Hi! On Tue, Aug 10, 2004 at 12:59:46PM +0100, Simon Marlow wrote:
On 09 August 2004 16:57, Remi Turk wrote:
Hm, I _was_ aware of mp_set_memory_functions being used by the RTS. I've seen it often enough in ltrace's ;) It does indeed sound rather plausible (and making big allocations and such does indeed cause it to happen earlier).
At which point my next question is: what now? I don't feel really confident about my GHC-hacking skills (huh? skills? where? ;) so does that mean I'm out of luck? *looks* Am I correct that I'd have to copy any GMP-allocated memory to my own memory before returning from C and vice-versa? I hope not :(
GHC's use of GMP does cause problems if you want to use GMP for your own purposes, or if you link with external code that wants to use GMP. The real problem is that GMP has internal state, which means it can't be used in a modular way. But there's not much we can do about that.
Possibilities:
[...]
- reset GMP's memory allocators before calling it from your code, and set them back to the RTS allocators afterward. Slow, but it should work. It doesn't solve the problem properly though: external libraries which use GMP are still broken.
I would be careful though: http://www.swox.com/gmp/manual/Custom-Allocation.html Be sure to call mp_set_memory_functions only when there are no active GMP objects allocated using the previous memory functions! Usually that means calling it before any other GMP function. Greetings, Carsten -- Carsten Schultz (2:38, 33:47), FB Mathematik, FU Berlin http://carsten.codimi.de/ PGP/GPG key on the pgp.net key servers, fingerprint on my home page.