[ABANDONED] Implement non-static methods of Promise and PromiseResolver.

Source/bindings/v8/custom/V8PromiseCustom.cpp

Index: Source/bindings/v8/custom/V8PromiseCustom.cpp
diff --git a/Source/bindings/v8/custom/V8PromiseCustom.cpp b/Source/bindings/v8/custom/V8PromiseCustom.cpp
index c9da71b9e89383867155271fdcf99798551f24dd..3a3d1b4c7e1a41620d237f1971c5eddec11005c2 100644
--- a/Source/bindings/v8/custom/V8PromiseCustom.cpp
+++ b/Source/bindings/v8/custom/V8PromiseCustom.cpp
@@ -33,13 +33,252 @@
 
 #include "V8Promise.h"
 #include "V8PromiseResolver.h"
+#include "bindings/v8/ScriptFunctionCall.h"
+#include "bindings/v8/ScriptValue.h"
 #include "bindings/v8/V8Binding.h"
+#include "bindings/v8/V8PerIsolateData.h"
 #include "bindings/v8/V8ScriptRunner.h"
 #include "bindings/v8/WrapperTypeInfo.h"
+#include "core/dom/Document.h"
+#include "core/dom/ExceptionCode.h"
+#include "core/page/DOMWindow.h"
+#include "core/platform/Task.h"
+#include "wtf/Functional.h"
+#include "wtf/PassOwnPtr.h"
 #include <v8.h>
 
 namespace WebCore {
 
+namespace {
+
+int wrapperCallbackTag = 0;
+int promiseFulfillCallbackTag = 0;
+int promiseResolveCallbackTag = 0;
+int promiseRejectCallbackTag = 0;
+
+// tag must be a pointer of one of the above tags.
+v8::Local<v8::Function> getFunction(v8::FunctionCallback callback, int* tag, v8::Isolate* isolate)
+{
+    WrapperWorldType worldType = WebCore::worldType(isolate);
+    V8PerIsolateData* data = V8PerIsolateData::from(isolate);
+    ASSERT(data);
+    V8PerIsolateData::TemplateMap::iterator result = data->templateMap(worldType).find(tag);
+    if (result != data->templateMap(worldType).end())
+        return result->value.newLocal(isolate)->GetFunction();
+
+    v8::HandleScope handleScope(isolate);
+    v8::Handle<v8::FunctionTemplate> templ = v8::FunctionTemplate::New(callback);
+    data->templateMap(worldType).add(tag, UnsafePersistent<v8::FunctionTemplate>(isolate, templ));
+    return handleScope.Close(templ)->GetFunction();

[abarth-chromium, 2013/06/27 03:25:16]

Don't you mean:

return handleScope.Close(templ->GetFunction());    ?

[yhirano, 2013/06/27 05:40:34]

Done.

+}
+
+class PromiseTask : public ScriptExecutionContext::Task {
+public:
+    PromiseTask(v8::Handle<v8::Function> callback, v8::Handle<v8::Value> receiver, v8::Handle<v8::Value> result)
+        : m_callback(callback), m_receiver(receiver), m_result(result)

[abarth-chromium, 2013/06/27 03:25:16]

Please split these up on to separate lines.

[yhirano, 2013/06/27 05:40:34]

Done.

+    {
+        ASSERT(!callback.IsEmpty());
+        ASSERT(!receiver.IsEmpty());
+        ASSERT(!result.IsEmpty());
+    }
+    virtual ~PromiseTask() { }
+
+    virtual void performTask(ScriptExecutionContext*) OVERRIDE;
+
+private:
+    ScriptValue m_callback;
+    ScriptValue m_receiver;
+    ScriptValue m_result;

[abarth-chromium, 2013/06/27 03:25:16]

You can use ScopedPersistent rather than ScriptValue here.  ScriptValue is for
code outside the bindings.

[yhirano, 2013/06/27 05:40:34]

Done.

