Module Picos_ioSource

Basic IO facilities based on OCaml standard libraries for Picos.

Modules

Examples

First we open some modules for convenience:

  open Picos_io
  open Picos_std_finally
  open Picos_std_structured

A pair of pipes

Here is a simple example of two fibers communicating through a pair of pipes:

  # Picos_mux_random.run_on ~n_domains:2 @@ fun () ->

    let@ msg_i, msg_o =
      finally Unix.close_pair @@ fun () ->
      Unix.socketpair ~cloexec:true
        PF_UNIX SOCK_STREAM 0
    in
    let@ syn_i, syn_o =
      finally Unix.close_pair @@ fun () ->
      Unix.socketpair ~cloexec:true
        PF_UNIX SOCK_STREAM 0
    in

    Unix.set_nonblock msg_i;
    Unix.set_nonblock msg_o;
    Unix.set_nonblock syn_i;
    Unix.set_nonblock syn_o;

    Flock.join_after ~on_return:`Terminate begin fun () ->
      Flock.fork begin fun () ->
        let bytes = Bytes.create 100 in
        while true do
          let n =
            Unix.read msg_i bytes 0 100
          in
          if n > 0 then begin
            Printf.printf "%s\n%!"
              (Bytes.sub_string bytes 0 n);
            let w =
              Unix.write_substring
                syn_o "!" 0 1
            in
            assert (w = 1)
          end
        done
      end;

      let send_string s =
        let n = String.length s in
        let w =
          Unix.write_substring msg_o s 0 n
        in
        assert (w = n);
        let r =
          Unix.read syn_i
            (Bytes.create 1) 0 1
        in
        assert (r = 1)
      in

      send_string "Hello, world!";
      send_string "POSIX with OCaml";
    end
  Hello, world!
  POSIX with OCaml
  - : unit = ()