1		% (c) 2009-2025 Lehrstuhl fuer Softwaretechnik und Programmiersprachen,
2		% Heinrich Heine Universitaet Duesseldorf
3		% This software is licenced under EPL 1.0 (http://www.eclipse.org/org/documents/epl-v10.html)
4
5		:- module(state_space,
6		[get_state_space_stats/3, get_state_space_stats/4,
7		gen_new_state_id/1,
8		history/1, forward_history/1,
9		get_action_trace/1, % old trace/1
10		get_action_trace_with_limit/2,
11		get_action_term_trace/1,
12		op_trace_ids/1, add_to_op_trace_ids/1, remove_from_op_trace_ids/1, reset_op_trace_ids/0,
13		get_state_id_trace/1,
14		current_state_id/1, current_expression/2,
15		set_current_state_id/1,
16		current_options/1, set_current_options/1,
17		get_current_predecessor_state_id/1,
18
19		add_id_at_front/1, add_id_at_end/1,
20		add_id_random/1, /* from state_space_open_nodes_c */
21		add_id_with_weight/2, add_id_to_process/3,
22		pop_id_from_front/1, pop_id_from_end/1, pop_id_oldest/1,
23		retract_open_node/1, open_ids_empty/0,
24		top_front_id/1, top_front_weight/1,
25
26		visited_expression/3, visited_expression/2, visited_expression_id/1,
27		find_hashed_packed_visited_expression/3,
28		retract_visited_expression/2,
29		not_all_transitions_added/1,
30		not_invariant_checked/1, set_invariant_checked/1,
31		invariant_not_yet_checked/1, invariant_still_to_be_checked/1,
32		not_interesting/1, % nodes ignored because they do not satisfy a user-provided scope predicate
33		mark_as_not_interesting/1,
34		max_reached_for_node/1,
35		max_reached_or_timeout_for_node/1,
36		use_no_timeout/1, time_out_for_node/1, time_out_for_node/3,
37		hash_to_id/2,id_to_marker/2, hash_to_nauty_id/2,
38		register_back_edge/2, try_compute_depth_of_state_id/2,
39		invariant_violated/1, time_out_for_invariant/1, time_out_for_assertions/1,
40		set_invariant_violated/1,
41
42		state_error_exists/0, state_error/3, store_state_error/3,
43		set_context_state/1, set_context_state/2,
44		update_context_state/1, clear_context_state/0, get_current_context_state/1,
45		store_error_for_context_state/2,
46		copy_current_errors_to_state/2,
47		store_abort_error_for_context_state_if_possible/4,
48		abort_error_exists_in_context_state/1,
49
50		transition/3,transition/4, any_transition/3,
51		store_transition/4,
52		deadlocked_state/1, % no outgoing edge
53		is_initial_state_id/1, is_concrete_constants_state_id/1,
54		multiple_concrete_constants_exist/0,
55		get_constants_state_for_id/2, get_constants_state_for_id/3,
56		get_constants_state_id_for_id/2,
57		try_get_unique_constants_state/1,
58		get_constants_id_for_state_id/2,
59		get_variables_state_for_id/2,
60		out_degree/2,
61		operation_not_yet_covered/1, operation_name_not_yet_covered/1,
62		get_operation_name_coverage_infos/4,
63		mark_operation_as_covered/1,
64		initialise_operation_not_yet_covered/0,
65
66		transition_info/2, store_transition_infos/2,
67		keep_transition_info/1,
68		compute_transitions_if_necessary/1,
69
70		state_space_initialise/0, state_space_initialise_with_stats/0,
71		state_space_reset/0,
72		state_space_add/2, state_space_packed_add/2,
73		delete_node/1,
74
75		current_state_corresponds_to_initialised_b_machine/0,
76		current_state_corresponds_to_fully_setup_b_machine/0,
77		current_state_corresponds_to_setup_constants_b_machine/0,
78		visited_state_corresponds_to_initialised_b_machine/1,
79		visited_state_corresponds_to_setup_constants_b_machine/1,
80
81		specialized_inv/2, %reuse_operation/4,
82		assert_max_reached_for_node/1, assert_time_out_for_node/3,
83		assert_time_out_for_invariant/1, assert_time_out_for_assertions/1,
84
85		set_max_nr_of_new_impl_trans_nodes/1,
86		get_max_nr_of_new_impl_trans_nodes/1,
87		impl_trans_term/3, impl_trans_term/4,
88		impl_trans_term_all/2,
89		impl_trans_id/4, impl_trans_not_complete/1,
90		compute_transitions_if_necessary_saved/1,
91		max_nr_of_new_nodes_limit_not_reached/0,
92
93		find_trace_to_initial_state/2, find_initialised_states/1,
94
95		tcltk_save_state_space/1, tcltk_load_state/1,
96		compute_full_state_space_hash/1,
97
98		execute_id_trace_from_current/1, execute_id_trace_from_current/3,
99		set_trace_by_transition_ids/1, try_set_trace_by_transition_ids/1,
100		extend_trace_by_transition_ids/1,
101		extract_term_trace_from_transition_ids/2,
102
103		add_counterexample_node/1, add_counterexample_op/1,
104		reset_counterexample/0, set_counterexample_by_transition_ids/1,
105		counterexample_node/1, counterexample_op/1 % specific predicates to register counter examples
106		]).
107
108		:- use_module(library(lists)).
109
110		:- use_module(self_check).
111		:- use_module(error_manager).
112		:- use_module(gensym).
113		:- use_module(preferences).
114		:- use_module(tools).
115		:- use_module(debug,[debug_println/1, debug_println/2]).
116		%:- use_module(state_space_exploration_modes,[compute_hash/3]).
117
118		:- use_module(extension('counter/counter'),
119		[counter_init/0, new_counter/1, get_counter/2, inc_counter/1, inc_counter/2, inc_counter_by/2, reset_counter/1, set_counter/2]).
120
121		:- use_module(module_information).
122		:- module_info(group,state_space).
123		:- module_info(description,'This module keeps track of the visited states by the animator/model checker.').
124
125		% ----------------------------------
126
127		:- load_files(library(system), [when(compile_time), imports([environ/2])]).
128		:- if((environ(prob_myheap,false) ; \+ predicate_property(load_foreign_resource(_), _))).
129		:- use_module(state_space_open_nodes). %% comment in to use only Prolog datastructures
130		:- else.
131		:- use_module(state_space_open_nodes_c). %% comment in to use C++ multimap queue; can make use of HEURISTIC_FUNCTION
132		:- endif.
133
134		% ----------------------------------
135
136		get_state_space_stats(NrNodes,NrTransitions,ProcessedNodes) :-
137		get_counter(states,N), NrNodes is N+1,
138		get_counter(transitions,NrTransitions),
139		get_counter(processed_nodes,ProcessedNodes).
140
141		get_state_space_stats(NrNodes,NrTransitions,ProcessedNodes,IgnoredNodes) :-
142		get_state_space_stats(NrNodes,NrTransitions,ProcessedNodes),
143		get_counter(not_interesting_nodes,IgnoredNodes).
144
145		gen_new_state_id(Nr) :-
146		inc_counter(states,N1), Nr is N1-1. % only one C call
147		%get_counter(states,Nr), inc_counter(states).
148		reset_state_counter :- reset_counter(states).
149		reset_state_counter(Nr) :- set_counter(states,Nr).
150
151		get_state_id_trace(StateIds) :-
152		history(History),
153		current_state_id(CurID),
154		reverse([CurID|History],StateIds).
155
156		get_current_predecessor_state_id(PriorID) :-
157		history([PriorID|_]).
158
159		:- dynamic history/1.
160		history([]).
161
162
163		:- dynamic forward_history/1.
164
165		:- dynamic current_state_id/1.
166		current_state_id(root).
167		/* INITIAL STATE, third arg: clp(fd) constraints as generated
168		by fd_copy_term */
169
170		current_expression(ID,State) :- current_state_id(ID),
171		visited_expression(ID,State).
172		current_packed_expression(ID,State) :- current_state_id(ID),
173		packed_visited_expression(ID,State).
174
175		:- use_module(specfile,[state_corresponds_to_initialised_b_machine/1,
176		state_corresponds_to_fully_setup_b_machine/1,
177		state_corresponds_to_set_up_constants/1]).
