Re: Exposing common type wrapping/unwrapping methods

[Ken Raeburn]

On Aug 19, 2005, at 03:57, Ludovic Courtès wrote:
> > +/* Return a newly-allocated `sockaddr' structure that reflects  
> > ADDRESS, being
> > +   an address of family FAMILY, with the family-specific  
> > parameters ARGS (see
> > +   the description of `connect' for details).  The returned  
> > structure may be
> > +   freed using `free ()'.  */
> > +struct sockaddr *
> > +scm_to_sockaddr (int family, SCM address, SCM args)

This reminds me... was there ever a decision on the "call malloc and  
free from the same object on Windows" issue?  I found some old  
discussion in the guile-devel mail archive in late 2001, between  
stefan and Dirk mostly, but I don't see a resolution.

Basically, malloc and free referenced from a DLL, say libguile.dll,  
may be different instances of the functions than the application or  
other DLLs might see, and they should thus be assumed to have  
different allocation pools that can't be mixed.  If a chunk of  
storage is allocated by one DLL's notion of "malloc", then it must be  
freed by that same DLL's notion of "free".  (I worded it a little  
funny here, because function pointers could be passed around such  
that, for example, the library always uses the application's  
allocator, or the application can allocate storage from the library's  
pool; shim functions work too.)  Interfaces like this, where the DLL  
allocates and the main program frees, can cause corruption.

Or, you just don't build DLLs for some packages.

Ken