(* Title: Pure/System/isabelle_process.ML
Author: Makarius
Isabelle process wrapper, based on private fifos for maximum
robustness and performance.
*)
signature ISABELLE_PROCESS =
sig
val isabelle_processN: string
val add_command: string -> (string list -> unit) -> unit
val command: string -> string list -> unit
val crashes: exn list Unsynchronized.ref
val init: string -> string -> unit
end;
structure Isabelle_Process: ISABELLE_PROCESS =
struct
(* print modes *)
val isabelle_processN = "isabelle_process";
val _ = Output.add_mode isabelle_processN Output.default_output Output.default_escape;
val _ = Markup.add_mode isabelle_processN YXML.output_markup;
(* commands *)
local
val global_commands = Unsynchronized.ref (Symtab.empty: (string list -> unit) Symtab.table);
in
fun add_command name cmd = CRITICAL (fn () =>
Unsynchronized.change global_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 (! global_commands) name of
NONE => error ("Undefined Isabelle process command " ^ quote name)
| SOME cmd => cmd args);
end;
(* message markup *)
local
fun chunk s = string_of_int (size s) ^ "\n" ^ s;
fun message _ _ _ "" = ()
| message out_stream ch raw_props body =
let
val robust_props = map (pairself YXML.escape_controls) raw_props;
val header = YXML.string_of (XML.Elem ((ch, robust_props), []));
in TextIO.output (out_stream, chunk header ^ chunk body) (*atomic output!*) end;
in
fun standard_message out_stream with_serial ch body =
message out_stream ch
((if with_serial then cons (Markup.serialN, serial_string ()) else I)
(Position.properties_of (Position.thread_data ()))) body;
fun init_message out_stream =
message out_stream "A" [(Markup.pidN, process_id ())] (Session.welcome ());
end;
(* channels *)
local
fun auto_flush stream =
let
val _ = TextIO.StreamIO.setBufferMode (TextIO.getOutstream stream, IO.BLOCK_BUF);
fun loop () =
(OS.Process.sleep (Time.fromMilliseconds 20); try TextIO.flushOut stream; loop ());
in loop end;
fun rendezvous f fifo =
let
val path = File.platform_path (Path.explode fifo);
val result = f fifo; (*should block until peer is ready*)
val _ =
if String.isSuffix "cygwin" ml_platform then () (*Cygwin 1.7: no proper blocking on open*)
else OS.FileSys.remove path; (*prevent future access*)
in result end;
in
fun setup_channels in_fifo out_fifo =
let
val in_stream = rendezvous TextIO.openIn in_fifo;
val out_stream = rendezvous TextIO.openOut out_fifo;
val _ = Simple_Thread.fork false (auto_flush out_stream);
val _ = Simple_Thread.fork false (auto_flush TextIO.stdOut);
val _ = Simple_Thread.fork false (auto_flush TextIO.stdErr);
in
Output.status_fn := standard_message out_stream false "B";
Output.report_fn := standard_message out_stream false "C";
Output.writeln_fn := standard_message out_stream true "D";
Output.tracing_fn := standard_message out_stream true "E";
Output.warning_fn := standard_message out_stream true "F";
Output.error_fn := standard_message out_stream true "G";
Output.debug_fn := standard_message out_stream true "H";
Output.priority_fn := ! Output.writeln_fn;
Output.prompt_fn := ignore;
(in_stream, out_stream)
end;
end;
(* protocol loop -- uninterruptible *)
val crashes = Unsynchronized.ref ([]: exn list);
local
fun recover crash =
(CRITICAL (fn () => Unsynchronized.change crashes (cons crash));
warning "Recovering from Isabelle process crash -- see also Isabelle_Process.crashes");
fun read_chunk stream len =
let
val n =
(case Int.fromString len of
SOME n => n
| NONE => error ("Isabelle process: malformed chunk header " ^ quote len));
val chunk = TextIO.inputN (stream, 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 stream =
(case TextIO.inputLine stream of
NONE => raise Runtime.TERMINATE
| SOME line => map (read_chunk stream) (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 stream =
let val continue =
(case read_command stream 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 stream else () end;
end;
(* init *)
fun init in_fifo out_fifo =
let
val _ = Unsynchronized.change print_mode
(fold (update op =) [isabelle_processN, Keyword.keyword_statusN, Pretty.symbolicN]);
val (in_stream, out_stream) = setup_channels in_fifo out_fifo;
val _ = init_message out_stream;
val _ = quick_and_dirty := true; (* FIXME !? *)
val _ = Keyword.status ();
val _ = Output.status (Markup.markup Markup.ready "");
val _ = Context.set_thread_data NONE;
val _ = Simple_Thread.fork false (fn () => (loop in_stream; quit ()));
in () end;
end;