+};
+
+void PromiseTask::performTask(ScriptExecutionContext* context)
+{
+    ASSERT(context->isDocument());
+    ScriptState* state = mainWorldScriptState(static_cast<Document*>(context)->frame());

[abarth-chromium, 2013/06/27 03:25:16]

We should ask the Document whether ActiveDOMObjects are stopped.  If they are,
we should drop this task on the floor.

[yhirano, 2013/06/27 05:40:34]

Done.

+    v8::HandleScope handleScope;
+    if (!state) {
+        // We can't execute the task. Ignore it.
+        return;
+    }

[abarth-chromium, 2013/06/27 03:25:16]

Can this occur?  If not we shouldn't handle this case.

[yhirano, 2013/06/27 05:40:34]

Done.

+    v8::Handle<v8::Context> v8Context = state->context();
+    if (v8Context.IsEmpty()) {
+        // We can't execute the task. Ignore it.
+        return;
+    }

[abarth-chromium, 2013/06/27 03:25:16]

Can this occur?  If not we shouldn't handle this case.

[yhirano, 2013/06/27 05:40:34]

Done.

+    v8::Context::Scope scope(v8Context);
+    v8::Handle<v8::Value> result = m_result.v8Value();
+    ASSERT(!m_callback.v8Value().IsEmpty());
+    ASSERT(m_callback.v8Value()->IsFunction());
+    v8::Local<v8::Function> callback = m_callback.v8Value().As<v8::Function>();
+    ASSERT(!m_receiver.v8Value().IsEmpty());
+    ASSERT(m_receiver.v8Value()->IsObject());
+    v8::Local<v8::Object> receiver =m_receiver.v8Value().As<v8::Object>();

[abarth-chromium, 2013/06/27 03:25:16]

You're missing a = before m_receiver.

[yhirano, 2013/06/27 05:40:34]

Done.

+    ASSERT(!result.IsEmpty());
+    v8::Local<v8::Value> v = V8ScriptRunner::callFunction(callback, context, receiver, 1, &result);

[abarth-chromium, 2013/06/27 03:25:16]

You don't need |v| here.  You can just ignore the return value.

[yhirano, 2013/06/27 05:40:34]

Done.

+};
+
+v8::Handle<v8::Value> postTask(v8::Handle<v8::Function> callback, v8::Handle<v8::Value> receiver, v8::Handle<v8::Value> value, v8::Isolate* isolate)
+{
+    DOMWindow* window = activeDOMWindow();
+    if (!window)
+        return setDOMException(INVALID_STATE_ERR, isolate);

[abarth-chromium, 2013/06/27 03:25:16]

Can this occur?  If not, we shouldn't handle this case.

[yhirano, 2013/06/27 05:40:34]

Done.

+    Document* document = window->document();
+    if (!document)
+        return setDOMException(INVALID_STATE_ERR, isolate);

[abarth-chromium, 2013/06/27 03:25:16]

This cannot occur.

[yhirano, 2013/06/27 05:40:34]

Done.

+    document->postTask(adoptPtr(new PromiseTask(callback, receiver, value)));
+    return v8::Undefined();

[abarth-chromium, 2013/06/27 03:25:16]

v8::Undefined(isolate)   ?

[yhirano, 2013/06/27 05:40:34]

Done.

+}
+
+void wrapperCallbackRaw(const v8::FunctionCallbackInfo<v8::Value>& args)
+{
+    v8::Isolate* isolate = args.GetIsolate();
+    v8SetReturnValue(args, v8::Undefined());

[abarth-chromium, 2013/06/27 03:25:16]

v8::Undefined(isolate)   ?

[yhirano, 2013/06/27 05:40:34]

Done.

+    v8::Local<v8::Object> environment;
+    v8::Local<v8::Value> result = v8::Undefined();

[abarth-chromium, 2013/06/27 03:25:16]

v8::Undefined(isolate)    ?

[yhirano, 2013/06/27 05:40:34]

Done.

+    if (args.Length() > 0 && !args[0].IsEmpty() && args[0]->IsObject())
+        environment = args[0].As<v8::Object>();
+    if (args.Length() > 1 && !args[1].IsEmpty())
+        result = args[1];
+    ASSERT(!environment.IsEmpty());

[abarth-chromium, 2013/06/27 03:25:16]

Why is this ASSERT valid?  If we don't execute line 139, then this ASSERT will
be false.

