1		% (c) 2009-2026 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, virtual_time_out_for_node/1,
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		root_sufficiently_explored/0,
56		get_constants_state_for_id/2, get_constants_state_for_id/3,
57		get_constants_state_id_for_id/2,
58		try_get_unique_constants_state/1,
59		get_constants_id_for_state_id/2,
60		get_variables_state_for_id/2,
61		out_degree/2,
62		operation_not_yet_covered/1, operation_name_not_yet_covered/1,
63		get_operation_name_coverage_infos/4,
64		mark_operation_as_covered/1,
65		initialise_operation_not_yet_covered/0,
66
67		transition_info/2, store_transition_infos/2,
68		keep_transition_info/1, check_relevant_transition_info_stored/2,
69		compute_transitions_if_necessary/1,
70
71		state_space_initialise/0, state_space_initialise_with_stats/0,
72		state_space_reset/0,
73		state_space_add/2, state_space_packed_add/2,
74		delete_node/1,
75
76		current_state_corresponds_to_initialised_b_machine/0,
77		current_state_corresponds_to_fully_setup_b_machine/0,
78		current_state_corresponds_to_setup_constants_b_machine/0,
79		visited_state_corresponds_to_initialised_b_machine/1,
80		visited_state_corresponds_to_setup_constants_b_machine/1,
81
82		specialized_inv/2, %reuse_operation/4,
83		assert_max_reached_for_node/1, assert_time_out_for_node/3,
84		assert_time_out_for_invariant/1, assert_time_out_for_assertions/1,
85
86		set_max_nr_of_new_impl_trans_nodes/1,
87		get_max_nr_of_new_impl_trans_nodes/1,
88		impl_trans_term/3, impl_trans_term/4,
89		impl_trans_term_all/2,
90		impl_trans_id/4, impl_trans_not_complete/1,
91		compute_transitions_if_necessary_saved/1,
92		max_nr_of_new_nodes_limit_not_reached/0,
93
94		find_trace_to_initial_state/2, find_initialised_states/1,
95
96		tcltk_save_state_space/1, tcltk_load_state/1,
97		compute_full_state_space_hash/1,
98
99		execute_id_trace_from_current/1, execute_id_trace_from_current/3,
100		set_trace_by_transition_ids/1, try_set_trace_by_transition_ids/1,
101		extend_trace_by_transition_ids/1,
102		extract_term_trace_from_transition_ids/2,
103
104		add_counterexample_node/1, add_counterexample_op/1,
105		reset_counterexample/0, set_counterexample_by_transition_ids/1,
106		counterexample_node/1, counterexample_op/1 % specific predicates to register counter examples
107		]).
108
109		:- use_module(library(lists)).
110
111		:- use_module(self_check).
112		:- use_module(error_manager).
113		:- use_module(gensym).
114		:- use_module(preferences).
115		:- use_module(tools).
116		:- use_module(debug,[debug_println/1, debug_println/2]).
117		%:- use_module(state_space_exploration_modes,[compute_hash/3]).
118
119		:- use_module(extension('counter/counter'),
120		[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]).
121
122		:- use_module(module_information).
123		:- module_info(group,state_space).
124		:- module_info(description,'This module keeps track of the visited states by the animator/model checker.').
125
126		% ----------------------------------
127
128		:- load_files(library(system), [when(compile_time), imports([environ/2])]).
129		:- if((environ(prob_myheap,false) ; \+ predicate_property(load_foreign_resource(_), _))).
130		:- use_module(state_space_open_nodes). %% comment in to use only Prolog datastructures
131		:- else.
132		:- use_module(state_space_open_nodes_c). %% comment in to use C++ multimap queue; can make use of HEURISTIC_FUNCTION
133		:- endif.
134
135		% ----------------------------------
136
137		get_state_space_stats(NrNodes,NrTransitions,ProcessedNodes) :-
138		get_counter(states,N), NrNodes is N+1,
139		get_counter(transitions,NrTransitions),
140		get_counter(processed_nodes,ProcessedNodes).
141
142		get_state_space_stats(NrNodes,NrTransitions,ProcessedNodes,IgnoredNodes) :-
143		get_state_space_stats(NrNodes,NrTransitions,ProcessedNodes),
144		get_counter(not_interesting_nodes,IgnoredNodes).
