c960d292ec
A mindless task for a lazy weekend: convert all the README and README.txt files to Markdown. Paired with the slow conversion of all of our man pages to Markdown, this gives a uniform language to the Open MPI docs. This commit moved a bunch of copyright headers out of the top-level README.txt file, so I updated the relevant copyright header years in the top-level LICENSE file to match what was removed from README.txt. Additionally, this commit did (very) little to update the actual content of the README files. A very small number of updates were made for topics that I found blatently obvious while Markdown-izing the content, but in general, I did not update content during this commit. For example, there's still quite a bit of text about ORTE that was not meaningfully updated. Signed-off-by: Jeff Squyres <jsquyres@cisco.com> Co-authored-by: Josh Hursey <jhursey@us.ibm.com>
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.
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
The MPI version of the canonical "hello world" program:
- 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 - C shmem.h:
hello_oshmem_c.c - Fortran shmem.fh:
hello_oshmemfh.f90
Ring
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 - C shmem.h:
ring_oshmem_c.c - Fortran shmem.fh:
ring_oshmemfh.f90
Connectivity Test
Additionally, there's one further example application, but this one only uses the MPI C bindings to test the connectivity between all processes:
- C:
connectivity_c.c
Makefile
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 mpif.h, the mpi
module, and the use mpi_f08 module), 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!