Don't report promise rejection events during the microtask checkpoint

third_party/WebKit/Source/bindings/core/v8/RejectedPromises.cpp

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "config.h"
 #include "bindings/core/v8/RejectedPromises.h"
 
 #include "bindings/core/v8/ScopedPersistent.h"
 #include "bindings/core/v8/ScriptState.h"
 #include "bindings/core/v8/ScriptValue.h"
 #include "bindings/core/v8/V8Binding.h"
 #include "core/dom/ExecutionContext.h"
 #include "core/events/EventTarget.h"
 #include "core/events/PromiseRejectionEvent.h"
 #include "core/inspector/ConsoleMessage.h"
 #include "core/inspector/ScriptArguments.h"
 #include "platform/RuntimeEnabledFeatures.h"
+#include "platform/Task.h"
+#include "public/platform/Platform.h"
+#include "public/platform/WebScheduler.h"
+#include "public/platform/WebTaskRunner.h"
+#include "public/platform/WebThread.h"
+#include "wtf/Functional.h"
 
 namespace blink {
 
 static const unsigned maxReportedHandlersPendingResolution = 1000;
 
 class RejectedPromises::Message final : public NoBaseWillBeGarbageCollectedFinalized<RejectedPromises::Message> {
 public:
     static PassOwnPtrWillBeRawPtr<Message> create(ScriptState* scriptState, v8::Local<v8::Promise> promise, const ScriptValue& exception, const String& errorMessage, const String& resourceName, int scriptId, int lineNumber, int columnNumber, PassRefPtrWillBeRawPtr<ScriptCallStack> callStack)
     {
         return adoptPtrWillBeNoop(new Message(scriptState, promise, exception, errorMessage, resourceName, scriptId, lineNumber, columnNumber, callStack));
@@ skipping 24 matching lines @@
             return;
         ExecutionContext* executionContext = m_scriptState->executionContext();
         if (!executionContext)
             return;
 
         ScriptState::Scope scope(m_scriptState);
         v8::Local<v8::Value> value = m_promise.newLocal(m_scriptState->isolate());
         // Either collected or https://crbug.com/450330
         if (value.IsEmpty() || !value->IsPromise())
             return;
-        ASSERT(!v8::Local<v8::Promise>::Cast(value)->HasHandler());

[jochen (gone - plz use gerrit), 2015/10/02 07:57:23]

that's no longer true, as we post a task to report the unhandled rejection, and
by the time it's reported there might already be a handler.

 
         EventTarget* target = executionContext->errorEventTarget();
         if (RuntimeEnabledFeatures::promiseRejectionEventEnabled() && target) {
             PromiseRejectionEventInit init;
             init.setPromise(ScriptPromise(m_scriptState, value));
             init.setReason(m_exception);
             init.setCancelable(true);
             RefPtrWillBeRawPtr<PromiseRejectionEvent> event = PromiseRejectionEvent::create(m_scriptState, EventTypeNames::unhandledrejection, init);
             // Log to console if event was not preventDefault()'ed.
             m_shouldLogToConsole = target->dispatchEvent(event);
@@ skipping 44 matching lines @@
             target->dispatchEvent(event);
         }
 
         if (m_shouldLogToConsole) {
             RefPtrWillBeRawPtr<ConsoleMessage> consoleMessage = ConsoleMessage::create(JSMessageSource, RevokedErrorMessageLevel, "Handler added to rejected promise");
             consoleMessage->setRelatedMessageId(m_consoleMessageId);
             executionContext->addConsoleMessage(consoleMessage.release());
         }
     }
 