145
146		gen_new_state_id(Nr) :-
147		inc_counter(states,N1), Nr is N1-1. % only one C call
148		%get_counter(states,Nr), inc_counter(states).
149		reset_state_counter :- reset_counter(states).
150		reset_state_counter(Nr) :- set_counter(states,Nr).
151
152		get_state_id_trace(StateIds) :-
153		history(History),
154		current_state_id(CurID),
155		reverse([CurID|History],StateIds).
156
157		get_current_predecessor_state_id(PriorID) :-
158		history([PriorID|_]).
159
160		:- dynamic history/1.
161		history([]).
162
163
164		:- dynamic forward_history/1.
165
166		:- dynamic current_state_id/1.
167		current_state_id(root).
168		/* INITIAL STATE, third arg: clp(fd) constraints as generated
169		by fd_copy_term */
170
171		current_expression(ID,State) :- current_state_id(ID),
172		visited_expression(ID,State).
173		current_packed_expression(ID,State) :- current_state_id(ID),
174		packed_visited_expression(ID,State).
175
176		:- use_module(specfile,[state_corresponds_to_initialised_b_machine/1,
177		state_corresponds_to_fully_setup_b_machine/1,
178		state_corresponds_to_set_up_constants/1]).
179		current_state_corresponds_to_initialised_b_machine :-
180		current_packed_expression(_,PS), unpack_state_top_level(PS,TLState),
181		state_corresponds_to_initialised_b_machine(TLState).
182		visited_state_corresponds_to_initialised_b_machine(ID) :-
183		packed_visited_expression(ID,PS), unpack_state_top_level(PS,TLState),
184		state_corresponds_to_initialised_b_machine(TLState).
185
186		current_state_corresponds_to_fully_setup_b_machine :-
187		current_packed_expression(_,PS), unpack_state_top_level(PS,TLState),
188		state_corresponds_to_fully_setup_b_machine(TLState).
189
190		current_state_corresponds_to_setup_constants_b_machine :-
191		current_packed_expression(_,PS), unpack_state_top_level(PS,TLState),
192		state_corresponds_to_set_up_constants(TLState).
193
194		visited_state_corresponds_to_setup_constants_b_machine(ID) :-
195		packed_visited_expression(ID,PS), unpack_state_top_level(PS,TLState),
196		state_corresponds_to_set_up_constants(TLState).
197
198		:- dynamic current_options/1.
199		current_options([]).
200
201		set_current_options(Options) :-
202		retractall( current_options(_) ),
203		assertz( current_options(Options) ).
204
205		:- dynamic packed_visited_expression/2.
206		%packed_visited_expression(v_0,true).
207
208		:- use_module(state_packing).
209
210		retract_visited_expression(ID,State) :- retract(packed_visited_expression(ID,PState)),
211		unpack_state(PState,State).
212
213		retractall_visited_expression(ID) :- retractall(packed_visited_expression(ID,_)).
214
215		state_space_packed_add(Id,PackedTerm) :- assertz(packed_visited_expression(Id,PackedTerm)).
216
217		state_space_add(Id,Term) :-
218		(pack_state(Term,PackedTerm) -> assertz(packed_visited_expression(Id,PackedTerm))
219		; add_internal_error('State packing failed: ',pack_state(Term,_)),
220		assertz(packed_visited_expression(Id,Term))).
221
222		% deprecated:
223		visited_expression(ID,State,true) :- visited_expression(ID,State).
224		% not call(CurBody); for the moment we always have true as last argument
225
226		visited_expression(A,B) :- packed_visited_expression(A,PB),
227		(unpack_state(PB,R) -> B=R ; add_internal_error('Unpacking state failed: ',unpack_state(PB,R)),R=A).
228
229		%visited_expression_id(A) :- packed_visited_expression(A,_). % avoid unpacking state
230		% even better: not to look up fact at all to avoid constructing state term, this is done below:
231		:- use_module(library(between),[between/3]).
232		visited_expression_id(ID) :- number(ID),!, ID>=0, get_counter(states,N), ID<N.
