openmp/runtime/test/worksharing/single/omp_single_nowait.c

   1 // RUN: %libomp-compile-and-run
   2 #include <stdio.h>
   3 #include "omp_testsuite.h"
   4
   5 /*
   6  * This test will hang if the nowait is not working properly
   7  *
   8  * It relies on a one thread skipping to the last single construct to
   9  * release the threads in the first three single constructs
  10  */
  11 volatile int release;
  12 volatile int count;
  13
  14 void wait_for_release_then_increment(int rank)
  15 {
  16   fprintf(stderr, "Thread nr %d enters first section"
  17     " and waits.\n", rank);
  18   while (release == 0);
  19   #pragma omp atomic
  20   count++;
  21 }
  22
  23 void release_and_increment(int rank)
  24 {
  25   fprintf(stderr, "Thread nr %d sets release to 1\n", rank);
  26   release = 1;
  27   #pragma omp atomic
  28   count++;
  29 }
  30
  31 int test_omp_single_nowait()
  32 {
  33   release = 0;
  34   count = 0;
  35
  36   #pragma omp parallel num_threads(4)
  37   {
  38     int rank;
  39     rank = omp_get_thread_num ();
  40     #pragma omp single nowait
  41     {
  42       wait_for_release_then_increment(rank);
  43     }
  44     #pragma omp single nowait
  45     {
  46       wait_for_release_then_increment(rank);
  47     }
  48     #pragma omp single nowait
  49     {
  50       wait_for_release_then_increment(rank);
  51     }
  52
  53     #pragma omp single
  54     {
  55       release_and_increment(rank);
  56     }
  57   }
  58   // Check to make sure all four singles were executed
  59   return (count==4);
  60 } /* end of check_single_nowait*/
  61
  62 int main()
  63 {
  64   int i;
  65   int num_failed=0;
  66
  67   for(i = 0; i < REPETITIONS; i++) {
  68     if(!test_omp_single_nowait()) {
  69       num_failed++;
  70     }
  71   }
  72   return num_failed;
  73 }