Changeset 243126 in webkit

Timestamp:

Mar 18, 2019 7:05:23 PM (5 years ago)

Author:

Simon Fraser

Message:

Scrolling state nodes should hold references to GraphicsLayers
​https://bugs.webkit.org/show_bug.cgi?id=195844
<rdar://problem/48949634>

Reviewed by Tim Horton.

GraphicsLayers are refcounted, and the scrolling tree keeps GraphicsLayer pointers,
so for safely the scrolling tree should store RefPtr<GraphicsLayer> instead.

I removed the union (since it would be weird with a RefPtr and raw pointer). This code
should probably use WTF::Variant<> in future.

• page/scrolling/ScrollingStateNode.h:

(WebCore::LayerRepresentation::LayerRepresentation):
(WebCore::LayerRepresentation::operator GraphicsLayer* const):

Location:

trunk/Source/WebCore

Files:

• ChangeLog (modified) (1 diff)
• page/scrolling/ScrollingStateNode.h (modified) (5 diffs)

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2019-03-18  Simon Fraser  <simon.fraser@apple.com>
+
+        Scrolling state nodes should hold references to GraphicsLayers
+        https://bugs.webkit.org/show_bug.cgi?id=195844
+        <rdar://problem/48949634>
+
+        Reviewed by Tim Horton.
+
+        GraphicsLayers are refcounted, and the scrolling tree keeps GraphicsLayer pointers,
+        so for safely the scrolling tree should store RefPtr<GraphicsLayer> instead.
+
+        I removed the union (since it would be weird with a RefPtr and raw pointer). This code
+        should probably use WTF::Variant<> in future.
+
+        * page/scrolling/ScrollingStateNode.h:
+        (WebCore::LayerRepresentation::LayerRepresentation):
+        (WebCore::LayerRepresentation::operator GraphicsLayer* const):
+
 2019-03-18  Commit Queue  <commit-queue@webkit.org>
 

trunk/Source/WebCore/page/scrolling/ScrollingStateNode.h

@@ -59 +59 @@
     };
 
-    LayerRepresentation()
-        : m_graphicsLayer(nullptr)
-        , m_layerID(0)
-        , m_representation(EmptyRepresentation)
-    { }
+    LayerRepresentation() = default;
 
     LayerRepresentation(GraphicsLayer* graphicsLayer)
@@ -73 +69 @@
     LayerRepresentation(PlatformLayer* platformLayer)
         : m_typelessPlatformLayer(makePlatformLayerTypeless(platformLayer))
-        , m_layerID(0)
         , m_representation(PlatformLayerRepresentation)
     {
@@ -80 +75 @@
 
     LayerRepresentation(GraphicsLayer::PlatformLayerID layerID)
-        : m_graphicsLayer(nullptr)
-        , m_layerID(layerID)
+        : m_layerID(layerID)
         , m_representation(PlatformLayerIDRepresentation)
     {
@@ -104 +98 @@
     {
         ASSERT(m_representation == GraphicsLayerRepresentation);
-        return m_graphicsLayer;
+        return m_graphicsLayer.get();
     }
 
@@ -180 +174 @@
     WEBCORE_EXPORT static void* makePlatformLayerTypeless(PlatformLayer*);
 
-    union {
-        GraphicsLayer* m_graphicsLayer;
-        void* m_typelessPlatformLayer;
-    };
-
-    GraphicsLayer::PlatformLayerID m_layerID;
-    Type m_representation;
+    RefPtr<GraphicsLayer> m_graphicsLayer;
+    void* m_typelessPlatformLayer { nullptr };
+    GraphicsLayer::PlatformLayerID m_layerID { 0 };
+    Type m_representation { EmptyRepresentation };
 };