233		visited_expression_id(ID) :- ID==root,!.
234		visited_expression_id(root).
235		visited_expression_id(Nr) :- Nr \== root, get_counter(states,N), N1 is N-1, between(0,N1,Nr).
236
237		% given a hash and a packed state: find ID (fail if does not exist)
238		find_hashed_packed_visited_expression(Hash,PackedState,ID) :-
239		hash_to_id(Hash,ID),
240		(packed_visited_expression(ID,PackedState)
241		-> true /* warning: may instantiate State if not ground */
242		; functor(PackedState,concrete_constants,1),
243		preference(maxNrOfInitialisations,Max), Max =< 4
244		-> debug_println(19,hash_collision_for_constants(Hash,ID)),fail
245		% this is not too bad if maxNrOfInitialisations small;
246		% can happen due to depth limit in term_depth_hash in compute_hash
247		; formatsilent('* hash collision for id=~w hash=~w~n',[ID,Hash]),fail
248		).
249
250
251		:- dynamic not_invariant_checked/1.
252		set_invariant_checked(ID) :- %print(inv_checked(ID)),nl,
253		retract(not_invariant_checked(ID)).
254
255		invariant_not_yet_checked(ID) :-
256		not_all_transitions_added(ID) ; /* assumption: if not all transitions added then we haven't checked invariant yet */
257		not_invariant_checked(ID) ;
258		not_interesting(ID). % assumption: if a node is marked as not interesting it will not be examined
259
260		% difference with invariant_not_yet_checked: not interesting nodes not reported and cannot be backtracked
261		invariant_still_to_be_checked(ID) :-
262		(not_all_transitions_added(ID) -> true ; not_invariant_checked(ID) -> true).
263
264		:- dynamic not_interesting/1.
265		%not_interesting(v_0).
266
267		:- dynamic max_reached_for_node/1.
268		/* true if not all outgoing transistions were computed due to the limit
269		on the number of operations/initialisations computed */
270		:- dynamic time_out_for_node/3, use_no_timeout/1, time_out_for_invariant/1, time_out_for_assertions/1.
271
272		time_out_for_node(ID) :- (var(ID) -> visited_expression_id(ID) ; true),
273		(time_out_for_node(ID,_,_) -> true ; fail).
274
275		% only succeeds for virtual time_outs
276		virtual_time_out_for_node(ID) :- (var(ID) -> visited_expression_id(ID) ; true),
277		(time_out_for_node(ID,_,virtual_time_out) -> true ; fail).
278
279		:- dynamic transition/4.
280		%transition(v_0,a,1,v_1).
281
282		store_transition(Org,Action,Dest,Id) :-
283		%get_counter(transitions,Id), inc_counter(transitions),
284		inc_counter(transitions,Id1), Id is Id1-1, % only one C call
285		assertz(transition(Org,Action,Id,Dest)).
286
287		deadlocked_state(Origin) :- \+ any_transition(Origin,_,_).
288
289		is_concrete_constants_state_id(ID) :-
290		logical_transition_from_root(ID),
291		packed_visited_expression(ID,PState), % Note: in CSP||B mode there is no csp_and_b wrapper
292		unpack_state_top_level(PState,concrete_constants(_)).
293
294		% get the transition to the first logical successor to root, jumping over start_cspm_MAIN in CSP||B mode
295		logical_transition_from_root(ID) :-
296		transition(root,T,_TransId,ID1),
297		(T=start_cspm_MAIN, csp_with_bz_mode
298		-> transition(ID1,_,_,ID) % the first logical successor of root is a successor of ID1
299		; ID1=ID
300		).
301
302		% check if we have explored a successor of root node to find constants (or initial state if no constants exist)
303		% i.e., did we compute successors of root, and in case of CSP||B did we from there set up constants or initialise machine
304		root_sufficiently_explored :-
305		transition(root,T,_TransId,ID1),!,
306		(T=start_cspm_MAIN, csp_with_bz_mode
307		-> \+ not_all_transitions_added(ID1)
308		; true
309		).
310
311		% check if we have multiple constant setups
312		multiple_concrete_constants_exist :-
313		is_concrete_constants_state_id(ID),
314		is_concrete_constants_state_id(ID2), ID2 \= ID,!.