[yhirano, 2013/06/27 05:40:34]

Done.

+
+    v8::Local<v8::Value> value;
+
+    value = environment->GetInternalField(V8PromiseCustom::WrapperCallbackEnvironmentPromiseIndex);
+    ASSERT(!value.IsEmpty());
+    ASSERT(value->IsObject());
+    v8::Local<v8::Object> promise = value.As<v8::Object>();
+
+    value = environment->GetInternalField(V8PromiseCustom::WrapperCallbackEnvironmentPromiseResolverIndex);
+    ASSERT(!value.IsEmpty());
+    ASSERT(value->IsObject());
+    v8::Local<v8::Object> resolver = value.As<v8::Object>();
+
+    value = environment->GetInternalField(V8PromiseCustom::WrapperCallbackEnvironmentCallbackIndex);
+    ASSERT(!value.IsEmpty());
+    ASSERT(value->IsFunction());
+    v8::Local<v8::Function> callback = value.As<v8::Function>();
+
+    v8::TryCatch trycatch;
+    result = V8ScriptRunner::callFunction(callback, getScriptExecutionContext(), promise, 1, &result);
+    if (result.IsEmpty()) {
+        V8PromiseCustom::rejectResolver(resolver, trycatch.Exception(), true, isolate);
+        return;
+    }
+    V8PromiseCustom::resolveResolver(resolver, result, true, isolate);
+}
+
+v8::Handle<v8::Function> wrapperCallback(v8::Handle<v8::Object> promise, v8::Handle<v8::Object> resolver, v8::Handle<v8::Function> callback, v8::Isolate* isolate)
+{
+    ASSERT(!promise.IsEmpty());
+    ASSERT(!resolver.IsEmpty());
+    ASSERT(!callback.IsEmpty());
+    // FIXME: v8::ObjectTemplate::New should be cached.
+    v8::Local<v8::ObjectTemplate> tmpl = v8::ObjectTemplate::New();

[abarth-chromium, 2013/06/27 03:25:16]

tmpl  -> template (please use complete words in variable names)

[yhirano, 2013/06/27 05:40:34]

Done.

+    tmpl->SetInternalFieldCount(V8PromiseCustom::WrapperCallbackEnvironmentFieldCount);
+    v8::Local<v8::Object> env = tmpl->NewInstance();

[abarth-chromium, 2013/06/27 03:25:16]

env ->  ???  (please use complete words in variable names)

[yhirano, 2013/06/27 05:40:34]

Done.

+    env->SetInternalField(V8PromiseCustom::WrapperCallbackEnvironmentPromiseIndex, promise);
+    env->SetInternalField(V8PromiseCustom::WrapperCallbackEnvironmentPromiseResolverIndex, resolver);
+    env->SetInternalField(V8PromiseCustom::WrapperCallbackEnvironmentCallbackIndex, callback);
+
+    // FIXME: If there is a way to bind an object to a function other than evaluate a JavaScript, it will be preferable.
+    // FIXME: script compilation should be cached.
+    // We should not depend on the global context that user can change, such as accessing a property, calling a method or so.
+    v8::Local<v8::String> script = v8::String::New("(function(f, v1) { return function(v2) { return f(v1, v2); }; })");
+    v8::Local<v8::Value> value = V8ScriptRunner::compileAndRunInternalScript(script, isolate);

[abarth-chromium, 2013/06/27 03:25:16]

There's got to be a better way to do this.

+    ASSERT(!value.IsEmpty());
+    ASSERT(value->IsFunction());
+
+    v8::Local<v8::Value> argv[] = {
+        getFunction(wrapperCallbackRaw, &wrapperCallbackTag, isolate),
+        env,
+    };
+    v8::Local<v8::Object> global = isolate->GetCurrentContext()->Global();

[abarth-chromium, 2013/06/27 03:25:16]

Why do you need to get the global?  Doesn't callFunction default to using the
global object of the current context?