178		current_state_corresponds_to_initialised_b_machine :-
179		current_packed_expression(_,PS), unpack_state_top_level(PS,TLState),
180		state_corresponds_to_initialised_b_machine(TLState).
181		visited_state_corresponds_to_initialised_b_machine(ID) :-
182		packed_visited_expression(ID,PS), unpack_state_top_level(PS,TLState),
183		state_corresponds_to_initialised_b_machine(TLState).
184
185		current_state_corresponds_to_fully_setup_b_machine :-
186		current_packed_expression(_,PS), unpack_state_top_level(PS,TLState),
187		state_corresponds_to_fully_setup_b_machine(TLState).
188
189		current_state_corresponds_to_setup_constants_b_machine :-
190		current_packed_expression(_,PS), unpack_state_top_level(PS,TLState),
191		state_corresponds_to_set_up_constants(TLState).
192
193		visited_state_corresponds_to_setup_constants_b_machine(ID) :-
194		packed_visited_expression(ID,PS), unpack_state_top_level(PS,TLState),
195		state_corresponds_to_set_up_constants(TLState).
196
197		:- dynamic current_options/1.
198		current_options([]).
199
200		set_current_options(Options) :-
201		retractall( current_options(_) ),
202		assertz( current_options(Options) ).
203
204		:- dynamic packed_visited_expression/2.
205		%packed_visited_expression(v_0,true).
206
207		:- use_module(state_packing).
208
209		retract_visited_expression(ID,State) :- retract(packed_visited_expression(ID,PState)),
210		unpack_state(PState,State).
211
212		retractall_visited_expression(ID) :- retractall(packed_visited_expression(ID,_)).
213
214		state_space_packed_add(Id,PackedTerm) :- assertz(packed_visited_expression(Id,PackedTerm)).
215
216		state_space_add(Id,Term) :-
217		(pack_state(Term,PackedTerm) -> assertz(packed_visited_expression(Id,PackedTerm))
218		; add_internal_error('State packing failed: ',pack_state(Term,_)),
219		assertz(packed_visited_expression(Id,Term))).
220
221		% deprecated:
222		visited_expression(ID,State,true) :- visited_expression(ID,State).
223		% not call(CurBody); for the moment we always have true as last argument
224
225	?	visited_expression(A,B) :- packed_visited_expression(A,PB),
226		(unpack_state(PB,R) -> B=R ; add_internal_error('Unpacking state failed: ',unpack_state(PB,R)),R=A).
227
228		%visited_expression_id(A) :- packed_visited_expression(A,_). % avoid unpacking state
229		% even better: not to look up fact at all to avoid constructing state term, this is done below:
230		:- use_module(library(between),[between/3]).
231		visited_expression_id(ID) :- number(ID),!, ID>=0, get_counter(states,N), ID<N.
232		visited_expression_id(ID) :- ID==root,!.
233		visited_expression_id(root).
234	?	visited_expression_id(Nr) :- Nr \== root, get_counter(states,N), N1 is N-1, between(0,N1,Nr).
235
236		% given a hash and a packed state: find ID (fail if does not exist)
237		find_hashed_packed_visited_expression(Hash,PackedState,ID) :-
238	?	hash_to_id(Hash,ID),
239		(packed_visited_expression(ID,PackedState)
240		-> true /* warning: may instantiate State if not ground */
241		; functor(PackedState,concrete_constants,1),
242		preference(maxNrOfInitialisations,Max), Max =< 4
243		-> debug_println(19,hash_collision_for_constants(Hash,ID)),fail
244		% this is not too bad if maxNrOfInitialisations small;
245		% can happen due to depth limit in term_depth_hash in compute_hash
246		; write(hash_collision(Hash,ID)),nl,fail
247		).
248
249
250		:- dynamic not_invariant_checked/1.
251		set_invariant_checked(ID) :- %print(inv_checked(ID)),nl,
252	?	retract(not_invariant_checked(ID)).
253
254		invariant_not_yet_checked(ID) :-
255		not_all_transitions_added(ID) ; /* assumption: if not all transitions added then we haven't checked invariant yet */
256		not_invariant_checked(ID) ;
257		not_interesting(ID). % assumption: if a node is marked as not interesting it will not be examined
258
259		% difference with invariant_not_yet_checked: not interesting nodes not reported and cannot be backtracked
260		invariant_still_to_be_checked(ID) :-
261		(not_all_transitions_added(ID) -> true ; not_invariant_checked(ID) -> true).
262
263		:- dynamic not_interesting/1.
264		%not_interesting(v_0).
265
266		:- dynamic max_reached_for_node/1.
267		/* true if not all outgoing transistions were computed due to the limit
268		on the number of operations/initialisations computed */
269		:- dynamic time_out_for_node/3, use_no_timeout/1, time_out_for_invariant/1, time_out_for_assertions/1.
270
271		time_out_for_node(ID) :- (var(ID) -> visited_expression_id(ID) ; true),
272		(time_out_for_node(ID,_,_) -> true ; fail).
273
274		:- dynamic transition/4.
275		%transition(v_0,a,1,v_1).
276
277		store_transition(Org,Action,Dest,Id) :-
278		%get_counter(transitions,Id), inc_counter(transitions),
279		inc_counter(transitions,Id1), Id is Id1-1, % only one C call
280		assertz(transition(Org,Action,Id,Dest)).
281
282	?	deadlocked_state(Origin) :- \+ any_transition(Origin,_,_).
283
284		is_concrete_constants_state_id(ID) :-
285	?	transition(root,_,ID),
286		packed_visited_expression(ID,concrete_constants(_)).
287
288		% check if we have multiple constant setups
289		multiple_concrete_constants_exist :-
290	?	is_concrete_constants_state_id(ID),
291	?	is_concrete_constants_state_id(ID2), ID2 \= ID,!.
292
293
294		is_initial_state_id(InitialStateID) :-
295		transition(root,_,State),
296		packed_visited_expression(State,P),
297		(P = concrete_constants(_) % also covers '$partial_setup_constants'
298		-> state_space:transition(State,_,InitialStateID)
299		; InitialStateID=State).
300
301		% get the constants for a state (if there are constants), avoid unpacking variables
302		get_constants_state_for_id(ID,CS) :- get_constants_state_for_id(ID,[],CS).
303		get_constants_state_for_id(ID,Opts,ConstantsState) :-
304		packed_visited_expression(ID,PState),
305		unpack_state_top_level(PState,TLState),
306		(TLState = const_and_vars(CID,_) -> get_constants_state_for_id(CID,[],ConstantsState)
307		; unpack_state(PState,UPState),
308		(UPState = concrete_constants(CS) -> ConstantsState=CS
309		; UPState = [_|_], member(allow_variable_list,Opts),
310		ConstantsState=UPState,
311		% could be that we have a state where constants and variables are mixed in a single list
312		% e.g., ProB2's FindStateCommand does currently not create new intermediate constant states
313		add_message(get_constants_state_for_id,'State is a list of bindings and has no reference to a constant valuation: ',ID)
314		)
315		).
316
317		% get the state id for associated constants state for a state (if there are constants)
318		get_constants_state_id_for_id(ID,CstID) :-
319		packed_visited_expression(ID,PState),
320		unpack_state_top_level(PState,TLState),
321		get_constants_id_for_id_aux(TLState,ID,CstID).
322		get_constants_id_for_id_aux(concrete_constants(_),ID,ID).
323		get_constants_id_for_id_aux(const_and_vars(ID,_),_,ID).
324
325		get_variables_state_for_id(ID,VarState) :-
326		visited_expression(ID,State),
327		get_vars_aux(State,VarState).
328		%get_vars_aux(concrete_constants(ConstantsState),[]).
329		get_vars_aux(const_and_vars(_,Vars),State) :- !, State=Vars.
330		get_vars_aux([],[]).
331		get_vars_aux([H|T],[H|T]).
332
333		% check if there is a unique constants state:
334		try_get_unique_constants_state(ConstantsState) :-
335		transition(root,_,_TransID,DestID),
336		\+ (transition(root,_,_,DestID2), DestID2 \= DestID), % no other transition exists
337		\+ max_reached_or_timeout_for_node(root),
338		DestID \= root, % DestID=root should never happen
339		get_constants_state_for_id(DestID,ConstantsState).