315
316
317		is_initial_state_id(InitialStateID) :-
318		logical_transition_from_root(State),
319		packed_visited_expression(State,P),
320		(P = concrete_constants(_) % also covers '$partial_setup_constants'
321		-> state_space:transition(State,_,InitialStateID)
322		; InitialStateID=State).
323
324		% get the constants for a state (if there are constants), avoid unpacking variables
325		get_constants_state_for_id(ID,CS) :- get_constants_state_for_id(ID,[],CS).
326		get_constants_state_for_id(ID,Opts,ConstantsState) :-
327		packed_visited_expression(ID,PState),
328		unpack_state_top_level(PState,TLState),
329		(get_const_and_vars_id(TLState,CID) -> get_constants_state_for_id(CID,[],ConstantsState)
330		; unpack_state(PState,UPState),
331		(UPState = concrete_constants(CS) -> ConstantsState=CS
332		; UPState = [_|_], member(allow_variable_list,Opts),
333		ConstantsState=UPState,
334		% could be that we have a state where constants and variables are mixed in a single list
335		% e.g., ProB2's FindStateCommand does currently not create new intermediate constant states
336		add_message(get_constants_state_for_id,'State is a list of bindings and has no reference to a constant valuation: ',ID)
337		)
338		).
339
340		get_const_and_vars_id(const_and_vars(CID,_),CID).
341		get_const_and_vars_id(csp_and_b(_,BState),CID) :- get_const_and_vars_id(BState,CID).
342
343		% get the state id for associated constants state for a state (if there are constants)
344		get_constants_state_id_for_id(ID,CstID) :-
345		packed_visited_expression(ID,PState),
346		unpack_state_top_level(PState,TLState),
347		get_constants_id_for_id_aux(TLState,ID,CstID).
348		get_constants_id_for_id_aux(concrete_constants(_),ID,ID).
349		get_constants_id_for_id_aux(const_and_vars(ID,_),_,ID).
350		get_constants_id_for_id_aux(csp_and_b(_,BState),ID,CstID) :- get_constants_id_for_id_aux(BState,ID,CstID).
351
352		get_variables_state_for_id(ID,VarState) :-
353		visited_expression(ID,State),
354		get_vars_aux(State,VarState).
355		%get_vars_aux(concrete_constants(ConstantsState),[]).
356		get_vars_aux(const_and_vars(_,Vars),State) :- !, State=Vars.
357		get_vars_aux([],[]).
358		get_vars_aux([H|T],[H|T]).
359
360		% check if there is a unique constants state:
361		try_get_unique_constants_state(ConstantsState) :-
362		logical_transition_from_root(DestID),
363		\+ (logical_transition_from_root(DestID2), DestID2 \= DestID), % no other transition exists
364		\+ max_reached_or_timeout_for_node(root),
365		DestID \= root, % DestID=root should never happen
366		get_constants_state_for_id(DestID,ConstantsState).
367
368		% returns id of constants state for a state (if it exists)
369		get_constants_id_for_state_id(ID,ConstID) :-
370		packed_visited_expression(ID,PState),
371		get_cstid_from_vars(PState,ConstID).
372
373		get_cstid_from_vars('$cst_vars'(ConstID,_),ConstID). % const_and_vars are always converted to this
374		get_cstid_from_vars(csp_and_b(_,B),ConstID) :- get_cstid_from_vars(B,ConstID).
375
376		any_transition(Origin,TransID,Destination) :- transition(Origin,_,TransID,Destination).
377
378		transition(Origin,Action,Destination) :- transition(Origin,Action,_TransID,Destination).
379
380		:- dynamic transition_info/2.
381		store_transition_infos([],_TransId).
382		store_transition_infos([Info|Irest],TransId) :-
383		store_transition_info(Info,TransId),
384		store_transition_infos(Irest,TransId).
385		store_transition_info(Info,TransId) :- %print(info(Info,TransId)),nl,
386		(keep_transition_info(Info)
387		-> assertz(transition_info(TransId,Info))
388		; true).
