+typedef HashMap<RefPtr<StringImpl>, StaticValueEntry*> OpaqueJSClassStaticValuesTable;
+typedef HashMap<RefPtr<StringImpl>, StaticFunctionEntry*> OpaqueJSClassStaticFunctionsTable;
+
+struct OpaqueJSClass;
+
+// An OpaqueJSClass (JSClass) is created without a context, so it can be used with any context, even across context groups.
+// This structure holds data members that vary across context groups.
+struct OpaqueJSClassContextData {
+ WTF_MAKE_NONCOPYABLE(OpaqueJSClassContextData); WTF_MAKE_FAST_ALLOCATED;
+public:
+ OpaqueJSClassContextData(JSC::JSGlobalData&, OpaqueJSClass*);
+ ~OpaqueJSClassContextData();
+
+ // It is necessary to keep OpaqueJSClass alive because of the following rare scenario:
+ // 1. A class is created and used, so its context data is stored in JSGlobalData hash map.
+ // 2. The class is released, and when all JS objects that use it are collected, OpaqueJSClass
+ // is deleted (that's the part prevented by this RefPtr).
+ // 3. Another class is created at the same address.
+ // 4. When it is used, the old context data is found in JSGlobalData and used.
+ RefPtr<OpaqueJSClass> m_class;
+
+ OpaqueJSClassStaticValuesTable* staticValues;
+ OpaqueJSClassStaticFunctionsTable* staticFunctions;
+ JSC::Weak<JSC::JSObject> cachedPrototype;
+};
+
+struct OpaqueJSClass : public ThreadSafeRefCounted<OpaqueJSClass> {
+ static PassRefPtr<OpaqueJSClass> create(const JSClassDefinition*);
+ static PassRefPtr<OpaqueJSClass> createNoAutomaticPrototype(const JSClassDefinition*);