Model life managment

Question

i have a Model and class - Factory which creates, load and save this model. I want completely release all references to this Model save and dispose, but i don't know how can i tell all classes who keep references to Model release it. I only see 2 solutions:

1. Return from Factory WeakReference to Model and keep strong reference only in Factory but i have no guarantee that Model will be destroyed right after releasing last strong reference.
2. Send some notifications from Model or to classes who owns Model to release reference.

Answer 1

If it's not technically about lifetime of the memory used, you could have a flag in the model, that you set once it's supposed to be destroyed. All operations of the model would check this flag and throw an exception if it's set, so it's unusable afterwards.

Some classes do this in their Disposable implementation, where you get an AlreadyDisposedException when you call methods after disposing it.