DevTools: Support XHR async call stacks in the debugger.

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 841c94667395ff8770fe72ba997c60f5fc033a48..a6c2424d863d569d1661d3a4910e486a768a9e26 100644
--- a/Source/core/inspector/AsyncCallStackTracker.cpp
+++ b/Source/core/inspector/AsyncCallStackTracker.cpp
@@ -35,6 +35,9 @@
 #include "core/dom/ExecutionContext.h"
 #include "core/events/EventTarget.h"
 #include "core/events/RegisteredEventListener.h"
+#include "core/xml/XMLHttpRequest.h"
+#include "core/xml/XMLHttpRequestUpload.h"
+#include "wtf/text/AtomicStringHash.h"
 #include "wtf/text/StringBuilder.h"
 
 namespace WebCore {
@@ -111,8 +114,19 @@ public:
     HashMap<int, RefPtr<AsyncCallChain> > m_timerCallChains;
     HashMap<int, RefPtr<AsyncCallChain> > m_animationFrameCallChains;
     HashMap<EventTarget*, EventListenerAsyncCallChainVectorHashMap> m_eventTargetCallChains;
+    HashMap<EventTarget*, RefPtr<AsyncCallChain> > m_xhrCallChains;
 };
 
+static XMLHttpRequest* xmlHttpRequestFor(EventTarget* eventTarget)

[yurys, 2013/12/23 09:11:57]

toXmlHttpRequest ?

[aandrey, 2013/12/23 12:09:38]

Done.

+{
+    const AtomicString& interfaceName = eventTarget->interfaceName();
+    if (interfaceName == EventTargetNames::XMLHttpRequest)
+        return static_cast<XMLHttpRequest*>(eventTarget);
+    if (interfaceName == EventTargetNames::XMLHttpRequestUpload)
+        return static_cast<XMLHttpRequestUpload*>(eventTarget)->xmlHttpRequest();
+    return 0;
+}
+
 AsyncCallStackTracker::AsyncCallStack::AsyncCallStack(const String& description, const ScriptValue& callFrames)
     : m_description(description)
     , m_callFrames(callFrames)
@@ -180,13 +194,14 @@ void AsyncCallStackTracker::willFireTimer(ExecutionContext* context, int timerId
     ASSERT(isEnabled());
     ASSERT(timerId > 0);
     ASSERT(!m_currentAsyncCallChain);
-    ExecutionContextData* data = m_executionContextDataMap.get(context);
-    if (!data)
-        return;
-    if (data->m_intervalTimerIds.contains(timerId))
-        setCurrentAsyncCallChain(data->m_timerCallChains.get(timerId));
-    else
-        setCurrentAsyncCallChain(data->m_timerCallChains.take(timerId));
+    if (ExecutionContextData* data = m_executionContextDataMap.get(context)) {
+        if (data->m_intervalTimerIds.contains(timerId))
+            setCurrentAsyncCallChain(data->m_timerCallChains.get(timerId));
+        else
+            setCurrentAsyncCallChain(data->m_timerCallChains.take(timerId));
+    } else {
+        setCurrentAsyncCallChain(0);

[yurys, 2013/12/23 09:11:57]

Can we test this branch?

[aandrey, 2013/12/23 12:09:38]

Added new test: LayoutTests/inspector/debugger/async-callstack-middle-run.html

[yurys, 2013/12/23 12:40:31]

Thank you!

+    }
 }
 
 void AsyncCallStackTracker::didRequestAnimationFrame(ExecutionContext* context, int callbackId, const ScriptValue& callFrames)
@@ -220,13 +235,15 @@ void AsyncCallStackTracker::willFireAnimationFrame(ExecutionContext* context, in
     ASSERT(!m_currentAsyncCallChain);
     if (ExecutionContextData* data = m_executionContextDataMap.get(context))
         setCurrentAsyncCallChain(data->m_animationFrameCallChains.take(callbackId));
+    else
+        setCurrentAsyncCallChain(0);
 }
 
 void AsyncCallStackTracker::didAddEventListener(EventTarget* eventTarget, const AtomicString& eventType, EventListener* listener, bool useCapture, const ScriptValue& callFrames)
 {
     ASSERT(eventTarget->executionContext());
     ASSERT(isEnabled());
-    if (!validateCallFrames(callFrames))
+    if (!validateCallFrames(callFrames) || xmlHttpRequestFor(eventTarget))
         return;
 
