test_omp_functions.c

#include <omp.h>
#include <stdio.h>

/*
 * Print OpenMP parameters using OpenMP library routines.
 */
int main() {
  printf("Max threads: %d\n", omp_get_max_threads());
  #pragma omp parallel
  {
    int id = omp_get_thread_num();
    printf("[%2d] Number of threads used: %d\n",
	   id, omp_get_num_threads());
  }
  printf("*** Now setting the number of threads.\n");
  omp_set_num_threads(8);
  printf("Max threads: %d\n", omp_get_max_threads());
  #pragma omp parallel
  {
    int id = omp_get_thread_num();
    printf("[%2d] Number of threads used: %d\n",
	   id, omp_get_num_threads());
  }
}