[Gcl-devel] Re: TMP_ALLOC in mpn_mul_n

[Niels Möller]

Kevin Ryde <address@hidden> writes:

> Camm Maguire <address@hidden> writes:
> >
> > 2) Anyway, all of that is gcl's problem and not gmp's -- but what
> >    about other systems using garbage collection?  The Boehm collector
> >    is becoming more popular these days for example, and it relies on a
> >    redirected malloc as well.
> 
> It reclaims blocks, but doesn't move anything does it?

My understanding is that a conservative collector like Boehm's really
can't move blocks. If the gc moves a block, it must also update all
pointers to it. But a conservative gc can never update a pointer,
because it doesn't know if a word that looks like a pointer to the
block being moved really is a pointer. It might be some unrelated
integer that the program behaviour depends upon, and in that case
"updating" it to a new value will break the program.

/Niels