+    void makePromiseWeak()
+    {
+        ASSERT(!m_promise.isEmpty() && !m_promise.isWeak());
+        m_promise.setWeak(this, &Message::didCollectPromise);
+    }
+
+    void makePromiseStrong()
+    {
+        ASSERT(!m_promise.isEmpty() && m_promise.isWeak());
+        m_promise.clearWeak();
+    }
+
 private:
     Message(ScriptState* scriptState, v8::Local<v8::Promise> promise, const ScriptValue& exception, const String& errorMessage, const String& resourceName, int scriptId, int lineNumber, int columnNumber, PassRefPtrWillBeRawPtr<ScriptCallStack> callStack)
         : m_scriptState(scriptState)
         , m_promise(scriptState->isolate(), promise)
         , m_exception(exception)
         , m_errorMessage(errorMessage)
         , m_resourceName(resourceName)
         , m_scriptId(scriptId)
         , m_lineNumber(lineNumber)
         , m_columnNumber(columnNumber)
         , m_callStack(callStack)
         , m_consoleMessageId(0)
         , m_collected(false)
         , m_shouldLogToConsole(true)
     {
-        m_promise.setWeak(this, &Message::didCollectPromise);
     }
 
     static void didCollectPromise(const v8::WeakCallbackInfo<Message>& data)
     {
         data.GetParameter()->m_collected = true;
         data.GetParameter()->m_promise.clear();
     }
 
     ScriptState* m_scriptState;
     ScopedPersistent<v8::Promise> m_promise;
@@ skipping 33 matching lines @@
         if (!(*it)->isCollected() && (*it)->hasPromise(data.GetPromise())) {
             m_queue.remove(it);
             return;
         }
     }
 
     // Then look it up in the reported errors.
     for (size_t i = 0; i < m_reportedAsErrors.size(); ++i) {
         auto& message = m_reportedAsErrors.at(i);
         if (!message->isCollected() && message->hasPromise(data.GetPromise())) {
-            message->revoke();
+            message->makePromiseStrong();
+            Platform::current()->currentThread()->scheduler()->timerTaskRunner()->postTask(FROM_HERE, new Task(bind(&RejectedPromises::revokeNow, this, message.release())));
             m_reportedAsErrors.remove(i);
             return;
         }
     }
 }
 
 void RejectedPromises::dispose()
 {
-    processQueue();
+    if (!m_queue.isEmpty()) {
+        OwnPtrWillBeRawPtr<WillBeHeapDeque<OwnPtrWillBeMember<Message>>> queue = adoptPtr(new WillBeHeapDeque<OwnPtrWillBeMember<Message>>());
+        queue->swap(m_queue);
+        processQueueNow(queue.release());
+    }
 }
 
 void RejectedPromises::processQueue()
 {
+    if (m_queue.isEmpty())
+        return;
+    OwnPtrWillBeRawPtr<WillBeHeapDeque<OwnPtrWillBeMember<Message>>> queue = adoptPtr(new WillBeHeapDeque<OwnPtrWillBeMember<Message>>());
+    queue->swap(m_queue);
+    Platform::current()->currentThread()->scheduler()->timerTaskRunner()->postTask(FROM_HERE, new Task(bind(&RejectedPromises::processQueueNow, this, queue.release())));
+}
+
+void RejectedPromises::processQueueNow(PassOwnPtrWillBeRawPtr<WillBeHeapDeque<OwnPtrWillBeMember<Message>>> queue)
+{
     // Remove collected handlers.
     for (size_t i = 0; i < m_reportedAsErrors.size();) {
         if (m_reportedAsErrors.at(i)->isCollected())
             m_reportedAsErrors.remove(i);
         else
             ++i;
     }
 
-    while (!m_queue.isEmpty()) {
-        OwnPtrWillBeRawPtr<Message> message = m_queue.takeFirst();
-        if (message->isCollected())
-            continue;
-
+    while (!queue->isEmpty()) {
+        OwnPtrWillBeRawPtr<Message> message = queue->takeFirst();
         message->report();
+        message->makePromiseWeak();
         m_reportedAsErrors.append(message.release());
         if (m_reportedAsErrors.size() > maxReportedHandlersPendingResolution)
             m_reportedAsErrors.remove(0, maxReportedHandlersPendingResolution / 10);
     }
 }
 
+void RejectedPromises::revokeNow(PassOwnPtrWillBeRawPtr<Message> message)
+{
+    message->revoke();
+}
+
 } // namespace blink