+
+    value = V8ScriptRunner::callFunction(value.As<v8::Function>(), getScriptExecutionContext(), global, WTF_ARRAY_LENGTH(argv), argv);
+    ASSERT(!value.IsEmpty());
+    ASSERT(value->IsFunction());
+    return value.As<v8::Function>();
+}
+
+void promiseFulfillCallback(const v8::FunctionCallbackInfo<v8::Value>& args)
+{
+    v8::Local<v8::Object> resolver;
+    v8::Local<v8::Value> result = v8::Undefined();
+    if (args.Length() > 0 && !args[0].IsEmpty() && args[0]->IsObject())
+        resolver = args[0].As<v8::Object>();
+    if (args.Length() > 1 && !args[1].IsEmpty())
+        result = args[1];
+
+    ASSERT(!resolver.IsEmpty());

[abarth-chromium, 2013/06/27 03:25:16]

Again, why do we have this ASSERT and the branch on line 208?

[yhirano, 2013/06/27 05:40:34]

Done.

+    V8PromiseCustom::fulfillResolver(resolver, result, true, args.GetIsolate());
+}
+
+void promiseResolveCallback(const v8::FunctionCallbackInfo<v8::Value>& args)
+{
+    v8::Local<v8::Object> resolver;
+    v8::Local<v8::Value> result = v8::Undefined();
+    if (args.Length() > 0 && !args[0].IsEmpty() && args[0]->IsObject())
+        resolver = args[0].As<v8::Object>();
+    if (args.Length() > 1 && !args[1].IsEmpty())
+        result = args[1];
+
+    ASSERT(!resolver.IsEmpty());
+    V8PromiseCustom::resolveResolver(resolver, result, true, args.GetIsolate());
+}
+
+void promiseRejectCallback(const v8::FunctionCallbackInfo<v8::Value>& args)
+{
+    v8::Local<v8::Object> resolver;
+    v8::Local<v8::Value> result = v8::Undefined();
+    if (args.Length() > 0 && !args[0].IsEmpty() && args[0]->IsObject())
+        resolver = args[0].As<v8::Object>();
+    if (args.Length() > 1 && !args[1].IsEmpty())
+        result = args[1];
+
+    ASSERT(!resolver.IsEmpty());
+    V8PromiseCustom::rejectResolver(resolver, result, true, args.GetIsolate());
+}
+
+v8::Local<v8::Function> promiseCallback(v8::Handle<v8::Object> resolver, V8PromiseCustom::PromiseAlgorithm algorithm, v8::Isolate* isolate)
+{
+    ASSERT(!resolver.IsEmpty());
+    v8::Local<v8::Function> callback;
+    switch (algorithm) {
+    case V8PromiseCustom::FulfillAlgorithm:
+        callback = getFunction(promiseFulfillCallback, &promiseFulfillCallbackTag, isolate);
+        break;
+    case V8PromiseCustom::ResolveAlgorithm:
+        callback = getFunction(promiseResolveCallback, &promiseResolveCallbackTag, isolate);
+        break;
+    case V8PromiseCustom::RejectAlgorithm:
+        callback = getFunction(promiseRejectCallback, &promiseRejectCallbackTag, isolate);
+        break;
+    default:
+        ASSERT(0);
+    }
+
+    // FIXME: If there is a way to bind an object to a function other than evaluate a JavaScript, it will be preferable.
+    // FIXME: script compilation should be cached.
+    // We should not depend on the global context that user can change, such as accessing a property, calling a method or so.
+    v8::Local<v8::String> script = v8::String::New("(function(f, v1) { return function(v2) { return f(v1, v2); }; })");
+    v8::Local<v8::Value> value = V8ScriptRunner::compileAndRunInternalScript(script, isolate);
+    ASSERT(!value.IsEmpty());
+    ASSERT(value->IsFunction());
+
+    v8::Local<v8::Value> argv[] = {
+        callback,
+        resolver,
+    };
+    v8::Local<v8::Object> receiver = isolate->GetCurrentContext()->Global();
+
+    value = V8ScriptRunner::callFunction(value.As<v8::Function>(), getScriptExecutionContext(), receiver, WTF_ARRAY_LENGTH(argv), argv);