340
341		% returns id of constants state for a state (if it exists)
342		get_constants_id_for_state_id(ID,ConstID) :-
343		packed_visited_expression(ID,'$cst_vars'(ConstID,_)).
344
345	?	any_transition(Origin,TransID,Destination) :- transition(Origin,_,TransID,Destination).
346
347	?	transition(Origin,Action,Destination) :- transition(Origin,Action,_TransID,Destination).
348
349		:- dynamic transition_info/2.
350		store_transition_infos([],_TransId).
351		store_transition_infos([Info|Irest],TransId) :-
352		store_transition_info(Info,TransId),
353		store_transition_infos(Irest,TransId).
354		store_transition_info(Info,TransId) :- %print(info(Info,TransId)),nl,
355		(keep_transition_info(Info)
356		-> assertz(transition_info(TransId,Info))
357		; true).
358
359		% Do not store path info by default
360		keep_transition_info(path(_)) :- !, preference(eventtrace,true).
361		keep_transition_info(eventtrace(_)) :- !,preference(eventtrace,true).
362		keep_transition_info(event(_)) :- !,preference(store_event_transinfo,true).
363		keep_transition_info(_). % store everything else
364
365		reset_transition_store :-
366		retractall(transition(_,_,_,_)),
367		retractall(transition_info(_,_)),
368		reset_counter(transitions),
369		reset_counterexample.
370
371		/*
372		Version with packing of transitions:
373		store_transition(Org,Action,Dest,Id) :-
374		retract(transition_counter(Id)),
375		NewId is Id+1,
376		assertz(transition_counter(NewId)),
377		Action =.. [ActionName|Parameters],
378		pack_values(Parameters,PackedParameters),
379		assertz(packed_transition(Org,ActionName,PackedParameters,Id,Dest)).
380
381		transition(Origin,Action,TransID,Destination) :- nonvar(Action),!,
382		Action =.. [ActionName|Parameters],
383		packed_transition(Origin,ActionName,PackedParameters,TransID,Destination),
384		unpack_values(PackedParameters,Parameters).
385		transition(Origin,Action,TransID,Destination) :-
386		packed_transition(Origin,ActionName,PackedParameters,TransID,Destination),
387		unpack_values(PackedParameters,Parameters),
388		Action =.. [ActionName|Parameters].
389		any_transition(Origin,TransID,Destination) :- packed_transition(Origin,_,_,TransID,Destination).
390		*/
391
392		% compute out-degree of a node
393		out_degree(ID,OutDegree) :- findall(0, transition(ID,_,_,_), L), length(L,OutDegree).
394
395	?	operation_name_not_yet_covered(OpName) :- operation_not_yet_covered(OpName).
396
397
398		get_operation_name_coverage_infos(PossibleNr,FeasibleNr,UncovNr,UncoveredList) :-
399		findall(ON, specfile:get_possible_event(ON), Possible), length(Possible,PossibleNr),
400		findall(OF, specfile:get_feasible_event(OF), Feasible), length(Feasible,FeasibleNr),
401		findall(OpName, state_space: operation_name_not_yet_covered(OpName), UncoveredList),
402		length(UncoveredList,UncovNr).
403
404
405		:- dynamic operation_not_yet_covered/1.
406		%operation_not_yet_covered(b).
407
408		:- use_module(probsrc(debug),[formatsilent/2]).
409		mark_operation_as_covered(OpName) :-
410		(operation_not_yet_covered(OpName), % small improvement in B/PerformanceTests/ModelChecking/EnumSetLookups.mch
411		retract(operation_not_yet_covered(OpName))
412		-> (preferences:get_preference(provide_trace_information,true)
413		-> formatsilent('Covered ~w~n',[OpName])
414		; true),
415	?	(operation_not_yet_covered(_) -> true ; formatsilent('~nALL OPERATIONS COVERED~n',[]))
416		; true
417		).
418
419		:- use_module(bmachine,[b_top_level_operation/1]).
420		:- use_module(probcspsrc(haskell_csp),[channel/2]).
421		initialise_operation_not_yet_covered :- retractall(operation_not_yet_covered(_)),
422		b_or_z_mode,
423	?	b_top_level_operation(Name),
424		% b_get_machine_operation(Name,_,Par,_), length(Par,Arity), functor(Op,Name,Arity),
425		% Note: no '-->' added
426		assertz(operation_not_yet_covered(Name)),
427		fail.
428		/* Missing: treat operations with return values */
429		initialise_operation_not_yet_covered :- csp_mode, \+ csp_with_bz_mode,
430	?	channel(Name,_),
431		assertz(operation_not_yet_covered(Name)),
432		fail.
433		initialise_operation_not_yet_covered.
434
435		state_error_exists :- state_error(_,_,_),!.
436		:- dynamic state_error/3.
437
438		%state_error([],invariant_violated).
439
440		reset_next_state_error_id_counter :- reset_counter(next_state_error_id).
441		:- use_module(tools_printing, [print_error/1, format_error_with_nl/2]).
442		:- use_module(error_manager,[print_error_span/1]).
443		store_state_error(State,Error,Id) :- state_error(State,Id,Error),!. % do not store identical error twice
444		store_state_error(State,Error,Id) :-
445		%retract( next_state_error_id(Id) ),
446		inc_counter(next_state_error_id,Id),
447		% tools_printing:print_term_summary(Error),nl, tools_printing:nested_print_term(Error),nl,
448		assertz( state_error(State,Id,Error) ).
449		store_error_for_context_state(Error,Id) :-
450		( context_state(State,Errs) ->
451		(Errs<25
452		-> store_state_error(State,Error,Id), E1 is Errs+1,
453		%assertz(context_state(State,E1))
454		set_context_number_of_errors(E1)
455		; store_state_error(State,max_state_errors_reached(25),Id)
456		)
457		;
458		add_internal_error('No known context when calling store_error_for_context_state: ',store_error_for_context_state(Error,Id)),
459		fail).
460
461		% check if we already have a certain type of error in the current context state
462		abort_error_exists_in_context_state(ErrType) :- get_current_context_state(State),
463		Error = abort_error(ErrType,_Msg,_Term,_Pos),
464		state_error(State,_Id,Error).
465
466		% copy current errors from error_manager to state errors
467		copy_current_errors_to_state(StateID,Context) :-
468		% error_manager:logged_error(Source,ErrMsg,_Context,Span), % will not retract
469		error_manager:get_error_with_span(Source,ErrMsg,Span), % will retract
470		store_state_error(StateID,abort_error(Source,ErrMsg,'',span_context(Span,Context)),SID),
471		% TO DO: use other error class
472		debug_println(stored(Source,SID,_Context,ErrMsg)),
473		fail.
474		copy_current_errors_to_state(_,_).
475
476		store_abort_error_for_context_state_if_possible(ErrType,Msg,Term,Span) :-
477		%print(store(Msg,Term,Span)),nl,
478		( get_current_context_state(State) ->
479		error_manager:get_error_context(Context),
480		(abort_error_for_same_location_exists(State,Id1,ErrType,Msg,Span),
481		abort_error_for_same_location_exists(State,Id2,ErrType,Msg,Span),
482		Id2>Id1
483		-> /* two errors of same type, for same state and same source location exists */
484		/* TO DO: maybe merge state errors */
485		simplify_span(Span,Span1),
486		compress_span(Span1,Span2),
487		store_state_error(State,abort_error(ErrType,'Further identical errors occurred (not stored !)',Term,span_context(Span2,Context)),_)
488		;
489		format_error_with_nl('! An error occurred in state ~w: ~w !',[State,ErrType]),
490		% usual errors: precondition_error, while_invariant_violation, while_variant_error,
491		% assert_error, well_definedness_error, card_overflow_error
492		print_error(Msg),
493		print_error_term(Term,Span),
494		% print_error(context_state_id(State)), % printed by print_error_context
495		print_error_context,
496		(debug_mode(on),visited_expression(State,S) -> translate:translate_bstate(S,O),print_error(O) ; true),
497		compress_span(Span,Span2),
498		print_error_span(Span2),
499		store_state_error(State,abort_error(ErrType,Msg,Term,span_context(Span2,Context)),_)
500		),
501		(add_new_event_in_error_scope(abort_error(ErrType)) -> true ; true), % should we use well_definedness_error?
