> Is the OCaml runtime Boehm-safe? That is, can it be run with Boehm > turned on and traversing OCaml's heap? (So that the OCaml heap can > provide roots to Boehm.)
I conjecture the answer is "yes", although it's hard to tell for sure without a precise specification of what is/is not OK with the Boehm-Demers-Weiser collector. >From the standpoint of this collector, OCaml's heap is just a set of large-ish blocks allocated with malloc() (*) and containing a zillion pointers within those blocks. OCaml doesn't play any dirty tricks with pointers: no xoring of two pointers, no pointers represented as offsets from a base, no pointers one below or one above a malloc-ed block. Most pointers are word-aligned but we sometimes play tricks with the low 2 bits. Of course, almost all Caml pointers point inside those malloc-ed blocks, not to the beginning, but I'm confident that the B-D-W collector can handle this, otherwise it would fail on pretty much any existing C code. This said, I agree with Basile that what you're trying to achieve (coexistence between several GCs) is risky, and that a design based on message passing and separated memory spaces would be more robust, if feasible. - Xavier Leroy (*) In 3.10 and earlier releases, OCaml sometimes used mmap() instead of malloc() to obtain these blocks. Starting from 3.11, malloc() is the only interface OCaml uses to obtain memory from the OS. _______________________________________________ Caml-list mailing list. Subscription management: http://yquem.inria.fr/cgi-bin/mailman/listinfo/caml-list Archives: http://caml.inria.fr Beginner's list: http://groups.yahoo.com/group/ocaml_beginners Bug reports: http://caml.inria.fr/bin/caml-bugs
