Newsgroups: comp.parallel.mpi
From: salo@mrjones.engr.sgi.com (Eric Salo)
Subject: Re: Fairness, When not, Why not, ...
Organization: Silicon Graphics, Inc.  Mountain View, CA
Date: 7 Feb 1996 20:05:25 GMT
Message-ID: <4fb0m5$95l@murrow.corp.sgi.com>

> The MPI standard (section 3.5) states that message delivery is
> not guaranteed to be fair in the sense that a message may
> never be delivered if it is continously overtaken by
> other messages. I think this situation is also being referred to
> as "livelock" in the literature.

Correct me if I am wrong, but I believe you are confusing fairness with
in-order delivery. MPI messages are non-overtaking, meaning that if
process A sends two identical messages to process B, they will arrive
in the order that they were sent. What MPI does *not* specify is the
order of arrival for messages from *different* senders.

Eric Salo         Silicon Graphics Inc.             "Do you know what the
(415)390-2998     2011 N. Shoreline Blvd, 7L-802     last Xon said, just
salo@sgi.com      Mountain View, CA   94043-1389     before he died?"

