[Mpi-forum] behavior of NBC for intracommunicators when root == MPI_PROC_NULL

[George Bosilca]

What's wrong with 5.2.3? From a practical point of view, returning
MPI_REQUEST_NULL makes sense (following the description about communication
with MPI_PROC_NULL from 3.11).

  George.


On Thu, Dec 11, 2014 at 5:22 PM, Anthony Skjellum <skjellum at auburn.edu>
wrote:

> Shouldn't it just be a trivial request -- why map to null ? - shortcut
> should of course happen internally but the request should be valid ---
> undesirable side effects possible Imho with a literal mapping !
>
> Anthony Skjellum, PhD
> 205-807-4968
>
>
> > On Dec 11, 2014, at 3:30 PM, Jeff Hammond <jeff.science at gmail.com>
> wrote:
> >
> > I would hope that the Ianything is matched with a corresponding
> > Test/Wait* call on every process that calls it.  To allow otherwise
> > seems pretty odd.
> >
> > Presumably, if Ibcast is a no-op when root=MPI_PROC_NULL, then the
> > request can be set to MPI_REQUEST_NULL and thus completing it is
> > trivial.
> >
> > If the standard says that completing a request known to be
> > MPI_REQUEST_NULL is not required, then I suppose the user can avoid
> > making the completion call, but I don't like that style.
> >
> > Jeff
> >
> >> On Thu, Dec 11, 2014 at 11:30 AM, Fab Tillier <ftillier at microsoft.com>
> wrote:
> >> Hi Folks,
> >>
> >>
> >>
> >> I can’t find anything in the standard document that explains the
> behavior
> >> for NBC requests on intercommunicators when root == MPI_PROC_NULL.
> Taking
> >> MPI_Ibcast as an example, what is the output value of request?  Is it
> >> MPI_REQUEST_NULL?  Is it not set at all?  Is it a valid request that
> must be
> >> completed?
> >>
> >>
> >>
> >> Thanks,
> >>
> >> -Fab
> >>
> >>
> >> _______________________________________________
> >> mpi-forum mailing list
> >> mpi-forum at lists.mpi-forum.org
> >> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpi-forum
> >
> >
> >
> > --
> > Jeff Hammond
> > jeff.science at gmail.com
> > http://jeffhammond.github.io/
> > _______________________________________________
> > mpi-forum mailing list
> > mpi-forum at lists.mpi-forum.org
> > http://lists.mpi-forum.org/mailman/listinfo.cgi/mpi-forum
> _______________________________________________
> mpi-forum mailing list
> mpi-forum at lists.mpi-forum.org
> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpi-forum
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mpi-forum.org/pipermail/mpi-forum/attachments/20141211/547c5334/attachment-0001.html>