+    ASSERT(!value.IsEmpty());
+    ASSERT(value->IsFunction());
+    return value.As<v8::Function>();
+}
+
+} // namespace
+
 void V8Promise::constructorCustom(const v8::FunctionCallbackInfo<v8::Value>& args)
 {
     v8SetReturnValue(args, v8::Local<v8::Value>());
@@ -48,30 +287,271 @@ void V8Promise::constructorCustom(const v8::FunctionCallbackInfo<v8::Value>& arg
         throwTypeError("Promise constructor takes a function argument", isolate);
         return;
     }
-    v8::Handle<v8::Function> init = args[0].As<v8::Function>();
+    v8::Local<v8::Function> init = args[0].As<v8::Function>();
+    v8::Local<v8::Object> promise, resolver;
+    V8PromiseCustom::createPromise(args.Holder(), &promise, &resolver, isolate);
+    v8::Handle<v8::Value> argv[] = {
+        resolver,
+    };
+    v8::TryCatch trycatch;
+    if (V8ScriptRunner::callFunction(init, getScriptExecutionContext(), promise, WTF_ARRAY_LENGTH(argv), argv).IsEmpty()) {
+        // An exception is thrown. Reject the promise.
+        V8PromiseCustom::rejectResolver(resolver, trycatch.Exception(), false, isolate);
+    }
+    v8SetReturnValue(args, promise);
+    return;
+}
+
+void V8Promise::thenMethodCustom(const v8::FunctionCallbackInfo<v8::Value>& args)
+{
+    v8::Isolate* isolate = args.GetIsolate();
+    v8SetReturnValue(args, v8::Local<v8::Value>());
+    v8::Local<v8::Function> fulfillWrapper, rejectWrapper;
+    v8::Local<v8::Object> promise, resolver;
+    V8PromiseCustom::createPromise(args.Holder(), &promise, &resolver, isolate);
+    if (args.Length() > 0 && !args[0].IsEmpty() && !args[0]->IsUndefined()) {
+        if (!args[0]->IsFunction()) {
+            throwTypeError("fulfillCallback must be a function or undefined", isolate);
+            return;
+        }
+        fulfillWrapper = wrapperCallback(promise, resolver, args[0].As<v8::Function>(), isolate);
+    } else {
+        fulfillWrapper = promiseCallback(resolver, V8PromiseCustom::FulfillAlgorithm, isolate);
+    }
+    if (args.Length() > 1 && !args[1].IsEmpty() && !args[1]->IsUndefined()) {
+        if (!args[1]->IsFunction()) {
+            throwTypeError("rejectCallback must be a function or undefined", isolate);
+            return;
+        }
+        rejectWrapper = wrapperCallback(promise, resolver, args[1].As<v8::Function>(), isolate);
+    } else {
+        rejectWrapper = promiseCallback(resolver, V8PromiseCustom::RejectAlgorithm, isolate);
+    }
+    V8PromiseCustom::append(args.Holder(), fulfillWrapper, rejectWrapper, isolate);
+    v8SetReturnValue(args, promise);
+}
+
+void V8Promise::catchMethodCustom(const v8::FunctionCallbackInfo<v8::Value>& args)
+{
+    v8::Isolate* isolate = args.GetIsolate();
+    v8SetReturnValue(args, v8::Local<v8::Value>());
+    v8::Local<v8::Function> fulfillWrapper, rejectWrapper;
+    v8::Local<v8::Object> promise, resolver;
+    V8PromiseCustom::createPromise(args.Holder(), &promise, &resolver, isolate);
+
+    if (args.Length() > 0 && !args[0].IsEmpty() && !args[0]->IsUndefined()) {
+        if (!args[0]->IsFunction()) {
+            throwTypeError("rejectCallback must be a function or undefined", isolate);
+            return;
+        }
+        rejectWrapper = wrapperCallback(promise, resolver, args[0].As<v8::Function>(), isolate);
+    } else {
+        rejectWrapper = promiseCallback(resolver, V8PromiseCustom::RejectAlgorithm, isolate);
+    }
+    fulfillWrapper = promiseCallback(resolver, V8PromiseCustom::FulfillAlgorithm, isolate);
