Merge pull request #27517 from mantidproject/27375_setting_max_threads_from_config

Make OpenMP for loops use max threads value from config

Framework/Algorithms/src/SofQWNormalisedPolygon.cpp

@@ -399,19 +399,6 @@ void SofQWNormalisedPolygon::exec() {
   const auto &inputIndices = inputWS->indexInfo();
   const auto &spectrumInfo = inputWS->spectrumInfo();
 
-  /*
-    On linux, the value value that is set at startup for the number of allowed
-    threads when mulitprocessing is not carried over to new execution threads.
-    As a result, mantid can segfault due to accessing workspaces that are
-    created in the main thread, as they have too few indexes that are supposed
-    to match the number of threads.
-
-    Resetting the number of threads here to what is set in the config file is a
-    temporary solution.
-    */
-  // TODO: Do this via a MultiThreaded.h macro via:
-  // https://github.com/mantidproject/mantid/issues/27375#issuecomment-553799284
-  FrameworkManager::Instance().setNumOMPThreadsToConfigValue();
   PARALLEL_FOR_IF(Kernel::threadSafe(*inputWS, *outputWS))
   for (int64_t i = 0; i < static_cast<int64_t>(nHistos); ++i) {
     PARALLEL_START_INTERUPT_REGION

Framework/Kernel/inc/MantidKernel/MultiThreaded.h

@@ -127,6 +127,7 @@ void AtomicOp(std::atomic<T> &f, T d, BinaryOp op) {
 // compiler.
 #ifdef _OPENMP
 
+#include "MantidKernel/ConfigService.h"
 #include <omp.h>
 
 /** Includes code to add OpenMP commands to run the next for loop in parallel.
@@ -135,14 +136,18 @@ void AtomicOp(std::atomic<T> &f, T d, BinaryOp op) {
  *   code to be executed in parallel
  */
 #define PARALLEL_FOR_IF(condition)                                             \
-    PRAGMA(omp parallel for if (condition) )
+  setMaxCoresToConfig();                                                       \
+  PARALLEL_SET_DYNAMIC(false);                                                 \
+  PRAGMA(omp parallel for if (condition) )
 
 /** Includes code to add OpenMP commands to run the next for loop in parallel.
  *   This includes no checks to see if workspaces are suitable
  *   and therefore should not be used in any loops that access workspaces.
  */
 #define PARALLEL_FOR_NO_WSP_CHECK()                                            \
-    PRAGMA(omp parallel for)
+  setMaxCoresToConfig();                                                       \
+  PARALLEL_SET_DYNAMIC(false);                                                 \
+  PRAGMA(omp parallel for)
 
 /** Includes code to add OpenMP commands to run the next for loop in parallel.
  *  and declare the variables to be firstprivate.
@@ -150,9 +155,13 @@ void AtomicOp(std::atomic<T> &f, T d, BinaryOp op) {
  *  and therefore should not be used in any loops that access workspace.
  */
 #define PARALLEL_FOR_NOWS_CHECK_FIRSTPRIVATE(variable)                         \
+  setMaxCoresToConfig();                                                       \
+  PARALLEL_SET_DYNAMIC(false);                                                 \
   PRAGMA(omp parallel for firstprivate(variable) )
 
 #define PARALLEL_FOR_NO_WSP_CHECK_FIRSTPRIVATE2(variable1, variable2)          \
+  setMaxCoresToConfig();                                                       \
+  PARALLEL_SET_DYNAMIC(false);                                                 \
   PRAGMA(omp parallel for firstprivate(variable1, variable2) )
 
 /** Ensures that the next execution line or block is only executed if
@@ -196,6 +205,14 @@ void AtomicOp(std::atomic<T> &f, T d, BinaryOp op) {
 
 #define PARALLEL_SECTION PRAGMA(omp section)
 
+inline void setMaxCoresToConfig() {
+  const auto maxCores = Mantid::Kernel::ConfigService::Instance().getValue<int>(
+      "MultiThreaded.MaxCores");
+  if (maxCores.get_value_or(0) > 0) {
+    PARALLEL_SET_NUM_THREADS(maxCores.get());
+  }
+}
+
 /** General purpose define for OpenMP, becomes the equivalent of
  * #pragma omp EXPRESSION
  * (if your compiler supports OpenMP)

buildconfig/CMake/MSVCSetup.cmake

@@ -14,7 +14,7 @@ include (InstallRequiredSystemLibraries)
 add_definitions ( -D_WINDOWS -DMS_VISUAL_STUDIO )
 add_definitions ( -D_USE_MATH_DEFINES -DNOMINMAX )
 add_definitions ( -DGSL_DLL -DJSON_DLL )
-add_definitions ( -DPOCO_DLL -DPOCO_NO_UNWINDOWS )
+add_definitions ( -DPOCO_DLL -DPOCO_NO_UNWINDOWS -DPOCO_NO_AUTOMATIC_LIBS)
 add_definitions ( -DBOOST_CONFIG_SUPPRESS_OUTDATED_MESSAGE )
 add_definitions ( -D_SCL_SECURE_NO_WARNINGS -D_CRT_SECURE_NO_WARNINGS )
   # Prevent deprecation errors from std::tr1 in googletest until it is fixed upstream. In MSVC 2017 and later