(* Title: Pure/System/isabelle_process.ML
Author: Makarius
Isabelle process wrapper, based on private fifos for maximum
robustness and performance.
Startup phases:
. raw Posix process startup with uncontrolled output on stdout/stderr
. stdout \002: ML running
.. stdin/stdout/stderr freely available (raw ML loop)
.. protocol thread initialization
... rendezvous on system channel
... out_fifo INIT(pid): channels ready
... out_fifo STATUS(keywords)
... out_fifo READY: main loop ready
*)
signature ISABELLE_PROCESS =
sig
val is_active: unit -> bool
val add_command: string -> (string list -> unit) -> unit
val command: string -> string list -> unit
val crashes: exn list Synchronized.var
val init_fifos: string -> string -> unit
val init_socket: string -> unit
end;
structure Isabelle_Process: ISABELLE_PROCESS =
struct
(* print mode *)
val isabelle_processN = "isabelle_process";
fun is_active () = Print_Mode.print_mode_active isabelle_processN;
val _ = Output.add_mode isabelle_processN Output.default_output Output.default_escape;
val _ = Markup.add_mode isabelle_processN YXML.output_markup;
(* commands *)
local
val commands =
Synchronized.var "Isabelle_Process.commands" (Symtab.empty: (string list -> unit) Symtab.table);
in
fun add_command name cmd =
Synchronized.change commands (fn cmds =>
(if not (Symtab.defined cmds name) then ()
else warning ("Redefining Isabelle process command " ^ quote name);
Symtab.update (name, cmd) cmds));
fun command name args =
(case Symtab.lookup (Synchronized.value commands) name of
NONE => error ("Undefined Isabelle process command " ^ quote name)
| SOME cmd => cmd args);
end;
(* message channels *)
local
fun chunk s = [string_of_int (size s), "\n", s];
fun message do_flush mbox ch raw_props body =
let
val robust_props = map (pairself YXML.embed_controls) raw_props;
val header = YXML.string_of (XML.Elem ((ch, robust_props), []));
in Mailbox.send mbox (chunk header @ chunk body, do_flush) end;
fun standard_message mbox opt_serial ch body =
if body = "" then ()
else
message false mbox ch
((case opt_serial of SOME i => cons (Markup.serialN, string_of_int i) | _ => I)
(Position.properties_of (Position.thread_data ()))) body;
fun message_output mbox channel =
let
fun flush () = ignore (try System_Channel.flush channel);
fun loop receive =
(case receive mbox of
SOME (msg, do_flush) =>
(List.app (fn s => System_Channel.output channel s) msg;
if do_flush then flush () else ();
loop (Mailbox.receive_timeout (seconds 0.02)))
| NONE => (flush (); loop (SOME o Mailbox.receive)));
in fn () => loop (SOME o Mailbox.receive) end;
in
fun setup_channels channel =
let
val _ = TextIO.StreamIO.setBufferMode (TextIO.getOutstream TextIO.stdOut, IO.LINE_BUF);
val _ = TextIO.StreamIO.setBufferMode (TextIO.getOutstream TextIO.stdErr, IO.LINE_BUF);
val mbox = Mailbox.create () : (string list * bool) Mailbox.T;
val _ = Simple_Thread.fork false (message_output mbox channel);
in
Output.Private_Hooks.status_fn := standard_message mbox NONE "B";
Output.Private_Hooks.report_fn := standard_message mbox NONE "C";
Output.Private_Hooks.writeln_fn := (fn s => standard_message mbox (SOME (serial ())) "D" s);
Output.Private_Hooks.tracing_fn := (fn s => standard_message mbox (SOME (serial ())) "E" s);
Output.Private_Hooks.warning_fn := (fn s => standard_message mbox (SOME (serial ())) "F" s);
Output.Private_Hooks.error_fn := (fn (i, s) => standard_message mbox (SOME i) "G" s);
Output.Private_Hooks.raw_message_fn := message true mbox "H";
Output.Private_Hooks.urgent_message_fn := ! Output.Private_Hooks.writeln_fn;
Output.Private_Hooks.prompt_fn := ignore;
message true mbox "A" [] (Session.welcome ())
end;
end;
(* protocol loop -- uninterruptible *)
val crashes = Synchronized.var "Isabelle_Process.crashes" ([]: exn list);
local
fun recover crash =
(Synchronized.change crashes (cons crash);
warning "Recovering from Isabelle process crash -- see also Isabelle_Process.crashes");
fun read_chunk channel len =
let
val n =
(case Int.fromString len of
SOME n => n
| NONE => error ("Isabelle process: malformed chunk header " ^ quote len));
val chunk = System_Channel.inputN channel n;
val m = size chunk;
in
if m = n then chunk
else error ("Isabelle process: bad chunk (" ^ string_of_int m ^ " vs. " ^ string_of_int n ^ ")")
end;
fun read_command channel =
(case System_Channel.input_line channel of
NONE => raise Runtime.TERMINATE
| SOME line => map (read_chunk channel) (space_explode "," line));
fun run_command name args =
Runtime.debugging (command name) args
handle exn =>
error ("Isabelle process command failure: " ^ name ^ "\n" ^ ML_Compiler.exn_message exn);
in
fun loop channel =
let val continue =
(case read_command channel of
[] => (Output.error_msg "Isabelle process: no input"; true)
| name :: args => (run_command name args; true))
handle Runtime.TERMINATE => false
| exn => (Output.error_msg (ML_Compiler.exn_message exn) handle crash => recover crash; true);
in if continue then loop channel else () end;
end;
(* init *)
fun init rendezvous = ignore (Simple_Thread.fork false (fn () =>
let
val _ = OS.Process.sleep (seconds 0.5); (*yield to raw ML toplevel*)
val _ = Output.physical_stdout Symbol.STX;
val _ = quick_and_dirty := true;
val _ = Goal.parallel_proofs := 0;
val _ =
if Multithreading.max_threads_value () < 2
then Multithreading.max_threads := 2 else ();
val _ = Context.set_thread_data NONE;
val _ =
Unsynchronized.change print_mode
(fn mode =>
(mode @ [Syntax_Trans.no_bracketsN, Syntax_Trans.no_type_bracketsN])
|> fold (update op =)
[Symbol.xsymbolsN, isabelle_processN, Keyword.keyword_statusN, Pretty.symbolicN]);
val channel = rendezvous ();
val _ = setup_channels channel;
val _ = Keyword.status ();
val _ = Thy_Info.status ();
val _ = Output.status (Markup.markup Markup.ready "process ready");
in loop channel end));
fun init_fifos fifo1 fifo2 = init (fn () => System_Channel.fifo_rendezvous fifo1 fifo2);
fun init_socket name = init (fn () => System_Channel.socket_rendezvous name);
end;