Support Promises event-based instrumentation on backend.

Source/core/inspector/PromiseTracker.cpp

Index: Source/core/inspector/PromiseTracker.cpp
diff --git a/Source/core/inspector/PromiseTracker.cpp b/Source/core/inspector/PromiseTracker.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..f73fe44b72fe9695e5492c922417617c4436cd25
--- /dev/null
+++ b/Source/core/inspector/PromiseTracker.cpp
@@ -0,0 +1,115 @@
+// Copyright 2014 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 "core/inspector/PromiseTracker.h"
+
+#include "bindings/core/v8/ScriptCallStackFactory.h"
+#include "bindings/core/v8/ScriptState.h"
+
+namespace blink {
+
+static int indexOf(PromiseTracker::PromiseDataVector* vector, const ScopedPersistent<v8::Object>& promise)
+{
+    for (size_t index = 0; index < vector->size(); ++index) {
+        RefPtr<PromiseTracker::PromiseData> data = vector->at(index);
+        if (data->promise() == promise)

[aandrey, 2014/08/25 09:48:37]

if (vector->at(index)->promise() == promise)

[Alexandra Mikhaylova, 2014/08/25 14:25:47]

Done.

+            return index;
+    }
+    return -1;
+}
+
+namespace {
+
+struct PromiseDataWrapper {
+    PromiseDataWrapper(WeakPtr<PromiseTracker::PromiseData> data, PromiseTracker::PromiseDataMap* map)
+        : m_data(data)
+        , m_promiseDataMap(map)
+    {
+    }
+
+    static void didRemovePromise(const v8::WeakCallbackData<v8::Object, PromiseDataWrapper>& data)
+    {
+        OwnPtr<PromiseDataWrapper> wrapper = adoptPtr(data.GetParameter());
+        WeakPtr<PromiseTracker::PromiseData> promiseData = wrapper->m_data;
+        if (!promiseData)
+            return;
+        PromiseTracker::PromiseDataMap* map = wrapper->m_promiseDataMap;
+        int promiseHash = promiseData->promiseHash();
+        PromiseTracker::PromiseDataVector* vector = &map->find(promiseHash)->value;
+        int index = indexOf(vector, promiseData->promise());
+        ASSERT(index >= 0);
+        vector->remove(index);
+        if (vector->size() == 0)
+            map->remove(promiseHash);
+    }
+
+    WeakPtr<PromiseTracker::PromiseData> m_data;
+    PromiseTracker::PromiseDataMap* m_promiseDataMap;
+};
+
+}
+
+PromiseTracker::PromiseData::PromiseData(v8::Isolate* isolate, int promiseHash, v8::Handle<v8::Object> promise, v8::Handle<v8::Object> parentPromise, int status, bool captureStack)
+    : m_promiseHash(promiseHash)
+    , m_promise(isolate, promise)
+    , m_parentPromise(isolate, parentPromise)
+    , m_status(status)
+    , m_weakPtrFactory(this)
+{
+    if (captureStack) {
+        v8::Handle<v8::StackTrace> stackTrace(v8::StackTrace::CurrentStackTrace(isolate, 1));
+        RefPtrWillBeRawPtr<ScriptCallStack> stack = createScriptCallStack(stackTrace, 1, isolate);
+        if (stack->size())
+            m_callFrame = stack->at(0);
+    }
+}
+
+void PromiseTracker::enable()
+{
+    m_isEnabled = true;
+}
+
+void PromiseTracker::disable()
+{
+    m_isEnabled = false;
+    clear();
+}
+
+void PromiseTracker::clear()
+{
+    m_promiseDataMap.clear();
+}
+
+void PromiseTracker::didReceiveV8PromiseEvent(ScriptState* scriptState, v8::Handle<v8::Object> promise, v8::Handle<v8::Value> parentPromise, int status)
+{
+    ASSERT(isEnabled());
+
+    int promiseHash = promise->GetIdentityHash();
+    PromiseDataVector* vector;
+    PromiseDataMap::iterator it = m_promiseDataMap.find(promiseHash);
+    if (it != m_promiseDataMap.end())
+        vector = &it->value;
+    else
+        vector = &m_promiseDataMap.add(promiseHash, PromiseDataVector()).storedValue->value;
+    for (size_t index = 0; index < vector->size(); ++index) {
+        RefPtr<PromiseData> data = vector->at(index);
+        if (data->m_promise == promise) {

[aandrey, 2014/08/25 09:48:37]

RefPtr<PromiseData> data;
size_t index = indexOf(vector, promise);
if (index == -1) {
    data = adoptRef(new PromiseData());
    // append_into_vector & set_weak
} else {
    data = vector->at(index);
}

if (parentPromise.IsEmpty()) {
    // %DebugPromiseEvent({ promise: promise, status: status, value: value });
    // ...
} else {
    // %DebugPromiseEvent({ promise: deferred.promise, parentPromise: this });
    ASSERT(parentPromise->IsPromise());
    // ...
}

[Alexandra Mikhaylova, 2014/08/25 14:25:47]

Done.

+            if (status != 0) {
+                data->m_status = status;
+            } else {
+                ASSERT(parentPromise->IsObject());
+                data->m_parentPromise.set(scriptState->isolate(), parentPromise->ToObject());
+            }
+            return;
+        }
+    }
+    bool captureStack = status == 0 && parentPromise.IsEmpty();
+    PromiseData* data = new PromiseData(scriptState->isolate(), promiseHash, promise, parentPromise->IsObject() ? parentPromise->ToObject() : v8::Handle<v8::Object>(), 0, captureStack);

[aandrey, 2014/08/25 09:48:37]

parentPromise->IsObject() will crash if parentPromise IsEmpty

[Alexandra Mikhaylova, 2014/08/25 14:25:47]

Fixed this method as described above.

+    PromiseDataWrapper* wrapper = new PromiseDataWrapper(data->m_weakPtrFactory.createWeakPtr(), &m_promiseDataMap);
+    data->m_promise.setWeak(wrapper, &PromiseDataWrapper::didRemovePromise);
+    vector->append(adoptRef(data));
+}
+
+} // namespace blink