package uwt

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type t
include module type of Handle with type t := t
val close : t -> Int_result.unit

Handles are closed automatically, if they are not longer referenced from the OCaml heap. Nevertheless, you should nearly always close them with close, because:

  • if they wrap a file descriptor, you will sooner or later run out of file descriptors. The OCaml garbage collector doesn't give any guarantee, when orphaned memory blocks are removed.
  • you might have registered some repeatedly called action (e.g. timeout, read_start,...), that prevent that all references get removed from the OCaml heap.

However, it's safe to write code in this manner:

let s = Uwt.Tcp.init () in
let c = Uwt.Tcp.init () in
Uwt.Tcp.nodelay s false;
Uwt.Tcp.simultaneous_accepts true;
if foobar () then (* no file descriptor yet assigned, no need to worry
                     about exceptions inside foobar,... *)
  Lwt.return_unit (* no need to close *)
else
  ...

If you want - for whatever reason - keep a file descriptor open for the whole lifetime of your process, remember to keep a reference to its handle.

val close_noerr : t -> unit
val close_wait : t -> unit Lwt.t

Prefer close or close_noerr to close_wait. close or close_noerr return immediately (there are no useful error messages, beside perhaps a notice, that you've already closed that handle).

close_wait is only useful, if you intend to wait until all concurrent write and read threads related to this handle are canceled.

val is_active : t -> bool
val ref' : t -> unit
val unref : t -> unit
val has_ref : t -> bool
val handle_type : t -> Misc.handle_type
val to_handle : t -> Handle.t
type stdio =
  1. | Inherit_file of file
  2. | Create_pipe of Pipe.t
  3. | Inherit_pipe of Pipe.t
  4. | Inherit_stream of Stream.t
type exit_cb = t -> exit_status:int -> term_signal:int -> unit
val spawn : ?stdin:stdio -> ?stdout:stdio -> ?stderr:stdio -> ?uid:int -> ?gid:int -> ?verbatim_arguments:bool -> ?detach:bool -> ?hide:bool -> ?env:string list -> ?cwd:string -> ?exit_cb:exit_cb -> string -> string list -> t uv_result
  • parameter verbatim_arguments

    default false

  • parameter detach

    default false

  • parameter hide

    default true

val spawn_exn : ?stdin:stdio -> ?stdout:stdio -> ?stderr:stdio -> ?uid:int -> ?gid:int -> ?verbatim_arguments:bool -> ?detach:bool -> ?hide:bool -> ?env:string list -> ?cwd:string -> ?exit_cb:exit_cb -> string -> string list -> t
val disable_stdio_inheritance : unit -> unit
val pid : t -> Int_result.int
val pid_exn : t -> int
val process_kill : t -> int -> Int_result.unit
val process_kill_exn : t -> int -> unit
val kill : pid:int -> signum:int -> Int_result.unit
val kill_exn : pid:int -> signum:int -> unit
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