[OpenMP] Add support for pause with omp_pause_stop_tool (#97100)

This patch adds support for pause resource with a new enumerator
omp_pause_stop_tool. The expected behavior of this enumerator is
* omp_pause_resource: not allowed
* omp_pause_resource_all: equivalent to omp_pause_hard

openmp/runtime/src/include/omp.h.var

@@ -476,7 +476,8 @@
     typedef enum omp_pause_resource_t {
       omp_pause_resume = 0,
       omp_pause_soft = 1,
-      omp_pause_hard = 2
+      omp_pause_hard = 2,
+      omp_pause_stop_tool = 3
     } omp_pause_resource_t;
     extern int __KAI_KMPC_CONVENTION omp_pause_resource(omp_pause_resource_t, int);
     extern int __KAI_KMPC_CONVENTION omp_pause_resource_all(omp_pause_resource_t);

openmp/runtime/src/include/omp_lib.F90.var

@@ -192,6 +192,7 @@
         integer (kind=omp_pause_resource_kind), parameter, public :: omp_pause_resume = 0
         integer (kind=omp_pause_resource_kind), parameter, public :: omp_pause_soft = 1
         integer (kind=omp_pause_resource_kind), parameter, public :: omp_pause_hard = 2
+        integer (kind=omp_pause_resource_kind), parameter, public :: omp_pause_stop_tool = 3
 
         integer (kind=omp_interop_fr_kind), parameter, public :: omp_ifr_cuda = 1
         integer (kind=omp_interop_fr_kind), parameter, public :: omp_ifr_cuda_driver = 2

openmp/runtime/src/include/omp_lib.h.var

@@ -248,6 +248,8 @@
       parameter(omp_pause_soft=1)
       integer(kind=omp_pause_resource_kind)omp_pause_hard
       parameter(omp_pause_hard=2)
+      integer(kind=omp_pause_resource_kind)omp_pause_stop_tool
+      parameter(omp_pause_stop_tool=3)
 
       integer(kind=omp_interop_fr_kind)omp_ifr_cuda
       parameter(omp_ifr_cuda=1)

openmp/runtime/src/kmp.h

@@ -4552,7 +4552,8 @@ extern int __kmpc_get_target_offload();
 typedef enum kmp_pause_status_t {
   kmp_not_paused = 0, // status is not paused, or, requesting resume
   kmp_soft_paused = 1, // status is soft-paused, or, requesting soft pause
-  kmp_hard_paused = 2 // status is hard-paused, or, requesting hard pause
+  kmp_hard_paused = 2, // status is hard-paused, or, requesting hard pause
+  kmp_stop_tool_paused = 3 // requesting stop_tool pause
 } kmp_pause_status_t;
 
 // This stores the pause state of the runtime

openmp/runtime/src/kmp_ftn_entry.h

@@ -1427,6 +1427,8 @@ int FTN_STDCALL KMP_EXPAND_NAME(FTN_PAUSE_RESOURCE)(kmp_pause_status_t kind,
 #ifdef KMP_STUB
   return 1; // just fail
 #else
+  if (kind == kmp_stop_tool_paused)
+    return 1; // stop_tool must not be specified
   if (device_num == KMP_EXPAND_NAME(FTN_GET_INITIAL_DEVICE)())
     return __kmpc_pause_resource(kind);
   else {

openmp/runtime/src/kmp_runtime.cpp

@@ -9132,7 +9132,8 @@ int __kmp_pause_resource(kmp_pause_status_t level) {
       __kmp_soft_pause();
       return 0;
     }
-  } else if (level == kmp_hard_paused) { // requesting hard pause
+  } else if (level == kmp_hard_paused || level == kmp_stop_tool_paused) {
+    // requesting hard pause or stop_tool pause
     if (__kmp_pause_status != kmp_not_paused) {
       // error message about already being paused
       return 1;

openmp/runtime/test/ompt/misc/pause_stop_tool.c

@@ -0,0 +1,44 @@
+// RUN: %libomp-compile-and-run | FileCheck %s
+// REQUIRES: ompt
+#include "callback.h"
+#include <omp.h>
+int main() {
+  int x = 0;
+  int ret = 0;
+#pragma omp parallel
+#pragma omp single
+  x++;
+  // Expected to fail; omp_pause_stop_tool must not be specified
+  ret = omp_pause_resource(omp_pause_stop_tool, omp_get_initial_device());
+  printf("omp_pause_resource %s\n", ret ? "failed" : "succeeded");
+#pragma omp parallel
+#pragma omp single
+  x++;
+  // Expected to succeed
+  ret = omp_pause_resource_all(omp_pause_stop_tool);
+  printf("omp_pause_resource_all %s\n", ret ? "failed" : "succeeded");
+#pragma omp parallel
+#pragma omp single
+  x++;
+  printf("x = %d\n", x);
+  return 0;
+
+  // Check if
+  // -- omp_pause_resource/resource_all returns expected code
+  // -- OMPT interface is shut down as expected
+
+  // CHECK-NOT: {{^}}0: Could not register callback
+  // CHECK: 0: NULL_POINTER=[[NULL:.*$]]
+
+  // CHECK: ompt_event_parallel_begin
+  // CHECK: ompt_event_parallel_end
+
+  // CHECK: omp_pause_resource failed
+
+  // CHECK: ompt_event_parallel_begin
+  // CHECK: ompt_event_parallel_end
+
+  // CHECK: omp_pause_resource_all succeeded
+
+  // CHECK-NOT: ompt_event
+}