MULTITASK_MPI
Carrying Out Multiple Tasks in MPI

MULTITASK_MPI is a FORTRAN77 program which demonstrates how to multitask, that is, to execute several unrelated and distinct tasks simultaneously, using MPI for parallel execution.

In this example, there is a "master" process, identified as process 0, and two worker processes, 1 and 2. Process 0 does nothing but choose the input for the worker processes, transmit it, and wait for the computed results to be returned. The programs executed by process 1 and by process 2 are quite different.

While the typical MPI model has all the worker processes executing the same program, this example shows that that is not necessary.

Licensing:

The computer code and data files described and made available on this web page are distributed under the GNU LGPL license.

Languages:

MULTITASK_MPI is available in a C version and a C++ version and a FORTRAN77 version and a FORTRAN90 version.

Related Data and Programs:

COMMUNICATOR_MPI, a FORTRAN77 program which creates new communicators involving a subset of initial set of MPI processes in the default communicator MPI_COMM_WORLD.

HEAT_MPI, a FORTRAN77 program which solves the 1D Time Dependent Heat Equation using MPI.

HELLO_MPI, a FORTRAN77 program which prints out "Hello, world!" using the MPI parallel programming environment.

MOAB, examples which illustrate the use of the MOAB job scheduler for a computer cluster.

MPI, FORTRAN77 programs which illustrate the use of the MPI application program interface for carrying out parallel computatioins in a distributed memory environment.

MULTITASK_OPENMP, a FORTRAN77 program which demonstrates how to "multitask", that is, to execute several unrelated and distinct tasks simultaneously, using OpenMP for parallel execution.

PRIME_MPI, a FORTRAN77 program which counts the number of primes between 1 and N, using MPI for parallel execution.

QUAD_MPI, a FORTRAN77 program which approximates an integral using a quadrature rule, and carries out the computation in parallel using MPI.

RANDOM_MPI, a FORTRAN77 program which demonstrates one way to generate the same sequence of random numbers for both sequential execution and parallel execution under MPI.

RING_MPI, a FORTRAN77 program which uses the MPI parallel programming environment, and measures the time necessary to copy a set of data around a ring of processes.

SATISFY_MPI, a FORTRAN77 program which demonstrates, for a particular circuit, an exhaustive search for solutions of the circuit satisfiability problem, using MPI to carry out the calculation in parallel.

SEARCH_MPI, a FORTRAN77 program which searches integers between A and B for a value J such that F(J) = C, using MPI for parallel execution.

WAVE_MPI, a FORTRAN77 program which uses finite differences and MPI to estimate a solution to the wave equation.

Reference:

1. William Gropp, Steven Huss-Lederman, Andrew Lumsdaine, Ewing Lusk, Bill Nitzberg, William Saphir, Marc Snir,
   MPI: The Complete Reference,
   Volume II: The MPI-2 Extensions,
   Second Edition,
   MIT Press, 1998.
2. William Gropp, Ewing Lusk, Anthony Skjellum,
   Using MPI: Portable Parallel Programming with the Message-Passing Interface,
   Second Edition,
   MIT Press, 1999,
   ISBN: 0262571323.
3. William Gropp, Ewing Lusk, Rajiv Thakur,
   Using MPI-2: Advanced Features of the Message-Passing Interface,
   Second Edition,
   MIT Press, 1999,
   ISBN: 0262571331.
4. Stan Openshaw, Ian Turton,
   High Performance Computing and the Art of Parallel Programming: an Introduction for Geographers, Social Scientists, and Engineers,
   Routledge, 2000,
   ISBN: 0415156920.
5. Peter Pacheco,
   Parallel Programming with MPI,
   Morgan Kaufman, 1996,
   ISBN: 1558603395,
   LC: QA76.642.P3.
6. Marc Snir, Steve Otto, Steven Huss-Lederman, David Walker, Jack Dongarra,
   MPI: The Complete Reference,
   Volume I: The MPI Core,
   Second Edition,
   MIT Press, 1998,
   ISBN: 0-262-69216-3,
   LC: QA76.642.M65.
7. The MPI web site at Argonne National Lab: http://www-unix.mcs.anl.gov/mpi/
8. The Message Passing Interface Forum,
   MPI: A Message Passing Interface Standard,
   1995,
   Available online from the MPI Forum.
9. The Message Passing Interface Forum,
   MPI-2: Extensions to the Message Passing Interface,
   1997,
   Available online from the MPI Forum.

Source Code:

• multitask_mpi.f, the source code.

Examples and Tests:

MULTITASK_FSU compiles and runs the program on the FSU HPC cluster.

• multitask_fsu.sh, the MOAB script.
• multitask_fsu_output.txt, the output file.

MULTITASK_LOCAL compiles and runs the program on the local system, which might work if OpenMPI is installed, and which might make sense if your system has multiple cores.

• multitask_local.sh, the script.
• multitask_local_output.txt, the output file.

You can go up one level to the FORTRAN77 source codes.