[Chicken-users] Re: C hang Solved (was Re: Calling out to C causing hang)

[Felix Winkelmann]

Chris Double wrote:
> On Tue, 08 Apr 2003 01:10, Felix Winkelmann wrote:
>
> > Not exactly a problem, but you have to make ABSOLUTELY SURE
> > that the do_event() (in your example) is a `foreign-callback-lambda[*]'.
> > That's essential! `foreign-lambda*' is wrong.
>
>
> Well, how about that. I changed my call of do_event to use:
>
> (define wrapper-do-event
>         (foreign-callback-lambda void "do_event" c_pointer))
>
> When I call this things work perfectly. When I use the SWIG wrapper things 
> fail. I guess the SWIG wrapper doesn't know that it's going to call a Scheme 
> callback so it has no idea to do this.
>
> I guess there's no problem after all!
>
> I've now got multiple OpenGL windows running with background threads in the 
> interpreter still operating at the same time, yay!
>
> Many thanks for your help here Felix. I'm glad it was so easily sorted. While 
> I could be disappointed about the time I spent debugging, at least I learnt a 
> lot about the internals of the Chicken garbage collector!

Yep, sorry for that misunderstanding. I will ask Jonah to
add a note in the SWIG docs about callbacks.


cheers,
felix