? Thanks!!

Answer 1

I would have simply put this as a comment, but I don't have enough reputation:

Could there be a closure in your view controller that is maintaining a strong reference to your view controller or some object in your controller? That is one way a retain cycle can be created. If that was it, I would think it would show up in instruments, but it's just a thought.

Also, is your view controller part of any kind of larger navigation system, such as a tab bar controller? That could be a factor. I'm not sure.

Answer 2

As I know your running app always have the strong reference to a window instance, which in turn has the reference to a view controller. If you go to the Debug View Hierarchy after closing your window, you'll still see it there.If you remove storyboard entry point to that window in your storyboard, you wont have that window at all.