Newsgroups: comp.parallel.mpi
From: snir@snir.watson.ibm.com (Marc Snir)
Subject: Re: MPI_IPROBE
Summary: Message matched by MPI_IPROBE can be received by any receive
Organization: IBM T. J. Watson Research
Date: 2 Sep 1994 18:19:13 GMT
Message-ID: <347qb1$j93@watnews1.watson.ibm.com>

In article <3411nhINNd8g@dubhe.anu.edu.au>,
M. Spinks <spimchon@cs.anu.edu.au> wrote:
>In the MPI Standard (p. 49, 4-10) the following is stated about MPI_IPROBE:
>
>'MPI_IPROBE...returns flag=true if there is a message that can be receive 
> and that matches the pattern specified by the arguments source, tag and 
> comm.   The call matches the same message that would have been received by 
>  a call to MPI_RECV... executed at the same point in the program...'
>
>Does anyone know if this means that MPI_IPROBE matches *only* messages 
> that would be received by MPI_RECV?   

A message matched by MPI_IPROBE can be subsequently received by any
receive operation.  The fact that it was matched by MPI_PROBE does not
change its statues or its eligibility to be received by any receive
operations. The statement on the standard is a specification of which
message MPI_IPROBE will match, and not of what happens to this message.  
-- 
g

