ANNOUNCE: GHC 6.10.2 Release Candidate 1

jutaro jnf at
Tue Mar 24 18:29:39 EDT 2009

This is the first answer I got from the gtk2hs mailing list. Please consider
this issue seriously.

Axel Simon wrote:
> Phew,
> I think we're doomed. We have many, many little methods that take a  
> user-given function, wrap it into a foreign export wrapper which is  
> freed by using an on-destroy callback to Haskell. These functions are  
> most likely installed into some widgets (or other reference-counted  
> objects) that will be eventually destroyed by the Haskell garbage  
> collector. So, basically, we can't easily change Gtk2Hs. It will  
> involve many modifications. I can understand that not allowing  
> callbacks during GC is a great simplification in the runtime but it  
> seemed to be common practice to free Stable and function pointers  
> from within Haskell using a callback.
> So, unless I'm wrong on why finalizers call back into Haskell land,  
> then this means that Gtk2Hs is fundamentally broken for the  
> foreseeable future.
> Axel.

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