[Caml-list] C bindings and Gc.compact

[Caml-list] C bindings and Gc.compact

[Pedro Borges]

Hi, everyone,

If a compactification is triggered do the values get rewritten or do
they become invalid?


Best Regards,

Pedro Borges

[Caml-list] Re: C bindings and Gc.compact

[Sylvain Le Gall]

Hello,

On 05-04-2011, Pedro Borges <pdhb.lists@gmail.com> wrote:
> Hi, everyone,
>
> If a compactification is triggered do the values get rewritten or do
> they become invalid?
>
>

If the value have been allocated outside the Gc (e.g. malloc-ed), the
pointer is still valid. If it is an OCaml value, it will get rewritten.
But this is already the case with the other Gc stage, and the reason why
you should use CAMLparam/CAMLreturn.

Cheers,
Sylvain Le Gall
-- 
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Re: [Caml-list] C bindings and Gc.compact

[Niki Yoshiuchi]

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The manual has a section on just this issue, although the manual can be a
little confusing at times:
http://caml.inria.fr/pub/docs/manual-ocaml/manual032.html#toc140

Sylvain Le Gall already mentioned the basics - registering the values with
the garbage collector using CAMLparam (and then releasing them with
CAMLreturn) prevents any problems.  Also local values should be declared
using CAMLlocal and global values should be registered using
caml_global_register_root.

On Tue, Apr 5, 2011 at 7:27 AM, Pedro Borges <pdhb.lists@gmail.com> wrote:

> Hi, everyone,
>
> If a compactification is triggered do the values get rewritten or do
> they become invalid?
>
>
> Best Regards,
>
> Pedro Borges
>
> --
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>
>

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