xref: /llvm-project/openmp/runtime/test/tasking/detach_nested_task.c (revision 3c76e992911afdf0cb2394e3fba3f13c17c15b26)
1 // RUN: %libomp-compile-and-run
2 
3 // Checked gcc 10.1 still does not support detach clause on task construct.
4 // UNSUPPORTED: gcc-4, gcc-5, gcc-6, gcc-7, gcc-8, gcc-9, gcc-10
5 // gcc 11 introduced detach clause, but gomp interface in libomp has no support
6 // XFAIL: gcc-11, gcc-12
7 // clang supports detach clause since version 11.
8 // UNSUPPORTED: clang-10, clang-9, clang-8, clang-7
9 // icc compiler does not support detach clause.
10 // UNSUPPORTED: icc
11 
12 // The outer detachable task creates multiple child tasks with dependencies
13 // when the last inner task incremented ret, the task calls omp_fulfill_event
14 // to release the outer task.
15 
16 #include <omp.h>
17 #include <stdio.h>
18 
19 int *buf;
20 
21 int foo(int n)
22 {
23   int ret = 0;
24   for (int i = 0; i < n; ++i) {
25     omp_event_handle_t event;
26     #pragma omp task detach(event) firstprivate(i,n) shared(ret) default(none)
27     {
28       for (int j = 0; j < n; ++j) {
29         #pragma omp task firstprivate(event,i,j,n) shared(ret) default(none) depend(out:ret)
30         {
31           //printf("Task %i, %i: %i\n", i, j, omp_get_thread_num());
32           #pragma omp atomic
33             ret++;
34 #if _OPENMP
35           if (j == n-1) {
36             //printf("Task %i, %i: omp_fulfill_event()\n", i, j);
37             omp_fulfill_event(event);
38           }
39 #endif
40         }
41       }
42     }
43   }
44   // the taskwait only guarantees the outer tasks to complete.
45   #pragma omp taskwait
46 
47   return ret;
48 }
49 
50 
51 int main()
52 {
53   int ret;
54 #pragma omp parallel
55 #pragma omp master
56   {
57     ret = foo(8);
58   }
59   printf("%i\n", ret);
60   //CHECK: 64
61   return 0;
62 }
63