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openmpi/examples
Jeff Squyres 253444c6d0 == Highlights ==
1. New mpifort wrapper compiler: you can utilize mpif.h, use mpi, and use mpi_f08 through this one wrapper compiler
 1. mpif77 and mpif90 still exist, but are sym links to mpifort and may be removed in a future release
 1. The mpi module has been re-implemented and is significantly "mo' bettah"
 1. The mpi_f08 module offers many, many improvements over mpif.h and the mpi module

This stuff is coming from a VERY long-lived mercurial branch (3 years!); it'll almost certainly take a few SVN commits and a bunch of testing before I get it correctly committed to the SVN trunk.

== More details ==

Craig Rasmussen and I have been working with the MPI-3 Fortran WG and Fortran J3 committees for a long, long time to make a prototype MPI-3 Fortran bindings implementation.  We think we're at a stable enough state to bring this stuff back to the trunk, with the goal of including it in OMPI v1.7.  

Special thanks go out to everyone who has been incredibly patient and helpful to us in this journey:

 * Rolf Rabenseifner/HLRS (mastermind/genius behind the entire MPI-3 Fortran effort)
 * The Fortran J3 committee
 * Tobias Burnus/gfortran
 * Tony !Goetz/Absoft
 * Terry !Donte/Oracle
 * ...and probably others whom I'm forgetting :-(

There's still opportunities for optimization in the mpi_f08 implementation, but by and large, it is as far along as it can be until Fortran compilers start implementing the new F08 dimension(..) syntax.

Note that gfortran is currently unsupported for the mpi_f08 module and the new mpi module.  gfortran users will a) fall back to the same mpi module implementation that is in OMPI v1.5.x, and b) not get the new mpi_f08 module.  The gfortran maintainers are actively working hard to add the necessary features to support both the new mpi_f08 module and the new mpi module implementations.  This will take some time.

As mentioned above, ompi/mpi/f77 and ompi/mpi/f90 no longer exist.  All the fortran bindings implementations have been collated under ompi/mpi/fortran; each implementation has its own subdirectory:

{{{
ompi/mpi/fortran/
  base/               - glue code
  mpif-h/             - what used to be ompi/mpi/f77
  use-mpi-tkr/        - what used to be ompi/mpi/f90
  use-mpi-ignore-tkr/ - new mpi module implementation
  use-mpi-f08/        - new mpi_f08 module implementation
}}}

There's also a prototype 6-function-MPI implementation under use-mpi-f08-desc that emulates the new F08 dimension(..) syntax that isn't fully available in Fortran compilers yet.  We did that to prove it to ourselves that it could be done once the compilers fully support it.  This directory/implementation will likely eventually replace the use-mpi-f08 version.

Other things that were done:

 * ompi_info grew a few new output fields to describe what level of Fortran support is included
 * Existing Fortran examples in examples/ were renamed; new mpi_f08 examples were added
 * The old Fortran MPI libraries were renamed:
   * libmpi_f77 -> libmpi_mpifh
   * libmpi_f90 -> libmpi_usempi
 * The configury for Fortran was consolidated and significantly slimmed down.  Note that the F77 env variable is now IGNORED for configure; you should only use FC. Example:
{{{
shell$ ./configure CC=icc CXX=icpc FC=ifort ...
}}}

All of this work was done in a Mercurial branch off the SVN trunk, and hosted at Bitbucket.  This branch has got to be one of OMPI's longest-running branches.  Its first commit was Tue Apr 07 23:01:46 2009 -0400 -- it's over 3 years old!  :-)  We think we've pulled in all relevant changes from the OMPI trunk (e.g., Fortran implementations of the new MPI-3 MPROBE stuff for mpif.h, use mpi, and use mpi_f08, and the recent Fujitsu Fortran patches).

I anticipate some instability when we bring this stuff into the trunk, simply because it touches a LOT of code in the MPI layer in the OMPI code base.  We'll try our best to make it as pain-free as possible, but please bear with us when it is committed.

