lock framebuffer stuff to prevent conflicts when reiniting the core or changing the renderer

src/frontend/qt_sdl/EmuInstance.cpp

@@ -1340,6 +1340,7 @@ bool EmuInstance::updateConsole(UpdateConsoleNDSArgs&& _ndsargs, UpdateConsoleGB
         args = &(*dsiargs);
     }
 
+    renderLock.lock();
     if ((!nds) || (consoleType != nds->ConsoleType))
     {
         NDS::Current = nullptr;
@@ -1387,6 +1388,7 @@ bool EmuInstance::updateConsole(UpdateConsoleNDSArgs&& _ndsargs, UpdateConsoleGB
             dsi->EjectGBACart();
         }
     }
+    renderLock.unlock();
 
     return true;
 }

src/frontend/qt_sdl/EmuInstance.h

@@ -150,6 +150,8 @@ public:
     void touchScreen(int x, int y);
     void releaseScreen();
 
+    QMutex renderLock;
+
 private:
     static int lastSep(const std::string& path);
     std::string getAssetPath(bool gba, const std::string& configpath, const std::string& ext, const std::string& file);

src/frontend/qt_sdl/EmuThread.cpp

@@ -231,6 +231,7 @@ void EmuThread::run()
             // update render settings if needed
             if (videoSettingsDirty)
             {
+                emuInstance->renderLock.lock();
                 if (useOpenGL)
                 {
                     emuInstance->setVSyncGL(true);
@@ -246,6 +247,7 @@ void EmuThread::run()
                 updateRenderer();
 
                 videoSettingsDirty = false;
+                emuInstance->renderLock.unlock();
             }
 
             // process input and hotkeys

src/frontend/qt_sdl/Screen.cpp

@@ -779,6 +779,7 @@ void ScreenPanelNative::paintEvent(QPaintEvent* event)
 
     if (emuThread->emuIsActive())
     {
+        emuInstance->renderLock.lock();
         auto nds = emuInstance->getNDS();
 
         assert(nds != nullptr);
@@ -801,6 +802,7 @@ void ScreenPanelNative::paintEvent(QPaintEvent* event)
             painter.setTransform(screenTrans[i]);
             painter.drawImage(screenrc, screen[screenKind[i]]);
         }
+        emuInstance->renderLock.unlock();
     }
 
     osdUpdate();