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From: Lisandro Dalcin (dalcinl_at_[hidden])
Date: 2007-07-28 16:41:22

On 7/28/07, Brian Barrett <bbarrett_at_[hidden]> wrote:
> In my opinion, we conform to the standard. We reference count the
> group, it's incremented on call to MPI_WIN_GROUP, and you can safely
> call MPI_GROUP_FREE on the group returned from MPI_WIN_GROUP. Groups
> are essentially immutable, so there's no way I can think of that we
> violate the MPI standard.

Your reasoning make a lot of sense. It there seems to be no point in
requiring a true 'duplicate' being returned by Win.Get_group().

> Others are, of course, free to disagree with me.

I do not strictly disagree with you, but the standard do (if it is
readed like a lawyer). In any case, this is other corner case that
should be clarified in the standard...

In the mean time, I would prefer to follow the standard as close as
possible. If not, some external, stupid test suite (like the one I
have for mip4py) would report that OMPI is wrong about this point.

BTW, Were is the place to disccuss this stantard isues? There is a
mailing list at


Lisandro Dalcín
Centro Internacional de Métodos Computacionales en Ingeniería (CIMEC)
Instituto de Desarrollo Tecnológico para la Industria Química (INTEC)
Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)
PTLC - Güemes 3450, (3000) Santa Fe, Argentina
Tel/Fax: +54-(0)342-451.1594