This commit was SVN r26283.
2012-04-18 15:57:29 +00:00
..
dtrace Updated README to use the OMPI_COMM_WORLD_RANK instead of the old vpid env-var. 2008-08-05 11:31:45 +00:00
connectivity_c.c Add simple test that sends a message between all the ranks in the job. 2007-02-28 21:38:02 +00:00
hello_c.c Add the new MPI-3 function MPI_GET_LIBRARY_VERSION. 2012-02-02 23:57:09 +00:00
hello_cxx.cc Add the new MPI-3 function MPI_GET_LIBRARY_VERSION. 2012-02-02 23:57:09 +00:00
hello_mpifh.f == Highlights == 2012-04-18 15:57:29 +00:00
hello_usempi.f90 == Highlights == 2012-04-18 15:57:29 +00:00
hello_usempif08.f90 == Highlights == 2012-04-18 15:57:29 +00:00
Hello.java Roll in Java bindings per telecon discussion. Man pages still under revision 2012-02-20 22:12:43 +00:00
Makefile == Highlights == 2012-04-18 15:57:29 +00:00
Makefile.include == Highlights == 2012-04-18 15:57:29 +00:00
README == Highlights == 2012-04-18 15:57:29 +00:00
ring_c.c - Convert MPI_Init(NULL, NULL) to MPI_Init(&argc, &argv) because 2006-08-08 13:01:17 +00:00
ring_cxx.cc * need to include iostream as well as stdio.h when doing the tricks with 2006-10-16 14:20:31 +00:00
ring_mpifh.f == Highlights == 2012-04-18 15:57:29 +00:00
ring_usempi.f90 == Highlights == 2012-04-18 15:57:29 +00:00
ring_usempif08.f90 == Highlights == 2012-04-18 15:57:29 +00:00
Ring.java Roll in Java bindings per telecon discussion. Man pages still under revision 2012-02-20 22:12:43 +00:00

Copyright (c) 2004-2006 The Trustees of Indiana University and Indiana
                        University Research and Technology
                        Corporation.  All rights reserved.
Copyright (c) 2006-2012 Cisco Systems, Inc.  All rights reserved.
Copyright (c) 2007-2009 Sun Microsystems, Inc.  All rights reserved.
Copyright (c) 2010      Oracle and/or its affiliates.  All rights reserved.

$COPYRIGHT$

The files in this directory are sample MPI applications provided both
as a trivial primer to MPI as well as simple tests to ensure that your
Open MPI installation is working properly.

If you are looking for a comprehensive MPI tutorial, these samples are
not enough.  Excellent MPI tutorials are available here:

        http://www.citutor.org/login.php

Get a free account and login; you can then browse to the list of
available courses.  Look for the ones with "MPI" in the title.

There are two MPI examples in this directory, each using one of six
different MPI interfaces: 

- Hello world
  C:                   hello_c.c
  C++:                 hello_cxx.cc
  Fortran mpif.h:      hello_mpifh.f
  Fortran use mpi:     hello_usempi.f90
  Fortran use mpi_f08: hello_usempif08.f90
  Java:                Hello.java

- Send a trivial message around in a ring
  C:                   ring_c.c
  C++:                 ring_cxx.cc
  Fortran mpif.h:      ring_mpifh.f
  Fortran use mpi:     ring_usempi.f90
  Fortran use mpi_f08: ring_usempif08.f90
  Java:                Ring.java

Additionally, there's one further example application, but this one
only uses the MPI C bindings:

- Test the connectivity between all processes
  C:   connectivity_c.c

The Makefile in this directory will build as many of the examples as
you have language support (e.g., if you do not have the Fortran "use
mpi" bindings compiled as part of Open MPI, the those examples will be
skipped).

The Makefile assumes that the wrapper compilers mpicc, mpic++, and
mpifort are in your path.

Although the Makefile is tailored for Open MPI (e.g., it checks the
"ompi_info" command to see if you have support for C++, mpif.h, use
mpi, and use mpi_f08 F90), all of the example programs are pure MPI,
and therefore not specific to Open MPI.  Hence, you can use a
different MPI implementation to compile and run these programs if you
wish.

Make today an Open MPI day!