+    V8PromiseCustom::append(args.Holder(), fulfillWrapper, rejectWrapper, isolate);
+    v8SetReturnValue(args, promise);
+}
+
+//
+// -- V8PromiseCustom --
+void V8PromiseCustom::createPromise(v8::Handle<v8::Object> creationContext, v8::Local<v8::Object>* promise, v8::Local<v8::Object>* resolver, v8::Isolate* isolate)
+{
+    // FIXME: v8::ObjectTemplate::New should be cached.
     v8::Local<v8::ObjectTemplate> internalTemplate = v8::ObjectTemplate::New();
-    internalTemplate->SetInternalFieldCount(V8PromiseCustom::InternalFieldCount);
+    internalTemplate->SetInternalFieldCount(InternalFieldCount);
     v8::Local<v8::Object> internal = internalTemplate->NewInstance();
-    v8::Local<v8::Object> promise = V8DOMWrapper::createWrapper(args.Holder(), &V8Promise::info, 0, isolate);
-    v8::Local<v8::Object> promiseResolver = V8DOMWrapper::createWrapper(args.Holder(), &V8PromiseResolver::info, 0, isolate);
+    *promise = V8DOMWrapper::createWrapper(creationContext, &V8Promise::info, 0, isolate);
+    *resolver = V8DOMWrapper::createWrapper(creationContext, &V8PromiseResolver::info, 0, isolate);
+
+    clearInternal(internal, V8PromiseCustom::Pending, v8::Undefined());
+
+    (*promise)->SetInternalField(v8DOMWrapperObjectIndex, internal);
+    (*resolver)->SetInternalField(v8DOMWrapperObjectIndex, internal);
+}
+
+void V8PromiseCustom::fulfillResolver(v8::Handle<v8::Object> resolver, v8::Handle<v8::Value> result, bool synchronous, v8::Isolate* isolate)
+{
+    ASSERT(!resolver.IsEmpty());
+    ASSERT(!result.IsEmpty());
+    v8::Local<v8::Object> internal = getInternal(resolver);
+    if (internal.IsEmpty() || getState(internal) != Pending) {
+        // The resolver is already fulfilled or rejected.
+        return;
+    }
+
+    v8::Local<v8::Value> value;
+    value = internal->GetInternalField(V8PromiseCustom::InternalFulfillCallbackIndex);
+    ASSERT(!value.IsEmpty());
+    ASSERT(value->IsArray());
+    v8::Local<v8::Array> callbacks = value.As<v8::Array>();
+    clearInternal(internal, Fulfilled, result);
+    // The internal object is no more needed in this PromiseResolver.
+    resolver->SetInternalField(v8DOMWrapperObjectIndex, v8::Null());
+
+    v8::Local<v8::Object> global = isolate->GetCurrentContext()->Global();
+    for (uint32_t i = 0, length = callbacks->Length(); i < length; ++i) {
+        value = callbacks->Get(i);
+        ASSERT(!value.IsEmpty());
+        ASSERT(value->IsFunction());
+        v8::Local<v8::Function> callback = value.As<v8::Function>();
+        call(callback, global, result, synchronous, isolate);
+    }
+}
+
+void V8PromiseCustom::resolveResolver(v8::Handle<v8::Object> resolver, v8::Handle<v8::Value> result, bool synchronous, v8::Isolate* isolate)
+{
+    ASSERT(!resolver.IsEmpty());
+    ASSERT(!result.IsEmpty());
+    v8::Local<v8::Object> internal = getInternal(resolver);
+    if (internal.IsEmpty() || getState(internal) != Pending) {
+        // The resolver is already fulfilled or rejected.
+        return;
+    }
+
+    v8::Local<v8::Value> then;
+    if (result->IsObject()) {
+        v8::TryCatch trycatch;
+        then = result.As<v8::Object>()->Get(v8::String::New("then"));
+        if (then.IsEmpty()) {
+            // If calling the [[Get]] internal method threw an exception, catch it and run reject.
+            rejectResolver(resolver, trycatch.Exception(), synchronous, isolate);
+            return;
+        }
+    }
 
