Parameter Server.1-Io
val read : socket -> Bigstringaf.t -> off:int -> len:int -> [ `Eof | `Ok of int ] Lwt.tval writev : socket -> Faraday.bigstring Faraday.iovec list -> [ `Closed | `Ok of int ] Lwt.tval shutdown_send : socket -> unitval shutdown_receive : socket -> unitval close : socket -> unit Lwt.tval state : socket -> [ `Open | `Error | `Closed ]