From 11ed7bd843867ed8a32473955d10728ee61e663a Mon Sep 17 00:00:00 2001
From: Paul Leroy <paul.leroy@univ-rennes1.fr>
Date: Tue, 13 Feb 2024 09:22:50 +0100
Subject: [PATCH] use ccQtHelpers::GetMaxThreadCount

---
 ContextBasedFeature.cpp |  5 ++++-
 PointFeature.cpp        |  5 ++++-
 q3DMASCClassifier.cpp   |  5 +++--
 q3DMASCTools.cpp        | 10 +++++++---
 4 files changed, 18 insertions(+), 7 deletions(-)

diff --git a/ContextBasedFeature.cpp b/ContextBasedFeature.cpp
index 9471118..eb158d5 100644
--- a/ContextBasedFeature.cpp
+++ b/ContextBasedFeature.cpp
@@ -23,6 +23,9 @@
 //qCC_db
 #include <ccScalarField.h>
 
+//CCPluginAPI
+#include <ccQtHelpers.h>
+
 //Qt
 #include <QMutex>
 
@@ -194,7 +197,7 @@ bool ContextBasedFeature::prepare(	const CorePoints& corePoints,
 			bool cancelled = false;
 #ifndef _DEBUG
 #if defined(_OPENMP)
-#pragma omp parallel for num_threads(std::max(1, omp_get_max_threads() - 2))
+#pragma omp parallel for num_threads(ccQtHelpers::GetMaxThreadCount(omp_get_max_threads()))
 #endif
 #endif
 			for (int i = 0; i < static_cast<int>(pointCount); ++i)
diff --git a/PointFeature.cpp b/PointFeature.cpp
index b73bd46..0017b69 100644
--- a/PointFeature.cpp
+++ b/PointFeature.cpp
@@ -89,6 +89,9 @@ constexpr const char* LAS_FIELD_NAMES[22] = {"X",
 //CCLib
 #include <WeibullDistribution.h>
 
+//CCPluginAPI
+#include <ccQtHelpers.h>
+
 //system
 #include <assert.h>
 
@@ -424,7 +427,7 @@ static bool ComputeMathOpWithNearestNeighbor(	const CorePoints& corePoints,
 	error.clear();
 #ifndef _DEBUG
 #if defined(_OPENMP)
-#pragma omp parallel for num_threads(std::max(1, omp_get_max_threads() - 2))
+#pragma omp parallel for num_threads(ccQtHelpers::GetMaxThreadCount(omp_get_max_threads()))
 #endif
 #endif
 	for (int i = 0; i < static_cast<int>(pointCount); ++i)
diff --git a/q3DMASCClassifier.cpp b/q3DMASCClassifier.cpp
index 8b09c47..ea3356e 100644
--- a/q3DMASCClassifier.cpp
+++ b/q3DMASCClassifier.cpp
@@ -30,8 +30,9 @@
 //qPDALIO
 #include "../../../core/IO/qPDALIO/include/LASFields.h"
 
-//qCC_plugins
+//CCPluginAPI
 #include <ccMainAppInterface.h>
+#include <ccQtHelpers.h>
 
 //Qt
 #include <QCoreApplication>
@@ -209,7 +210,7 @@ bool Classifier::classify(	const Feature::Source::Set& featureSources,
 	int numberOfTrees = static_cast<int>(m_rtrees->getRoots().size());
 #ifndef _DEBUG
 #if defined(_OPENMP)
-#pragma omp parallel for num_threads(std::max(1, omp_get_max_threads() - 2))
+#pragma omp parallel for num_threads(ccQtHelpers::GetMaxThreadCount(omp_get_max_threads()))
 #endif
 #endif
 	for (int i = 0; i < static_cast<int>(cloud->size()); ++i)
diff --git a/q3DMASCTools.cpp b/q3DMASCTools.cpp
index d8deeec..32833dd 100644
--- a/q3DMASCTools.cpp
+++ b/q3DMASCTools.cpp
@@ -30,6 +30,9 @@
 #include <ccScalarField.h>
 #include <ccPointCloud.h>
 
+//CCPluginAPI
+#include <ccQtHelpers.h>
+
 //qPDALIO
 #include "../../../core/IO/qPDALIO/include/LASFields.h"
 
@@ -1229,15 +1232,16 @@ bool Tools::PrepareFeatures(const CorePoints& corePoints, Feature::Set& features
 				progressCb->setMethodTitle("Compute features");
 				progressCb->setInfo(qPrintable(logMessage));
 			}
-			ccLog::Print(logMessage + " , nb threads " + QString::number(omp_get_max_threads() - 2) + ", nb points " + QString::number(pointCount));
+			ccLog::Print(logMessage + ", nb points " + QString::number(pointCount));
 			CCCoreLib::NormalizedProgress nProgress(progressCb, pointCount);
-			nProgress.reset();
 
 			QMutex mutex;
 
 #ifndef _DEBUG
 #if defined(_OPENMP)
-#pragma omp parallel for num_threads(std::max(1, omp_get_max_threads() - 2))
+			int num_threads = ccQtHelpers::GetMaxThreadCount(omp_get_max_threads());
+			ccLog::Print("Using OpenMP with " + QString::number(num_threads) +  " threads ");
+#pragma omp parallel for num_threads(num_threads)
 #endif
 #endif
 			for (int i = 0; i < static_cast<int>(pointCount); ++i)