Prevent softlock on shutdown and various cleanup

src/citra/emu_window/emu_window_sdl2.cpp

@@ -227,7 +227,6 @@ void EmuWindow_SDL2::Present() {
     while (IsOpen()) {
         VideoCore::g_renderer->TryPresent(100);
         SDL_GL_SwapWindow(render_window);
-        VideoCore::g_renderer->PresentComplete();
     }
     SDL_GL_MakeCurrent(render_window, nullptr);
 }

src/citra_qt/bootmanager.cpp

@@ -86,7 +86,6 @@ GRenderWindow::GRenderWindow(QWidget* parent, EmuThread* emu_thread)
     setWindowTitle(QStringLiteral("Citra %1 | %2-%3")
                        .arg(Common::g_build_name, Common::g_scm_branch, Common::g_scm_desc));
     setAttribute(Qt::WA_AcceptTouchEvents);
-    connect(this, &QOpenGLWidget::frameSwapped, this, &GRenderWindow::OnFrameSwapped);
     InputCommon::Init();
 }
 
@@ -104,10 +103,6 @@ void GRenderWindow::DoneCurrent() {
 
 void GRenderWindow::PollEvents() {}
 
-void OnFrameSwapped() {
-    VideoCore::g_renderer->PresentComplete();
-}
-
 // On Qt 5.0+, this correctly gets the size of the framebuffer (pixels).
 //
 // Older versions get the window size (density independent pixels),
@@ -303,10 +298,6 @@ void GRenderWindow::paintGL() {
     update();
 }
 
-void GRenderWindow::OnFrameSwapped() {
-    VideoCore::g_renderer->PresentComplete();
-}
-
 void GRenderWindow::showEvent(QShowEvent* event) {
     QWidget::showEvent(event);
 }

src/citra_qt/bootmanager.h

@@ -164,7 +164,6 @@ public slots:
     void OnEmulationStarting(EmuThread* emu_thread);
     void OnEmulationStopping();
     void OnFramebufferSizeChanged();
-    void OnFrameSwapped();
 
 signals:
     /// Emitted when the window is closed

src/video_core/renderer_base.h

@@ -35,9 +35,6 @@ public:
     /// specific implementation)
     virtual void TryPresent(int timeout_ms) = 0;
 
-    /// Marks the presentation buffer as complete and swaps it back into the pool
-    virtual void PresentComplete() = 0;
-
     /// Prepares for video dumping (e.g. create necessary buffers, etc)
     virtual void PrepareVideoDumping() = 0;
 

src/video_core/renderer_opengl/renderer_opengl.cpp

@@ -50,8 +50,8 @@ namespace OpenGL {
 
 // If the size of this is too small, it ends up creating a soft cap on FPS as the renderer will have
 // to wait on available presentation frames. There doesn't seem to be much of a downside to a larger
-// number but 8 seems to be a good trade off for now
+// number but 9 swap textures at 60FPS presentation allows for 800% speed so thats probably fine
-constexpr std::size_t SWAP_CHAIN_SIZE = 8;
+constexpr std::size_t SWAP_CHAIN_SIZE = 9;
 
 class OGLTextureMailbox : public Frontend::TextureMailbox {
 public:
@@ -72,6 +72,11 @@ public:
     ~OGLTextureMailbox() override {
         // lock the mutex and clear out the present and free_queues and notify any people who are
         // blocked to prevent deadlock on shutdown
+        std::scoped_lock lock(swap_chain_lock);
+        free_queue.clear();
+        present_queue.clear();
+        free_cv.notify_all();
+        present_cv.notify_all();
     }
 
     void ReloadPresentFrame(Frontend::Frame* frame, u32 height, u32 width) override {
@@ -120,7 +125,16 @@ public:
     Frontend::Frame* GetRenderFrame() override {
         std::unique_lock<std::mutex> lock(swap_chain_lock);
         // wait for new entries in the free_queue
-        free_cv.wait(lock, [&] { return !free_queue.empty(); });
+        // we want to break at some point to prevent a softlock on close if the presentation thread
+        // stops consuming buffers
+        free_cv.wait_for(lock, std::chrono::milliseconds(100), [&] { return !free_queue.empty(); });
+
+        // If theres no free frames, we will reuse the oldest render frame
+        if (free_queue.empty()) {
+            auto frame = present_queue.back();
+            present_queue.pop_back();
+            return frame;
+        }
 
         Frontend::Frame* frame = free_queue.front();
         free_queue.pop_front();
@@ -396,7 +410,7 @@ void RendererOpenGL::SwapBuffers() {
 
     // Recreate the frame if the size of the window has changed
     if (layout.width != frame->width || layout.height != frame->height) {
-        LOG_CRITICAL(Render_OpenGL, "Reloading render frame");
+        LOG_DEBUG(Render_OpenGL, "Reloading render frame");
         render_window.mailbox->ReloadRenderFrame(frame, layout.width, layout.height);
     }
 
@@ -846,6 +860,8 @@ void RendererOpenGL::TryPresent(int timeout_ms) {
         return;
     }
 
+    // Clearing before a full overwrite of a fbo can signal to drivers that they can avoid a
+    // readback since we won't be doing any blending
     glClear(GL_COLOR_BUFFER_BIT);
 
     // Recreate the presentation FBO if the color attachment was changed
@@ -867,10 +883,8 @@ void RendererOpenGL::TryPresent(int timeout_ms) {
     /* insert fence for the main thread to block on */
     frame->present_fence = glFenceSync(GL_SYNC_GPU_COMMANDS_COMPLETE, 0);
     glFlush();
-}
 
-void RendererOpenGL::PresentComplete() {
+    glBindFramebuffer(GL_READ_FRAMEBUFFER, 0);
-    //    render_window.mailbox->PresentationComplete();
 }
 
 /// Updates the framerate

src/video_core/renderer_opengl/renderer_opengl.h

@@ -60,9 +60,6 @@ public:
     /// context
     void TryPresent(int timeout_ms) override;
 
-    /// Finializes the presentation and sets up the presentation frame to go back into the mailbox
-    void PresentComplete() override;
-
     /// Prepares for video dumping (e.g. create necessary buffers, etc)
     void PrepareVideoDumping() override;