-    internal->SetInternalField(V8PromiseCustom::InternalStateIndex, v8::NumberObject::New(V8PromiseCustom::Pending));
-    internal->SetInternalField(V8PromiseCustom::InternalResultIndex, v8::Undefined());
+    if (!then.IsEmpty() && then->IsFunction()) {
+        ASSERT(result->IsObject());
+        v8::TryCatch trycatch;
+        v8::Handle<v8::Value> argv[] = {
+            promiseCallback(resolver, ResolveAlgorithm, isolate),
+            promiseCallback(resolver, RejectAlgorithm, isolate),
+        };
+        if (V8ScriptRunner::callFunction(then.As<v8::Function>(), getScriptExecutionContext(), result.As<v8::Object>(), WTF_ARRAY_LENGTH(argv), argv).IsEmpty())
+            rejectResolver(resolver, trycatch.Exception(), synchronous, isolate);
+        return;
+    }
+    fulfillResolver(resolver, result, synchronous, isolate);
+}
+
+void V8PromiseCustom::rejectResolver(v8::Handle<v8::Object> resolver, v8::Handle<v8::Value> result, bool synchronous, v8::Isolate* isolate)
+{
+    ASSERT(!resolver.IsEmpty());
+    ASSERT(!result.IsEmpty());
+    v8::Local<v8::Object> internal = getInternal(resolver);
+    if (internal.IsEmpty() || getState(internal) != Pending) {
+        // The resolver is already fulfilled or rejected.
+        return;
+    }
+
+    v8::Local<v8::Value> value;
+    value = internal->GetInternalField(V8PromiseCustom::InternalRejectCallbackIndex);
+    ASSERT(!value.IsEmpty());
+    ASSERT(value->IsArray());
+    v8::Local<v8::Array> callbacks = value.As<v8::Array>();
+    clearInternal(internal, Rejected, result);
+    // The internal object is no more needed from this PromiseResolver.
+    resolver->SetInternalField(v8DOMWrapperObjectIndex, v8::Null());
+
+    v8::Local<v8::Object> global = isolate->GetCurrentContext()->Global();
+    for (uint32_t i = 0, length = callbacks->Length(); i < length; ++i) {
+        value = callbacks->Get(i);
+        ASSERT(!value.IsEmpty());
+        ASSERT(value->IsFunction());
+        v8::Local<v8::Function> callback = value.As<v8::Function>();
+        call(callback, global, result, synchronous, isolate);
+    }
+}
+
+void V8PromiseCustom::append(v8::Handle<v8::Object> promise, v8::Handle<v8::Function> fulfillCallback, v8::Handle<v8::Function> rejectCallback, v8::Isolate* isolate)
+{
+    v8::Local<v8::Object> internal = getInternal(promise);
+    ASSERT(!internal.IsEmpty());
+
+    PromiseState state = getState(internal);
+    if (state == Fulfilled) {
+        if (!fulfillCallback.IsEmpty()) {
+            v8::Local<v8::Value> result = internal->GetInternalField(V8PromiseCustom::InternalResultIndex);
+            v8::Local<v8::Object> global = isolate->GetCurrentContext()->Global();
+            call(fulfillCallback, global, result, false, isolate);
+        }
+        return;
+    }
+    if (state == Rejected) {
+        if (!rejectCallback.IsEmpty()) {
+            v8::Local<v8::Value> result = internal->GetInternalField(V8PromiseCustom::InternalResultIndex);
+            v8::Local<v8::Object> global = isolate->GetCurrentContext()->Global();
+            call(rejectCallback, global, result, false, isolate);
+        }
+        return;
+    }
+
+    ASSERT(state == Pending);
+    if (!fulfillCallback.IsEmpty()) {
+        v8::Local<v8::Value> value = internal->GetInternalField(InternalFulfillCallbackIndex);
+        ASSERT(!value.IsEmpty());
+        ASSERT(value->IsArray());
+        v8::Local<v8::Array> callbacks = value.As<v8::Array>();
+        callbacks->Set(callbacks->Length(), fulfillCallback);
+    }
+    if (!rejectCallback.IsEmpty()) {
+        v8::Local<v8::Value> value = internal->GetInternalField(InternalRejectCallbackIndex);
+        ASSERT(!value.IsEmpty());
+        ASSERT(value->IsArray());
+        v8::Local<v8::Array> callbacks = value.As<v8::Array>();
+        callbacks->Set(callbacks->Length(), rejectCallback);
+    }
+}
+
+v8::Local<v8::Object> V8PromiseCustom::getInternal(v8::Handle<v8::Object> promiseOrPromiseResolver)
+{
+    ASSERT(!promiseOrPromiseResolver.IsEmpty());
+    v8::Local<v8::Value> value = promiseOrPromiseResolver->GetInternalField(v8DOMWrapperObjectIndex);
+    ASSERT(!value.IsEmpty());
+    if (value->IsNull())
+        return v8::Local<v8::Object>();
+    ASSERT(value->IsObject());
+    return value.As<v8::Object>();
+}
+
+void V8PromiseCustom::clearInternal(v8::Handle<v8::Object> internal, PromiseState state, v8::Handle<v8::Value> value)
+{
+    ASSERT(!internal.IsEmpty());
+
+    setState(internal, state);
+    internal->SetInternalField(V8PromiseCustom::InternalResultIndex, value);
     internal->SetInternalField(V8PromiseCustom::InternalFulfillCallbackIndex, v8::Array::New());
     internal->SetInternalField(V8PromiseCustom::InternalRejectCallbackIndex, v8::Array::New());
+}
 
