From 70f2ee917e1f6b1eba29e0f44885cb2f42fba209 Mon Sep 17 00:00:00 2001
From: Alexander Alekhin <alexander.a.alekhin@gmail.com>
Date: Wed, 10 Oct 2018 13:53:46 +0300
Subject: [PATCH 1/2] cmake: add DllMain() into each OpenCV DLL

to detect process termination after ExitProcess() call
---
 cmake/OpenCVModule.cmake       |  8 ++++++++
 cmake/templates/dllmain.cpp.in | 36 ++++++++++++++++++++++++++++++++++
 modules/core/src/precomp.hpp   |  5 +++--
 3 files changed, 47 insertions(+), 2 deletions(-)
 create mode 100644 cmake/templates/dllmain.cpp.in

diff --git a/cmake/OpenCVModule.cmake b/cmake/OpenCVModule.cmake
index a869de5cc8..c0b189836f 100644
--- a/cmake/OpenCVModule.cmake
+++ b/cmake/OpenCVModule.cmake
@@ -909,6 +909,13 @@ macro(_ocv_create_module)
       source_group("Src" FILES "${_VS_VERSION_FILE}")
     endif()
   endif()
+  if(WIN32 AND NOT ("${the_module}" STREQUAL "opencv_core" OR "${the_module}" STREQUAL "opencv_world")
+      AND (BUILD_SHARED_LIBS AND NOT "x${OPENCV_MODULE_TYPE}" STREQUAL "xSTATIC")
+      AND NOT OPENCV_SKIP_DLLMAIN_GENERATION
+  )
+      set(_DLLMAIN_FILE "${CMAKE_CURRENT_BINARY_DIR}/${the_module}_main.cpp")
+      configure_file("${OpenCV_SOURCE_DIR}/cmake/templates/dllmain.cpp.in" "${_DLLMAIN_FILE}" @ONLY)
+  endif()
 
   source_group("Include" FILES "${OPENCV_CONFIG_FILE_INCLUDE_DIR}/cvconfig.h" "${OPENCV_CONFIG_FILE_INCLUDE_DIR}/opencv2/opencv_modules.hpp")
   source_group("Src" FILES "${${the_module}_pch}")
@@ -918,6 +925,7 @@ macro(_ocv_create_module)
     "${OPENCV_CONFIG_FILE_INCLUDE_DIR}/cvconfig.h" "${OPENCV_CONFIG_FILE_INCLUDE_DIR}/opencv2/opencv_modules.hpp"
     ${${the_module}_pch}
     ${_VS_VERSION_FILE}
+    ${_DLLMAIN_FILE}
   )
   set_target_properties(${the_module} PROPERTIES LABELS "${OPENCV_MODULE_${the_module}_LABEL};Module")
   set_source_files_properties(${OPENCV_MODULE_${the_module}_HEADERS} ${OPENCV_MODULE_${the_module}_SOURCES} ${${the_module}_pch}
diff --git a/cmake/templates/dllmain.cpp.in b/cmake/templates/dllmain.cpp.in
new file mode 100644
index 0000000000..6b3005f654
--- /dev/null
+++ b/cmake/templates/dllmain.cpp.in
@@ -0,0 +1,36 @@
+// This file is part of OpenCV project.
+// It is subject to the license terms in the LICENSE file found in the top-level directory
+// of this distribution and at http://opencv.org/license.html.
+
+#ifndef _WIN32
+#error "Build configuration error"
+#endif
+#ifndef CVAPI_EXPORTS
+#error "Build configuration error"
+#endif
+
+#define WIN32_LEAN_AND_MEAN
+#include <windows.h>
+
+#define OPENCV_MODULE_S "@the_module@"
+
+namespace cv {
+extern __declspec(dllimport) bool __termination;  // Details: #12750
+}
+
+extern "C"
+BOOL WINAPI DllMain(HINSTANCE, DWORD fdwReason, LPVOID lpReserved);
+
+extern "C"
+BOOL WINAPI DllMain(HINSTANCE, DWORD fdwReason, LPVOID lpReserved)
+{
+    if (fdwReason == DLL_THREAD_DETACH || fdwReason == DLL_PROCESS_DETACH)
+    {
+        if (lpReserved != NULL) // called after ExitProcess() call
+        {
+            //printf("OpenCV: terminating: " OPENCV_MODULE_S "\n");
+            cv::__termination = true;
+        }
+    }
+    return TRUE;
+}
diff --git a/modules/core/src/precomp.hpp b/modules/core/src/precomp.hpp
index 6349aa2dfd..6b3b23cddb 100644
--- a/modules/core/src/precomp.hpp
+++ b/modules/core/src/precomp.hpp
@@ -308,8 +308,9 @@ TLSData<CoreTLSData>& getCoreTlsData();
 #define CL_RUNTIME_EXPORT
 #endif
 
-extern bool __termination; // skip some cleanups, because process is terminating
-                           // (for example, if ExitProcess() was already called)
+extern CV_EXPORTS
+bool __termination;  // skip some cleanups, because process is terminating
+                     // (for example, if ExitProcess() was already called)
 
 cv::Mutex& getInitializationMutex();
 

From 11e2a216c513e302e6bc1c475c40b7717fbb8ed0 Mon Sep 17 00:00:00 2001
From: Alexander Alekhin <alexander.a.alekhin@gmail.com>
Date: Wed, 10 Oct 2018 18:04:39 +0000
Subject: [PATCH 2/2] ocl(win32): bypass deallocate() during process
 termination

---
 modules/core/src/ocl.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/modules/core/src/ocl.cpp b/modules/core/src/ocl.cpp
index 0e98c08659..42aaf8da29 100644
--- a/modules/core/src/ocl.cpp
+++ b/modules/core/src/ocl.cpp
@@ -4779,6 +4779,10 @@ public:
 
     void deallocate_(UMatData* u) const
     {
+#ifdef _WIN32
+        if (cv::__termination)  // process is not in consistent state (after ExitProcess call) and terminating
+            return;             // avoid any OpenCL calls
+#endif
         if(u->tempUMat())
         {
             CV_Assert(u->origdata);