OMPT backend: configurable source of ImplicitTaskEnd event.

Optionally use barrier-related execution model events.

Merge branch 'feature/configurableImplicitTaskEnd' into develop

Author: jblueh

.gitlab-ci.yml

@@ -27,13 +27,17 @@ clang-macro:
 
 clang-ompt:
   image: fedora:41
+  parallel:
+    matrix:
+      - FLAGS: ["-DOPDI_OMPT_BACKEND_IMPLICIT_TASK_END_SOURCE=1", "-DOPDI_OMPT_BACKEND_IMPLICIT_TASK_END_SOURCE=2"]
   script:
     - dnf install -y diffutils binutils clang git
     - git clone --depth 1 --branch develop https://github.com/SciCompKL/CoDiPack.git
     - export CODI_DIR=$(pwd)/CoDiPack/include
     - export OPDI_DIR=$(pwd)/include
     - cd tests
     - export CXX=clang++
+    - export CXXFLAGS="$FLAGS"
     - export BACKEND=OMPT
     - make all
 

include/opdi/backend/ompt/implicitTaskCallbacks.hpp

@@ -29,6 +29,7 @@
 #include <omp.h>
 #include <omp-tools.h>
 
+#include "../../config.hpp"
 #include "../../helpers/exceptions.hpp"
 #include "../../helpers/macros.hpp"
 #include "../../logic/logicInterface.hpp"
@@ -60,7 +61,12 @@ namespace opdi {
           taskData->ptr = logic->onImplicitTaskBegin(false, actualParallelism, index, parallelData->ptr);
         }
         else {
-          logic->onImplicitTaskEnd(taskData->ptr);
+          #if OPDI_OMPT_BACKEND_IMPLICIT_TASK_END_SOURCE == OPDI_OMPT_IMPLICIT_TASK_END
+            logic->onImplicitTaskEnd(taskData->ptr);
+          #else
+            if (index == 0)  // master thread always produces ImplicitTaskEnd here
+              logic->onImplicitTaskEnd(taskData->ptr);
+          #endif
         }
       }
 

include/opdi/backend/ompt/syncRegionCallbacks.hpp

@@ -50,9 +50,12 @@ namespace opdi {
           void const* codeptr) {
 
         OPDI_UNUSED(parallelData);
-        OPDI_UNUSED(taskData);
         OPDI_UNUSED(codeptr);
 
+        #if OPDI_OMPT_BACKEND_IMPLICIT_TASK_END_SOURCE != OPDI_SYNC_REGION_END
+          OPDI_UNUSED(taskData);
+        #endif
+
         LogicInterface::ScopeEndpoint endpoint;
         if (ompt_scope_begin == _endpoint) {
           endpoint = LogicInterface::ScopeEndpoint::Begin;
@@ -79,11 +82,18 @@ namespace opdi {
           case ompt_sync_region_barrier_implementation:
             logic->onSyncRegion(LogicInterface::SyncRegionKind::BarrierImplementation, endpoint);
             break;
-#if _OPENMP >= 202011
+        #if _OPENMP >= 202011
           case ompt_sync_region_barrier_implicit_parallel:
-#else  // fallback for compilers with _OPENMP < 202011 that already support fine-grained sync region types
+        #else  // fallback for compilers with _OPENMP < 202011 that already support fine-grained sync region types
           case 9:  // ompt_sync_region_barrier_implicit_parallel
-#endif
+        #endif
+            // implicit barriers on parallel regions themselves do not require treatment
+            // however, we optionally use this to generate ImplicitTaskEnd events of non-master threads
+          #if OPDI_OMPT_BACKEND_IMPLICIT_TASK_END_SOURCE == OPDI_OMPT_SYNC_REGION_END
+            if (LogicInterface::ScopeEndpoint::Begin == endpoint && omp_get_thread_num() != 0) {
+              opdi::logic->onImplicitTaskEnd(taskData->ptr);
+            }
+          #endif
             break;  // no treatment needed
           case ompt_sync_region_reduction: // does not occur in this callback
             OPDI_WARNING("Unexpected kind argument ompt_sync_region_reduction.");

include/opdi/config.hpp

@@ -39,9 +39,24 @@
 #define OPDI_SCOPE_ENDPOINT_END 2
 #define OPDI_SCOPE_ENDPOINT_BOTH 3
 
+#define OPDI_OMPT_IMPLICIT_TASK_END 1
+#define OPDI_OMPT_SYNC_REGION_END 2
+
 /* ------------------ configuration ------------------ */
 
-/* logic options */
+/* ----- backend configuration ----- */
+
+#ifndef OPDI_OMPT_BACKEND_IMPLICIT_TASK_END_SOURCE
+  #define OPDI_OMPT_BACKEND_IMPLICIT_TASK_END_SOURCE OPDI_OMPT_IMPLICIT_TASK_END
+#endif
+
+static_assert(0 < OPDI_OMPT_BACKEND_IMPLICIT_TASK_END_SOURCE);
+static_assert(OPDI_OMPT_BACKEND_IMPLICIT_TASK_END_SOURCE <= 2);
+
+
+/* ----- logic configuration ----- */
+
+/* general logic options */
 
 #ifndef OPDI_OMP_LOGIC_INSTRUMENT
   #define OPDI_OMP_LOGIC_INSTRUMENT 0
@@ -95,7 +110,7 @@ static_assert(OPDI_SYNC_REGION_BARRIER_IMPLEMENTATION_BEHAVIOUR <= 3);
 static_assert(0 < OPDI_SYNC_REGION_BARRIER_REVERSE_BEHAVIOUR);
 static_assert(OPDI_SYNC_REGION_BARRIER_REVERSE_BEHAVIOUR <= 3);
 
-/* error handling options */
+/* ----- error handling ----- */
 
 #ifndef OPDI_ENABLE_WARNINGS
   #define OPDI_ENABLE_WARNINGS 1