replace omp_set_nested with omp_set_max_active_levels

Author: fabien servant

src/CMakeLists.txt

@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.25)
+cmake_minimum_required(VERSION 3.30)
 message("CMake version: ${CMAKE_MAJOR_VERSION}.${CMAKE_MINOR_VERSION}")
 
 # ==============================================================================
@@ -253,6 +253,7 @@ endif()
 if (ALICEVISION_USE_OPENMP STREQUAL "OFF")
     set(ALICEVISION_HAVE_OPENMP 0)
 else() # ON OR AUTO
+    set(OpenMP_RUNTIME_MSVC "llvm")
     find_package(OpenMP)
 
     if (OPENMP_FOUND)

src/aliceVision/alicevision_omp.hpp

@@ -17,7 +17,7 @@ inline int omp_get_thread_num() { return 0; }
 inline int omp_get_max_threads() { return 1; }
 inline void omp_set_num_threads(int num_threads) {}
 inline int omp_get_num_procs() { return 1; }
-inline void omp_set_nested(int nested) {}
+inline void omp_set_max_active_levels(int levels) {}
 
 inline void omp_init_lock(omp_lock_t* lock) {}
 inline void omp_destroy_lock(omp_lock_t* lock) {}

src/aliceVision/featureEngine/FeatureExtractor.cpp

@@ -149,7 +149,7 @@ void FeatureExtractor::process(const HardwareContext& hContext, const image::EIm
         nbThreads = std::min(cpuJobs.size(), nbThreads);
 
         ALICEVISION_LOG_INFO("# threads for extraction: " << nbThreads);
-        omp_set_nested(1);
+        omp_set_max_active_levels(2);
 
 #pragma omp parallel for num_threads(nbThreads)
         for (int i = 0; i < cpuJobs.size(); ++i)

src/aliceVision/fuseCut/PointCloud.cpp

@@ -141,7 +141,7 @@ void createVerticesWithVisibilities(const StaticVector<int>& cams,
     for (auto& lock : locks)
         omp_init_lock(&lock);
 
-    omp_set_nested(1);
+    omp_set_max_active_levels(2);
 #pragma omp parallel for num_threads(3)
     for (int c = 0; c < cams.size(); ++c)
     {
@@ -229,7 +229,7 @@ void createVerticesWithVisibilities(const StaticVector<int>& cams,
             }
         }
     }
-    omp_set_nested(0);
+    omp_set_max_active_levels(1);
 
     for (auto& lock : locks)
         omp_destroy_lock(&lock);
@@ -294,7 +294,7 @@ void PointCloud::fuseFromDepthMaps(const StaticVector<int>& cams, const Point3d
 
     ALICEVISION_LOG_INFO("Load depth maps and add points.");
     {
-        omp_set_nested(1);
+        omp_set_max_active_levels(2);
 #pragma omp parallel for num_threads(3)
         for (int c = 0; c < cams.size(); c++)
         {
@@ -424,7 +424,7 @@ void PointCloud::fuseFromDepthMaps(const StaticVector<int>& cams, const Point3d
                 }
             }
         }
-        omp_set_nested(0);
+        omp_set_max_active_levels(1);
     }
 
     ALICEVISION_LOG_INFO("Filter initial 3D points by pixel size to remove duplicates.");