(*  Title:      HOL/Tools/ATP_Manager/atp_manager.ML

     Author:     Fabian Immler, TU Muenchen

     Author:     Makarius

     Author:     Jasmin Blanchette, TU Muenchen

 Central manager component for ATP threads.

 *)

 signature ATP_MANAGER =

 sig

   type name_pool = Sledgehammer_HOL_Clause.name_pool

   type relevance_override = Sledgehammer_Fact_Filter.relevance_override

   type minimize_command = Sledgehammer_Proof_Reconstruct.minimize_command

   type params =

     {debug: bool,

      verbose: bool,

      overlord: bool,

      atps: string list,

      full_types: bool,

      explicit_apply: bool,

      respect_no_atp: bool,

      relevance_threshold: real,

      relevance_convergence: real,

      theory_relevant: bool option,

      defs_relevant: bool,

      isar_proof: bool,

      isar_shrink_factor: int,

      timeout: Time.time,

      minimize_timeout: Time.time}

   type problem =

     {subgoal: int,

      goal: Proof.context * (thm list * thm),

      relevance_override: relevance_override,

      axiom_clauses: (thm * (string * int)) list option,

      filtered_clauses: (thm * (string * int)) list option}

   datatype failure =

     Unprovable | TimedOut | OutOfResources | OldSpass | MalformedInput |

     MalformedOutput | UnknownError

   type prover_result =

     {outcome: failure option,

      message: string,

      pool: name_pool option,

      relevant_thm_names: string list,

      atp_run_time_in_msecs: int,

      output: string,

      proof: string,

      internal_thm_names: string Vector.vector,

      conjecture_shape: int list list,

      filtered_clauses: (thm * (string * int)) list}

   type prover =

     params -> minimize_command -> Time.time -> problem -> prover_result

   val kill_atps: unit -> unit

   val running_atps: unit -> unit

   val messages: int option -> unit

   val add_prover: string * prover -> theory -> theory

   val get_prover: theory -> string -> prover

   val available_atps: theory -> unit

   val start_prover_thread:

     params -> Time.time -> Time.time -> int -> int -> relevance_override

     -> (string -> minimize_command) -> Proof.state -> string -> unit

 end;

 structure ATP_Manager : ATP_MANAGER =

 struct

 open Sledgehammer_Util

 open Sledgehammer_Fact_Filter

 open Sledgehammer_Proof_Reconstruct

 (** problems, results, provers, etc. **)

 type params =

   {debug: bool,

    verbose: bool,

    overlord: bool,

    atps: string list,

    full_types: bool,

    explicit_apply: bool,

    respect_no_atp: bool,

    relevance_threshold: real,

    relevance_convergence: real,

    theory_relevant: bool option,

    defs_relevant: bool,

    isar_proof: bool,

    isar_shrink_factor: int,

    timeout: Time.time,

    minimize_timeout: Time.time}

 type problem =

   {subgoal: int,

    goal: Proof.context * (thm list * thm),

    relevance_override: relevance_override,

    axiom_clauses: (thm * (string * int)) list option,

    filtered_clauses: (thm * (string * int)) list option};

 datatype failure =

   Unprovable | TimedOut | OutOfResources | OldSpass | MalformedInput |

   MalformedOutput | UnknownError

 type prover_result =

   {outcome: failure option,

    message: string,

    pool: name_pool option,

    relevant_thm_names: string list,

    atp_run_time_in_msecs: int,

    output: string,

    proof: string,

    internal_thm_names: string Vector.vector,

    conjecture_shape: int list list,

    filtered_clauses: (thm * (string * int)) list};

 type prover =

   params -> minimize_command -> Time.time -> problem -> prover_result

 (** preferences **)

 val message_store_limit = 20;

 val message_display_limit = 5;

 (** thread management **)

 (* data structures over threads *)

 structure Thread_Heap = Heap

 (

   type elem = Time.time * Thread.thread;

   fun ord ((a, _), (b, _)) = Time.compare (a, b);

 );

 fun lookup_thread xs = AList.lookup Thread.equal xs;

 fun delete_thread xs = AList.delete Thread.equal xs;

 fun update_thread xs = AList.update Thread.equal xs;

