[inspector] avoid cloning of async call chains

src/inspector/v8-debugger-agent-impl.cc

Index: src/inspector/v8-debugger-agent-impl.cc
diff --git a/src/inspector/v8-debugger-agent-impl.cc b/src/inspector/v8-debugger-agent-impl.cc
index 81e48085570b648f330e986ab8f895707d677e7a..68d337f681b51a216b8921d9139e72826541e4ce 100644
--- a/src/inspector/v8-debugger-agent-impl.cc
+++ b/src/inspector/v8-debugger-agent-impl.cc
@@ -34,7 +34,6 @@ using protocol::Debugger::BreakpointId;
 using protocol::Debugger::CallFrame;
 using protocol::Runtime::ExceptionDetails;
 using protocol::Runtime::ScriptId;
-using protocol::Runtime::StackTrace;
 using protocol::Runtime::RemoteObject;
 
 namespace DebuggerAgentState {
@@ -598,7 +597,8 @@ Response V8DebuggerAgentImpl::searchInContent(
 Response V8DebuggerAgentImpl::setScriptSource(
     const String16& scriptId, const String16& newContent, Maybe<bool> dryRun,
     Maybe<protocol::Array<protocol::Debugger::CallFrame>>* newCallFrames,
-    Maybe<bool>* stackChanged, Maybe<StackTrace>* asyncStackTrace,
+    Maybe<bool>* stackChanged,
+    Maybe<protocol::Runtime::StackTrace>* asyncStackTrace,
     Maybe<protocol::Runtime::ExceptionDetails>* optOutCompileError) {
   if (!enabled()) return Response::Error(kDebuggerNotEnabled);
 
@@ -631,7 +631,7 @@ Response V8DebuggerAgentImpl::setScriptSource(
 Response V8DebuggerAgentImpl::restartFrame(
     const String16& callFrameId,
     std::unique_ptr<Array<CallFrame>>* newCallFrames,
-    Maybe<StackTrace>* asyncStackTrace) {
+    Maybe<protocol::Runtime::StackTrace>* asyncStackTrace) {
   if (!isPaused()) return Response::Error(kDebuggerNotPaused);
   InjectedScript::CallFrameScope scope(m_inspector, m_session->contextGroupId(),
                                        callFrameId);
@@ -1028,9 +1028,14 @@ Response V8DebuggerAgentImpl::currentCallFrames(
   return Response::OK();
 }
 
-std::unique_ptr<StackTrace> V8DebuggerAgentImpl::currentAsyncStackTrace() {
-  if (!isPaused()) return nullptr;
-  return V8StackTraceImpl::buildInspectorObjectForTail(m_debugger);
+std::unique_ptr<protocol::Runtime::StackTrace>
+V8DebuggerAgentImpl::currentAsyncStackTrace() {
+  std::shared_ptr<AsyncStackTrace> asyncParent =
+      m_debugger->currentAsyncParent();
+  if (!asyncParent) return nullptr;
+  return asyncParent->buildInspectorObject(
+      m_debugger->currentAsyncCreation().get(),
+      m_debugger->maxAsyncCallChainDepth() - 1);

[dgozman, 2017/04/17 23:03:15]

Why -1? Should we turn the parameter into maxChainLength (including the top)?

[kozy, 2017/04/18 01:04:38]

I'd like to have this value aligned with maxDepth passed to protocol method and
maxChainLength = 0 doesn't have any sense - we always report sync stack trace.

Here it's -1 because this argument describe maximum amount of async chain in
addition to current stack trace.

 }
 
 bool V8DebuggerAgentImpl::isPaused() const { return m_debugger->isPaused(); }