Hi Sylvain, Thanks for the help. I figured out the issue, I was inadvertently calling CAMLparam* more than once for a given value because I would pass the value in the wrapper function implementation with an intermediate function that took a parameter of type "value". Calling CAMLparam more than once on a given value seems to muck up the garbage collector...which probably indicates why the program was jamming in a (seemingly) nondeterministic manner. The program probably locked up whenever the garbage collector was invoked.
The Gc module looks useful though, thanks for the tip! -mas On Jan 17, 6:01 am, Sylvain Le Gall <[email protected]> wrote: > Hello, > > On 17-01-2011, mas <[email protected]> wrote: > > > > > > > > > > > Hello all, > > I've been struggling with a problem with OCaml's C interface and can't > > seem to deduce the problem. Here's what's going on in a nutshell: > > > - I used OCaml's C interface to develop a series of OCaml wrappers for > > C functions. > > - The functions operate correctly for the most part....however when I > > call the functions repeatedly (anywhere between a dozen to a few > > hundred invocations), the function does not return and locks up. > > - I have been able to track down the problem to points where I call > > caml memory allocation calls (e.g. caml_copy_double) in the C code. > > Turns out that on random occasions this function does not return and > > ends up utilizing 100% of the CPU! > > > My gut feeling is that I'm exceeding the memory size the OCaml runtime > > allocates for its internal C stack/heap and the call fails. Rather > > than return something like a NULL, my guess is that the allocator is > > waiting for space to free up. However as there is no error message or > > indication of what is failing, I'm not sure what to do. Any ideas for > > what this could be and how I can find more info? Is there any way I > > can print out info about the VM state? > > You can get various VM info through the Gc module. > > The best you can do is to provide us with a minimal example of what is > not working. You can even try to call Gc.compact/full_major/major/minor > that should help to speed up memory problems... > > The most common problem with OCaml/C stub is the lack of CAMLparamX, > CAMLlocal or CAMLreturn which leads to inconsistent memory. > > Cheers, > Sylvain Le Gall > -- > My company:http://www.ocamlcore.com > Linkedin: http://fr.linkedin.com/in/sylvainlegall > Start an OCaml project here:http://forge.ocamlcore.org > OCaml blogs: http://planet.ocamlcore.org -- You received this message because you are subscribed to the Google Groups "ocaml-developer" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/ocaml-developer?hl=en For other OCaml forums, see http://caml.inria.fr/resources/forums.en.html
