wenzelm@23961: (*  Title:      Pure/ML-Systems/multithreading_polyml.ML
wenzelm@23961:     Author:     Makarius
wenzelm@23961: 
wenzelm@28254: Multithreading in Poly/ML 5.2 or later (cf. polyml/basis/Thread.sml).
wenzelm@23961: *)
wenzelm@23961: 
wenzelm@25704: signature MULTITHREADING_POLYML =
wenzelm@25704: sig
wenzelm@26083:   val interruptible: ('a -> 'b) -> 'a -> 'b
wenzelm@26083:   val uninterruptible: ((('c -> 'd) -> 'c -> 'd) -> 'a -> 'b) -> 'a -> 'b
wenzelm@26098:   val system_out: string -> string * int
wenzelm@25704:   structure TimeLimit: TIME_LIMIT
wenzelm@25704: end;
wenzelm@25704: 
wenzelm@25704: signature BASIC_MULTITHREADING =
wenzelm@25704: sig
wenzelm@25704:   include BASIC_MULTITHREADING
wenzelm@25704:   include MULTITHREADING_POLYML
wenzelm@25704: end;
wenzelm@25704: 
wenzelm@24208: signature MULTITHREADING =
wenzelm@24208: sig
wenzelm@24208:   include MULTITHREADING
wenzelm@25704:   include MULTITHREADING_POLYML
wenzelm@24208: end;
wenzelm@24208: 
wenzelm@23961: structure Multithreading: MULTITHREADING =
wenzelm@23961: struct
wenzelm@23961: 
wenzelm@24072: (* options *)
wenzelm@24069: 
wenzelm@24119: val trace = ref 0;
wenzelm@28465: 
wenzelm@24119: fun tracing level msg =
wenzelm@28465:   if level > ! trace then ()
wenzelm@28465:   else (TextIO.output (TextIO.stdErr, (">>> " ^ msg () ^ "\n")); TextIO.flushOut TextIO.stdErr)
wenzelm@28465:     handle _ (*sic*) => ();
wenzelm@23961: 
wenzelm@23981: val available = true;
wenzelm@25775: 
wenzelm@23973: val max_threads = ref 1;
wenzelm@23973: 
wenzelm@25775: fun max_threads_value () =
wenzelm@25775:   let val m = ! max_threads
wenzelm@28161:   in if m <= 0 then Int.max (Thread.numProcessors (), 1) else m end;
wenzelm@25775: 
wenzelm@28555: fun enabled () = max_threads_value () > 1;
wenzelm@28555: 
wenzelm@23973: 
wenzelm@24069: (* misc utils *)
wenzelm@24069: 
wenzelm@24208: fun show "" = "" | show name = " " ^ name;
wenzelm@24208: fun show' "" = "" | show' name = " [" ^ name ^ "]";
wenzelm@24208: 
wenzelm@26098: fun read_file name =
wenzelm@26098:   let val is = TextIO.openIn name
wenzelm@26504:   in Exn.release (Exn.capture TextIO.inputAll is before TextIO.closeIn is) end;
wenzelm@26098: 
wenzelm@26098: fun write_file name txt =
wenzelm@26098:   let val os = TextIO.openOut name
wenzelm@26504:   in Exn.release (Exn.capture TextIO.output (os, txt) before TextIO.closeOut os) end;
wenzelm@26098: 
wenzelm@24208: 
wenzelm@24208: (* thread attributes *)
wenzelm@24208: 
wenzelm@28161: val no_interrupts =
wenzelm@28161:   [Thread.EnableBroadcastInterrupt false, Thread.InterruptState Thread.InterruptDefer];
wenzelm@28161: 
wenzelm@28161: val regular_interrupts =
wenzelm@28161:   [Thread.EnableBroadcastInterrupt true, Thread.InterruptState Thread.InterruptAsynchOnce];
wenzelm@28161: 
wenzelm@28466: val safe_interrupts = map
wenzelm@28466:   (fn Thread.InterruptState Thread.InterruptAsynch =>
wenzelm@28466:       Thread.InterruptState Thread.InterruptAsynchOnce
wenzelm@28466:     | x => x);
wenzelm@28466: 
wenzelm@24208: fun with_attributes new_atts f x =
wenzelm@24208:   let
wenzelm@29550:     val orig_atts = safe_interrupts (Thread.getAttributes ());
wenzelm@24208:     fun restore () = Thread.setAttributes orig_atts;
wenzelm@28466:     val result =
wenzelm@28466:       (Thread.setAttributes (safe_interrupts new_atts);
wenzelm@28466:         Exn.Result (f orig_atts x) before restore ())
wenzelm@29550:       handle e => Exn.Exn e before restore ();
wenzelm@28466:   in Exn.release result end;
wenzelm@24208: 
wenzelm@28161: fun interruptible f = with_attributes regular_interrupts (fn _ => f);
wenzelm@28150: 
wenzelm@26083: fun uninterruptible f =
wenzelm@28150:   with_attributes no_interrupts (fn atts => f (fn g => with_attributes atts (fn _ => g)));
wenzelm@24668: 
wenzelm@24688: 
wenzelm@24688: (* execution with time limit *)
