Improve robustness and error handling of DXVsyncSource

app/streaming/video/ffmpeg-renderers/pacer/dxvsyncsource.cpp

@@ -10,6 +10,8 @@ DxVsyncSource::DxVsyncSource(Pacer* pacer) :
     m_LastMonitor(nullptr)
 {
     SDL_zero(m_WaitForVblankEventParams);
+    m_WaitForVblankEventParams.VidPnSourceId = D3DDDI_ID_UNINITIALIZED;
+    SDL_zero(m_AdapterLuid);
 }
 
 DxVsyncSource::~DxVsyncSource()
@@ -72,41 +74,43 @@ bool DxVsyncSource::isAsync()
     return false;
 }
 
-void DxVsyncSource::waitForVsync()
+bool DxVsyncSource::waitForVsync()
 {
     NTSTATUS status;
 
     // If the monitor has changed from last time, open the new adapter
     HMONITOR currentMonitor = MonitorFromWindow(m_Window, MONITOR_DEFAULTTONEAREST);
-    if (currentMonitor != m_LastMonitor) {
+    if (!currentMonitor || currentMonitor != m_LastMonitor) {
+        // Close the old adapter
+        if (m_WaitForVblankEventParams.hAdapter != 0) {
+            D3DKMT_CLOSEADAPTER closeAdapterParams = {};
+            closeAdapterParams.hAdapter = m_WaitForVblankEventParams.hAdapter;
+            m_D3DKMTCloseAdapter(&closeAdapterParams);
+            m_WaitForVblankEventParams.hAdapter = 0;
+        }
+        m_LastMonitor = nullptr;
+
+        // We can't wait if we're not on any monitor
+        if (!currentMonitor) {
+            return false;
+        }
+
         MONITORINFOEXA monitorInfo = {};
         monitorInfo.cbSize = sizeof(monitorInfo);
         if (!GetMonitorInfoA(currentMonitor, &monitorInfo)) {
             SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
                          "GetMonitorInfo() failed: %d",
                          GetLastError());
-            return;
+            return false;
         }
 
-        DEVMODEA monitorMode;
+        DEVMODEA monitorMode = {};
         monitorMode.dmSize = sizeof(monitorMode);
         if (!EnumDisplaySettingsA(monitorInfo.szDevice, ENUM_CURRENT_SETTINGS, &monitorMode)) {
             SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
                          "EnumDisplaySettings() failed: %d",
                          GetLastError());
-            return;
-        }
-
-        SDL_LogInfo(SDL_LOG_CATEGORY_APPLICATION,
-                    "Monitor changed: %s %d Hz",
-                    monitorInfo.szDevice,
-                    monitorMode.dmDisplayFrequency);
-
-        // Close the old adapter
-        if (m_WaitForVblankEventParams.hAdapter != 0) {
-            D3DKMT_CLOSEADAPTER closeAdapterParams = {};
-            closeAdapterParams.hAdapter = m_WaitForVblankEventParams.hAdapter;
-            m_D3DKMTCloseAdapter(&closeAdapterParams);
+            return false;
         }
 
         D3DKMT_OPENADAPTERFROMHDC openAdapterParams = {};
@@ -115,7 +119,7 @@ void DxVsyncSource::waitForVsync()
             SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
                          "CreateDC() failed: %d",
                          GetLastError());
-            return;
+            return false;
         }
 
         // Open the new adapter
@@ -126,21 +130,38 @@ void DxVsyncSource::waitForVsync()
             SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
                          "D3DKMTOpenAdapterFromHdc() failed: %x",
                          status);
-            return;
+            return false;
+        }
+
+        // VidPnSourceId is scoped to the adapter, so we must also check the adapter LUID
+        if (m_AdapterLuid.LowPart != openAdapterParams.AdapterLuid.LowPart ||
+                m_AdapterLuid.HighPart != openAdapterParams.AdapterLuid.HighPart ||
+                m_WaitForVblankEventParams.VidPnSourceId != openAdapterParams.VidPnSourceId) {
+            SDL_LogInfo(SDL_LOG_CATEGORY_APPLICATION,
+                        "Monitor changed: %s %d Hz",
+                        monitorInfo.szDevice,
+                        monitorMode.dmDisplayFrequency);
         }
 
         m_WaitForVblankEventParams.hAdapter = openAdapterParams.hAdapter;
         m_WaitForVblankEventParams.hDevice = 0;
         m_WaitForVblankEventParams.VidPnSourceId = openAdapterParams.VidPnSourceId;
 
+        m_AdapterLuid = openAdapterParams.AdapterLuid;
         m_LastMonitor = currentMonitor;
     }
 
     status = m_D3DKMTWaitForVerticalBlankEvent(&m_WaitForVblankEventParams);
     if (status != STATUS_SUCCESS) {
-        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
-                     "D3DKMTWaitForVerticalBlankEvent() failed: %x",
-                     status);
-        return;
+        if (status != STATUS_GRAPHICS_PRESENT_OCCLUDED) {
+            SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
+                         "D3DKMTWaitForVerticalBlankEvent() failed: %x",
+                         status);
+        }
+
+        m_LastMonitor = nullptr;
+        return false;
     }
+
+    return true;
 }

app/streaming/video/ffmpeg-renderers/pacer/dxvsyncsource.h

@@ -10,6 +10,7 @@ typedef UINT D3DKMT_HANDLE;
 typedef UINT D3DDDI_VIDEO_PRESENT_SOURCE_ID;
 #define STATUS_SUCCESS ((NTSTATUS)0x00000000L)
 #define STATUS_GRAPHICS_PRESENT_OCCLUDED ((NTSTATUS)0xC01E0006L)
+#define D3DDDI_ID_UNINITIALIZED (UINT)(~0)
 typedef struct _D3DKMT_OPENADAPTERFROMHDC {
   HDC hDc;
   D3DKMT_HANDLE hAdapter;
@@ -39,13 +40,14 @@ public:
 
     virtual bool isAsync() override;
 
