Don't report promise rejection events during the microtask checkpoint

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

Index: third_party/WebKit/Source/bindings/core/v8/RejectedPromises.cpp
diff --git a/third_party/WebKit/Source/bindings/core/v8/RejectedPromises.cpp b/third_party/WebKit/Source/bindings/core/v8/RejectedPromises.cpp
index 3ed8d247ee5d1659fbe25554de1e4a079984cff1..e88c277eb7a4b4a7eebe4782af8811efe5afd822 100644
--- a/third_party/WebKit/Source/bindings/core/v8/RejectedPromises.cpp
+++ b/third_party/WebKit/Source/bindings/core/v8/RejectedPromises.cpp
@@ -15,6 +15,12 @@
 #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 {
 
@@ -59,7 +65,7 @@ public:
         // Either collected or https://crbug.com/450330
         if (value.IsEmpty() || !value->IsPromise())
             return;
-        ASSERT(!v8::Local<v8::Promise>::Cast(value)->HasHandler());
+        ASSERT(!hasHandler());
 
         EventTarget* target = executionContext->errorEventTarget();
         if (RuntimeEnabledFeatures::promiseRejectionEventEnabled() && target) {
@@ -124,6 +130,27 @@ public:
         }
     }
 
+    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();
+    }
+
+    bool hasHandler()
+    {
+        if (isCollected())
+            return false;
+        ScriptState::Scope scope(m_scriptState);
+        v8::Local<v8::Value> value = m_promise.newLocal(m_scriptState->isolate());
+        return v8::Local<v8::Promise>::Cast(value)->HasHandler();
+    }
+
 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)
@@ -139,7 +166,6 @@ private:
         , m_collected(false)
         , m_shouldLogToConsole(true)
     {
-        m_promise.setWeak(this, &Message::didCollectPromise);
     }
 
     static void didCollectPromise(const v8::WeakCallbackInfo<Message>& data)
@@ -193,7 +219,8 @@ void RejectedPromises::handlerAdded(v8::PromiseRejectMessage data)
     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;
         }
@@ -202,11 +229,24 @@ void RejectedPromises::handlerAdded(v8::PromiseRejectMessage data)
 
 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())));

[sof, 2015/10/04 20:06:21]

To have the closure retain a RefPtr<> to the RejectedPromises object(*), you
need to explicitly convert it on construction to make that clear --

  s/this/PassRefPtrWillBeRawPtr<RejectedPromises>(this)/

As-is, the closure retains a bare pointer to the object, which results in things
like


https://storage.googleapis.com/chromium-layout-test-archives/WebKit_Linux_ASA...

* - is it required to use a RefPtr<> to implement the semantics? (the underlying
question being.. do the pending tasks here for a shut down worker need to run?)

+}
+
+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())
@@ -215,16 +255,21 @@ void RejectedPromises::processQueue()
             ++i;
     }
 
-    while (!m_queue.isEmpty()) {
-        OwnPtrWillBeRawPtr<Message> message = m_queue.takeFirst();
-        if (message->isCollected())
-            continue;
-
-        message->report();
-        m_reportedAsErrors.append(message.release());
-        if (m_reportedAsErrors.size() > maxReportedHandlersPendingResolution)
-            m_reportedAsErrors.remove(0, maxReportedHandlersPendingResolution / 10);
+    while (!queue->isEmpty()) {
+        OwnPtrWillBeRawPtr<Message> message = queue->takeFirst();
+        if (!message->hasHandler()) {
+            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