Mirage: Infinite timestamp logger

build-output

$ mirage configure --unix
Mirage      Using scanned config file: config.ml
Mirage      Processing: /home/jake/prog/mirage-experiments/broadcast-streams/timestamp/config.ml
Mirage      => rm -rf /home/jake/prog/mirage-experiments/broadcast-streams/timestamp/_build/config.*
Mirage      => cd /home/jake/prog/mirage-experiments/broadcast-streams/timestamp && ocamlbuild -use-ocamlfind -tags annot,bin_annot -pkg mirage config.cmxs
console     Using configuration: /home/jake/prog/mirage-experiments/broadcast-streams/timestamp/config.ml
console     1 job [Unikernel.Main]
console     Generating: main.ml
console     Now run 'make depend' to install the package dependencies for this unikernel.

$ make depend
opam install mirage-clock-unix mirage-console-unix mirage-unix --verbose
[NOTE] Package mirage-unix is already installed (current version is 1.1.0).
[NOTE] Package mirage-console-unix is already installed (current version is 1.0.0).
[NOTE] Package mirage-clock-unix is already installed (current version is 1.0.0).

$ make
ocamlbuild -classic-display -use-ocamlfind -pkgs lwt.syntax,mirage-clock-unix,mirage-console-unix,mirage-types.lwt -tags "syntax(camlp4o),annot,bin_annot,strict_sequence,principal" -cflag -g -lflags -g,-linkpkg main.native
ocamlfind ocamldep -package mirage-types.lwt -package mirage-console-unix -package mirage-clock-unix -package lwt.syntax -syntax camlp4o -modules main.ml > main.ml.depends
ocamlfind ocamldep -package mirage-types.lwt -package mirage-console-unix -package mirage-clock-unix -package lwt.syntax -syntax camlp4o -modules unikernel.ml > unikernel.ml.depends
ocamlfind ocamlc -c -g -annot -bin-annot -principal -strict-sequence -package mirage-types.lwt -package mirage-console-unix -package mirage-clock-unix -package lwt.syntax -syntax camlp4o -o unikernel.cmo unikernel.ml
+ ocamlfind ocamlc -c -g -annot -bin-annot -principal -strict-sequence -package mirage-types.lwt -package mirage-console-unix -package mirage-clock-unix -package lwt.syntax -syntax camlp4o -o unikernel.cmo unikernel.ml
File "unikernel.ml", line 7, characters 20-200:
Warning 40: this record of type CLK.tm contains fields that are 
not visible in the current scope: tm_sec tm_min tm_hour tm_mday tm_mon tm_year tm_wday tm_yday tm_isdst.
They will not be selected if the type becomes unknown.
ocamlfind ocamlc -c -g -annot -bin-annot -principal -strict-sequence -package mirage-types.lwt -package mirage-console-unix -package mirage-clock-unix -package lwt.syntax -syntax camlp4o -o main.cmo main.ml
+ ocamlfind ocamlc -c -g -annot -bin-annot -principal -strict-sequence -package mirage-types.lwt -package mirage-console-unix -package mirage-clock-unix -package lwt.syntax -syntax camlp4o -o main.cmo main.ml
File "main.ml", line 17, characters 2-7:
Error: Unbound value clock
Command exited with code 2.
make: *** [main.native] Error 10

config.ml

open Mirage

let main =
  foreign "Unikernel.Main" (console @-> clock @-> job)

let () =
  register "console" [ main $ default_console $ default_clock ]

main.ml

(* Generated by Mirage (Tue, 2 Sep 2014 19:22:32 GMT). *)

open Lwt

let _ = Printexc.record_backtrace true

let console1 () =
  Console.connect "0"

module M2 = Unikernel.Main(Console)

let t2 = console1

module M1 = Unikernel.Main(Console)(Clock)

let t1 () =
  clock () >>= function
  | `Error e -> fail (Failure "clock")
  | `Ok clock ->
  console1 () >>= function
  | `Error e -> fail (Failure "console1")
  | `Ok console1 ->
  M1.start console1 clock

let () =
  OS.Main.run (join [t1 ()])

unikernel.ml

open V1
open Lwt

module Main (C: CONSOLE)(CLK: CLOCK) = struct

let current_time () =
  let tm_to_string ({
          tm_sec = sec; tm_min = min; tm_hour = hour;
          tm_mday = mday; tm_mon = mon; tm_year = year;
          tm_wday = wday; tm_yday = yday; tm_isdst = isdst
        } : CLK.tm) =
    Printf.sprintf "[%d-%d-%d %d:%d:%d]" (year+1900) (mon+1) mday hour min sec
  in
  let (|>) x f = f x in
  CLK.time () |> CLK.gmtime |> tm_to_string

let start console clock =
  while true do
    C.log console (current_time ())
  done ;
  return ()
end