-    promise->SetInternalField(v8DOMWrapperObjectIndex, internal);
-    promiseResolver->SetInternalField(v8DOMWrapperObjectIndex, internal);
+V8PromiseCustom::PromiseState V8PromiseCustom::getState(v8::Handle<v8::Object> internal)
+{
+    ASSERT(!internal.IsEmpty());
+    v8::Handle<v8::Value> value = internal->GetInternalField(V8PromiseCustom::InternalStateIndex);
+    ASSERT(!value.IsEmpty());
+    ASSERT(value->IsNumber());
+    double number = value.As<v8::Number>()->Value();
+    ASSERT(number == Pending || number == Fulfilled || number == Rejected);
+    return static_cast<PromiseState>(number);
+}
 
-    v8::Handle<v8::Value> argv[] = {
-        promiseResolver,
-    };
-    v8::TryCatch trycatch;
-    if (V8ScriptRunner::callFunction(init, getScriptExecutionContext(), promise, WTF_ARRAY_LENGTH(argv), argv).IsEmpty()) {
-        // FIXME: An exception is thrown. Reject the promise.
+void V8PromiseCustom::setState(v8::Handle<v8::Object> internal, PromiseState state)
+{
+    ASSERT(!internal.IsEmpty());
+    ASSERT(state == Pending || state == Fulfilled || state == Rejected);
+    internal->SetInternalField(V8PromiseCustom::InternalStateIndex, v8::Number::New(state));
+}
+
+void V8PromiseCustom::call(v8::Handle<v8::Function> function, v8::Handle<v8::Object> receiver, v8::Handle<v8::Value> result, bool synchronous, v8::Isolate* isolate)
+{
+    ASSERT(!function.IsEmpty());
+    ASSERT(!receiver.IsEmpty());
+    if (synchronous) {
+        v8::TryCatch trycatch;
+        V8ScriptRunner::callFunction(function, getScriptExecutionContext(), receiver, 1, &result);
+    } else {
+        postTask(function, receiver, result, isolate);
     }
-    v8SetReturnValue(args, promise);
-    return;
 }
 
 } // namespace WebCore