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Date: Tue, 25 May 2010 23:29:28 +0400
Message-ID: <AANLkTik8RlicxkdiITwEg8nejkx0X4yYl-bkXNq3TCFI@mail.gmail.com>
Subject: Re: [Caml-list] Bigarrays and blocking_section..
From: Dmitry Bely <dmitry.bely@gmail.com>
To: Romain Beauxis <toots@rastageeks.org>
Cc: caml-list@yquem.inria.fr
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X-Spam: no; 0.00; bigarrays:01 segfault:01 bigarrays:01 val:01 val:01 bigarray:01 struct:01 buffer:01 height:98 wrote:01 dmitry:01 dmitry:01 caml-list:01 int:01 int:01 

On Tue, May 25, 2010 at 8:25 PM, Romain Beauxis <toots@rastageeks.org> wrot=
e:
> =A0 =A0 =A0 =A0Hi all !
>
> I am trying to understand some segfault that we observe and I have a ques=
tion
> about the relationships between bigarrays in C and the Gc.
>
> We have the following code:
>
> static frame *frame_of_value(value v, frame *f)
> {
> =A0f->data =3D Caml_ba_data_val(Field(v,0));
> =A0f->width =3D Int_val(Field(v,1));
> =A0f->height =3D Int_val(Field(v,2));
> =A0f->stride =3D Int_val(Field(v,3));
>
> =A0return f;
> }

Are you sure that you correctly calculate the bigarray size in your
Caml code? Why not just use struct caml_ba_array fields? I suspect
it's not GC problem but just a buffer overrun in memset().

- Dmitry Bely