 (* state of thread manager *)

 type state =

  {manager: Thread.thread option,

   timeout_heap: Thread_Heap.T,

   active: (Thread.thread * (Time.time * Time.time * string)) list,

   cancelling: (Thread.thread * (Time.time * string)) list,

   messages: string list,

   store: string list};

 fun make_state manager timeout_heap active cancelling messages store : state =

   {manager = manager, timeout_heap = timeout_heap, active = active,

     cancelling = cancelling, messages = messages, store = store};

 val global_state = Synchronized.var "atp_manager"

   (make_state NONE Thread_Heap.empty [] [] [] []);

 (* unregister ATP thread *)

 fun unregister ({verbose, ...} : params) message thread =

   Synchronized.change global_state

   (fn state as {manager, timeout_heap, active, cancelling, messages, store} =>

     (case lookup_thread active thread of

       SOME (birth_time, _, desc) =>

         let

           val active' = delete_thread thread active;

           val now = Time.now ()

           val cancelling' = (thread, (now, desc)) :: cancelling;

           val message' =

             desc ^ "\n" ^ message ^

             (if verbose then

                "Total time: " ^ Int.toString (Time.toMilliseconds

                                           (Time.- (now, birth_time))) ^ " ms.\n"

              else

                "")

           val messages' = message' :: messages;

           val store' = message' ::

             (if length store <= message_store_limit then store

              else #1 (chop message_store_limit store));

         in make_state manager timeout_heap active' cancelling' messages' store' end

     | NONE => state));

 (* main manager thread -- only one may exist *)

 val min_wait_time = Time.fromMilliseconds 300;

 val max_wait_time = Time.fromSeconds 10;

 (* This is a workaround for Proof General's off-by-a-few sendback display bug,

    whereby "pr" in "proof" is not highlighted. *)

 val break_into_chunks =

   map (replace_all "\n\n" "\000") #> maps (space_explode "\000")

 fun print_new_messages () =

   case Synchronized.change_result global_state

          (fn {manager, timeout_heap, active, cancelling, messages, store} =>

              (messages, make_state manager timeout_heap active cancelling []

                                    store)) of

     [] => ()

   | msgs =>

     msgs |> break_into_chunks

          |> (fn msg :: msgs => "Sledgehammer: " ^ msg :: msgs)

          |> List.app priority

 fun check_thread_manager params = Synchronized.change global_state

   (fn state as {manager, timeout_heap, active, cancelling, messages, store} =>

     if (case manager of SOME thread => Thread.isActive thread | NONE => false) then state

     else let val manager = SOME (Toplevel.thread false (fn () =>

       let

         fun time_limit timeout_heap =

           (case try Thread_Heap.min timeout_heap of

             NONE => Time.+ (Time.now (), max_wait_time)

           | SOME (time, _) => time);

         (*action: find threads whose timeout is reached, and interrupt cancelling threads*)

         fun action {manager, timeout_heap, active, cancelling, messages, store} =

           let val (timeout_threads, timeout_heap') =

             Thread_Heap.upto (Time.now (), Thread.self ()) timeout_heap;

           in

             if null timeout_threads andalso null cancelling

             then NONE

             else

               let

                 val _ = List.app (Simple_Thread.interrupt o #1) cancelling;

                 val cancelling' = filter (Thread.isActive o #1) cancelling;

                 val state' = make_state manager timeout_heap' active cancelling' messages store;

               in SOME (map #2 timeout_threads, state') end

           end;

       in

         while Synchronized.change_result global_state

           (fn state as {timeout_heap, active, cancelling, messages, store, ...} =>

             if null active andalso null cancelling andalso null messages

             then (false, make_state NONE timeout_heap active cancelling messages store)

             else (true, state))

         do

           (Synchronized.timed_access global_state (SOME o time_limit o #timeout_heap) action

             |> these

             |> List.app (unregister params "Timed out.\n");

             print_new_messages ();

             (*give threads some time to respond to interrupt*)

             OS.Process.sleep min_wait_time)

       end))

     in make_state manager timeout_heap active cancelling messages store end);

