From: Chain-Wu Lee <lee-d@cs.buffalo.edu>
Newsgroups: comp.parallel.mpi
Subject: MPI_File_open problem
Date: 24 Mar 1999 19:16:15 GMT
Organization: University at Buffalo
Message-Id: <7dbdlv$n0c$1@prometheus.acsu.buffalo.edu>
NNTP-Posting-User: lee-d
Originator: lee-d@pegasus.cse.Buffalo.EDU
Xref: ukc comp.parallel.mpi:4828


Hi,
  There is a small i/o program (simpleio.c) comes with MPICH distribution, in 
the program, it opens files with the call 

    MPI_File_open(MPI_COMM_SELF, ....)

  I wonder why it is not opened with MPI_COMM_WORLD? Is that because each 
process opens its own file? If so, then is it right that when we want to
use shared file pointer, we have to open it with MPI_COMM_WORLD?

 Thanks a lot!

-Chain-Wu