1  int
       2  main ()
       3  {
       4    int a, b, c, d;
       5    #pragma omp parallel num_threads (6)
       6    #pragma omp single
       7    {
       8      #pragma omp task depend(out: c)
       9        c = 1;
      10      #pragma omp task depend(out: a)
      11        a = 2;
      12      #pragma omp task depend(out: b)
      13        b = 3;
      14      /* The above 3 tasks can be scheduled in any order.  */
      15      #pragma omp task depend(in: a) depend(mutexinoutset: c)
      16        c += a;
      17      #pragma omp task depend(in: b) depend(mutexinoutset: c)
      18        c += b;
      19      /* The above 2 tasks are mutually exclusive and need to wait
      20         for the first and second or first and third tasks respectively.  */
      21      #pragma omp task depend(in: c)
      22        d = c;
      23      /* The above task needs to wait for the mutexinoutset tasks.  */
      24    }
      25    if (d != 6)
      26      __builtin_abort ();
      27    return 0;
      28  }