hphp/hack/src/utils/lwt_utils.mli

   1 val select:
   2   Unix.file_descr list ->
   3   Unix.file_descr list ->
   4   Unix.file_descr list ->
   5   float ->
   6   (Unix.file_descr list * Unix.file_descr list * Unix.file_descr list) Lwt.t
   7 (** Drop-in replacement for [Unix.select] that works even when the Lwt main loop
   8 is running (i.e. your function has [Lwt_main.run] somewhere higher up in the
   9 call stack).
  10
  11 The Lwt main loop is an event loop pumped by [Unix.select], and so regular
  12 [Unix.select] calls are prone to raising `EINTR`. The implementation of this
  13 function does not use [Unix.select] at all, but Lwt primitives that accomplish
  14 the same thing.
  15 *)
  16
  17 module Process_success: sig
  18   type t = {
  19     command_line: string;
  20     stdout: string;
  21     stderr: string;
  22   }
  23 end
  24
  25 module Process_failure: sig
  26   type t = {
  27     command_line: string;
  28     process_status: Unix.process_status;
  29     stdout: string;
  30     stderr: string;
  31     exn: exn option;
  32   }
  33
  34   val to_string: t -> string
  35 end
  36
  37 val exec_checked:
  38     ?input:string ->
  39     ?env:string array ->
  40     string ->
  41     string array ->
  42     (Process_success.t, Process_failure.t) Lwt_result.t
  43 (** Run a command with a given input and return the output. If the command exits
  44 with an exit status other than zero, raises [Process_failure] instead.
  45
  46 NOTE: on cancellation, this function will not kill the underlying process. (I
  47 tried to implement it, but after killing the process, both [Lwt_io.close] and
  48 [Lwt_io.abort] would hang when trying to close the process's
  49 stdin/stdout/stderr.)
  50 *)
  51
  52 val try_finally:
  53   f:(unit -> 'a Lwt.t) ->
  54   finally:(unit -> unit Lwt.t) ->
  55   'a Lwt.t
  56 (** Asynchronous version of [Utils.try_finally]. Run and wait for [f] to
  57 complete, and be sure to invoke [finally] asynchronously afterward, even if [f]
  58 raises an exception. *)
  59
  60 val read_all: string -> (string, string) Lwt_result.t
  61 (** Reads all the contents from the given file on disk, or returns an error
  62 message if unable to do so. *)