Mpi examples

docs.it4i/software/mpi/ompi-examples.md

+# OpenMPI Sample Applications
+
+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.
+
+## Examples
+
+There are two MPI examples, each using one of six different MPI interfaces:
+
+**Hello world**
+
+* C:                   [hello_c.c](../../src/ompi/hello_c.c)
+* C++:                 [hello_cxx.cc](../../src/ompi/hello_cxx.cc)
+* Fortran mpif.h:      [hello_mpifh.f](../../src/ompi/hello_mpifh.f)
+* Fortran use mpi:     [hello_usempi.f90](../../src/ompi/hello_usempi.f90)
+* Fortran use mpi_f08: [hello_usempif08.f90](../../src/ompi/hello_usempif08.f90)
+* Java:                [Hello.java](../../src/ompi/Hello.java)
+* C shmem.h:           [hello_oshmem_c.c](../../src/ompi/hello_oshmem_c.c)
+* Fortran shmem.fh:    [hello_oshmemfh.f90](../../src/ompi/hello_oshmemfh.f90)
+
+**Send a trivial message around in a ring**
+
+* C:                   [ring_c.c](../../src/ompi/ring_c.c)
+* C++:                 [ring_cxx.cc](../../src/ompi/ring_cxx.cc)
+* Fortran mpif.h:      [ring_mpifh.f](../../src/ompi/ring_mpifh.f)
+* Fortran use mpi:     [ring_usempi.f90](../../src/ompi/ring_usempi.f90)
+* Fortran use mpi_f08: [ring_usempif08.f90](../../src/ompi/ring_usempif08.f90)
+* Java:                [Ring.java](../../src/ompi/Ring.java)
+* C shmem.h:           [ring_oshmem_c.c](../../src/ompi/ring_oshmem_c.c)
+* Fortran shmem.fh:    [ring_oshmemfh.f90](../../src/ompi/ring_oshmemfh.f90)
+
+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](../../src/ompi/connectivity_c.c)
+
+## Build Examples
+
+Download [examples](../../src/ompi/ompi.tar.gz).
+
+The Makefile in this directory will build the examples for the supported languages (e.g., if you do not have the Fortran "use mpi" bindings compiled as part of Open MPI, 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 *mpi_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.
+
+```console
+[login@cn204.anselm ]$ tar xvf ompi.tar.gz
+./
+./connectivity_c.c
+./Hello.java
+./ring_mpifh.f
+./hello_oshmem_cxx.cc
+...
+...
+./hello_cxx.cc
+[login@cn204.anselm ]$ ml OpenMPI/2.1.1-GCC-6.3.0-2.27
+[login@cn204.anselm ]$ make
+mpicc -g  hello_c.c  -o hello_c
+mpicc -g  ring_c.c  -o ring_c
+mpicc -g  connectivity_c.c  -o connectivity_c
+mpicc -g  spc_example.c  -o spc_example
+mpic++ -g  hello_cxx.cc  -o hello_cxx
+mpic++ -g  ring_cxx.cc  -o ring_cxx
+mpifort -g  hello_mpifh.f  -o hello_mpifh
+mpifort -g  ring_mpifh.f  -o ring_mpifh
+mpifort -g  hello_usempi.f90  -o hello_usempi
+mpifort -g  ring_usempi.f90  -o ring_usempi
+mpifort -g  hello_usempif08.f90  -o hello_usempif08
+mpifort -g  ring_usempif08.f90  -o ring_usempif08
+mpijavac Hello.java
+mpijavac Ring.java
+shmemcc -g  hello_oshmem_c.c  -o hello_oshmem
+shmemc++ -g  hello_oshmem_cxx.cc  -o hello_oshmemcxx
+shmemcc -g  ring_oshmem_c.c  -o ring_oshmem
+shmemcc -g  oshmem_shmalloc.c  -o oshmem_shmalloc
+shmemcc -g  oshmem_circular_shift.c  -o oshmem_circular_shift
+shmemcc -g  oshmem_max_reduction.c  -o oshmem_max_reduction
+shmemcc -g  oshmem_strided_puts.c  -o oshmem_strided_puts
+shmemcc -g  oshmem_strided_puts.c  -o oshmem_strided_puts
+shmemcc -g  oshmem_symmetric_data.c  -o oshmem_symmetric_data
+shmemfort -g  hello_oshmemfh.f90  -o hello_oshmemfh
+shmemfort -g  ring_oshmemfh.f90  -o ring_oshmemfh
+[login@cn204.anselm ]$ find . -executable -type f
+./hello_oshmem
+./dtrace/myppriv.sh
+./dtrace/partrace.sh
+./oshmem_shmalloc
+./ring_cxx
+./ring_usempi
+./hello_mpifh
+./hello_cxx
+./oshmem_max_reduction
+./oshmem_symmetric_data
+./oshmem_strided_puts
+./hello_usempif08
+./ring_usempif08
+./spc_example
+./hello_oshmemfh
+./ring_oshmem
+./oshmem_circular_shift
+./hello_c
+./ring_c
+./hello_usempi
+./ring_oshmemfh
+./connectivity_c
+./ring_mpifh
+```