Re: [Gc] Two-phase finalization?

* David Kastrup:

> Now the problem we encounter is that if some structure A points to B and
> some structure B points to A and both A and B are placed into
> finalization, then the finalization of A will delete the associated C++
> structure.  If now a mark pass is allowed through B, it will try to
> access the deleted C++ structure of A.
>
> Topological ordering will not do the trick since cyclical references are
> quite typical (a NoteHead has a reference to the corresponding Stem, a
> Stem has references to all corresponding NoteHeads).

Have all of them corresponding C++ objects?  Do you want the garbage
collector to devise a safe deallocation order, or does deallocation
happen by another mechanism?