502		assert_real_error_occurred(abort_error) % Note that in this case the error manager list of errors maybe empty even though real_error_occured is true. (see ProB2 kernel test de.prob.cli.integration.rules.RulesMachineTest > testReuseStateSpace)
503		; % no current context_state exists:
504		compress_span(Span,Span2),
505		add_error(ErrType,Msg,Term,Span2)
506		).
507
508
509		:- use_module(bsyntaxtree, [find_identifier_uses/3]).
510		compress_span(span_context(Span,C),span_context(CS,C)) :- !,
511		compress_span(Span,CS).
512		compress_span(pos_context(Span1,C,Span2),pos_context(CS1,C,CS2)) :- !,
513		compress_span(Span1,CS1),
514		compress_span(Span2,CS2).
515		compress_span(span_predicate(Pred,LS,S),Res) :- find_identifier_uses(Pred,[],Ids),
516		sort(Ids,SIds),
517		filter_state(LS,SIds,FLS),
518		filter_state(S,SIds,FS), % TODO: do we need to store the global state? we can reconstruct it ?
519		% format('Compressed span_predicate (~w)~n',[Ids]),
520		!,
521		Res = span_predicate(Pred,FLS,FS).
522		compress_span(S,S).
523		% avoid storing large useless values
524		% TO DO: probably we should stop storing spans when a certain threshold of number of errors is reached
525
526
527		:- use_module(library(ordsets),[ord_member/2]).
528		filter_state([],_,[]).
529		filter_state([bind(ID,L)|T],Vars,Res) :-
530		(ord_member(ID,Vars) -> Res = [bind(ID,L)|RT] ; Res=RT),
531		filter_state(T,Vars,RT).
532
533
534		:- use_module(translate, [translate_error_term/3]).
535		print_error_term(T,S) :- (var(T);var(S)),!,
536		print_error('### VARIABLE error term or span:'), print_error(print_error_term(T,S)).
537		print_error_term(Term,Span) :- translate_error_term(Term,Span,S),
538		(S='' -> true ; print_error(S)).
539
540		abort_error_for_same_location_exists(State,Id,ErrType,Msg,Span) :-
541	?	state_error(State,Id,abort_error(ErrType,Msg,_Term2,span_context(Span2,_Ctxt2))),
542		same_span_location(Span2,Span).
543		% should be moved to error_manager ?
544		same_span_location(span_context(Span1,C),span_context(Span2,C)) :- !, same_span_location(Span1,Span2).
545		same_span_location(pos_context(Span1,C,_),pos_context(Span2,C,_)) :- !,
546		same_span_location(Span1,Span2). % should we check second span?
547		same_span_location(span_predicate(Pred1,_,_),span_predicate(Pred2,_,_)) :- !,Pred1=Pred2.
548		same_span_location(X,X).
549
550		:- dynamic saved_nested_context_state/2.
551		save_nested_context_state(_S) :-
552		bb_get(state_space_context_state,ID),
553		bb_get(state_space_context_errors,Errs),!,
554		%print(saving_context_state(_S,ID,Errs)),nl,
555		asserta(saved_nested_context_state(ID,Errs)).
556		save_nested_context_state(_).
557
558		% actually pops context state
559		clear_context_state :-
560	?	retract(saved_nested_context_state(ID,Errs)),!, %print(restoring_nested(ID,Errs)),nl,
561		bb_put(state_space_context_state,ID),
562		bb_put(state_space_context_errors,Errs).
563		clear_context_state :-
564		(bb_delete(state_space_context_state,_) -> true ; true).
565		%(retract(context_state(_,_)) -> true ; true). % retractall seems to be slowing down with use
566
567		% Note: Each Prolog module maintains its own blackboard for bb_get/bb_put
568		context_state(ID,Errs) :-
569		bb_get(state_space_context_state,ID), bb_get(state_space_context_errors,Errs).
570
571		% sets a new context state; pushing the previous one if necessary
572		set_context_state(State) :- %print(set_id(State)),nl,
573		save_nested_context_state(State),
574		bb_put(state_space_context_state,State),
575		bb_put(state_space_context_errors,0).
576
577		set_context_state(State,_Context) :- % Context can be used for debugging later
578		set_context_state(State).
579
580		% update current context state, without storing nested states
581		update_context_state(State) :-
582		bb_put(state_space_context_state,State),
583		bb_put(state_space_context_errors,0).
584
585		get_current_context_state(ID) :- bb_get(state_space_context_state,ID).
586		%get_current_context_state(ID) :- context_state(ID,_).
587
588		set_context_number_of_errors(Errs) :- bb_put(state_space_context_errors,Errs).
589
590		retractall_invariant_violated(State) :-
591		retractall(state_error(State,_,invariant_violated)).
592		invariant_violated(State) :-
593	?	state_error(State,_,invariant_violated).
594		set_invariant_violated(State) :-
595		( invariant_violated(State) -> true
596		; time_out_for_invariant(ID) -> print('Timeout for node: '), print(ID),nl,
597		print('Not setting invariant violation status'),nl
598		; store_state_error(State,invariant_violated,_)
599		).
600
601		%:- set_invariant_violated([]). % why is this ??
602
603
604		:- dynamic hash_to_id/2.
605		:- dynamic id_to_marker/2.
606		:- dynamic id_back_edge/3. % optional facts to keep track where a state was constructed from
607
608		:- dynamic hash_to_nauty_id/2. % used in nauty mode to map nauty id's to hash values
609
610		:- dynamic specialized_inv/2. /* stores whether for a node a specialized invariant
611		version could be computed */
612
613		% :- dynamic reuse_operation/4. /* when for a state and given operation name we can reuse the operation computed for another state */
614		% used to be used for OPERATION_REUSE TRUE
615
616		:- use_module(hashing).
617		state_space_startup :- % call once at startup to ensure all counters exist
618		counter_init,
619		new_counter(states), new_counter(processed_nodes), new_counter(transitions),
620		new_counter(next_state_error_id),
621		new_counter(not_interesting_nodes),
622		reset_open_ids. % also calls myheap init
623		state_space_initialise :- counter_init, reset_gennum, reset_gensym,
624		new_counter(states), new_counter(processed_nodes), new_counter(transitions),
625		new_counter(next_state_error_id), new_counter(not_interesting_nodes),
626		reset_state_counter, reset_processed_nodes_counter, reset_next_state_error_id_counter,
627		retractall_visited_expression(_),
628		reset_open_ids,
629		reset_stored_values, % state_packing
630		retractall(not_invariant_checked(_)),
631		reset_not_interesting,
632		retractall(max_reached_for_node(_)),
633		retractall(time_out_for_node(_,_,_)),
634		retractall(time_out_for_invariant(_)),
635		retractall(time_out_for_assertions(_)),
636		retractall(use_no_timeout(_)),
637		retractall(state_error(_,_,_)),
638		clear_context_state,
639		reset_transition_store,
640		retractall(operation_not_yet_covered(_)),
641		retractall(hash_to_id(_,_)),
642		retractall(id_back_edge(_,_,_)),
643		retractall(hash_to_nauty_id(_,_)),
644		retractall(id_to_marker(_,_)),
645		retractall(specialized_inv(_,_)),
646		%retractall(reuse_operation(_,_,_,_)),
647		state_space_add(root,root),
648		add_id_at_front(root),
649		my_term_hash(root,RootHash),
650		assertz(hash_to_id(RootHash,root)),
651		%assertz(not_invariant_checked(root)),
652		state_space_reset.
653
654		:- use_module(eventhandling,[register_event_listener/3]).
655		:- register_event_listener(startup_prob,state_space_startup,
656		'Initialise Statespace Counters.').
657		:- register_event_listener(reset_specification,state_space_initialise,
658		'Reset Statespace.').
659		:- register_event_listener(change_of_animation_mode,state_space_initialise,
660		'Reset Statespace.').
661		:- register_event_listener(specification_initialised,initialise_operation_not_yet_covered,
662		'Init coverage info.').
663		:- register_event_listener(reset_prob,state_space_initialise,
664		'Reset Statespace.').
