changes by Fabian Immler:
improved handling of prover errors;
explicit treatment of clauses that are too trivial for resolution;
(* Title: HOL/Tools/atp_manager.ML
ID: $Id$
Author: Fabian Immler, TU Muenchen
ATP threads are registered here.
Threads with the same birth-time are seen as one group.
All threads of a group are killed when one thread of it has been successful,
or after a certain time,
or when the maximum number of threads exceeds; then the oldest thread is killed.
*)
signature ATP_MANAGER =
sig
val get_atps: unit -> string
val set_atps: string -> unit
val get_max_atps: unit -> int
val set_max_atps: int -> unit
val get_timeout: unit -> int
val set_timeout: int -> unit
val kill: unit -> unit
val info: unit -> unit
type prover = int -> Proof.state -> bool * string
val add_prover: string -> prover -> theory -> theory
val print_provers: theory -> unit
val sledgehammer: string list -> Proof.state -> unit
end;
structure AtpManager: ATP_MANAGER =
struct
(** preferences **)
local
val atps = ref "e";
val max_atps = ref 5; (* ~1 means infinite number of atps *)
val timeout = ref 60;
in
fun get_atps () = CRITICAL (fn () => ! atps);
fun set_atps str = CRITICAL (fn () => atps := str);
fun get_max_atps () = CRITICAL (fn () => ! max_atps);
fun set_max_atps number = CRITICAL (fn () => max_atps := number);
fun get_timeout () = CRITICAL (fn () => ! timeout);
fun set_timeout time = CRITICAL (fn () => timeout := time);
val _ =
ProofGeneralPgip.add_preference "Proof"
(Preferences.string_pref atps
"ATP: provers" "Default automatic provers (separated by whitespace)");
val _ = ProofGeneralPgip.add_preference "Proof"
(Preferences.int_pref max_atps
"ATP: maximum number" "How many provers may run in parallel");
val _ = ProofGeneralPgip.add_preference "Proof"
(Preferences.int_pref timeout
"ATP: timeout" "ATPs will be interrupted after this time (in seconds)");
end;
(** thread management **)
(* data structures over threads *)
structure ThreadHeap = HeapFun
(
type elem = Time.time * Thread.thread;
fun ord ((a, _), (b, _)) = Time.compare (a, b);
);
val lookup_thread = AList.lookup Thread.equal;
val delete_thread = AList.delete Thread.equal;
val update_thread = AList.update Thread.equal;
(* state of thread manager *)
datatype T = State of
{timeout_heap: ThreadHeap.T,
oldest_heap: ThreadHeap.T,
active: (Thread.thread * (Time.time * Time.time * string)) list,
cancelling: (Thread.thread * (Time.time * Time.time * string)) list};
fun make_state timeout_heap oldest_heap active cancelling =
State {timeout_heap = timeout_heap, oldest_heap = oldest_heap,
active = active, cancelling = cancelling};
val state = Synchronized.var "atp_manager" (make_state ThreadHeap.empty ThreadHeap.empty [] []);
(* the managing thread *)
(*watches over running threads and interrupts them if required*)
val managing_thread = ref (NONE: Thread.thread option);
(* unregister thread from thread manager -- move to cancelling *)
fun unregister (success, message) thread = Synchronized.change_result state
(fn State {timeout_heap, oldest_heap, active, cancelling} =>
let
val info = lookup_thread active thread
(* get birthtime of unregistering thread if successful - for group-killing*)
val birthtime = case info of NONE => Time.zeroTime
| SOME (tb, _, _) => if success then tb else Time.zeroTime
(* move unregistering thread to cancelling *)
val active' = delete_thread thread active
val cancelling' = case info of NONE => cancelling
| SOME (tb, _, desc) => update_thread (thread, (tb, Time.now (), desc)) cancelling
(* move all threads of the same group to cancelling *)
val group_threads = active |> map_filter (fn (th, (tb, _, desc)) =>
if tb = birthtime then SOME (th, (tb, Time.now (), desc)) else NONE)
val active'' = filter_out (fn (_, (tb, _, _)) => tb = birthtime) active'
val cancelling'' = append group_threads cancelling'
(* message for user *)
val message' = case info of NONE => ""
| SOME (_, _, desc) => "Sledgehammer: " ^ desc ^ "\n" ^ message ^
