openmp/runtime/test/worksharing/sections/omp_sections_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 thread skipping to the second sections construct to
   9  * release the threads in the first sections construct
  10  *
  11  * Also, since scheduling of sections is implementation defined, it is
  12  * necessary to have all four sections in the second sections construct
  13  * release the threads since we can't guarantee which section a single thread
  14  * will execute.
  15  */
  16 volatile int release;
  17 volatile int count;
  18
  19 void wait_for_release_then_increment(int rank)
  20 {
  21   fprintf(stderr, "Thread nr %d enters first section"
  22     " and waits.\n", rank);
  23   while (release == 0);
  24   #pragma omp atomic
  25   count++;
  26 }
  27
  28 void release_and_increment(int rank)
  29 {
  30   fprintf(stderr, "Thread nr %d sets release to 1\n", rank);
  31   release = 1;
  32   #pragma omp flush(release)
  33   #pragma omp atomic
  34   count++;
  35 }
  36
  37 int test_omp_sections_nowait()
  38 {
  39   release = 0;
  40   count = 0;
  41
  42   #pragma omp parallel num_threads(4)
  43   {
  44     int rank;
  45     rank = omp_get_thread_num ();
  46     #pragma omp sections nowait
  47     {
  48       #pragma omp section
  49       {
  50         wait_for_release_then_increment(rank);
  51       }
  52       #pragma omp section
  53       {
  54         wait_for_release_then_increment(rank);
  55       }
  56       #pragma omp section
  57       {
  58         wait_for_release_then_increment(rank);
  59       }
  60       #pragma omp section
  61       {
  62         fprintf(stderr, "Thread nr %d enters first sections and goes "
  63           "immediately to next sections construct to release.\n", rank);
  64         #pragma omp atomic
  65         count++;
  66       }
  67     }
  68     /* Begin of second sections environment */
  69     #pragma omp sections
  70     {
  71       #pragma omp section
  72       {
  73         release_and_increment(rank);
  74       }
  75       #pragma omp section
  76       {
  77         release_and_increment(rank);
  78       }
  79       #pragma omp section
  80       {
  81         release_and_increment(rank);
  82       }
  83       #pragma omp section
  84       {
  85         release_and_increment(rank);
  86       }
  87     }
  88   }
  89   // Check to make sure all eight sections were executed
  90   return (count==8);
  91 }
  92
  93 int main()
  94 {
  95   int i;
  96   int num_failed=0;
  97
  98   for(i = 0; i < REPETITIONS; i++) {
  99     if(!test_omp_sections_nowait()) {
 100       num_failed++;
 101     }
 102   }
 103   return num_failed;
 104 }