-    virtual void waitForVsync() override;
+    virtual bool waitForVsync() override;
 
 private:
     Pacer* m_Pacer;
     HMODULE m_Gdi32Handle;
     HWND m_Window;
     HMONITOR m_LastMonitor;
+    LUID m_AdapterLuid;
     D3DKMT_WAITFORVERTICALBLANKEVENT m_WaitForVblankEventParams;
 
     PFND3DKMTOPENADAPTERFROMHDC m_D3DKMTOpenAdapterFromHdc;

app/streaming/video/ffmpeg-renderers/pacer/pacer.cpp

@@ -115,13 +115,20 @@ int Pacer::vsyncThread(void *context)
     while (!me->m_Stopping) {
         if (async) {
             // Wait for the VSync source to invoke signalVsync() or 100ms to elapse
-            me->m_FrameQueueLock.lock();
+            QMutexLocker locker(&me->m_FrameQueueLock);
             me->m_VsyncSignalled.wait(&me->m_FrameQueueLock, 100);
-            me->m_FrameQueueLock.unlock();
         }
         else {
             // Let the VSync source wait in the context of our thread
-            me->m_VsyncSource->waitForVsync();
+            if (!me->m_VsyncSource->waitForVsync()) {
+                // Fall back to a fixed delay if the VSync source fails
+                //
+                // NB: We don't actually expect signalVsync() to be called, since
+                // this is a synchronous VSync source, but we wait on m_VsyncSignalled
+                // anyway so that the destructor can immediately wake us on shutdown.
+                QMutexLocker locker(&me->m_FrameQueueLock);
+                me->m_VsyncSignalled.wait(&me->m_FrameQueueLock, 1000 / me->m_DisplayFps);
+            }
         }
 
         if (me->m_Stopping) {
@@ -148,24 +155,25 @@ int Pacer::renderThread(void* context)
         // Wait for the renderer to be ready for the next frame
         me->m_VsyncRenderer->waitToRender();
 
-        // Acquire the frame queue lock to protect the queue and
-        // the not empty condition
-        me->m_FrameQueueLock.lock();
+        AVFrame* frame;
+        {
+            // Acquire the frame queue lock to protect the queue and
+            // the not empty condition
+            QMutexLocker locker(&me->m_FrameQueueLock);
 
-        // Wait for a frame to be ready to render
-        while (!me->m_Stopping && me->m_RenderQueue.isEmpty()) {
-            me->m_RenderQueueNotEmpty.wait(&me->m_FrameQueueLock);
+            // Wait for a frame to be ready to render
+            while (!me->m_Stopping && me->m_RenderQueue.isEmpty()) {
+                me->m_RenderQueueNotEmpty.wait(&me->m_FrameQueueLock);
+            }
+
+            if (me->m_Stopping) {
+                // Exit this thread
+                break;
+            }
+
+            frame = me->m_RenderQueue.dequeue();
         }
 
-        if (me->m_Stopping) {
-            // Exit this thread
-            me->m_FrameQueueLock.unlock();
-            break;
-        }
-
-        AVFrame* frame = me->m_RenderQueue.dequeue();
-        me->m_FrameQueueLock.unlock();
-
         me->renderFrame(frame);
     }
 
@@ -349,7 +357,7 @@ void Pacer::renderFrame(AVFrame* frame)
     av_frame_free(&frame);
 
     // Drop frames if we have too many queued up for a while
-    m_FrameQueueLock.lock();
+    QMutexLocker frameQueueLocker(&m_FrameQueueLock);
 
     int frameDropTarget;
 
@@ -382,13 +390,11 @@ void Pacer::renderFrame(AVFrame* frame)
         AVFrame* frame = m_RenderQueue.dequeue();
 
         // Drop the lock while we call av_frame_free()
-        m_FrameQueueLock.unlock();
+        frameQueueLocker.unlock();
         m_VideoStats->pacerDroppedFrames++;
         av_frame_free(&frame);
-        m_FrameQueueLock.lock();
+        frameQueueLocker.relock();
     }
-
-    m_FrameQueueLock.unlock();
 }
 
 void Pacer::dropFrameForEnqueue(QQueue<AVFrame*>& queue)

app/streaming/video/ffmpeg-renderers/pacer/pacer.h

@@ -22,9 +22,10 @@ public:
     // sources require calls to waitForVsync().
     virtual bool isAsync() = 0;
 
-    virtual void waitForVsync() {
+    virtual bool waitForVsync() {
         // Synchronous sources must implement waitForVsync()!
         SDL_assert(false);
+        return false;
     }
 };