hello_openmp


hello_openmp, a C code which illustrates the use of the OpenMP application program interface within a simple "Hello, world!" program.

This program is so trivial that there is no point in checking its parallel performance. What it is useful for is checking that the compiler works properly and that the OpenMP environment is set up correctly.

The program prints "Hello" from a nonparallel region, and then from a parallel region. The number of "Hello's" produced is an indication of how many threads of execution have been set up.

Licensing:

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

Languages:

hello_openmp is available in a C version and a C++ version and a FORTRAN90 version.

Related Data and Programs:

DIJKSTRA_OPENMP, a C code which uses OpenMP to parallelize a simple example of Dijkstra's minimum distance algorithm for graphs.

FFT_OPENMP, a C code which demonstrates the computation of a Fast Fourier Transform in parallel, using OpenMP.

FUNCTIONS_OPENMP, a C code which demonstrates the behavior of a few of the OpenMP library functions.

HEATED_PLATE_OPENMP, a C code which solves the steady (time independent) heat equation in a 2D rectangular region, using OpenMP to run in parallel.

HELLO, a C code which prints out "Hello, world!".

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

hello_openmp_test

IMAGE_DENOISE_OPENMP, a C code which applies simple filtering techniques to remove noise from an image, carrying out the operation in parallel using OpenMP.

JACOBI_OPENMP, a C code which illustrates the use of the OpenMP application program interface to parallelize a Jacobi iteration solving A*x=b.

julia_set_openmp, a C code which produces an image of a Julia set, using OpenMP to carry out the computation in parallel.

MANDELBROT_OPENMP, a C code which generates an ASCII Portable Pixel Map (PPM) image of the Mandelbrot set, using OpenMP for parallel execution.

MD_OPENMP, a C code which carries out a molecular dynamics simulation using OpenMP.

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

MXM_OPENMP, a C code which computes a dense matrix product C=A*B, using OpenMP for parallel execution.

MXV_OPENMP, a C code which computes a dense matrix-vector product b=A*x, using OpenMP for parallel execution.

openmp_test, C codes which use the OpenMP application program interface for carrying out parallel computations in a shared memory environment.

POISSON_OPENMP, a C code which computes an approximate solution to the Poisson equation in a rectangle, using the Jacobi iteration to solve the linear system, and OpenMP to carry out the Jacobi iteration in parallel.

PRIME_OPENMP, a C code which counts the number of primes between 1 and N, using OpenMP for parallel execution.

PTHREADS, C codes which illustrate the use of the POSIX thread library to carry out parallel program execution.

QUAD_OPENMP, a C code which approximates an integral using a quadrature rule, and carries out the computation in parallel using OpenMP.

QUAD2_OPENMP, a C code which approximates a multidimensional integral using a quadrature rule. The quadrature computation is done with OpenMP.

QUAD2D_OPENMP, a C code which estimates an integral over a 2D rectangular domain by using an averaging technique, and uses OpenMP to carry out the calculation in parallel.

RANDOM_OPENMP, a C code which illustrates how a parallel program using OpenMP can generate multiple distinct streams of random numbers.

SATISFY_OPENMP, a C code which demonstrates, for a particular circuit, an exhaustive search for solutions of the circuit satisfiability problem, using OpenMP for parallel execution.

SCHEDULE_OPENMP, a C code which demonstrates the default, static, and dynamic methods of "scheduling" loop iterations in OpenMP to avoid work imbalance.

SGEFA_OPENMP, a C code which reimplements the SGEFA/SGESL linear algebra routines from LINPACK for use with OpenMP.

SUPERLU_OPENMP, C codes which illustrate the use of the SUPERLU_OPENMP library, a version of SUPERLU compiled with the OpenMP parallel programming interface, for the fast direct solution of large sparse systems of linear equations.

ZIGGURAT_OPENMP, a C code which demonstrates how the ZIGGURAT library can be used to generate random numbers in an OpenMP parallel program.

Reference:

  1. Peter Arbenz, Wesley Petersen,
    Introduction to Parallel Computing - A practical guide with examples in C,
    Oxford University Press,
    ISBN: 0-19-851576-6,
    LC: QA76.58.P47.
  2. Rohit Chandra, Leonardo Dagum, Dave Kohr, Dror Maydan, Jeff McDonald, Ramesh Menon,
    Parallel Programming in OpenMP,
    Morgan Kaufmann, 2001,
    ISBN: 1-55860-671-8,
    LC: QA76.642.P32.
  3. Barbara Chapman, Gabriele Jost, Ruud vanderPas, David Kuck,
    Using OpenMP: Portable Shared Memory Parallel Processing,
    MIT Press, 2007,
    ISBN13: 978-0262533027,
    LC: QA76.642.C49.
  4. OpenMP Architecture Review Board,
    OpenMP Application Program Interface,
    Version 3.0,
    May 2008.

Source code:


Last revised on 01 August 2020.