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..75216e946344490b5b8695fad7f825dfbad29019 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)
+    {
+        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;
     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)
@@ -168,6 +220,59 @@ void AsyncCallStackTracker::willFireAnimationFrame(ExecutionContext* context, in
         m_currentAsyncCallChain = 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;
+    // FIXME: Handle events being fired synchronously right after they are added.
+    // ASSERT(!m_currentAsyncCallChain);
+    if (ExecutionContextData* data = m_executionContextDataMap.get(eventTarget->executionContext()))
+        m_currentAsyncCallChain = data->get(eventTarget, eventType, RegisteredEventListener(listener, useCapture));
+}
+
 void AsyncCallStackTracker::didFireAsyncCall()
 {
     m_currentAsyncCallChain = 0;