(if null group_threads then ""
else "\nInterrupted " ^ string_of_int (length group_threads - 1) ^ " other group members")
in (message', make_state timeout_heap oldest_heap active'' cancelling'') end);
(* kill excessive atp threads *)
fun excessive_atps active =
let val max = get_max_atps ()
in length active > max andalso max > ~1 end;
local
fun kill_oldest () =
let exception Unchanged in
Synchronized.change_result state (fn State {timeout_heap, oldest_heap, active, cancelling} =>
if ThreadHeap.is_empty oldest_heap orelse not (excessive_atps active)
then raise Unchanged
else
let val ((_, oldest_thread), oldest_heap') = ThreadHeap.min_elem oldest_heap
in (oldest_thread, make_state timeout_heap oldest_heap' active cancelling) end)
|> (priority o unregister (false, "Interrupted (maximum number of ATPs exceeded)"))
handle Unchanged => ()
end;
in
fun kill_excessive () =
let val State {active, ...} = Synchronized.value state
in if excessive_atps active then (kill_oldest (); kill_excessive ()) else () end;
end;
(* start a watching thread which runs forever -- only one may exist *)
fun check_thread_manager () = CRITICAL (fn () =>
if (case ! managing_thread of SOME thread => Thread.isActive thread | NONE => false)
then () else managing_thread := SOME (SimpleThread.fork false (fn () =>
let
val min_wait_time = Time.fromMilliseconds 300
val max_wait_time = Time.fromSeconds 10
(* wait for next thread to cancel, or maximum*)
fun time_limit (State {timeout_heap, ...}) =
(case try ThreadHeap.min timeout_heap of
NONE => SOME (Time.+ (Time.now (), max_wait_time))
| SOME (time, _) => SOME time)
(* action: cancel find threads whose timeout is reached, and interrupt cancelling threads *)
fun action (State {timeout_heap, oldest_heap, active, cancelling}) =
let val (timeout_threads, timeout_heap') =
ThreadHeap.upto (Time.now (), Thread.self ()) timeout_heap
in
if null timeout_threads andalso null cancelling andalso not (excessive_atps active)
then NONE
else
let
val _ = List.app (SimpleThread.interrupt o #1) cancelling
val cancelling' = filter (Thread.isActive o #1) cancelling
val state' = make_state timeout_heap' oldest_heap active cancelling'
in SOME (map #2 timeout_threads, state') end
end
in
while true do
(Synchronized.timed_access state time_limit action
|> these
|> List.app (priority o unregister (false, "Interrupted (reached timeout)"));
kill_excessive ();
(*give threads time to respond to interrupt*)
OS.Process.sleep min_wait_time)
end)));
(* thread is registered here by sledgehammer *)
fun register birthtime deadtime (thread, desc) =
(check_thread_manager ();
Synchronized.change state (fn State {timeout_heap, oldest_heap, active, cancelling} =>
let
val timeout_heap' = ThreadHeap.insert (deadtime, thread) timeout_heap
val oldest_heap' = ThreadHeap.insert (birthtime, thread) oldest_heap
val active' = update_thread (thread, (birthtime, deadtime, desc)) active
in make_state timeout_heap' oldest_heap' active' cancelling end));
(** user commands **)
(* kill: move all threads to cancelling *)
fun kill () = Synchronized.change state
(fn State {timeout_heap, oldest_heap, active, cancelling} =>
let val formerly_active = map (fn (th, (tb, _, desc)) => (th, (tb, Time.now (), desc))) active
in make_state timeout_heap oldest_heap [] (formerly_active @ cancelling) end);
(* info: information on running threads *)
fun info () =
let
val State {timeout_heap, oldest_heap, active, cancelling} = Synchronized.value state
fun running_info (_, (birth_time, dead_time, desc)) = "Running: "
^ (string_of_int o Time.toSeconds) (Time.- (Time.now (), birth_time))
^ " s -- "
^ (string_of_int o Time.toSeconds) (Time.- (dead_time, Time.now ()))
^ " s to live:\n" ^ desc
fun cancelling_info (_, (_, dead_time, desc)) = "Trying to interrupt thread since "
^ (string_of_int o Time.toSeconds) (Time.- (Time.now (), dead_time))
^ " s:\n" ^ desc
val running =
if null active then "No ATPs running."
