From mboxrd@z Thu Jan  1 00:00:00 1970
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Date: Fri, 20 Jan 2006 09:37:16 +0100
From: Jan Kiszka <jan.kiszka@domain.hid>
MIME-Version: 1.0
Subject: Re: [Xenomai-help] Meassage Queue c++
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To: Stephan Zimmermann <s.zimmermann@domain.hid>
Cc: xenomai@xenomai.org

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Stephan Zimmermann wrote:
> Am Donnerstag, 19. Januar 2006 18:04 schrieb Nathaniel Villaume:
>> Hi Stephan,
>>
>> I don't know if it is related, but I wouldn't return a pointer to a
>> local variable:
>>
>> void *data;
>> ...
>> return data;
>>
>> Maybe something is happening where when the queue is empty the size is=
 0
>> --so malloc returns who-knows-what?
>=20
> Hi,=20
> thanks for the hint, but I don't think this is the Problem, because the=
=20
> Program crashes befor the read function returns. I think it is related =
with=20
> the way I create/bind the queue in the constructor, but I am not sure.
>=20
> Please don't think too much about it, I decided to stop my c++=20
> realtime-experiments anyway, will code plain c instead.

Some further things to try before giving C++ up - and maybe stumbling
over the same issue with C:

 o Did you mlockall() your program? If not, lazy-mapped pages may cause
   SEGFAULTS in the RT domain which will kill your program.

 o Does your kernel log contain any hints of Xenomai about what's going
   on?

 o Try running your program inside a debugger to catch the fault and its
   location. When your system is head-less, use gdbserver.

Jan


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