 (* register ATP thread *)

 fun register params birth_time death_time (thread, desc) =

  (Synchronized.change global_state

     (fn {manager, timeout_heap, active, cancelling, messages, store} =>

       let

         val timeout_heap' = Thread_Heap.insert (death_time, thread) timeout_heap;

         val active' = update_thread (thread, (birth_time, death_time, desc)) active;

         val state' = make_state manager timeout_heap' active' cancelling messages store;

       in state' end);

   check_thread_manager params);

 (** user commands **)

 (* kill ATPs *)

 fun kill_atps () = Synchronized.change global_state

   (fn {manager, timeout_heap, active, cancelling, messages, store} =>

     let

       val killing = map (fn (th, (_, _, desc)) => (th, (Time.now (), desc))) active;

       val state' = make_state manager timeout_heap [] (killing @ cancelling) messages store;

       val _ = if null active then ()

               else priority "Killed active Sledgehammer threads."

     in state' end);

 (* running_atps *)

 fun seconds time = string_of_int (Time.toSeconds time) ^ "s";

 fun running_atps () =

   let

     val {active, cancelling, ...} = Synchronized.value global_state;

     val now = Time.now ();

     fun running_info (_, (birth_time, death_time, desc)) =

       "Running: " ^ seconds (Time.- (now, birth_time)) ^ " -- " ^

         seconds (Time.- (death_time, now)) ^ " to live:\n" ^ desc;

     fun cancelling_info (_, (deadth_time, desc)) =

       "Trying to interrupt thread since " ^ seconds (Time.- (now, deadth_time)) ^ ":\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 priority (running ^ "\n" ^ interrupting) end;

 fun messages opt_limit =

   let

     val limit = the_default message_display_limit opt_limit;

     val {store, ...} = Synchronized.value global_state;

     val header =

       "Recent ATP messages" ^

         (if length store <= limit then ":" else " (" ^ string_of_int limit ^ " displayed):");

   in List.app priority (header :: break_into_chunks (#1 (chop limit store))) end

 (** The Sledgehammer **)

 (* named provers *)

 fun err_dup_prover name = error ("Duplicate prover: " ^ quote name ^ ".");

 structure Data = Theory_Data

 (

   type T = (prover * stamp) Symtab.table;

   val empty = Symtab.empty;

   val extend = I;

   fun merge data : T = Symtab.merge (eq_snd op =) data

     handle Symtab.DUP name => err_dup_prover name;

 );

 fun add_prover (name, prover) thy =

   Data.map (Symtab.update_new (name, (prover, stamp ()))) thy

   handle Symtab.DUP name => err_dup_prover name;

 fun get_prover thy name =

   case Symtab.lookup (Data.get thy) name of

     SOME (prover, _) => prover

   | NONE => error ("Unknown ATP: " ^ name)

 fun available_atps thy =

   priority ("Available ATPs: " ^

             commas (sort_strings (Symtab.keys (Data.get thy))) ^ ".")

 (* start prover thread *)

 fun start_prover_thread (params as {timeout, ...}) birth_time death_time i n

                         relevance_override minimize_command proof_state name =

   let

     val prover = get_prover (Proof.theory_of proof_state) name

     val {context = ctxt, facts, goal} = Proof.goal proof_state;

     val desc =

       "ATP " ^ quote name ^ " for subgoal " ^ string_of_int i ^ ":\n" ^

       Syntax.string_of_term ctxt (Thm.term_of (Thm.cprem_of goal i));

     val _ = Toplevel.thread true (fn () =>

       let

         val _ = register params birth_time death_time (Thread.self (), desc)

         val problem =

           {subgoal = i, goal = (ctxt, (facts, goal)),

            relevance_override = relevance_override, axiom_clauses = NONE,

            filtered_clauses = NONE}

         val message =

           #message (prover params (minimize_command name) timeout problem)

           handle Sledgehammer_HOL_Clause.TRIVIAL => metis_line i n []

                | ERROR message => "Error: " ^ message ^ "\n"

         val _ = unregister params message (Thread.self ());

       in () end)

   in () end

 end;