On Sun, 2011-05-22 at 23:19 -0700, Luke Crook wrote: > On Sun, May 22, 2011 at 2:10 PM, Luís Oliveira <luis...@gmail.com> wrote: > > > On Sat, May 21, 2011 at 1:21 AM, Luke Crook <l...@balooga.com> wrote: > > > I think the problem is that CFFI does not allow memory to be freed if > > that > > > memory has not also been allocated using CFFI. > > > > Indeed, you shouldn't call FOREIGN-FREE on pointers to memory not > > allocated by FOREIGN-ALLOC. You should be able to (defcfun free ...) > > and use that. > > > > > > > In my code below, a new 'sdl-version' struct is returned by > > > (sdl-mixer-cffi::linked-version). The error seems to occur when I try to > > > free the struct at the end of the function using foreign-free. > > > > However, under SBCL FOREIGN-FREE is equivalent to free() -- not sure > > about CCL. According to SDL_Mixer's documentation, > > Mix_Linked_Version() returns a const pointer, so it seems that the bug > > here is that you're trying to free() non-malloc()ed memory. > > > > > Thank you for pointing that out. I will fix that bug in my code. > > /* rcg06192001 get linked library's version. */ > > 139 <http://hg.libsdl.org/SDL_mixer/file/4b699c9a269d/mixer.c#l139> > const SDL_version *Mix_Linked_Version(void) > > 140 <http://hg.libsdl.org/SDL_mixer/file/4b699c9a269d/mixer.c#l140> { > > 141 <http://hg.libsdl.org/SDL_mixer/file/4b699c9a269d/mixer.c#l141> > static SDL_version linked_version; > > 142 <http://hg.libsdl.org/SDL_mixer/file/4b699c9a269d/mixer.c#l142> > SDL_MIXER_VERSION(&linked_version); > > 143 <http://hg.libsdl.org/SDL_mixer/file/4b699c9a269d/mixer.c#l143> > return(&linked_version); > > 144 <http://hg.libsdl.org/SDL_mixer/file/4b699c9a269d/mixer.c#l144> } > > FYI; Lispworks doesn't complain about freeing the pointer.
Which probably means that Lispworks' foreign-free doesn't check that the pointer is valid, silently corrupting memory -- Stelian Ionescu a.k.a. fe[nl]ix Quidquid latine dictum sit, altum videtur. http://common-lisp.net/project/iolib
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