665
666		/* A version of reset which checks how much memory is used by each fact */
667		/* state_space:init_with_stats */
668		state_space_initialise_with_stats :-
669		reset_gennum, reset_gensym, reset_state_counter, reset_processed_nodes_counter,
670		reset_next_state_error_id_counter,
671	?	retract_open_ids_with_statistics,
672	?	retract_with_statistics(state_space,[packed_visited_expression(_,_),
673		not_invariant_checked(_),
674		not_interesting(_),
675		max_reached_for_node(_),
676		time_out_for_node(_,_,_),
677		time_out_for_invariant(_),
678		time_out_for_assertions(_),
679		use_no_timeout(_),
680		state_error(_,_,_),
681		transition(_,_,_,_),
682		transition_info(_,_),
683		operation_not_yet_covered(_),
684		hash_to_id(_,_),
685		hash_to_nauty_id(_,_),
686		id_to_marker(_,_),
687		specialized_inv(_,_),
688		%reuse_operation(_,_,_,_),
689		history(_), forward_history(_), op_trace_ids(_)]),
690		reset_not_interesting,
691	?	retract_stored_values_with_statistics,
692		clear_context_state,
693		reset_transition_store,
694		state_space_add(root,root),
695		add_id_at_front(root),
696		%assertz(not_invariant_checked(root)),
697		state_space_reset,
698		initialise_operation_not_yet_covered.
699
700
701
702		:- dynamic op_trace_ids/1.
703		reset_trace :- retractall(op_trace_ids(_)), assertz(op_trace_ids([])).
704		get_action_trace(T) :- trace(T).
705		get_action_term_trace(PT) :- get_action_trace_with_limit(0,T), project_on_action_term(T,PT).
706		trace(Trace) :- get_action_trace_with_limit(500,Trace).
707		get_action_trace_with_limit(Limit,Trace) :-
708		op_trace_ids(IDT), reverse(IDT,RIDT),
709		extract_trace_from_transition_ids(RIDT,root,Limit,[],Trace).
710
711		reset_op_trace_ids :- retractall(op_trace_ids(_)), assertz(op_trace_ids([])).
712		add_to_op_trace_ids(OpID) :- retract(op_trace_ids(OpIDS)), assertz(op_trace_ids([OpID|OpIDS])).
713		remove_from_op_trace_ids(OpID) :- retract(op_trace_ids(OpIDS)),
714		(OpIDS = [R|Rest]
715		-> assertz(op_trace_ids(Rest)), OpID = R
716		; assertz(op_trace_ids(OpIDS)), fail).
717
718		% translate a list of transition ids (from root) into a list of operation terms
719		extract_term_trace_from_transition_ids(TransIDListFromRoot,Trace) :-
720		extract_trace_from_transition_ids(TransIDListFromRoot,root,0,[],ActionTrace),
721		reverse_and_project_on_action_term(ActionTrace,[],Trace).
722
723		reverse_and_project_on_action_term([],A,A).
724		reverse_and_project_on_action_term([action(_,Term)|T],Acc,Res) :- !,
725		reverse_and_project_on_action_term(T,[Term|Acc],Res).
726		reverse_and_project_on_action_term([H|T],Acc,Res) :-
727		add_error(reverse_and_project_on_action_term,'Illegal action: ',H),
728		reverse_and_project_on_action_term(T,[H|Acc],Res).
729
730		project_on_action_term([],[]).
731		project_on_action_term([action(_,Term)|T],Res) :- !, Res=[Term|TR],
732		project_on_action_term(T,TR).
733		project_on_action_term([H|T],Res) :-
734		add_error(project_on_action_term,'Illegal action: ',H),
735		project_on_action_term(T,Res).
736
737		extract_trace_from_transition_ids([],_CurrentState,_,Trace,Trace).
738		extract_trace_from_transition_ids([TransId|Rest],CurrentState,Limit,AccTrace,Trace) :-
739		compute_op_string(TransId,CurrentState,Limit,OpTerm,OpString,DestState),!,
740		extract_trace_from_transition_ids(Rest,DestState,Limit,
741		[action(OpString,OpTerm)|AccTrace],Trace).
742		extract_trace_from_transition_ids([TransId|_],CurrentState,_,_,_Trace) :-
743		add_error(state_space,'Could not execute transition id: ', TransId:from(CurrentState)),fail.
744
745		:- use_module(translate,[translate_event_with_src_and_target_id/5]).
746		compute_op_string(jump(TO),_CurID,_,Term,String,DestID) :- !, Term=jump,String=jump,DestID=TO.
747		compute_op_string(TransId,CurID,Limit,Term,String,DestID) :- transition(CurID,Term,TransId,DestID),
748		translate_event_with_src_and_target_id(Term,CurID,DestID,Limit,String).
749
750		% reset history and forward history, but not state-space itself
751		state_space_reset :-
752		reset_trace,
753		retractall(history(_)),
754		retractall(forward_history(_)),
755		retractall(current_state_id(_)),
756		retractall(current_options(_)),
757		assertz(history([])),
758		assertz(current_state_id(root)).
759
760		reset_not_interesting :- retractall(not_interesting(_)), reset_counter(not_interesting_nodes).
761
762		mark_as_not_interesting(ID) :- assertz(not_interesting(ID)), inc_counter(not_interesting_nodes).
763
764		set_current_state_id(ID) :- (retract(current_state_id(_)) -> true ; true),
765		assertz(current_state_id(ID)).
766
767		state_space_clean_all :-
768		retractall(state_space_version_in_file(_)),
769		retractall_visited_expression(_),
770		reset_open_ids,
771		retractall(not_invariant_checked(_)),
772		reset_not_interesting,
773		retractall(max_reached_for_node(_)),
774		retractall(time_out_for_node(_,_,_)),
775		retractall(time_out_for_invariant(_)),
776		retractall(time_out_for_assertions(_)),
777		retractall(use_no_timeout(_)),
778		retractall(state_error(_,_,_)),
779		clear_context_state,
780		reset_transition_store,
781		retractall(operation_not_yet_covered(_)),
782		retractall(hash_to_id(_,_)),
783		retractall(id_back_edge(_,_,_)),
784		retractall(hash_to_nauty_id(_,_)),
785		retractall(id_to_marker(_,_)),
786		retractall(specialized_inv(_,_)),
787		%retractall(reuse_operation(_,_,_,_)),
788		retractall(history(_)),
789		retractall(forward_history(_)),
790		retractall(op_trace_ids(_)),
791		retractall(current_state_id(_)),
792		retractall(current_options(_)).
793
794		% this is only used from within the Tcl/Tk animator at the moment:
795		delete_node(ID) :- print(deleting(ID)),nl,
796		retractall_visited_expression(ID),
797		retractall_invariant_violated(ID),
798		retract_open_node_and_update_processed_nodes(ID),
799		retractall(not_invariant_checked(ID)),
800		(retract(not_interesting(ID)) -> inc_counter_by(not_interesting_nodes,-1) ; true),
801		retractall(max_reached_for_node(ID)),
802		retractall(time_out_for_node(ID,_,_)),
803		retractall(time_out_for_invariant(ID)),
804		retractall(time_out_for_assertions(ID)),
805		retractall(use_no_timeout(ID)),
806		retractall(state_error(ID,_,_)),
807		retractall(transition(ID,_,_,_)),
808		% to do: check if operation_not_yet_covered(_) changes
809		retract_hash(ID),
810		retractall(id_to_marker(ID,_)).
811
812		retract_hash(ID) :- retract(hash_to_id(Hash,ID)), retractall(hash_to_nauty_id(_TermHash,Hash)),fail.
813		retract_hash(_).
814
815		assert_max_reached_for_node(Id) :- %print_message(max_reached_for_node(Id)),
816		(max_reached_for_node(Id) -> true ; assertz(max_reached_for_node(Id))).
817
818		:- use_module(probsrc(debug),[debug_mode/1]).
819		assert_time_out_for_node(Id,OpName,TypeOfTimeOut) :-
820		(debug_mode(off),functor(TypeOfTimeOut,virtual_time_out,_) -> true % can easily happen when parameters are unbounded
821		; print_message(time_out_for_node(Id,OpName,TypeOfTimeOut))),
822		(time_out_for_node(Id,OpName,_) -> true ; assertz(time_out_for_node(Id,OpName,TypeOfTimeOut))).
823		assert_time_out_for_invariant(Id) :- print_message(time_out_for_invariant(Id)),
824		(time_out_for_invariant(Id) -> true ; assertz(time_out_for_invariant(Id))).
