Method ReleaseConn2

library/cpp/neh/http2.cpp:484–491

        }

        inline THttpConnRef ReleaseConn2() noexcept {
            THttpConnRef c;
            {
                TGuard<TSpinLock> g(SL_);
                c.Swap(Conn2_);
            }
            return c;
        }

        TSpinLock SL_; //guaranted calling notify() only once (prevent race between asio thread and current)
        THandleRef Hndl_;