[racket] FFI dynamic library reloading

At Wed, 11 Aug 2010 13:46:38 -0400, Christopher Bowron wrote:
> One thing I've noticed is that if I change the C library, I need to
> restart DrRacket for it to be able to reload the changed dynamic
> library.  It seems appears that the first time I run in DrRacket it
> loads the library, but subsequent runs can only refer the library as
> it existed on the first run.  I don't know if this is a limitation of
> the platform or it is something specific to the way DrRacket loads
> libraries.

It's mostly a Racket limitation. We've never worked out a protocol for
unloading shared libraries that could be made safe. (That is, it's not
just inherently unsafe, but also that there needs to be a protocol that
could be used to make wrappers safe.)