389
390		% Do not store path info by default
391		keep_transition_info(path(_)) :- !,
392		preference(eventtrace,true). % STORE_DETAILED_TRANSITION_INFOS
393		keep_transition_info(eventtrace(_)) :- !,preference(eventtrace,true).
394		keep_transition_info(event(_)) :- !,
395		preference(store_event_transinfo,true). % store info about parameters and abstract Rodin events
396		keep_transition_info(_). % store everything else
397
398		% check if all relevant transition infos have been stored for a transition
399		check_relevant_transition_info_stored([],_).
400		check_relevant_transition_info_stored([Info|Irest],TransId) :-
401		(keep_transition_info(Info) -> transition_info(TransId,Info) ; true),
402		check_relevant_transition_info_stored(Irest,TransId).
403
404
405		reset_transition_store :-
406		retractall(transition(_,_,_,_)),
407		retractall(transition_info(_,_)),
408		reset_counter(transitions),
409		reset_counterexample.
410
411		/*
412		Version with packing of transitions:
413		store_transition(Org,Action,Dest,Id) :-
414		retract(transition_counter(Id)),
415		NewId is Id+1,
416		assertz(transition_counter(NewId)),
417		Action =.. [ActionName|Parameters],
418		pack_values(Parameters,PackedParameters),
419		assertz(packed_transition(Org,ActionName,PackedParameters,Id,Dest)).
420
421		transition(Origin,Action,TransID,Destination) :- nonvar(Action),!,
422		Action =.. [ActionName|Parameters],
423		packed_transition(Origin,ActionName,PackedParameters,TransID,Destination),
424		unpack_values(PackedParameters,Parameters).
425		transition(Origin,Action,TransID,Destination) :-
426		packed_transition(Origin,ActionName,PackedParameters,TransID,Destination),
427		unpack_values(PackedParameters,Parameters),
428		Action =.. [ActionName|Parameters].
429		any_transition(Origin,TransID,Destination) :- packed_transition(Origin,_,_,TransID,Destination).
430		*/
431
432		% compute out-degree of a node
433		out_degree(ID,OutDegree) :- findall(0, transition(ID,_,_,_), L), length(L,OutDegree).
434
435		operation_name_not_yet_covered(OpName) :- operation_not_yet_covered(OpName).
436
437
438		get_operation_name_coverage_infos(PossibleNr,FeasibleNr,UncovNr,UncoveredList) :-
439		findall(ON, specfile:get_possible_event(ON), Possible), length(Possible,PossibleNr),
440		findall(OF, specfile:get_feasible_event(OF), Feasible), length(Feasible,FeasibleNr),
441		findall(OpName, state_space: operation_name_not_yet_covered(OpName), UncoveredList),
442		length(UncoveredList,UncovNr).
443
444
445		:- dynamic operation_not_yet_covered/1.
446		%operation_not_yet_covered(b).
447
448		:- use_module(probsrc(debug),[formatsilent/2]).
449		mark_operation_as_covered(OpName) :-
450		(operation_not_yet_covered(OpName), % small improvement in B/PerformanceTests/ModelChecking/EnumSetLookups.mch
451		retract(operation_not_yet_covered(OpName))
452		-> (preferences:get_preference(provide_trace_information,true)
453		-> formatsilent('Covered ~w~n',[OpName])
454		; true),
455		(operation_not_yet_covered(_) -> true ; formatsilent('~nALL OPERATIONS COVERED~n',[]))
456		; true
457		).
458
459		:- use_module(bmachine,[b_top_level_operation/1]).
460		:- use_module(probcspsrc(haskell_csp),[channel/2]).
461		initialise_operation_not_yet_covered :- retractall(operation_not_yet_covered(_)),
462		b_or_z_mode,
463	?	b_top_level_operation(Name),
464		% b_get_machine_operation(Name,_,Par,_), length(Par,Arity), functor(Op,Name,Arity),
465		% Note: no '-->' added
466		assertz(operation_not_yet_covered(Name)),
467		fail.
468		/* Missing: treat operations with return values */
469		initialise_operation_not_yet_covered :- csp_mode, \+ csp_with_bz_mode,
470		channel(Name,_),
471		assertz(operation_not_yet_covered(Name)),
472		fail.
