+ // Queued data, if any. Protected by the owning Server's <queued_data_mutex>.
+ // The data pointers in the iovec are owned by us.
+ std::vector<iovec> queued_data;
+
+ // Index of the last element in queued_data that is suitable to start streaming at.
+ // -1 if none.
+ int queued_data_last_starting_point;
+