Re: MPI and Threads

Tony Skjellum (tony@Aurora.CS.MsState.Edu)
Mon, 17 Mar 1997 17:03:44 -0600 (CST)

I think that, in this case, MPI should mandate a complete syntax and
semantics for thread calls, which can be wrappers, or special
implementations, but again provide complete portability. Currently,
we will not have true portability of threaded programs. This will
limit MPI's usefulness in systems as threads become a dominant form
of local programming expression.

Or, we think that the current half-measures should be removed completely
so that the Forum cannot claim to have addressed MPI and threads properly.

-Tony

On Mon, 17 Mar 1997, Rusty Lusk wrote:

> Date: Mon, 17 Mar 1997 15:08:40 -0600
> From: Rusty Lusk <lusk@mcs.anl.gov>
> To: Eric Salo <salo@mrjones.engr.sgi.com>
> Cc: "'mpi-external@mcs.anl.gov'" <mpi-external@mcs.anl.gov>
> Subject: Re: MPI and Threads
>
>
> | I gotta disagree. But to some extent this is a moot issue. I see no benefit
> | at all to officially blessing any one threads package in the MPI
> | standard. If users want pthreads in sufficient numbers then the market will
> | adapt to fill this need. And if they don't, then we would be better off not
> | attempting to dictate otherwise in the standard.
>
> I gotta agree. One reason that we should not require or endorse any
> particular thread syntax, and instead focus on the semantics as we have
> been doing, is that for MPI, the semantics is the point. To make this
> explicit, one can envisage a system that has a POSIX-compliant pthread package
> that does *NOT* follow the rules in our "MPI and Threads" discussion, but also
> has another thread package that does do so. Then the programmer must not
> use pthreads, but the threads that work well with MPI. The program might
> not be as portable as it was before the programmer introduced explicit
> multithreading, but that is the fault of the threads packages, not MPI.
>
> Rusty
>
>

Anthony Skjellum, PhD, Associate Professor of Computer Science;
Mississippi State University, Department of Computer Science & NSF ERC
Butler, Rm 300, PO Box 9637, Corner of Perry&Barr, Mississippi State,MS 39762
(601)325-8435 FAX: (601)325-8997; http://www.erc.msstate.edu/~tony;
"Procrastination is the 8th Deadly Sin." ; tony@cs.msstate.edu; Support MPI!