wenzelm@24688: 
wenzelm@24688: structure TimeLimit =
wenzelm@24688: struct
wenzelm@24688: 
wenzelm@24688: exception TimeOut;
wenzelm@24688: 
wenzelm@26083: fun timeLimit time f x = uninterruptible (fn restore_attributes => fn () =>
wenzelm@26083:   let
wenzelm@26083:     val worker = Thread.self ();
wenzelm@26083:     val timeout = ref false;
wenzelm@26083:     val watchdog = Thread.fork (fn () =>
wenzelm@26083:       (OS.Process.sleep time; timeout := true; Thread.interrupt worker), []);
wenzelm@24688: 
wenzelm@26083:     val result = Exn.capture (restore_attributes f) x;
wenzelm@28443:     val was_timeout = (case result of Exn.Exn Exn.Interrupt => ! timeout | _ => false);
wenzelm@24688: 
wenzelm@26083:     val _ = Thread.interrupt watchdog handle Thread _ => ();
wenzelm@26083:   in if was_timeout then raise TimeOut else Exn.release result end) ();
wenzelm@24688: 
wenzelm@24688: end;
wenzelm@24668: 
wenzelm@24069: 
wenzelm@26098: (* system shell processes, with propagation of interrupts *)
wenzelm@26098: 
wenzelm@28254: fun system_out script = uninterruptible (fn restore_attributes => fn () =>
wenzelm@26098:   let
wenzelm@26098:     val script_name = OS.FileSys.tmpName ();
wenzelm@26098:     val _ = write_file script_name script;
wenzelm@26098: 
wenzelm@26098:     val pid_name = OS.FileSys.tmpName ();
wenzelm@26098:     val output_name = OS.FileSys.tmpName ();
wenzelm@26098: 
wenzelm@26098:     (*result state*)
wenzelm@26098:     datatype result = Wait | Signal | Result of int;
wenzelm@26098:     val result = ref Wait;
wenzelm@26098:     val result_mutex = Mutex.mutex ();
wenzelm@26098:     val result_cond = ConditionVar.conditionVar ();
wenzelm@26098:     fun set_result res =
wenzelm@26098:       (Mutex.lock result_mutex; result := res; Mutex.unlock result_mutex;
wenzelm@26098:         ConditionVar.signal result_cond);
wenzelm@26098: 
wenzelm@26098:     val _ = Mutex.lock result_mutex;
wenzelm@26098: 
wenzelm@26098:     (*system thread*)
wenzelm@26098:     val system_thread = Thread.fork (fn () =>
wenzelm@26098:       let
wenzelm@26098:         val status =
wenzelm@26098:           OS.Process.system ("perl -w \"$ISABELLE_HOME/lib/scripts/system.pl\" group " ^
wenzelm@26098:             script_name ^ " " ^ pid_name ^ " " ^ output_name);
wenzelm@26098:         val res =
wenzelm@26098:           (case Posix.Process.fromStatus status of
wenzelm@26098:             Posix.Process.W_EXITED => Result 0
wenzelm@26098:           | Posix.Process.W_EXITSTATUS 0wx82 => Signal
wenzelm@26098:           | Posix.Process.W_EXITSTATUS w => Result (Word8.toInt w)
wenzelm@26098:           | Posix.Process.W_SIGNALED s =>
wenzelm@26098:               if s = Posix.Signal.int then Signal
wenzelm@26098:               else Result (256 + LargeWord.toInt (Posix.Signal.toWord s))
wenzelm@26098:           | Posix.Process.W_STOPPED s => Result (512 + LargeWord.toInt (Posix.Signal.toWord s)));
wenzelm@28398:       in set_result res end handle _ (*sic*) => set_result (Result 2), []);
wenzelm@26098: 
wenzelm@26098:     (*main thread -- proxy for interrupts*)
wenzelm@26098:     fun kill n =
wenzelm@26098:       (case Int.fromString (read_file pid_name) of
wenzelm@26098:         SOME pid =>
wenzelm@26098:           Posix.Process.kill
wenzelm@26098:             (Posix.Process.K_GROUP (Posix.Process.wordToPid (LargeWord.fromInt pid)),
wenzelm@26098:               Posix.Signal.int)
wenzelm@26098:       | NONE => ())
wenzelm@26098:       handle OS.SysErr _ => () | IO.Io _ =>
wenzelm@26098:         (OS.Process.sleep (Time.fromMilliseconds 100); if n > 0 then kill (n - 1) else ());
wenzelm@26098: 
wenzelm@26098:     val _ = while ! result = Wait do
wenzelm@26098:       restore_attributes (fn () =>
wenzelm@26098:         (ConditionVar.waitUntil (result_cond, result_mutex, Time.now () + Time.fromMilliseconds 100); ())