473		initialise_operation_not_yet_covered.
474
475		state_error_exists :- state_error(_,_,_),!.
476		:- dynamic state_error/3.
477
478		%state_error([],invariant_violated).
479
480		reset_next_state_error_id_counter :- reset_counter(next_state_error_id).
481		:- use_module(tools_printing, [print_error/1, format_error_with_nl/2]).
482		:- use_module(error_manager,[print_error_span/1]).
483		store_state_error(State,Error,Id) :- state_error(State,Id,Error),!. % do not store identical error twice
484		store_state_error(State,Error,Id) :-
485		%retract( next_state_error_id(Id) ),
486		inc_counter(next_state_error_id,Id),
487		% tools_printing:print_term_summary(Error),nl, tools_printing:nested_print_term(Error),nl,
488		assertz( state_error(State,Id,Error) ).
489		store_error_for_context_state(Error,Id) :-
490		( context_state(State,Errs) ->
491		(Errs<25
492		-> store_state_error(State,Error,Id), E1 is Errs+1,
493		%assertz(context_state(State,E1))
494		set_context_number_of_errors(E1)
495		; store_state_error(State,max_state_errors_reached(25),Id)
496		)
497		;
498		add_internal_error('No known context when calling store_error_for_context_state: ',store_error_for_context_state(Error,Id)),
499		fail).
500
501		% check if we already have a certain type of error in the current context state
502		abort_error_exists_in_context_state(ErrType) :- get_current_context_state(State),
503		Error = abort_error(ErrType,_Msg,_Term,_Pos),
504		state_error(State,_Id,Error).
505
506		% copy current errors from error_manager to state errors
507		copy_current_errors_to_state(StateID,Context) :-
508		% error_manager:logged_error(Source,ErrMsg,_Context,Span), % will not retract
509		error_manager:get_error_with_span(Source,ErrMsg,Span), % will retract
510		store_state_error(StateID,abort_error(Source,ErrMsg,'',span_context(Span,Context)),SID),
511		% TO DO: use other error class
512		debug_println(4,stored_state_error(Source,SID,_Context,ErrMsg)),
513		fail.
514		copy_current_errors_to_state(_,_).
515
516		store_abort_error_for_context_state_if_possible(ErrType,Msg,Term,Span) :-
517		%print(store(Msg,Term,Span)),nl,
518		( get_current_context_state(State) ->
519		error_manager:get_error_context(Context),
520		(abort_error_for_same_location_exists(State,Id1,ErrType,Msg,Span),
521		abort_error_for_same_location_exists(State,Id2,ErrType,Msg,Span),
522		Id2>Id1
523		-> /* two errors of same type, for same state and same source location exists */
524		/* TO DO: maybe merge state errors */
525		simplify_span(Span,Span1),
526		compress_span(Span1,Span2),
527		store_state_error(State,abort_error(ErrType,'Further identical errors occurred (not stored !)',Term,span_context(Span2,Context)),_)
528		;
529		format_error_with_nl('! An error occurred in state ~w: ~w !',[State,ErrType]),
530		% usual errors: precondition_error, while_invariant_violation, while_variant_error,
531		% assert_error, well_definedness_error, card_overflow_error
532		print_error(Msg),
533		print_error_term(Term,Span),
534		% print_error(context_state_id(State)), % printed by print_error_context
535		print_error_context,
536		(debug_mode(on),visited_expression(State,S) -> translate:translate_bstate(S,O),print_error(O) ; true),
537		compress_span(Span,Span2),
538		print_error_span(Span2),
539		store_state_error(State,abort_error(ErrType,Msg,Term,span_context(Span2,Context)),_)
540		),
541		(add_new_event_in_error_scope(abort_error(ErrType)) -> true ; true), % should we use well_definedness_error?
542		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)
543		; % no current context_state exists:
544		compress_span(Span,Span2),
545		add_error(ErrType,Msg,Term,Span2)
546		).
547
548
549		:- use_module(bsyntaxtree, [find_identifier_uses/3]).
550		compress_span(span_context(Span,C),span_context(CS,C)) :- !,
551		compress_span(Span,CS).
