fix dispatcher

        // sled::MutexLock lock(&mutex_);

        sled::SharedMutexReadLock lock(&rwlock_);

        for (auto &handler : handlers_) {

            if (handler->HandleMessage(message)) { return DispatchResult::kHandled; }

            if (handler->HandleMessage(message)) {

                handler->OnMessage(message);

                return DispatchResult::kHandled;

            }

        }

        return DispatchResult::kNotFound;

    }