[GStreamer] De-initialize only if leaks tracer is active

https://bugs.webkit.org/show_bug.cgi?id=268977

Reviewed by Xabier Rodriguez-Calvar.

The `gst_deinit()` call is useful only if the leaks tracer is active. Otherwise resources will be
freed anyway when the WebProcess terminates.

* Source/WebCore/platform/graphics/gstreamer/GRefPtrGStreamer.cpp:
(WTF::adoptGRef):
(WTF::refGPtr<GstTracer>):
(WTF::derefGPtr<GstTracer>):
* Source/WebCore/platform/graphics/gstreamer/GRefPtrGStreamer.h:
* Source/WebCore/platform/graphics/gstreamer/GStreamerCommon.cpp:
(WebCore::deinitializeGStreamer):

Canonical link: https://commits.webkit.org/274811@main

Author: philn

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

@@ -549,6 +549,28 @@ void derefGPtr<GstDevice>(GstDevice* ptr)
         gst_object_unref(ptr);
 }
 
+template<>
+GRefPtr<GstTracer> adoptGRef(GstTracer* ptr)
+{
+    return GRefPtr<GstTracer>(ptr, GRefPtrAdopt);
+}
+
+template<>
+GstTracer* refGPtr<GstTracer>(GstTracer* ptr)
+{
+    if (ptr)
+        gst_object_ref(GST_OBJECT_CAST(ptr));
+
+    return ptr;
+}
+
+template<>
+void derefGPtr<GstTracer>(GstTracer* ptr)
+{
+    if (ptr)
+        gst_object_unref(ptr);
+}
+
 template <> GRefPtr<WebKitVideoSink> adoptGRef(WebKitVideoSink* ptr)
 {
     ASSERT(!ptr || !g_object_is_floating(ptr));

Source/WebCore/platform/graphics/gstreamer/GRefPtrGStreamer.h

@@ -173,6 +173,10 @@ template<> GRefPtr<GstDevice> adoptGRef(GstDevice*);
 template<> GstDevice* refGPtr<GstDevice>(GstDevice*);
 template<> void derefGPtr<GstDevice>(GstDevice*);
 
+template<> GRefPtr<GstTracer> adoptGRef(GstTracer*);
+template<> GstTracer* refGPtr<GstTracer>(GstTracer*);
+template<> void derefGPtr<GstTracer>(GstTracer*);
+
 #if USE(GSTREAMER_GL)
 template<> GRefPtr<GstGLDisplay> adoptGRef(GstGLDisplay* ptr);
 template<> GstGLDisplay* refGPtr<GstGLDisplay>(GstGLDisplay* ptr);

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

@@ -497,6 +497,18 @@ void deinitializeGStreamer()
     teardownVideoEncoderSingleton();
 #endif
 
+    bool isLeaksTracerActive = false;
+    auto activeTracers = gst_tracing_get_active_tracers();
+    while (activeTracers) {
+        auto tracer = adoptGRef(GST_TRACER_CAST(activeTracers->data));
+        if (!isLeaksTracerActive && !g_strcmp0(G_OBJECT_TYPE_NAME(G_OBJECT(tracer.get())), "GstLeaksTracer"))
+            isLeaksTracerActive = true;
+        activeTracers = g_list_delete_link(activeTracers, activeTracers);
+    }
+
+    if (!isLeaksTracerActive)
+        return;
+
     // Make sure there is no active pipeline left. Those might trigger deadlocks during gst_deinit().
     {
         Locker locker { s_activePipelinesMapLock };