On Tue, Mar 30, 2010 at 11:57, Xavier Leroy <Xavier.Leroy@inria.fr> wrote:
> Yes.  Actually, it is forbidden to call any function of the OCaml
> runtime system from a noalloc function.

It may not always be clear to developers whether a function provided
by the OCaml API is safe.  E.g. calling Val_int is fine (at least now
and for the foreseeable future), but caml_copy_string is not.  I agree
that people should generally avoid noalloc.  The speed difference is
clearly negligible in almost all practical cases.

Note, too, that sometimes people forget that they had declared a
previously safe function as "noalloc", but later change the C-code in
ways that breaks this property.  The tiny extra performance may not be
worth that risk.

Regards,
Markus

-- 
Markus Mottl        http://www.ocaml.info        markus.mottl@gmail.com