From: Markus Mottl <markus.mottl@gmail.com>
To: "Török Edwin" <edwin+ml-ocaml@etorok.net>
Cc: caml-list@inria.fr
Subject: Re: [Caml-list] Segfault in C++ stub with many 'new' allocations
Date: Sat, 17 Nov 2012 14:50:56 -0500 [thread overview]
Message-ID: <CAP_800ohy77t5SQ7VLmpWWEkxsq4r_z4DcH+OkGXgTRK64sjdg@mail.gmail.com> (raw)
In-Reply-To: <50A7E138.9090601@etorok.net>
On Sat, Nov 17, 2012 at 2:10 PM, Török Edwin <edwin+ml-ocaml@etorok.net> wrote:
> I don't think this is safe. Shouldn't the return value be wrapped in a custom block?
> If the GC tries to interpret this as an OCaml value (which it isn't) it might crash.
The GC will never follow pointers that point outside the OCaml heap.
When done correctly (which requires great care), you can therefore
pass around pointers to C-land. You'll, of course, then have to
manually deallocate C/C++-heap objects by making the appropriate calls
(free / delete). Just make sure you never pass around pointers to
memory that has already been deallocated. Otherwise OCaml might
eventually claim it and cause crashes when following pointers.
Regards,
Markus
--
Markus Mottl http://www.ocaml.info markus.mottl@gmail.com
next prev parent reply other threads:[~2012-11-17 19:50 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-11-17 18:29 Samuel Hornus
2012-11-17 18:35 ` Kakadu
2012-11-17 18:42 ` Samuel Hornus
2012-11-17 19:10 ` Török Edwin
2012-11-17 19:18 ` Samuel Hornus
2012-11-17 19:50 ` Markus Mottl [this message]
2012-11-17 19:46 ` Markus Mottl
2012-11-17 22:45 ` Samuel Hornus
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