Newsgroups: comp.parallel.mpi
From: Reto Koradi <kor@mol.biol.ethz.ch>
Subject: Re: Shmem_get equivalent in MPI?
Organization: Swiss Federal Institute of Technology (ETHZ)
Date: Tue, 30 Sep 1997 18:21:52 +0200
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Message-ID: <34312720.6322@mol.biol.ethz.ch>

Charles Packer wrote:
> How would I emulate a shmem_get in MPI? We're trying to
> make some Cray Fortran 90 code portable.
> 
> When you issue a shmem_get, it fetches from the memory of
> a remote processor without the need for you to code a
> corresponding put operation to be executed by that
> processor.

You can't do that with standard MPI 1. In "Using MPI" (MIT Press),
section 10.3 relates to that. It starts with:

  The most characteristic feature of the message-passing model is
  that one process cannot access the memory of another process
  without its explicit consent.

It then discusses possible extensions which could make this
possible (active messages). This is mentioned as a possibility for
MPI 2. I understand that at least a draft standard exists in the
meantime, maybe somebody more knowledgable can tell us what's
in there?
-- 
Reto Koradi (kor@mol.biol.ethz.ch, http://www.mol.biol.ethz.ch/~kor)