825		assert_time_out_for_assertions(Id) :- print_message(time_out_for_assertions(Id)),
826		(time_out_for_assertions(Id) -> true ; assertz(time_out_for_assertions(Id))).
827
828		max_reached_or_timeout_for_node(Id) :-
829	?	(max_reached_for_node(Id) ; time_out_for_node(Id,_,_)).
830		/* ---------------------- */
831		/* state space saving */
832		/* ---------------------- */
833
834		:- dynamic state_space_version_in_file/1. %
835		state_space_version(1).
836
837		check_state_space_version :- state_space_version(V),
838		(state_space_version_in_file(F) -> true ; F=0),
839		(V>F -> add_message(state_space,'Warning: saved state_space may be incompatible with current version: ',F:V) ; true).
840
841		% save all infos of state space (transitions, evaluated invariants, ...)
842		tcltk_save_state_space(File) :-
843		print('% saving full state space to: '), print(File),nl,
844		open(File,write,Stream,[encoding(utf8)]),
845		print_state_space(Stream),
846		close(Stream),
847		print_message(done).
848
849
850		:- use_module(tools_printing, [print_dynamic_fact/2,print_dynamic_pred/4]).
851		print_state_space(Stream) :-
852		state_space_version(V),
853		print_dynamic_fact(Stream,state_space_version_in_file(V)),
854		% TO DO: maybe also save some important preferences, and warn user and/or propose to adapt preferences ?
855		print_dynamic_pred(Stream,state_space,history,1),
856		print_dynamic_pred(Stream,state_space,forward_history,1),
857		print_dynamic_pred(Stream,state_space,op_trace_ids,1),
858		print_dynamic_pred(Stream,state_space,current_state_id,1),
859		print_dynamic_pred(Stream,state_space,current_options,1),
860		print_dynamic_pred(Stream,state_space,packed_visited_expression,2),
861		print_dynamic_pred(Stream,state_space,not_invariant_checked,1),
862		print_dynamic_pred(Stream,state_space,not_interesting,1),
863		print_dynamic_pred(Stream,state_space,max_reached_for_node,1),
864		print_dynamic_pred(Stream,state_space,time_out_for_node,3),
865		print_dynamic_pred(Stream,state_space,use_no_timeout,1),
866		print_dynamic_pred(Stream,state_space,transition,4),
867		print_dynamic_pred(Stream,state_space,transition_info,2),
868		print_dynamic_pred(Stream,state_space,operation_not_yet_covered,1),
869		print_dynamic_pred(Stream,state_space,state_error,3),
870		print_state_space_open_nodes(Stream),
871		print_stored_values(Stream),
872		get_counter(states,X),
873		write_term(Stream,saved_gennum_count(X),[quoted(true)]),write(Stream,'.'),nl(Stream).
874
875		saved_gennum_count(99999).
876
877		/* ---------------------- */
878		/* state space loading */
879		/* ---------------------- */
880
881		tcltk_load_state(File) :- state_space_clean_all,
882		print('Loading: '), print(File),nl,
883		user_consult_without_redefine_warning(File), % this will read in bind_skeleton/2, ..., next_value_id/1
884		check_state_space_version,
885		print('Generating open node info'),nl,
886		transfer_open_node_info,
887		print('Transfer state packing info'),nl,
888		transfer_state_packing_info,
889		print('Recomputing hash index'),nl,
890		recompute_all_hash,
891		(saved_gennum_count(X) -> reset_state_counter(X) ; true),
892		reset_processed_nodes_counter, % TO DO: restore or save it
893		reset_next_state_error_id_counter, % DITTO
894		print('Done'),nl,!.
895		tcltk_load_state(File) :-
896		add_error(tcltk_load_state,'Could not load state from file: ',File),
897		state_space_initialise.
898
899		:- dynamic not_all_z_saved/1, not_all_transitions_added_saved/1.
900		:- dynamic bind_skeleton/2, stored_value/2, stored_value_hash_to_id/2, next_value_id/1.
901
902		% transfer facts read into state_space into other modules:
903		transfer_open_node_info :- retract(not_all_z_saved(X)), %print(not_all_z(X)),nl,
904		assert_not_all_z(X),fail.
905		transfer_open_node_info :- retract(not_all_transitions_added_saved(X)),
906		assert_not_all_transitions_added(X),fail.
907		transfer_open_node_info.
908		% now for transferring to state_packing module info generated by print_stored_values
909		transfer_state_packing_info :- retract(bind_skeleton(X,Y)), %print(skel(X)),nl,
910		assertz(state_packing:bind_skeleton(X,Y)),fail.
911		transfer_state_packing_info :- retract(stored_value(X,Y)),
912		assertz(state_packing:stored_value(X,Y)),fail.
913		transfer_state_packing_info :- retract(stored_value_hash_to_id(X,Y)),
914		assertz(state_packing:stored_value_hash_to_id(X,Y)),fail.
915		transfer_state_packing_info :- retract(next_value_id(X)),
916		state_packing:set_next_value_id(X),fail.
917		transfer_state_packing_info.
918
919		recompute_all_hash :-
920		retractall(hash_to_id(_,_)),retractall(id_to_marker(_,_)),
921		retractall(hash_to_nauty_id(_,_)),
922	?	visited_expression(ID,StateTemplate),
923		state_space_exploration_modes:compute_hash(StateTemplate,Hash,Marker),
924		assertz(hash_to_id(Hash,ID)),
925		assertz(id_to_marker(ID,Marker)),
926		fail.
927		recompute_all_hash.
928
929		:- use_module(hashing,[my_term_hash/2]).
930		% generates a hash for the entire state space not depending on the order in which states where added
931		compute_full_state_space_hash(Hash) :-
932		%listing(hash_to_id/2), listing(packed_visited_expression/2),
933		findall(Hash,hash_to_id(Hash,_),ListOfHashCodes),
934		sort(ListOfHashCodes,SortedList),
935		my_term_hash(SortedList,Hash).
936		% TO DO: also provide transition hashes
937
938		:- use_module(tools_meta,[safe_on_exception/3]).
939		user_consult_without_redefine_warning(File) :-
940		get_set_optional_prolog_flag(redefine_warnings, Old, off),
941		get_set_optional_prolog_flag(single_var_warnings, Old2, off),
942		(safe_on_exception(Exc,
943		%consult(File), %
944		load_files([File], [load_type(source),compilation_mode(consult),encoding(utf8)]),
945		(nl,print('Exception occurred:'),print(Exc),nl,fail))
946		-> OK=true ; OK=false),
947		get_set_optional_prolog_flag(redefine_warnings, _, Old),
948		get_set_optional_prolog_flag(single_var_warnings, _, Old2),
949		OK=true.
950
951		% execute a transition id list from current ID and update animator history,...
952		execute_id_trace_from_current(OperationIDList) :-
953		current_state_id(CurID),
954		get_state_list_from_opids(OperationIDList,CurID,StateIDList,NewCurID),
955		execute_id_trace_from_current(NewCurID,OperationIDList,StateIDList).
956
957		get_state_list_from_opids([],CurID,[],CurID).
958		get_state_list_from_opids([TransId|TO],CurID,[NextCurID|TS],FinalCurID) :-
959		transition(CurID,_,TransId,NextCurID),
960		get_state_list_from_opids(TO,NextCurID,TS,FinalCurID).
961
962
963		% execute_id_trace_from_current(NewCurID,OperationIDList,StateIDList)
964		execute_id_trace_from_current(ID,OpIDL,StateIDList) :-
965		current_state_id(CurID),
966		reverse([CurID|StateIDList],Rev),
967		Rev = [Dest|TRev],
968		(Dest==ID -> true ; print(not_eq(Dest,ID)),nl),
969		retract(history(H)),
970		update_forward_history(OpIDL), % check if OpIDL conforms to forward history and keep it
971		append(TRev,H,NewH),
972		assertz(history(NewH)),
973		retract(op_trace_ids(OldTrace)),
974		reverse(OpIDL,NewTrace),
975		append(NewTrace,OldTrace,Trace),
976		assertz(op_trace_ids(Trace)),
977		retractall(current_state_id(_)),
978		assertz(current_state_id(ID)).
979		%execute_trace_to_node(OpL,StateIDList). /* <----- BOTTLENECK FOR LONG SEQUENCES */
980		%generate_trace([],Acc,Acc).
