DevTools: Capture async stacks for event listeners.

Source/core/inspector/AsyncCallStackTracker.cpp

Index: Source/core/inspector/AsyncCallStackTracker.cpp
diff --git a/Source/core/inspector/AsyncCallStackTracker.cpp b/Source/core/inspector/AsyncCallStackTracker.cpp
index d3a1982af2b16a22b3dffa3f6248143237aee4e9..04ab4a8a7097e180105da6511ce91c2ddf2e512b 100644
--- a/Source/core/inspector/AsyncCallStackTracker.cpp
+++ b/Source/core/inspector/AsyncCallStackTracker.cpp
@@ -33,12 +33,19 @@
 
 #include "core/dom/ContextLifecycleObserver.h"
 #include "core/dom/ExecutionContext.h"
+#include "core/events/EventTarget.h"
+#include "core/events/RegisteredEventListener.h"
+#include "wtf/text/StringBuilder.h"
 
 namespace WebCore {
 
 class AsyncCallStackTracker::ExecutionContextData : public ContextLifecycleObserver {
     WTF_MAKE_FAST_ALLOCATED;
 public:
+    typedef std::pair<RegisteredEventListener, RefPtr<AsyncCallChain> > EventListenerAsyncCallChain;
+    typedef Vector<EventListenerAsyncCallChain, 1> EventListenerAsyncCallChainVector;
+    typedef HashMap<AtomicString, EventListenerAsyncCallChainVector> EventListenerAsyncCallChainVectorHashMap;
+
     ExecutionContextData(AsyncCallStackTracker* tracker, ExecutionContext* executionContext)
         : ContextLifecycleObserver(executionContext)
         , m_tracker(tracker)
@@ -51,12 +58,57 @@ public:
         ContextLifecycleObserver::contextDestroyed();
     }
 
+    void add(EventTarget* eventTarget, const AtomicString& eventType, const EventListenerAsyncCallChain& item)

[yurys, 2013/12/17 13:01:59]

addEventListenerData?

[aandrey, 2013/12/17 13:24:03]

Done.

+    {
+        HashMap<EventTarget*, EventListenerAsyncCallChainVectorHashMap>::iterator it = m_eventTargetCallChains.find(eventTarget);
+        if (it == m_eventTargetCallChains.end())
+            it = m_eventTargetCallChains.set(eventTarget, EventListenerAsyncCallChainVectorHashMap()).iterator;
+        EventListenerAsyncCallChainVectorHashMap& map = it->value;
+        EventListenerAsyncCallChainVectorHashMap::iterator it2 = map.find(eventType);
+        if (it2 == map.end())
+            it2 = map.set(eventType, EventListenerAsyncCallChainVector()).iterator;
+        it2->value.append(item);
+    }
+
+    void remove(EventTarget* eventTarget, const AtomicString& eventType, const RegisteredEventListener& item)
+    {
+        get(eventTarget, eventType, item, true);
+    }
+
+    PassRefPtr<AsyncCallChain> get(EventTarget* eventTarget, const AtomicString& eventType, const RegisteredEventListener& item, bool remove = false)
+    {
+        HashMap<EventTarget*, EventListenerAsyncCallChainVectorHashMap>::iterator it = m_eventTargetCallChains.find(eventTarget);
+        if (it == m_eventTargetCallChains.end())
+            return 0;
+        EventListenerAsyncCallChainVectorHashMap& map = it->value;
+        EventListenerAsyncCallChainVectorHashMap::iterator it2 = map.find(eventType);
+        if (it2 == map.end())
+            return 0;
+        RefPtr<AsyncCallChain> result;
+        EventListenerAsyncCallChainVector& vector = it2->value;
+        for (size_t i = 0; i < vector.size(); ++i) {
+            if (vector[i].first == item) {
+                result = vector[i].second;
+                if (remove) {
+                    vector.remove(i);
+                    if (vector.isEmpty())
+                        map.remove(it2);
+                    if (map.isEmpty())
+                        m_eventTargetCallChains.remove(it);
+                }
+                break;
+            }
+        }
+        return result.release();
+    }
+
 private:
     friend class AsyncCallStackTracker;

[yurys, 2013/12/17 13:01:59]

All these field should be public since ExecutionContextData is an implementation
detail of AsyncCallStackTracker

[aandrey, 2013/12/17 13:24:03]

Done.

     AsyncCallStackTracker* m_tracker;
     HashSet<int> m_intervalTimerIds;
     HashMap<int, RefPtr<AsyncCallChain> > m_timerCallChains;
     HashMap<int, RefPtr<AsyncCallChain> > m_animationFrameCallChains;
+    HashMap<EventTarget*, EventListenerAsyncCallChainVectorHashMap> m_eventTargetCallChains;
 };
 
 AsyncCallStackTracker::AsyncCallStack::AsyncCallStack(const String& description, const ScriptValue& callFrames)
@@ -125,14 +177,13 @@ void AsyncCallStackTracker::willFireTimer(ExecutionContext* context, int timerId
     if (!isEnabled())
         return;
     ASSERT(timerId > 0);
-    ASSERT(!m_currentAsyncCallChain);

[yurys, 2013/12/17 13:01:59]

Why did you remove this assert? Can it fail in a wrong place?

[aandrey, 2013/12/17 13:07:48]

We can receive nested willHandleEvent() callbacks, thus this ASSERT is not valid
there. I'm not sure about willFireTimer() though.

[aandrey, 2013/12/17 13:24:03]

Done.

