openmp/runtime/test/parallel/omp_parallel_num_threads.c

   1 // RUN: %libomp-compile-and-run
   2 #include <stdio.h>
   3 #include "omp_testsuite.h"
   4
   5 int test_omp_parallel_num_threads()
   6 {
   7   int num_failed;
   8   int threads;
   9   int nthreads;
  10   int max_threads = 0;
  11
  12   num_failed = 0;
  13
  14   /* first we check how many threads are available */
  15   #pragma omp parallel
  16   {
  17     #pragma omp master
  18     max_threads = omp_get_num_threads ();
  19   }
  20
  21   /* we increase the number of threads from one to maximum:*/
  22   for(threads = 1; threads <= max_threads; threads++) {
  23     nthreads = 0;
  24     #pragma omp parallel reduction(+:num_failed) num_threads(threads)
  25     {
  26       num_failed = num_failed + !(threads == omp_get_num_threads());
  27       #pragma omp atomic
  28       nthreads += 1;
  29     }
  30     num_failed = num_failed + !(nthreads == threads);
  31   }
  32   return (!num_failed);
  33 }
  34
  35 int main()
  36 {
  37   int i;
  38   int num_failed=0;
  39
  40   for(i = 0; i < REPETITIONS; i++) {
  41     if(!test_omp_parallel_num_threads()) {
  42       num_failed++;
  43     }
  44   }
  45   return num_failed;
  46 }