[GStreamer] Leak fixes for GL display, registries and video encoder

https://bugs.webkit.org/show_bug.cgi?id=266964

Reviewed by Carlos Garcia Campos.

The GL display and app contexts were persistent, so never destroyed, thus reported by the leak
tracer. The encoder was also leaking a GstElementFactory so its state is now cleared before
deinitialization. The MSE registry is also now cleaned-up as well.

* Source/WebCore/platform/graphics/PlatformDisplay.h:
* Source/WebCore/platform/graphics/gstreamer/GLVideoSinkGStreamer.cpp:
(requestGLContext):
* Source/WebCore/platform/graphics/gstreamer/GStreamerCommon.cpp:
(WebCore::registerWebKitGStreamerElements):
(WebCore::registerWebKitGStreamerVideoEncoder):
(WebCore::deinitializeGStreamer):
* Source/WebCore/platform/graphics/gstreamer/GStreamerRegistryScanner.cpp:
(WebCore::GStreamerRegistryScanner::singletonWasInitialized):
(WebCore::teardownGStreamerRegistryScanner):
(WebCore::GStreamerRegistryScanner::singletonNeedsInitialization): Deleted.
* Source/WebCore/platform/graphics/gstreamer/GStreamerRegistryScanner.h:
* Source/WebCore/platform/graphics/gstreamer/PlatformDisplayGStreamer.cpp:
(WebCore::PlatformDisplay::clearGStreamerGLState):
* Source/WebCore/platform/graphics/gstreamer/mse/GStreamerRegistryScannerMSE.cpp:
(WebCore::GStreamerRegistryScannerMSE::singleton):
(WebCore::teardownGStreamerRegistryScannerMSE):
* Source/WebCore/platform/graphics/gstreamer/mse/GStreamerRegistryScannerMSE.h:
* Source/WebCore/platform/gstreamer/VideoEncoderPrivateGStreamer.cpp:
(teardownVideoEncoderSingleton):
* Source/WebCore/platform/gstreamer/VideoEncoderPrivateGStreamer.h:

Canonical link: https://commits.webkit.org/272551@main

Author: philn

Source/WebCore/platform/graphics/PlatformDisplay.h

@@ -98,6 +98,7 @@ class PlatformDisplay {
 #if ENABLE(VIDEO) && USE(GSTREAMER_GL)
     GstGLDisplay* gstGLDisplay() const;
     GstGLContext* gstGLContext() const;
+    void clearGStreamerGLState();
 #endif
 
 #if USE(LCMS)

Source/WebCore/platform/graphics/gstreamer/GLVideoSinkGStreamer.cpp

@@ -151,13 +151,13 @@ std::optional<GRefPtr<GstContext>> requestGLContext(const char* contextType)
         return std::nullopt;
 
     if (!g_strcmp0(contextType, GST_GL_DISPLAY_CONTEXT_TYPE)) {
-        GRefPtr<GstContext> displayContext = adoptGRef(gst_context_new(GST_GL_DISPLAY_CONTEXT_TYPE, TRUE));
+        GRefPtr<GstContext> displayContext = adoptGRef(gst_context_new(GST_GL_DISPLAY_CONTEXT_TYPE, FALSE));
         gst_context_set_gl_display(displayContext.get(), gstGLDisplay);
         return displayContext;
     }
 
     if (!g_strcmp0(contextType, "gst.gl.app_context")) {
-        GRefPtr<GstContext> appContext = adoptGRef(gst_context_new("gst.gl.app_context", TRUE));
+        GRefPtr<GstContext> appContext = adoptGRef(gst_context_new("gst.gl.app_context", FALSE));
         GstStructure* structure = gst_context_writable_structure(appContext.get());
         gst_structure_set(structure, "context", GST_TYPE_GL_CONTEXT, gstGLContext, nullptr);
         return appContext;

Source/WebCore/platform/graphics/gstreamer/GStreamerCommon.cpp

@@ -33,6 +33,7 @@
 #include "GUniquePtrGStreamer.h"
 #include "GstAllocatorFastMalloc.h"
 #include "IntSize.h"
+#include "PlatformDisplay.h"
 #include "RuntimeApplicationChecks.h"
 #include "SharedBuffer.h"
 #include "WebKitAudioSinkGStreamer.h"
@@ -461,6 +462,10 @@ void unregisterPipeline(const GRefPtr<GstElement>& pipeline)
 
 void deinitializeGStreamer()
 {
+#if USE(GSTREAMER_GL)
+    auto& sharedDisplay = PlatformDisplay::sharedDisplayForCompositing();
+    sharedDisplay.clearGStreamerGLState();
+#endif
 #if ENABLE(MEDIA_SOURCE)
     teardownGStreamerRegistryScannerMSE();
 #endif
@@ -489,6 +494,9 @@ void deinitializeGStreamer()
         activePipelinesMap().clear();
     }
 
+#if ENABLE(VIDEO)
+    teardownVideoEncoderSingleton();
+#endif
     gst_deinit();
 }
 

Source/WebCore/platform/graphics/gstreamer/PlatformDisplayGStreamer.cpp

@@ -134,3 +134,9 @@ GstGLContext* PlatformDisplay::gstGLContext() const
         return nullptr;
     return m_gstGLContext.get();
 }
+
+void PlatformDisplay::clearGStreamerGLState()
+{
+    m_gstGLDisplay = nullptr;
+    m_gstGLContext = nullptr;
+}

Source/WebCore/platform/gstreamer/VideoEncoderPrivateGStreamer.cpp

@@ -170,6 +170,11 @@ class Encoders {
     }
 };
 
+void teardownVideoEncoderSingleton()
+{
+    Encoders::singleton().clear();
+}
+
 /* Internal bin structure: videoconvert ! inputCapsFilter ! encoder ! outputCapsFilter ! (optional
    parser) ! capsFilter */
 struct _WebKitVideoEncoderPrivate {

Source/WebCore/platform/gstreamer/VideoEncoderPrivateGStreamer.h

@@ -46,3 +46,4 @@ GType webkit_video_encoder_get_type(void);
 
 bool videoEncoderSupportsFormat(WebKitVideoEncoder*, const GRefPtr<GstCaps>&);
 bool videoEncoderSetFormat(WebKitVideoEncoder*, GRefPtr<GstCaps>&&);
+void teardownVideoEncoderSingleton();