[yurys, 2013/12/18 09:22:15]

I agree that it make sense for willHandleEvent which can be nested but how can
we get willFireTimer or willFireAnimationFrame nested in another event?

[aandrey, 2013/12/18 09:32:09]

I think they can not. Added those ASSERT's back.

     ExecutionContextData* data = m_executionContextDataMap.get(context);
     if (!data)
         return;
     if (data->m_intervalTimerIds.contains(timerId))
-        m_currentAsyncCallChain = data->m_timerCallChains.get(timerId);
+        setCurrentAsyncCallChain(data->m_timerCallChains.get(timerId));
     else
-        m_currentAsyncCallChain = data->m_timerCallChains.take(timerId);
+        setCurrentAsyncCallChain(data->m_timerCallChains.take(timerId));
 }
 
 void AsyncCallStackTracker::didRequestAnimationFrame(ExecutionContext* context, int callbackId, const ScriptValue& callFrames)
@@ -163,14 +214,64 @@ void AsyncCallStackTracker::willFireAnimationFrame(ExecutionContext* context, in
     if (!isEnabled())
         return;
     ASSERT(callbackId > 0);
-    ASSERT(!m_currentAsyncCallChain);
     if (ExecutionContextData* data = m_executionContextDataMap.get(context))
-        m_currentAsyncCallChain = data->m_animationFrameCallChains.take(callbackId);
+        setCurrentAsyncCallChain(data->m_animationFrameCallChains.take(callbackId));
+}
+
+void AsyncCallStackTracker::didAddEventListener(EventTarget* eventTarget, const AtomicString& eventType, EventListener* listener, bool useCapture, const ScriptValue& callFrames)
+{
+    ASSERT(eventTarget->executionContext());
+    ASSERT(isEnabled());
+    if (!validateCallFrames(callFrames))
+        return;
+
+    StringBuilder description;
+    description.append(eventTarget->interfaceName());
+    if (!description.isEmpty())
+        description.append(".");
+    if (listener->isAttribute()) {
+        description.append("on");
+        description.append(eventType);
+    } else {
+        description.append("addEventListener(\"");
+        description.append(eventType);
+        description.append("\")");
+    }
+
+    ExecutionContextData* data = createContextDataIfNeeded(eventTarget->executionContext());
+    data->add(eventTarget, eventType, std::make_pair(RegisteredEventListener(listener, useCapture), createAsyncCallChain(description.toString(), callFrames)));
+}
+
+void AsyncCallStackTracker::didRemoveEventListener(EventTarget* eventTarget, const AtomicString& eventType, EventListener* listener, bool useCapture)
+{
+    ASSERT(eventTarget->executionContext());
+    if (!isEnabled())
+        return;
+    if (ExecutionContextData* data = m_executionContextDataMap.get(eventTarget->executionContext()))
+        data->remove(eventTarget, eventType, RegisteredEventListener(listener, useCapture));
+}
+
+void AsyncCallStackTracker::didRemoveAllEventListeners(EventTarget* eventTarget)
+{
+    ASSERT(eventTarget->executionContext());
+    if (!isEnabled())
+        return;
+    if (ExecutionContextData* data = m_executionContextDataMap.get(eventTarget->executionContext()))
+        data->m_eventTargetCallChains.remove(eventTarget);
+}
+
+void AsyncCallStackTracker::willHandleEvent(EventTarget* eventTarget, const AtomicString& eventType, EventListener* listener, bool useCapture)
+{
+    ASSERT(eventTarget->executionContext());
+    if (!isEnabled())
+        return;
+    if (ExecutionContextData* data = m_executionContextDataMap.get(eventTarget->executionContext()))
+        setCurrentAsyncCallChain(data->get(eventTarget, eventType, RegisteredEventListener(listener, useCapture)));
 }
 
 void AsyncCallStackTracker::didFireAsyncCall()
 {
-    m_currentAsyncCallChain = 0;
+    setCurrentAsyncCallChain(0);
 }
 
 PassRefPtr<AsyncCallStackTracker::AsyncCallChain> AsyncCallStackTracker::createAsyncCallChain(const String& description, const ScriptValue& callFrames)
@@ -182,6 +283,18 @@ PassRefPtr<AsyncCallStackTracker::AsyncCallChain> AsyncCallStackTracker::createA
     return chain.release();
 }
 
+void AsyncCallStackTracker::setCurrentAsyncCallChain(PassRefPtr<AsyncCallChain> chain)
+{
+    if (m_currentAsyncCallChain) {
+        m_nestedAsyncCallCount += chain ? 1 : -1;
+        if (!m_nestedAsyncCallCount)
+            m_currentAsyncCallChain = 0;
+    } else if (chain) {
+        m_currentAsyncCallChain = chain;
+        m_nestedAsyncCallCount = 1;
+    }
+}
+
 void AsyncCallStackTracker::ensureMaxAsyncCallChainDepth(AsyncCallChain* chain, unsigned maxDepth)
 {
     while (chain->m_callStacks.size() > maxDepth)
@@ -213,6 +326,7 @@ AsyncCallStackTracker::ExecutionContextData* AsyncCallStackTracker::createContex
 void AsyncCallStackTracker::clear()
 {
     m_currentAsyncCallChain = 0;
+    m_nestedAsyncCallCount = 0;
     Vector<ExecutionContextData*> contextsData;
     copyValuesToVector(m_executionContextDataMap, contextsData);
     m_executionContextDataMap.clear();