Method OnError

library/cpp/neh/tcp2.cpp:963–975

must be called only from asio thread

                //must be called only from asio thread
                void OnError(const TString& err, const i32 systemCode = 0) {
                    if (AtomicGet(State_) != Closed) {
                        Error_ = err;
                        SystemCode_ = systemCode;
                        AtomicSet(State_, Closed);
                        AS_.AsyncCancel();
                    }
                    SafeOnError();
                    for (auto& it : ReqsInFly_) {
                        it.second->OnError(err);
                    }
                    ReqsInFly_.clear();
                }

                void SafeOnError() {
                    TRequest* reqPtr;