[inspector] introduced stepIntoAsync for chained callbacks

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 280 matching lines @@
   m_executionState.Clear();
 }
 
 void V8Debugger::stepIntoStatement() {
   DCHECK(isPaused());
   DCHECK(!m_executionState.IsEmpty());
   v8::debug::PrepareStep(m_isolate, v8::debug::StepIn);
   continueProgram();
 }
 
+Response V8Debugger::stepIntoAsync() {
+  DCHECK(isPaused());
+  DCHECK(!m_executionState.IsEmpty());
+  if (!m_currentCreatedAsyncTask) {
+    return Response::Error("No scheduled chained callback");
+  }
+  m_asyncTasksWithScheduledBreak.insert(m_currentCreatedAsyncTask);
+  v8::debug::ClearStepping(m_isolate);
+  continueProgram();
+  return Response::OK();
+}
+
 void V8Debugger::stepOverStatement() {
   DCHECK(isPaused());
   DCHECK(!m_executionState.IsEmpty());
   v8::debug::PrepareStep(m_isolate, v8::debug::StepNext);
   continueProgram();
 }
 
 void V8Debugger::stepOutOfFunction() {
   DCHECK(isPaused());
   DCHECK(!m_executionState.IsEmpty());
@@ skipping 249 matching lines @@
 bool V8Debugger::IsFunctionBlackboxed(v8::Local<v8::debug::Script> script,
                                       const v8::debug::Location& start,
                                       const v8::debug::Location& end) {
   V8DebuggerAgentImpl* agent = agentForScript(m_inspector, script);
   if (!agent) return false;
   return agent->isFunctionBlackboxed(String16::fromInteger(script->Id()), start,
                                      end);
 }
 
 void V8Debugger::PromiseEventOccurred(v8::debug::PromiseDebugActionType type,
-                                      int id, int parentId) {
+                                      int id) {
   if (!m_maxAsyncCallStackDepth) return;
   // Async task events from Promises are given misaligned pointers to prevent
   // from overlapping with other Blink task identifiers. There is a single
   // namespace of such ids, managed by src/js/promise.js.
   void* ptr = reinterpret_cast<void*>(id * 2 + 1);
   switch (type) {
-    case v8::debug::kDebugPromiseCreated:
-      asyncTaskCreated(
-          ptr, parentId ? reinterpret_cast<void*>(parentId * 2 + 1) : nullptr);
-      break;
     case v8::debug::kDebugEnqueueAsyncFunction:
       asyncTaskScheduled("async function", ptr, true);
       break;
     case v8::debug::kDebugEnqueuePromiseResolve:
       asyncTaskScheduled("Promise.resolve", ptr, true);
       break;
     case v8::debug::kDebugEnqueuePromiseReject:
       asyncTaskScheduled("Promise.reject", ptr, true);
       break;
     case v8::debug::kDebugPromiseCollected:
       asyncTaskCanceled(ptr);
       break;
     case v8::debug::kDebugWillHandle:
       asyncTaskStarted(ptr);
       break;
     case v8::debug::kDebugDidHandle:
       asyncTaskFinished(ptr);
       break;
   }
 }
 
+void V8Debugger::PromiseCreatedEvent(int id, int parentId, bool isBreakable) {
+  if (!m_maxAsyncCallStackDepth) return;
+  void* task = reinterpret_cast<void*>(id * 2 + 1);

[Yang, 2017/01/30 19:40:33]

why is this void* and not intptr_t?

+  void* parentTask =
+      parentId ? reinterpret_cast<void*>(parentId * 2 + 1) : nullptr;
+  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

[Yang, 2017/01/30 19:40:33]

s/gets/get/

[kozy, 2017/02/15 01:00:54]

Done.

+  // from V8 for promise events only.
+  // Passing one as maxStackSize forces no async chain for the new stack and
+  // allows us to not grow exponentially.
+  std::unique_ptr<V8StackTraceImpl> creationStack =
+      V8StackTraceImpl::capture(this, 0, 1, String16());
+  if (creationStack && !creationStack->isEmpty()) {
+    m_asyncTaskCreationStacks[task] = std::move(creationStack);
+    registerAsyncTaskIfNeeded(task);
+  }
+  if (!parentTask || !isBreakable) return;
+  V8DebuggerAgentImpl* agent =
+      m_inspector->enabledDebuggerAgentForGroup(currentContextGroupId());
+  if (!agent) return;
+  m_currentCreatedAsyncTask = task;
+  agent->asyncTaskCreated();
+  m_currentCreatedAsyncTask = nullptr;
+}
+
 V8StackTraceImpl* V8Debugger::currentAsyncCallChain() {
   if (!m_currentStacks.size()) return nullptr;
   return m_currentStacks.back().get();
 }
 
