[inspector] added creation frame for async call chains for promises

src/inspector/v8-debugger.cc

 // Copyright 2016 the V8 project 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 "src/inspector/v8-debugger.h"
 
 #include "src/inspector/debugger-script.h"
 #include "src/inspector/inspected-context.h"
 #include "src/inspector/protocol/Protocol.h"
 #include "src/inspector/script-breakpoint.h"
@@ skipping 840 matching lines @@
   for (const auto& pair : m_maxAsyncCallStackDepthMap) {
     if (pair.second > maxAsyncCallStackDepth)
       maxAsyncCallStackDepth = pair.second;
   }
 
   if (m_maxAsyncCallStackDepth == maxAsyncCallStackDepth) return;
   m_maxAsyncCallStackDepth = maxAsyncCallStackDepth;
   if (!maxAsyncCallStackDepth) allAsyncTasksCanceled();
 }
 
+void V8Debugger::registerAsyncTaskIfNeeded(void* task) {
+  if (m_taskToId.find(task) != m_taskToId.end()) return;
+
+  int id = ++m_lastTaskId;
+  m_taskToId[task] = id;
+  m_idToTask[id] = task;
+  if (static_cast<int>(m_idToTask.size()) > m_maxAsyncCallStacks) {
+    void* taskToRemove = m_idToTask.begin()->second;
+    asyncTaskCanceled(taskToRemove);
+  }
+}
+
 void V8Debugger::asyncTaskCreated(void* task, void* parentTask) {
   if (!m_maxAsyncCallStackDepth) return;
   if (parentTask) m_parentTask[task] = parentTask;
+  v8::HandleScope scope(m_isolate);
+  // We don't need to pass context group id here because we gets
+  // this callback from V8 for promise events only.
+  std::unique_ptr<V8StackTraceImpl> chain =

[dgozman, 2017/01/24 23:57:44]

chain -> creationStack

[kozy, 2017/01/25 00:45:43]

Done.

+      V8StackTraceImpl::capture(this, 0, 1, String16());

[dgozman, 2017/01/24 23:57:44]

Let's comment that passing 1 here force no async chain for the new stack, which
allows us to not grow exponentially.

[kozy, 2017/01/25 00:45:43]

Done.

+  if (chain && !chain->isEmpty()) {
+    m_asyncTaskCreationStacks[task] = std::move(chain);
+    registerAsyncTaskIfNeeded(task);
+  }
 }
 
 void V8Debugger::asyncTaskScheduled(const StringView& taskName, void* task,
                                     bool recurring) {
   if (!m_maxAsyncCallStackDepth) return;
   asyncTaskScheduled(toString16(taskName), task, recurring);
 }
 
 void V8Debugger::asyncTaskScheduled(const String16& taskName, void* task,
                                     bool recurring) {
   if (!m_maxAsyncCallStackDepth) return;
   v8::HandleScope scope(m_isolate);
   int contextGroupId =
       m_isolate->InContext()
           ? m_inspector->contextGroupId(m_isolate->GetCurrentContext())
           : 0;
   std::unique_ptr<V8StackTraceImpl> chain = V8StackTraceImpl::capture(
       this, contextGroupId, V8StackTraceImpl::maxCallStackSizeToCapture,
       taskName);
   if (chain) {
     m_asyncTaskStacks[task] = std::move(chain);
     if (recurring) m_recurringTasks.insert(task);
-    int id = ++m_lastTaskId;
-    m_taskToId[task] = id;
-    m_idToTask[id] = task;
-    if (static_cast<int>(m_idToTask.size()) > m_maxAsyncCallStacks) {
-      void* taskToRemove = m_idToTask.begin()->second;
-      asyncTaskCanceled(taskToRemove);
-    }
+    registerAsyncTaskIfNeeded(task);
   }
 }
 
 void V8Debugger::asyncTaskCanceled(void* task) {
   if (!m_maxAsyncCallStackDepth) return;
   m_asyncTaskStacks.erase(task);
   m_recurringTasks.erase(task);
   m_parentTask.erase(task);
+  m_asyncTaskCreationStacks.erase(task);
   auto it = m_taskToId.find(task);
   if (it == m_taskToId.end()) return;
   m_idToTask.erase(it->second);
   m_taskToId.erase(it);
 }
 
 void V8Debugger::asyncTaskStarted(void* task) {
   if (!m_maxAsyncCallStackDepth) return;
   m_currentTasks.push_back(task);
   auto parentIt = m_parentTask.find(task);
   AsyncTaskToStackTrace::iterator stackIt = m_asyncTaskStacks.find(
       parentIt == m_parentTask.end() ? task : parentIt->second);
   // Needs to support following order of events:
   // - asyncTaskScheduled
   //   <-- attached here -->
   // - asyncTaskStarted
   // - asyncTaskCanceled <-- canceled before finished
   //   <-- async stack requested here -->
   // - asyncTaskFinished
   std::unique_ptr<V8StackTraceImpl> stack;
   if (stackIt != m_asyncTaskStacks.end() && stackIt->second)
     stack = stackIt->second->cloneImpl();
+  auto itCreation = m_asyncTaskCreationStacks.find(task);
+  if (stack && itCreation != m_asyncTaskCreationStacks.end()) {
+    stack->setCreation(itCreation->second->cloneImpl());
+  }
   m_currentStacks.push_back(std::move(stack));
 }
 
 void V8Debugger::asyncTaskFinished(void* task) {
   if (!m_maxAsyncCallStackDepth) return;
   // We could start instrumenting half way and the stack is empty.
   if (!m_currentStacks.size()) return;
 
   DCHECK(m_currentTasks.back() == task);
   m_currentTasks.pop_back();
 
   m_currentStacks.pop_back();
   if (m_recurringTasks.find(task) == m_recurringTasks.end()) {
     asyncTaskCanceled(task);
   }
 }
 
 void V8Debugger::allAsyncTasksCanceled() {
   m_asyncTaskStacks.clear();
   m_recurringTasks.clear();
   m_currentStacks.clear();
   m_currentTasks.clear();
   m_parentTask.clear();
+  m_asyncTaskCreationStacks.clear();
   m_idToTask.clear();
   m_taskToId.clear();
   m_lastTaskId = 0;
 }
 
 void V8Debugger::muteScriptParsedEvents() {
   ++m_ignoreScriptParsedEventsCounter;
 }
 
 void V8Debugger::unmuteScriptParsedEvents() {
@@ skipping 12 matching lines @@
 
   size_t stackSize =
       fullStack ? V8StackTraceImpl::maxCallStackSizeToCapture : 1;
   if (m_inspector->enabledRuntimeAgentForGroup(contextGroupId))
     stackSize = V8StackTraceImpl::maxCallStackSizeToCapture;
 
   return V8StackTraceImpl::capture(this, contextGroupId, stackSize);
 }
 
 }  // namespace v8_inspector