core: update allocSingleton implementation, valgrind suppression

modules/core/include/opencv2/core/private.hpp

@@ -142,9 +142,13 @@ namespace cv
 CV_EXPORTS void scalarToRawData(const cv::Scalar& s, void* buf, int type, int unroll_to = 0);
 
 //! Allocate all memory buffers which will not be freed, ease filtering memcheck issues
-template <typename T>
-T* allocSingleton(size_t count) { return static_cast<T*>(fastMalloc(sizeof(T) * count)); }
-}
+CV_EXPORTS void* allocSingletonBuffer(size_t size);
+
+//! Allocate all memory buffers which will not be freed, ease filtering memcheck issues
+template <typename T> static inline
+T* allocSingleton(size_t count = 1) { return static_cast<T*>(allocSingletonBuffer(sizeof(T) * count)); }
+
+} // namespace
 
 #if 1 // TODO: Remove in OpenCV 4.x
 

modules/core/src/system.cpp

@@ -70,6 +70,8 @@ static bool param_dumpErrors = utils::getConfigurationParameterBool("OPENCV_DUMP
 #endif
 );
 
+void* allocSingletonBuffer(size_t size) { return fastMalloc(size); }
+
 } // namespace cv
 
 #ifndef CV_ERROR_SET_TERMINATE_HANDLER  // build config option

platforms/scripts/valgrind.supp

@@ -12,6 +12,13 @@
    fun:_ZN2cv22getInitializationMutexEv
 }
 
+{
+   OpenCV-SingletonBuffer
+   Memcheck:Leak
+   ...
+   fun:_ZN2cv20allocSingletonBufferEm
+}
+
 {
    OpenCV-getStdAllocator
    Memcheck:Leak