981		%generate_trace([OpTerm|T],Acc,Res) :-
982		% translate:translate_event(OpTerm,OpString),
983		% generate_trace(T,[action(OpString,OpTerm)|Acc],Res).
984
985		update_forward_history(TransitionIds) :-
986		(retract(forward_history(Forward)),
987		prune_forward_history(TransitionIds,Forward,NewForward)
988		-> assert(forward_history(NewForward))
989		; true).
990		% try and prune forward history if it matches operation trace
991		prune_forward_history([],ForwardHistory,ForwardHistory).
992		prune_forward_history([TransID|T],[forward(_,TransID)|TF],Res) :-
993		prune_forward_history(T,TF,Res).
994
995		try_set_trace_by_transition_ids(TransIds) :-
996		(set_trace_by_transition_ids(TransIds) -> true
997		; add_internal_error('Call failed:',set_trace_by_transition_ids(TransIds))).
998
999		set_trace_by_transition_ids(TransitionIds) :-
1000		extract_history_from_transition_ids(TransitionIds,root,[],[],Last,History,OpTrace),
1001		%visited_expression(Last,LastState,LastCond),
1002		retractall(history(_)),
1003		retractall(forward_history(_)), % TODO: we could try and recover a new forward history if transition ids match current history^forward history
1004		update_forward_history(TransitionIds),
1005		retractall(current_state_id(_)),
1006		retractall(op_trace_ids(_)),
1007		assertz(history(History)),
1008		assertz(op_trace_ids(OpTrace)),
1009		assertz(current_state_id(Last)).
1010
1011
1012		extract_history_from_transition_ids([],CurrentState,History,Trace,CurrentState,History,Trace).
1013		extract_history_from_transition_ids([TransId|Rest],CurrentState,AccHist,AccTrace,Last,History,Trace) :-
1014		transition(CurrentState,_,TransId,DestState),!,
1015		extract_history_from_transition_ids(Rest,DestState,[CurrentState|AccHist],
1016		[TransId|AccTrace],Last,History,Trace).
1017		extract_history_from_transition_ids([skip|Rest],CurrentState,AccHist,AccTrace,Last,History,Trace) :- !,
1018		extract_history_from_transition_ids(Rest,CurrentState,AccHist,AccTrace,Last,History,Trace).
1019		extract_history_from_transition_ids([TransId|_],CurrentState,_,_,_,_,_Trace) :-
1020		add_error(state_space,'Could not execute transition id: ', TransId:from(CurrentState)),fail.
1021
1022		% extend trace from current state
1023		extend_trace_by_transition_ids(TransitionIds) :-
1024		current_state_id(CurID),
1025		history(OldH), op_trace_ids(OldOT),
1026		extract_history_from_transition_ids(TransitionIds,CurID,OldH,OldOT,Last,History,OpTrace),
1027		retractall(history(_)), retractall(forward_history(_)),
1028		retractall(current_state_id(_)),
1029		retractall(op_trace_ids(_)),
1030		assertz(history(History)),
1031		assertz(op_trace_ids(OpTrace)),
1032		assertz(current_state_id(Last)).
1033
1034		/* --------------------------------- */
1035		:- dynamic max_nr_of_new_nodes/1.
1036
1037		% negative number or non-number signifies no limit
1038		set_max_nr_of_new_impl_trans_nodes(MaxNrOfNewNodes) :-
1039		retractall(max_nr_of_new_nodes(_)),
1040		(number(MaxNrOfNewNodes), MaxNrOfNewNodes>=0
1041		-> assertz(max_nr_of_new_nodes(MaxNrOfNewNodes))
1042		; true). % no need to store limit; we will explore as much as needed
1043
1044		get_max_nr_of_new_impl_trans_nodes(MaxNrOfNewNodes) :-
1045		(max_nr_of_new_nodes(Max) -> MaxNrOfNewNodes=Max; MaxNrOfNewNodes = 0).
1046
1047		% used e.g., in refinement or ltl checker
1048		impl_trans_term(From,ActionAsTerm,TransID,To) :-
1049		compute_transitions_if_necessary_saved(From),
1050	?	transition(From,ActionAsTerm,TransID,To).
1051		impl_trans_term(From,ActionAsTerm,To) :-
1052		compute_transitions_if_necessary_saved(From),
1053	?	transition(From,ActionAsTerm,_TID,To).
1054
1055		% a variation also giving the transition id:
1056		impl_trans_id(From,ActionAsTerm,TransitionID,To) :-
1057		compute_transitions_if_necessary_saved(From),
1058	?	transition(From,ActionAsTerm,TransitionID,To).
1059
1060		impl_trans_term_all(From,Ops) :-
1061		compute_transitions_if_necessary_saved(From),
1062		findall(op(Id,ActionAsTerm,To),
1063		transition(From,ActionAsTerm,Id,To),
1064		Ops).
1065
1066		% true if e.g., a time-out occurred during computation of all transitions
1067		impl_trans_not_complete(From) :- max_reached_or_timeout_for_node(From).
1068
1069		compute_transitions_if_necessary_saved(From) :-
1070		catch(
1071		compute_transitions_if_necessary(From),
1072		error(forced_interrupt_error('User has interrupted the current execution'),_),
1073		user_interrupts:process_interrupted_error_message).
1074
1075		:- use_module(tcltk_interface,[compute_all_transitions_if_necessary/2]).
1076		compute_transitions_if_necessary(From) :-
1077		not_all_transitions_added(From),!,
1078		decrease_max_nr_of_new_nodes(From),
1079		compute_all_transitions_if_necessary(From,false).
1080		compute_transitions_if_necessary(_From).
1081
1082		decrease_max_nr_of_new_nodes(ID) :-
1083		retract(max_nr_of_new_nodes(Max)),!,
1084		( Max>0 ->
1085		NewMax is Max-1,
1086		assertz(max_nr_of_new_nodes(NewMax))
1087		; Max=0 -> NM is -1,
1088		assertz(max_nr_of_new_nodes(NM)),
1089		add_warning(state_space,'Maximum number of new nodes reached for CTL/LTL/refinement check, node id = ',ID),
1090		fail
1091		; % negative number: re-assert and fail
1092		assertz(max_nr_of_new_nodes(Max)),
1093		fail).
1094		decrease_max_nr_of_new_nodes(_). % no limit stored; just proceed
1095
1096		% will be called from TCL/TK side
1097		max_nr_of_new_nodes_limit_not_reached :-
1098		max_nr_of_new_nodes(N),N>0.
1099
1100		:- use_module(specfile,[b_or_z_mode/0, csp_mode/0, csp_with_bz_mode/0]).
1101		retract_open_node(NodeID) :- retract_open_node_and_update_processed_nodes(NodeID),
1102		(b_or_z_mode -> assertz(not_invariant_checked(NodeID)) ; true).
1103
1104		reset_processed_nodes_counter :- reset_counter(processed_nodes).
1105		%reset_processed_nodes_counter(Nr) :- set_counter(processed_nodes,Nr).
1106
1107		retract_open_node_and_update_processed_nodes(NodeID) :-
1108		retract_open_node_direct(NodeID),
1109		inc_processed.
1110
1111		inc_processed :-
1112		inc_counter(processed_nodes).
1113
1114		pop_id_from_front(ID) :- pop_id_from_front_direct(ID), inc_processed.
1115		pop_id_from_end(ID) :- pop_id_from_end_direct(ID), inc_processed.
1116	?	pop_id_oldest(ID) :- pop_id_oldest_direct(ID), inc_processed.
1117
1118
1119
1120		/* --------------------------------- */
1121
1122		% find initialised states; very similar to is_initial_state_id/1
1123		% but is used by ltl/ctl/sap
1124		% TO DO: merge these two variations of the same concept
1125
1126		:- use_module(specfile,[animation_mode/1]).
1127
1128		find_initialised_states(Init) :-
1129		animation_mode(Mode),
1130		( init_states_mode_cst_init(Mode) ->
1131		findall(I,find_init1(root,I,_),Init)
1132		; init_states_mode_one_step(Mode) ->
1133		next_states_from_root(Init)
1134		;
1135		fail).
1136
1137		% find trace to some initialised state
1138		find_trace_to_initial_state(Target,Trace) :- animation_mode(Mode),
1139	?	find_aux(Mode,Target,Trace).
