Changeset 47267 in webkit for trunk/JavaScriptCore/runtime/JSObject.h

Timestamp:

Aug 13, 2009, 10:35:33 PM (16 years ago)

Author:

[email protected]

Message:

Devirtualise marking
​https://bugs.webkit.org/show_bug.cgi?id=28294

Reviewed by Maciej Stachowiak.

Add a bit to TypeInfo to indicate that an object uses the standard
JSObject::markChildren method. This allows us to devirtualise marking
of most objects (though a branch is still needed). We also add a branch
to identify arrays thus devirtualising marking in that case as well.

In order to make the best use of this devirtualisation I've also reworked
the MarkStack::drain() logic to make the iteration more efficient.

File:

• trunk/JavaScriptCore/runtime/JSObject.h (modified) (4 diffs)

trunk/JavaScriptCore/runtime/JSObject.h

@@ -28 +28 @@
 #include "CommonIdentifiers.h"
 #include "CallFrame.h"
+#include "JSCell.h"
 #include "JSNumberCell.h"
+#include "MarkStack.h"
 #include "PropertySlot.h"
 #include "PutPropertySlot.h"
@@ -75 +77 @@
 
         virtual void markChildren(MarkStack&);
+        ALWAYS_INLINE void markChildrenDirect(MarkStack& markStack);
 
         // The inline virtual destructor cannot be the first virtual function declared
@@ -202 +205 @@
         static PassRefPtr<Structure> createStructure(JSValue prototype)
         {
-            return Structure::create(prototype, TypeInfo(ObjectType, HasStandardGetOwnPropertySlot));
+            return Structure::create(prototype, TypeInfo(ObjectType, HasStandardGetOwnPropertySlot | HasDefaultMark));
         }
 
@@ -628 +631 @@
 }
 
+ALWAYS_INLINE void JSObject::markChildrenDirect(MarkStack& markStack)
+{
+    JSCell::markChildren(markStack);
+    m_structure->markAggregate(markStack);
+    
+    PropertyStorage storage = propertyStorage();
+    size_t storageSize = m_structure->propertyStorageSize();
+    markStack.appendValues(reinterpret_cast<JSValue*>(storage), storageSize);
+}
+
 } // namespace JSC