Changeset 164347 in webkit for trunk/Source/JavaScriptCore/runtime/JSString.cpp

Timestamp:

Feb 18, 2014, 7:21:47 PM (11 years ago)

Author:

[email protected]

Message:

Add fast mapping from StringImpl to JSString
​https://bugs.webkit.org/show_bug.cgi?id=128625

Reviewed by Geoff Garen & Andreas Kling.

Source/JavaScriptCore:

• runtime/JSString.cpp:

(JSC::JSString::WeakOwner::finalize):

• once the JSString weakly owned by a StringImpl becomed unreachable remove the WeakImpl.

• runtime/JSString.h:

(JSC::jsStringWithWeakOwner):

• create a JSString wrapping a StringImpl, and weakly caches the JSString on the StringImpl.

• runtime/VM.cpp:

(JSC::VM::VM):

• initialize jsStringWeakOwner.

(JSC::VM::createLeakedForMainThread):

• initialize jsStringWeakOwner - the main thread gets to use the weak pointer on StringImpl to cache a JSString wrapper.

• runtime/VM.h:
  • renamed createLeaked -> createLeakedForMainThread to make it clear this should only be used to cretae the main thread VM.

Source/WebCore:

Removed JSStringCache from WebCore; call JSC::jsStringWithWeakOwner instead.

• bindings/js/DOMWrapperWorld.cpp:

(WebCore::DOMWrapperWorld::clearWrappers):

• removed JSStringCache.

• bindings/js/DOMWrapperWorld.h:
  • removed JSStringCache.
• bindings/js/JSDOMBinding.h:

(WebCore::jsStringWithCache):

• call jsStringWithWeakOwner insead of using JSStringCache.

• bindings/js/JSDOMWindowBase.cpp:

(WebCore::JSDOMWindowBase::commonVM):

• renamed createLeaked -> createLeakedForMainThread.

• bindings/scripts/StaticString.pm:

(GenerateStrings):

• StringImpl has an additional field.

Source/WTF:

Add weak pointer from StringImpl to JSString.

• wtf/text/StringImpl.cpp:

(WTF::StringImpl::~StringImpl):

• ASSERT m_weakJSString is null.

• wtf/text/StringImpl.h:

(WTF::StringImpl::StringImpl):

• initialize m_weakJSString.

(WTF::StringImpl::weakJSString):
(WTF::StringImpl::setWeakJSString):

• added acessors for m_weakJSString.

File:

• trunk/Source/JavaScriptCore/runtime/JSString.cpp (modified) (1 diff)

trunk/Source/JavaScriptCore/runtime/JSString.cpp

@@ -299 +299 @@
 }
 
+void JSString::WeakOwner::finalize(Handle<Unknown>, void* context)
+{
+    StringImpl* impl = static_cast<StringImpl*>(context);
+    WeakSet::deallocate(impl->weakJSString());
+    impl->setWeakJSString(nullptr);
+}
+
 } // namespace JSC