 void V8Debugger::compileDebuggerScript() {
   if (!m_debuggerScript.IsEmpty()) {
     UNREACHABLE();
     return;
   }
@@ skipping 218 matching lines @@
     return v8::Null(m_isolate);
   if (!markAsInternal(context, location, V8InternalValueType::kLocation))
     return v8::Null(m_isolate);
   return location;
 }
 
 bool V8Debugger::isPaused() { return !m_pausedContext.IsEmpty(); }
 
 std::unique_ptr<V8StackTraceImpl> V8Debugger::createStackTrace(
     v8::Local<v8::StackTrace> stackTrace) {
-  int contextGroupId =
-      m_isolate->InContext()
-          ? m_inspector->contextGroupId(m_isolate->GetCurrentContext())
-          : 0;
-  return V8StackTraceImpl::create(this, contextGroupId, stackTrace,
+  return V8StackTraceImpl::create(this, currentContextGroupId(), stackTrace,
                                   V8StackTraceImpl::maxCallStackSizeToCapture);
 }
 
 void V8Debugger::setAsyncCallStackDepth(V8DebuggerAgentImpl* agent, int depth) {
   if (depth <= 0)
     m_maxAsyncCallStackDepthMap.erase(agent);
   else
     m_maxAsyncCallStackDepthMap[agent] = depth;
 
   int maxAsyncCallStackDepth = 0;
@@ skipping 12 matching lines @@
 
   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.
-  // Passing one as maxStackSize forces no async chain for the new stack and
-  // allows us to not grow exponentially.
-  std::unique_ptr<V8StackTraceImpl> creationStack =
-      V8StackTraceImpl::capture(this, 0, 1, String16());
-  if (creationStack && !creationStack->isEmpty()) {
-    m_asyncTaskCreationStacks[task] = std::move(creationStack);
-    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);
+      this, currentContextGroupId(),
+      V8StackTraceImpl::maxCallStackSizeToCapture, taskName);
   if (chain) {
     m_asyncTaskStacks[task] = std::move(chain);
     if (recurring) m_recurringTasks.insert(task);
     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);
+  if (m_currentCreatedAsyncTask == task) m_currentCreatedAsyncTask = nullptr;
+  m_asyncTasksWithScheduledBreak.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));
+  if (m_asyncTasksWithScheduledBreak.find(task) ==
+      m_asyncTasksWithScheduledBreak.end())
+    return;
+  V8DebuggerAgentImpl* agent =
+      m_inspector->enabledDebuggerAgentForGroup(currentContextGroupId());
+  if (!agent) return;
+  agent->asyncTaskStarted();
 }
 
 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_asyncTasksWithScheduledBreak.find(task) !=
+      m_asyncTasksWithScheduledBreak.end()) {
+    V8DebuggerAgentImpl* agent =
+        m_inspector->enabledDebuggerAgentForGroup(currentContextGroupId());
+    if (!agent) return;
+    agent->asyncTaskFinished();
+    m_asyncTasksWithScheduledBreak.erase(task);
+  }
+
   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_currentCreatedAsyncTask = nullptr;
+  m_asyncTasksWithScheduledBreak.clear();
   m_idToTask.clear();
   m_taskToId.clear();
   m_lastTaskId = 0;
 }
 
 void V8Debugger::muteScriptParsedEvents() {
   ++m_ignoreScriptParsedEventsCounter;
 }
 
 void V8Debugger::unmuteScriptParsedEvents() {
   --m_ignoreScriptParsedEventsCounter;
   DCHECK_GE(m_ignoreScriptParsedEventsCounter, 0);
 }
 
 std::unique_ptr<V8StackTraceImpl> V8Debugger::captureStackTrace(
     bool fullStack) {
-  if (!m_isolate->InContext()) return nullptr;
+  int contextGroupId = currentContextGroupId();
+  if (!contextGroupId) return nullptr;
 
   v8::HandleScope handles(m_isolate);
-  int contextGroupId =
-      m_inspector->contextGroupId(m_isolate->GetCurrentContext());
-  if (!contextGroupId) return nullptr;
-
   size_t stackSize =
       fullStack ? V8StackTraceImpl::maxCallStackSizeToCapture : 1;
   if (m_inspector->enabledRuntimeAgentForGroup(contextGroupId))
     stackSize = V8StackTraceImpl::maxCallStackSizeToCapture;
 
   return V8StackTraceImpl::capture(this, contextGroupId, stackSize);
 }
 
+int V8Debugger::currentContextGroupId() {
+  if (!m_isolate->InContext()) return 0;
+  return m_inspector->contextGroupId(m_isolate->GetCurrentContext());
+}
+
 }  // namespace v8_inspector