Estevo,

To get where you are at now - at the current point, are you happy with what Gambit does right now, or are you still seeing an issue?

If so, can you provide like a three-line example illustrating the problem and how it could be resolved?

Happy Holidays,
Mikael




2013/12/24 Estevo <euccastro@gmail.com>
>> I've experimented in the past with making a macro that would generate the
>> appropriate ffi code to create and manage c structs/unions/types.  The
>> challenge was to handle references obtained from accessors to fields
>> containing other structs/union/types within them in such a way that
>> - no copying was necessary, and
>> - the original structure wouldn't be released as long as derived references
>> existed
>
> Anyone know what guile does?  If anything?
>
> -- hendrik

Well, I was interested in how to make it work in Gambit as is.  If we consider modifications to Gambit, there is an easy solution: give foreign objects a 'data' field that holds a user-settable strong reference to a Scheme object.  Then, whenever you need to make sure that object A is not reclaimed while foreign object B is reachable, you just say (foreign-data-set! B A).

Indeed, after having tried hard, my current impression is that the above can't be done in a way that is robust and seamless to the user without modifying Gambit.  I'd be very happy to be proven wrong in this!

I have made a pull request proposing that change:

https://github.com/feeley/gambit/pull/59

but I don't know whether the cost of one extra pointer per foreign object is a showstopper here.

_______________________________________________
Gambit-list mailing list
Gambit-list@iro.umontreal.ca
https://webmail.iro.umontreal.ca/mailman/listinfo/gambit-list