omp_hello.c revision 1.1.1.1 
1/******************************************************************************
2* FILE: omp_hello.c
3* DESCRIPTION:
4*   OpenMP Example - Hello World - C/C++ Version
5*   In this simple example, the master thread forks a parallel region.
6*   All threads in the team obtain their unique thread number and print it.
7*   The master thread only prints the total number of threads.  Two OpenMP
8*   library routines are used to obtain the number of threads and each
9*   thread's number.
10* AUTHOR: Blaise Barney  5/99
11* LAST REVISED: 04/06/05
12******************************************************************************/
13#include <omp.h>
14#include <stdio.h>
15#include <stdlib.h>
16
17int main (int argc, char *argv[]) {
18
19int nthreads, tid;
20
21/* Fork a team of threads giving them their own copies of variables */
22#pragma omp parallel private(nthreads, tid)
23  {
24
25  /* Obtain thread number */
26  tid = omp_get_thread_num();
27  printf("Hello World from thread = %d\n", tid);
28
29  /* Only master thread does this */
30  if (tid == 0)
31    {
32    nthreads = omp_get_num_threads();
33    printf("Number of threads = %d\n", nthreads);
34    }
35
36  }  /* All threads join master thread and disband */
37
38  return 0;
39}
40