1140		find_aux(Mode,Target,[root,Target]) :-
1141		init_states_mode_one_step(Mode).
1142		find_aux(Mode,Target,[root|Trace]) :-
1143		init_states_mode_cst_init(Mode),
1144	?	find_init1(root,Target,Trace).
1145
1146
1147		init_states_mode_cst_init(b).
1148		init_states_mode_cst_init(z).
1149		init_states_mode_cst_init(csp_and_b).
1150
1151		init_states_mode_one_step(csp).
1152		init_states_mode_one_step(cspm).
1153		init_states_mode_one_step(xtl).
1154		%init_states_mode_one_step(promela).
1155
1156		next_states_from_root(States) :-
1157		impl_trans_term_all(root,Ops),
1158		findall(S, member(op(_Id,_,S),Ops), States).
1159
1160		find_init1(Start,Init,Trace) :- Start==Init,!,Trace=[]. % usually called with Start=Init=root
1161		find_init1(Start,Init,[State|Rest]) :-
1162	?	impl_trans_term(Start,O,State),
1163	?	find_init2(O,State,Init,Rest).
1164		find_init2(O,Init,Init,[]) :-
1165		has_functor_and_maybe_tau(O,'$initialise_machine').
1166		find_init2(O,State,Init,Path) :-
1167		has_functor_and_maybe_tau(O,'$setup_constants'),
1168	?	find_init1(State,Init,Path).
1169		find_init2(start_cspm_MAIN,State,Init,Path) :-
1170	?	find_init1(State,Init,Path).
1171		find_init2(start_cspm(_Proc),State,Init,Path) :-
1172		find_init1(State,Init,Path).
1173
1174		% has_functor_and_maybe_tau(Term,Functor)
1175		% checks if Term has the form "Functor(...)" or "tau(Functor(...))"
1176		% this is used for CSP||B specification where the initialisation is wrapped with
1177		% in a tau operator
1178		has_functor_and_maybe_tau(tau(Term),Functor) :-
1179		has_functor_and_maybe_tau(Term,Functor),!.
1180		has_functor_and_maybe_tau(Term,Functor) :-
1181		functor(Term,Functor,_).
1182
1183		% compute how far the state is from the root node using back_edge markers (if available)
1184		try_compute_depth_of_state_id(root,R) :- !, R=0.
1185		try_compute_depth_of_state_id(Node,Depth) :- id_back_edge(Node,Depth,_Back).
1186
1187		% optional registering of back_edges: to quickly find trace from root and to computed depth/diameter
1188		register_back_edge(ID,FromID) :-
1189		try_compute_depth_of_state_id(FromID,D),!,
1190		D1 is D+1,
1191		assertz(id_back_edge(ID,D1,FromID)).
1192		register_back_edge(ID,FromID) :- write(cannot_store_back_edge(ID,FromID)),nl.
1193
1194		/* --------------------------------- */
1195
1196		%
1197		% Code to compute equivalence classes
1198		% using the standard DFA minimization algorithm
1199
1200		:- dynamic equivalent/2.
1201		% state_space:compute_equivalence_classes
1202		:- public compute_equivalence_classes/0.
1203
1204		compute_equivalence_classes :- init_equi,
1205		split_equivalence_classes,nl,
1206		print_equi.
1207
1208		print_equi :- state_space:equivalent(A,B), visited_expression(A,State),
1209		visited_expression(B,StateB),
1210		nl,
1211		print(A), print(' : '), print(State),nl,
1212		print(B), print(' : '), print(StateB),nl,fail.
1213		print_equi.
1214
1215		init_equi :- retractall(equivalent(_,_)),
1216		packed_visited_expression(ID,_State),
1217		\+ not_all_transitions_added(ID),
1218		findall(Action,transition(ID,Action,_,_),List),
1219		packed_visited_expression(ID2,_S2), ID2 @> ID,
1220		\+ not_all_transitions_added(ID2),
1221		findall(Action,transition(ID2,Action,_,_),List),
1222		assertz(equivalent(ID,ID2)), % they have the same signature
1223		%print(equivalent(ID,ID2)),nl,
1224		fail.
1225		init_equi :- print(finished_initialising),nl.
1226
1227		split_equivalence_classes :- retractall(echange),
1228		equivalent(ID1,ID2),
1229		transition(ID1,A,_,Dest1),
1230		transition(ID2,A,_,Dest2),
1231		\+ check_equi(Dest1,Dest2),
1232		retract(equivalent(ID1,ID2)), % splitting class
1233		% print(diff(ID1,ID2, A, Dest1, Dest2)),nl,
1234		assert_echange,
1235		fail.
1236		split_equivalence_classes :- echange -> split_equivalence_classes ; true.
1237
1238		:- dynamic echange/0.
1239		assert_echange :- echange -> true ; assertz(echange),print('.'),flush_output.
1240
1241		check_equi(A,B) :- A=B -> true ; A @<B -> equivalent(A,B) ; equivalent(B,A).
1242
1243		/*
1244		% benchmark how much time it takes to copy the state space state_space:bench_state_space.
1245		bench_state_space :-
1246		statistics(walltime,_),
1247		(state_space:packed_visited_expression(ID,S), assertz(pve(ID,S)),fail ; true),
1248		statistics(walltime,[_,Delta]), format('Time to copy packed_visited_expression: ~w ms~n',[Delta]),
1249		(state_space:transition(A,B,C,D), assertz(tr(A,B,C,D)),fail ; true),
1250		statistics(walltime,[_,Delta2]), format('Time to copy transition: ~w ms~n',[Delta2]),
1251		(state_packing:stored_value(A,B), assertz(sv(A,B)),fail ; true),
1252		(state_packing:stored_value_hash_to_id(A,B), assertz(svhi(A,B)),fail ; true),
1253		statistics(walltime,[_,Delta3]), format('Time to copy stored_value: ~w ms~n',[Delta3]).
1254		*/
1255
1256		:- public portray_state_space/0.
1257		portray_state_space :- packed_visited_expression(ID,S), functor(S,F,N),
1258		format('State ~w : ~w/~w~n',[ID,F,N]), fail.
1259		portray_state_space :- transition(ID,Action,TransID,DestID),
1260		format(' ~w: ~w -- ~w --> ~w~n',[TransID,ID,Action,DestID]),fail.
1261		portray_state_space.
1262
1263		bench_state_space :- statistics(walltime,[W1,_]),
1264		(packed_visited_expression(_,_), fail ; true),
1265		statistics(walltime,[W2,_]), T1 is W2-W1,
1266		format('Time to inspect all states: ~w ms walltime~n',[T1]),
1267		(visited_expression(_,_), fail ; true),
1268		statistics(walltime,[W3,_]), T2 is W3-W2,
1269		format('Time to inspect and unpack all states: ~w ms walltime~n',[T2]),
1270		(transition(_,_,_,_), fail ; true),
1271		statistics(walltime,[W4,_]), T3 is W4-W3,
1272		format('Time to inspect all transitions: ~w ms walltime~n',[T3]),
1273		(visited_expression(_,E), my_term_hash(E,_), fail ; true),
1274		statistics(walltime,[W5,_]), T4 is W5-W4,
1275		format('Time to inspect, unpack and hash all states: ~w ms walltime~n',[T4]).
1276
1277		% ----------------------------
1278		% COUNTER EXAMPLE MANAGEMENT
1279
1280		% store counter example nodes and transition ids; used by LTL model checking for example
1281
1282
1283		:- dynamic counterexample_node/1.
1284		:- dynamic counterexample_op/1.
1285
1286		add_counterexample_node(NodeID) :- assertz(counterexample_node(NodeID)).
1287		add_counterexample_op(TransID) :-
1288		(counterexample_op(TransID) -> true ; assertz(counterexample_op(TransID))).
1289
1290
1291		reset_counterexample :-
1292		retractall(counterexample_node(_)),
1293		retractall(counterexample_op(_)).
1294
1295		:- register_event_listener(play_counterexample,reset_counterexample,
1296		'Reset marked nodes from previous counterexamples.').
1297
1298		set_counterexample_by_transition_ids(TransIds) :-
1299		set_trace_by_transition_ids(TransIds),
1300		maplist(add_counterexample_op,TransIds),
1301		extract_history_from_transition_ids(TransIds,root,[],[],_Last,History,_OpTrace),
1302		maplist(add_counterexample_node,History).