Introduce v8::Object::CreationContext method.

That allows to find out a global context in which the object
was created.

Review URL: http://codereview.chromium.org/6759054

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7476 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

include/v8.h

@@ -1652,6 +1652,11 @@ class Object : public Value {
    */
   V8EXPORT Local<Object> Clone();
 
+  /**
+   * Returns the context in which the object was created.
+   */
+  V8EXPORT Local<Context> CreationContext();
+
   /**
    * Set the backing store of the indexed properties to be managed by the
    * embedding layer. Access to the indexed properties will follow the rules

src/api.cc

@@ -2879,6 +2879,33 @@ Local<v8::Object> v8::Object::Clone() {
 }
 
 
+static i::Context* GetCreationContext(i::JSObject* object) {
+  i::Object* constructor = object->map()->constructor();
+  i::JSFunction* function;
+  if (!constructor->IsJSFunction()) {
+    // API functions have null as a constructor,
+    // but any JSFunction knows its context immediately.
+    ASSERT(object->IsJSFunction() &&
+           i::JSFunction::cast(object)->shared()->IsApiFunction());
+    function = i::JSFunction::cast(object);
+  } else {
+    function = i::JSFunction::cast(constructor);
+  }
+  return function->context()->global_context();
+}
+
+
+Local<v8::Context> v8::Object::CreationContext() {
+  i::Isolate* isolate = Utils::OpenHandle(this)->GetIsolate();
+  ON_BAILOUT(isolate,
+             "v8::Object::CreationContext()", return Local<v8::Context>());
+  ENTER_V8(isolate);
+  i::Handle<i::JSObject> self = Utils::OpenHandle(this);
+  i::Context* context = GetCreationContext(*self);
+  return Utils::ToLocal(i::Handle<i::Context>(context));
+}
+
+
 int v8::Object::GetIdentityHash() {
   i::Isolate* isolate = Utils::OpenHandle(this)->GetIsolate();
   ON_BAILOUT(isolate, "v8::Object::GetIdentityHash()", return 0);

test/cctest/test-api.cc

@@ -13629,3 +13629,102 @@ TEST(DefinePropertyPostDetach) {
   context->DetachGlobal();
   define_property->Call(proxy, 0, NULL);
 }
+
+
+static void InstallContextId(v8::Handle<Context> context, int id) {
+  Context::Scope scope(context);
+  CompileRun("Object.prototype").As<Object>()->
+      Set(v8_str("context_id"), v8::Integer::New(id));
+}
+
+
+static void CheckContextId(v8::Handle<Object> object, int expected) {
+  CHECK_EQ(expected, object->Get(v8_str("context_id"))->Int32Value());
+}
+
+
+THREADED_TEST(CreationContext) {
+  HandleScope handle_scope;
+  Persistent<Context> context1 = Context::New();
+  InstallContextId(context1, 1);
+  Persistent<Context> context2 = Context::New();
+  InstallContextId(context2, 2);
+  Persistent<Context> context3 = Context::New();
+  InstallContextId(context3, 3);
+
+  Local<v8::FunctionTemplate> tmpl = v8::FunctionTemplate::New();
+
+  Local<Object> object1;
+  Local<Function> func1;
+  {
+    Context::Scope scope(context1);
+    object1 = Object::New();
+    func1 = tmpl->GetFunction();
+  }
+
+  Local<Object> object2;
+  Local<Function> func2;
+  {
+    Context::Scope scope(context2);
+    object2 = Object::New();
+    func2 = tmpl->GetFunction();
+  }
+
+  Local<Object> instance1;
+  Local<Object> instance2;
+
+  {
+    Context::Scope scope(context3);
+    instance1 = func1->NewInstance();
+    instance2 = func2->NewInstance();
+  }
+
+  CHECK(object1->CreationContext() == context1);
+  CheckContextId(object1, 1);
+  CHECK(func1->CreationContext() == context1);
+  CheckContextId(func1, 1);
+  CHECK(instance1->CreationContext() == context1);
+  CheckContextId(instance1, 1);
+  CHECK(object2->CreationContext() == context2);
+  CheckContextId(object2, 2);
+  CHECK(func2->CreationContext() == context2);
+  CheckContextId(func2, 2);
+  CHECK(instance2->CreationContext() == context2);
+  CheckContextId(instance2, 2);
+
+  {
+    Context::Scope scope(context1);
+    CHECK(object1->CreationContext() == context1);
+    CheckContextId(object1, 1);
+    CHECK(func1->CreationContext() == context1);
+    CheckContextId(func1, 1);
+    CHECK(instance1->CreationContext() == context1);
+    CheckContextId(instance1, 1);
+    CHECK(object2->CreationContext() == context2);
+    CheckContextId(object2, 2);
+    CHECK(func2->CreationContext() == context2);
+    CheckContextId(func2, 2);
+    CHECK(instance2->CreationContext() == context2);
+    CheckContextId(instance2, 2);
+  }
+
+  {
+    Context::Scope scope(context2);
+    CHECK(object1->CreationContext() == context1);
+    CheckContextId(object1, 1);
+    CHECK(func1->CreationContext() == context1);
+    CheckContextId(func1, 1);
+    CHECK(instance1->CreationContext() == context1);
+    CheckContextId(instance1, 1);
+    CHECK(object2->CreationContext() == context2);
+    CheckContextId(object2, 2);
+    CHECK(func2->CreationContext() == context2);
+    CheckContextId(func2, 2);
+    CHECK(instance2->CreationContext() == context2);
+    CheckContextId(instance2, 2);
+  }
+
+  context1.Dispose();
+  context2.Dispose();
+  context3.Dispose();
+}