wenzelm@28443:           handle Exn.Interrupt => kill 10) ();
wenzelm@26098: 
wenzelm@26098:     (*cleanup*)
wenzelm@26098:     val output = read_file output_name handle IO.Io _ => "";
wenzelm@26098:     val _ = OS.FileSys.remove script_name handle OS.SysErr _ => ();
wenzelm@26098:     val _ = OS.FileSys.remove pid_name handle OS.SysErr _ => ();
wenzelm@26098:     val _ = OS.FileSys.remove output_name handle OS.SysErr _ => ();
wenzelm@26098:     val _ = Thread.interrupt system_thread handle Thread _ => ();
wenzelm@28443:     val rc = (case ! result of Signal => raise Exn.Interrupt | Result rc => rc);
wenzelm@26098:   in (output, rc) end) ();
wenzelm@26098: 
wenzelm@26098: 
wenzelm@23961: (* critical section -- may be nested within the same thread *)
wenzelm@23961: 
wenzelm@23961: local
wenzelm@23961: 
wenzelm@24063: val critical_lock = Mutex.mutex ();
wenzelm@24063: val critical_thread = ref (NONE: Thread.thread option);
wenzelm@24063: val critical_name = ref "";
wenzelm@24063: 
wenzelm@23961: in
wenzelm@23961: 
wenzelm@23961: fun self_critical () =
wenzelm@23961:   (case ! critical_thread of
wenzelm@23961:     NONE => false
wenzelm@28150:   | SOME t => Thread.equal (t, Thread.self ()));
wenzelm@23961: 
wenzelm@23991: fun NAMED_CRITICAL name e =
wenzelm@23961:   if self_critical () then e ()
wenzelm@23961:   else
wenzelm@26083:     uninterruptible (fn restore_attributes => fn () =>
wenzelm@24208:       let
wenzelm@24208:         val name' = ! critical_name;
wenzelm@24208:         val _ =
wenzelm@24208:           if Mutex.trylock critical_lock then ()
wenzelm@24208:           else
wenzelm@24208:             let
wenzelm@24208:               val timer = Timer.startRealTimer ();
wenzelm@24208:               val _ = tracing 4 (fn () => "CRITICAL" ^ show name ^ show' name' ^ ": waiting");
wenzelm@24208:               val _ = Mutex.lock critical_lock;
wenzelm@24208:               val time = Timer.checkRealTimer timer;
wenzelm@26493:               val trace_time =
wenzelm@26493:                 if Time.>= (time, Time.fromMilliseconds 1000) then 1
wenzelm@26493:                 else if Time.>= (time, Time.fromMilliseconds 100) then 2
wenzelm@26493:                 else if Time.>= (time, Time.fromMilliseconds 10) then 3 else 4;
wenzelm@26493:               val _ = tracing trace_time (fn () =>
wenzelm@24208:                 "CRITICAL" ^ show name ^ show' name' ^ ": passed after " ^ Time.toString time);
wenzelm@24208:             in () end;
wenzelm@24208:         val _ = critical_thread := SOME (Thread.self ());
wenzelm@24208:         val _ = critical_name := name;
wenzelm@26083:         val result = Exn.capture (restore_attributes e) ();
wenzelm@24208:         val _ = critical_name := "";
wenzelm@24208:         val _ = critical_thread := NONE;
wenzelm@24208:         val _ = Mutex.unlock critical_lock;
wenzelm@24208:       in Exn.release result end) ();
wenzelm@23961: 
wenzelm@23991: fun CRITICAL e = NAMED_CRITICAL "" e;
wenzelm@23981: 
wenzelm@23961: end;
wenzelm@23961: 
wenzelm@23973: 
wenzelm@25704: (* serial numbers *)
wenzelm@25704: 
wenzelm@25704: local
wenzelm@25704: 
wenzelm@25704: val serial_lock = Mutex.mutex ();
wenzelm@25704: val serial_count = ref 0;
wenzelm@25704: 
wenzelm@25704: in
wenzelm@25704: 
wenzelm@25704: val serial = uninterruptible (fn _ => fn () =>
wenzelm@25704:   let
wenzelm@25704:     val _ = Mutex.lock serial_lock;
wenzelm@28124:     val _ = serial_count := ! serial_count + 1;
wenzelm@28124:     val res = ! serial_count;
wenzelm@25704:     val _ = Mutex.unlock serial_lock;
wenzelm@25704:   in res end);
wenzelm@25704: 
wenzelm@23961: end;
wenzelm@23961: 
wenzelm@25704: end;
wenzelm@24688: 
wenzelm@25704: structure BasicMultithreading: BASIC_MULTITHREADING = Multithreading;
wenzelm@25704: open BasicMultithreading;