     StringBuilder description;
@@ -266,13 +283,45 @@ void AsyncCallStackTracker::willHandleEvent(EventTarget* eventTarget, const Atom
 {
     ASSERT(eventTarget->executionContext());
     ASSERT(isEnabled());
+    if (XMLHttpRequest* xhr = xmlHttpRequestFor(eventTarget)) {
+        willHandleXHREvent(xhr, eventTarget, eventType);
+        return;
+    }
     if (ExecutionContextData* data = m_executionContextDataMap.get(eventTarget->executionContext()))
         setCurrentAsyncCallChain(data->findEventListenerData(eventTarget, eventType, RegisteredEventListener(listener, useCapture)));
+    else
+        setCurrentAsyncCallChain(0);
+}
+
+void AsyncCallStackTracker::willLoadXHR(XMLHttpRequest* xhr, const ScriptValue& callFrames)
+{
+    DEFINE_STATIC_LOCAL(String, xhrSendName, ("XMLHttpRequest.send"));

[yurys, 2013/12/23 09:11:57]

This is not thread-safe and may be called on Worker's thread.

[aandrey, 2013/12/23 12:09:38]

Done. I also removed other DEFINE_STATIC_LOCAL's

+
+    ASSERT(xhr->executionContext());
+    ASSERT(isEnabled());
+    if (!validateCallFrames(callFrames))
+        return;
+    ExecutionContextData* data = createContextDataIfNeeded(xhr->executionContext());
+    data->m_xhrCallChains.set(xhr, createAsyncCallChain(xhrSendName, callFrames));
+}
+
+void AsyncCallStackTracker::willHandleXHREvent(XMLHttpRequest* xhr, EventTarget* eventTarget, const AtomicString& eventType)
+{
+    ASSERT(xhr->executionContext());
+    ASSERT(isEnabled());
+    if (ExecutionContextData* data = m_executionContextDataMap.get(xhr->executionContext())) {
+        if (xhr == eventTarget && eventType == EventTypeNames::loadend)

[yurys, 2013/12/23 09:11:57]

What is xhr == eventTarget? Is it check for upload vs download?

[aandrey, 2013/12/23 12:09:38]

Yes, essentially.
The "loadend" on XHR is the corresponding "did" event to willLoadXHR. We should
store XHR data between the two.

[yurys, 2013/12/23 12:40:31]

Consider assigning it to a named variable like isUpload = (xhr != eventTarget);
for better readability.

[aandrey, 2013/12/23 13:01:29]

Assigned to isXHRDownload.

+            setCurrentAsyncCallChain(data->m_xhrCallChains.take(xhr));
+        else
+            setCurrentAsyncCallChain(data->m_xhrCallChains.get(xhr));
+    } else {
+        setCurrentAsyncCallChain(0);
+    }
 }
 
 void AsyncCallStackTracker::didFireAsyncCall()
 {
-    setCurrentAsyncCallChain(0);
+    clearCurrentAsyncCallChain();
 }
 
 PassRefPtr<AsyncCallStackTracker::AsyncCallChain> AsyncCallStackTracker::createAsyncCallChain(const String& description, const ScriptValue& callFrames)
@@ -286,15 +335,22 @@ PassRefPtr<AsyncCallStackTracker::AsyncCallChain> AsyncCallStackTracker::createA
 void AsyncCallStackTracker::setCurrentAsyncCallChain(PassRefPtr<AsyncCallChain> chain)
 {
     if (m_currentAsyncCallChain) {
-        m_nestedAsyncCallCount += chain ? 1 : -1;
-        if (!m_nestedAsyncCallCount)
-            m_currentAsyncCallChain = 0;
+        ++m_nestedAsyncCallCount;
     } else if (chain) {
         m_currentAsyncCallChain = chain;
         m_nestedAsyncCallCount = 1;
     }
 }
 
+void AsyncCallStackTracker::clearCurrentAsyncCallChain()
+{
+    if (!m_nestedAsyncCallCount)
+        return;
+    --m_nestedAsyncCallCount;
+    if (!m_nestedAsyncCallCount)
+        m_currentAsyncCallChain.clear();
+}
+
 void AsyncCallStackTracker::ensureMaxAsyncCallChainDepth(AsyncCallChain* chain, unsigned maxDepth)
 {
     while (chain->m_callStacks.size() > maxDepth)
@@ -318,7 +374,7 @@ AsyncCallStackTracker::ExecutionContextData* AsyncCallStackTracker::createContex
 
 void AsyncCallStackTracker::clear()
 {
-    m_currentAsyncCallChain = 0;
+    m_currentAsyncCallChain.clear();
     m_nestedAsyncCallCount = 0;
     ExecutionContextDataMap copy;
     m_executionContextDataMap.swap(copy);