else space_implode "\n\n" ("Running ATPs:" :: map running_info active)
val interrupting =
if null cancelling then ""
else space_implode "\n\n"
("Trying to interrupt the following ATPs:" :: map cancelling_info cancelling)
in writeln (running ^ "\n" ^ interrupting) end;
(** The Sledgehammer **)
(* named provers *)
type prover = int -> Proof.state -> bool * string;
fun err_dup_prover name = error ("Duplicate prover: " ^ quote name);
structure Provers = TheoryDataFun
(
type T = (prover * stamp) Symtab.table
val empty = Symtab.empty
val copy = I
val extend = I
fun merge _ tabs : T = Symtab.merge (eq_snd op =) tabs
handle Symtab.DUP dup => err_dup_prover dup
);
fun add_prover name prover thy =
Provers.map (Symtab.update_new (name, (prover, stamp ()))) thy
handle Symtab.DUP dup => err_dup_prover dup;
fun print_provers thy = Pretty.writeln
(Pretty.strs ("external provers:" :: sort_strings (Symtab.keys (Provers.get thy))));
(* start prover thread *)
fun start_prover name birthtime deadtime i proof_state =
(case Symtab.lookup (Provers.get (Proof.theory_of proof_state)) name of
NONE => warning ("Unknown external prover: " ^ quote name)
| SOME (prover, _) =>
let
val (ctxt, (_, goal)) = Proof.get_goal proof_state
val desc =
"external prover " ^ quote name ^ " for subgoal " ^ string_of_int i ^ ":\n" ^
Syntax.string_of_term ctxt (Thm.term_of (Thm.cprem_of goal i))
val _ = SimpleThread.fork true (fn () =>
let
val _ = register birthtime deadtime (Thread.self (), desc)
val result = prover i proof_state
handle ResHolClause.TOO_TRIVIAL
=> (true, "Empty clause: Try this command: " ^ Markup.markup Markup.sendback "apply metis")
| ERROR msg
=> (false, "Error: " ^ msg)
val _ = priority (unregister result (Thread.self ()))
in () end handle Interrupt => ())
in () end);
(* sledghammer for first subgoal *)
fun sledgehammer names proof_state =
let
val provers =
if null names then String.tokens (Symbol.is_ascii_blank o String.str) (get_atps ())
else names
val birthtime = Time.now ()
val deadtime = Time.+ (birthtime, Time.fromSeconds (get_timeout ()))
in List.app (fn name => start_prover name birthtime deadtime 1 proof_state) provers end;
(** Isar command syntax **)
local structure K = OuterKeyword and P = OuterParse in
val _ =
OuterSyntax.improper_command "atp_kill" "kill all managed provers" K.diag
(Scan.succeed (Toplevel.no_timing o Toplevel.imperative kill));
val _ =
OuterSyntax.improper_command "atp_info" "print information about managed provers" K.diag
(Scan.succeed (Toplevel.no_timing o Toplevel.imperative info));
val _ =
OuterSyntax.improper_command "print_atps" "print external provers" K.diag
(Scan.succeed (Toplevel.no_timing o Toplevel.unknown_theory o
Toplevel.keep (print_provers o Toplevel.theory_of)));
val _ =
OuterSyntax.command "sledgehammer" "call all automatic theorem provers" K.diag
(Scan.repeat P.xname >> (fn names => Toplevel.no_timing o Toplevel.unknown_proof o
Toplevel.keep ((sledgehammer names) o Toplevel.proof_of)));
end;
end;