val create : max_size:int32 -> wnd:Window.t -> tval remove_all : t -> unitval add_r : t -> Cstruct.t option -> unit Lwt.tval take_l : t -> Cstruct.t option Lwt.tval cur_size : t -> int32val max_size : t -> int32val monitor : t -> int32 Lwt_mvar.t -> unit