Introduce KeepAliveWhilePending to ScriptPromiseResolverWithContext.

Source/bindings/v8/ScriptPromiseResolverWithContext.cpp

Index: Source/bindings/v8/ScriptPromiseResolverWithContext.cpp
diff --git a/Source/bindings/v8/ScriptPromiseResolverWithContext.cpp b/Source/bindings/v8/ScriptPromiseResolverWithContext.cpp
index 1a39cac07223f4c777f9d4df80e891041609d0fa..0ee8b58bc76df0b02cc17cd68a77ced3120c44d9 100644
--- a/Source/bindings/v8/ScriptPromiseResolverWithContext.cpp
+++ b/Source/bindings/v8/ScriptPromiseResolverWithContext.cpp
@@ -9,6 +9,10 @@
 
 namespace WebCore {
 
+namespace {
+const char hiddenPropertyName[] = "blink::keepObjectWhilePending";
+} // namespace
+
 ScriptPromiseResolverWithContext::ScriptPromiseResolverWithContext(ScriptState* scriptState)
     : ActiveDOMObject(scriptState->executionContext())
     , m_state(Pending)
@@ -18,6 +22,16 @@ ScriptPromiseResolverWithContext::ScriptPromiseResolverWithContext(ScriptState*
 {
 }
 
+ScriptPromiseResolverWithContext::~ScriptPromiseResolverWithContext()
+{
+    if (m_state != ResolvedOrRejected) {
+        ScriptState::Scope scope(m_scriptState.get());
+        unregisterKeptObject();
+        reject(v8::Exception::Error(v8::String::NewFromUtf8(m_scriptState->isolate(),
+            "ScriptPromiseResolverWithContext is destructed without resolve / reject")));
+    }
+}
+
 void ScriptPromiseResolverWithContext::suspend()
 {
     m_timer.stop();
@@ -31,6 +45,8 @@ void ScriptPromiseResolverWithContext::resume()
 
 void ScriptPromiseResolverWithContext::stop()
 {
+    ScriptState::Scope scope(m_scriptState.get());
+    unregisterKeptObject();
     m_timer.stop();
     clear();
 }
@@ -53,9 +69,11 @@ void ScriptPromiseResolverWithContext::resolveOrRejectImmediately()
         V8RecursionScope scope(m_scriptState->isolate(), m_scriptState->executionContext());
         if (m_state == Resolving) {
             m_resolver->resolve(m_value.newLocal(m_scriptState->isolate()));
+            unregisterKeptObject();
         } else {
             ASSERT(m_state == Rejecting);
             m_resolver->reject(m_value.newLocal(m_scriptState->isolate()));
+            unregisterKeptObject();
         }
     }
     clear();
@@ -74,4 +92,31 @@ void ScriptPromiseResolverWithContext::clear()
     // |this| may be deleted here.
 }
 
+void ScriptPromiseResolverWithContext::keepObjectWhilePendingInternal(v8::Handle<v8::Value> value)
+{
+    ScriptState::Scope scope(m_scriptState.get());
+    if (!m_resolver)
+        return;
+    ScriptPromise promise = this->promise();
+    if (promise.isEmpty())
+        return;
+    v8::Local<v8::Promise> v8Promise = promise.v8Value().As<v8::Promise>();
+    v8::Local<v8::String> name = v8::String::NewFromUtf8(m_scriptState->isolate(), hiddenPropertyName);
+    ASSERT(v8Promise->GetHiddenValue(name).IsEmpty());
+    v8Promise->SetHiddenValue(name, value);
+}
+
+void ScriptPromiseResolverWithContext::unregisterKeptObject()
+{
+    if (!m_resolver)
+        return;
+    ASSERT(m_scriptState->isolate()->InContext());
+    ScriptPromise promise = this->promise();

[jrummell, 2014/06/12 20:10:24]

The comment for promise() states "an empty ScriptPromise will be returned after
resolve or reject is called." On lines 72 & 76 this method is called after
resolve/reject, so will the isEmpty() call below always return true?

[yhirano, 2014/06/13 04:19:30]

You are right, thanks for pointing it out.
Fixed.

+    if (promise.isEmpty())
+        return;
+    v8::Local<v8::Promise> v8Promise = promise.v8Value().As<v8::Promise>();
+    v8::Local<v8::String> name = v8::String::NewFromUtf8(m_scriptState->isolate(), hiddenPropertyName);
+    v8Promise->DeleteHiddenValue(name);
+}
+
 } // namespace WebCore