--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/WebCore/bindings/v8/V8IsolatedContext.h	Fri Sep 17 09:02:29 2010 +0300
@@ -0,0 +1,115 @@
+/*
+ * Copyright (C) 2009 Google Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef V8IsolatedContext_h
+#define V8IsolatedContext_h
+
+#include "IsolatedWorld.h"
+#include "ScriptSourceCode.h" // for WebCore::ScriptSourceCode
+#include "V8DOMWindow.h"
+#include "V8Proxy.h"
+#include "V8Utilities.h"
+#include <v8.h>
+
+namespace WebCore {
+
+class V8Proxy;
+
+// V8IsolatedContext
+//
+// V8IsolatedContext represents a isolated execution environment for
+// JavaScript.  Each isolated world executes in parallel with the main
+// JavaScript world.  An isolated world has access to the same DOM data
+// structures as the main world but none of the JavaScript pointers.
+//
+// It is an error to ever share a JavaScript pointer between two isolated
+// worlds or between an isolated world and the main world.  Because
+// isolated worlds have access to the DOM, they need their own DOM wrappers
+// to avoid having pointers to the main world's DOM wrappers (which are
+// JavaScript objects).
+class V8IsolatedContext {
+public:
+    // Creates an isolated world. To destroy it, call destroy().
+    // This will delete the isolated world when the context it owns is GC'd.
+    V8IsolatedContext(V8Proxy* proxy, int extensionGroup);
+    ~V8IsolatedContext();
+
+    // Call this to destroy the isolated world. It will be deleted sometime
+    // after this call, once all script references to the world's context
+    // have been dropped.
+    void destroy();
+
+    // Returns the isolated world associated with
+    // v8::Context::GetEntered().  Because worlds are isolated, the entire
+    // JavaScript call stack should be from the same isolated world.
+    // Returns 0 if the entered context is from the main world.
+    //
+    // FIXME: Consider edge cases with DOM mutation events that might
+    // violate this invariant.
+    //
+    static V8IsolatedContext* getEntered()
+    {
+        // This is a temporary performance optimization.   Essentially,
+        // GetHiddenValue is too slow for this code path.  We need to get the
+        // V8 team to add a real property to v8::Context for isolated worlds.
+        // Until then, we optimize the common case of not having any isolated
+        // worlds at all.
+        if (!IsolatedWorld::count())
+            return 0;
+        if (!v8::Context::InContext())
+            return 0;
+        return reinterpret_cast<V8IsolatedContext*>(getGlobalObject(v8::Context::GetEntered())->GetPointerFromInternalField(V8DOMWindow::enteredIsolatedWorldIndex));
+    }
+
+    v8::Handle<v8::Context> context() { return m_context->get(); }
+    PassRefPtr<SharedPersistent<v8::Context> > sharedContext() { return m_context; }
+
+    IsolatedWorld* world() const { return m_world.get(); }
+
+private:
+    static v8::Handle<v8::Object> getGlobalObject(v8::Handle<v8::Context> context)
+    {
+        return v8::Handle<v8::Object>::Cast(context->Global()->GetPrototype());
+    }
+
+    // Called by the garbage collector when our JavaScript context is about
+    // to be destroyed.
+    static void contextWeakReferenceCallback(v8::Persistent<v8::Value> object, void* isolatedContext);
+
+    // The underlying v8::Context. This object is keep on the heap as
+    // long as |m_context| has not been garbage collected.
+    RefPtr<SharedPersistent<v8::Context> > m_context;
+
+    RefPtr<IsolatedWorld> m_world;
+};
+
+} // namespace WebCore
+
+#endif // V8IsolatedContext_h