552		compress_span(pos_context(Span1,C,Span2),pos_context(CS1,C,CS2)) :- !,
553		compress_span(Span1,CS1),
554		compress_span(Span2,CS2).
555		compress_span(span_predicate(Pred,LS,S),Res) :- find_identifier_uses(Pred,[],Ids),
556		sort(Ids,SIds),
557		filter_state(LS,SIds,FLS),
558		filter_state(S,SIds,FS), % TODO: do we need to store the global state? we can reconstruct it ?
559		% format('Compressed span_predicate (~w)~n',[Ids]),
560		!,
561		Res = span_predicate(Pred,FLS,FS).
562		compress_span(S,S).
563		% avoid storing large useless values
564		% TO DO: probably we should stop storing spans when a certain threshold of number of errors is reached
565
566
567		:- use_module(library(ordsets),[ord_member/2]).
568		filter_state([],_,[]).
569		filter_state([bind(ID,L)|T],Vars,Res) :-
570		(ord_member(ID,Vars) -> Res = [bind(ID,L)|RT] ; Res=RT),
571		filter_state(T,Vars,RT).
572
573
574		:- use_module(translate, [translate_error_term/3]).
575		print_error_term(T,S) :- (var(T);var(S)),!,
576		print_error('### VARIABLE error term or span:'), print_error(print_error_term(T,S)).
577		print_error_term(Term,Span) :- translate_error_term(Term,Span,S),
578		(S='' -> true ; print_error(S)).
579
580		abort_error_for_same_location_exists(State,Id,ErrType,Msg,Span) :-
581		state_error(State,Id,abort_error(ErrType,Msg,_Term2,span_context(Span2,_Ctxt2))),
582		same_span_location(Span2,Span).
583		% should be moved to error_manager ?
584		same_span_location(span_context(Span1,C),span_context(Span2,C)) :- !, same_span_location(Span1,Span2).
585		same_span_location(pos_context(Span1,C,_),pos_context(Span2,C,_)) :- !,
586		same_span_location(Span1,Span2). % should we check second span?
587		same_span_location(span_predicate(Pred1,_,_),span_predicate(Pred2,_,_)) :- !,Pred1=Pred2.
588		same_span_location(X,X).
589
590		:- dynamic saved_nested_context_state/2.
591		save_nested_context_state(_S) :-
592		bb_get(state_space_context_state,ID),
593		bb_get(state_space_context_errors,Errs),!,
594		%print(saving_context_state(_S,ID,Errs)),nl,
595		asserta(saved_nested_context_state(ID,Errs)).
596		save_nested_context_state(_).
597
598		% actually pops context state
599		clear_context_state :-
600		retract(saved_nested_context_state(ID,Errs)),!, %print(restoring_nested(ID,Errs)),nl,
601		bb_put(state_space_context_state,ID),
602		bb_put(state_space_context_errors,Errs).
603		clear_context_state :-
604		(bb_delete(state_space_context_state,_) -> true ; true).
605		%(retract(context_state(_,_)) -> true ; true). % retractall seems to be slowing down with use
606
607		% Note: Each Prolog module maintains its own blackboard for bb_get/bb_put
608		context_state(ID,Errs) :-
609		bb_get(state_space_context_state,ID), bb_get(state_space_context_errors,Errs).
610
611		% sets a new context state; pushing the previous one if necessary
612		set_context_state(State) :- %print(set_id(State)),nl,
613		save_nested_context_state(State),
614		bb_put(state_space_context_state,State),
615		bb_put(state_space_context_errors,0).
616
617		set_context_state(State,_Context) :- % Context can be used for debugging later
618		set_context_state(State).
619
620		% update current context state, without storing nested states
621		update_context_state(State) :-
622		bb_put(state_space_context_state,State),
623		bb_put(state_space_context_errors,0).
624
625		get_current_context_state(ID) :- bb_get(state_space_context_state,ID).
626		%get_current_context_state(ID) :- context_state(ID,_).
627
628		set_context_number_of_errors(Errs) :- bb_put(state_space_context_errors,Errs).
629
630		retractall_invariant_violated(State) :-
631		retractall(state_error(State,_,invariant_violated)).
632		invariant_violated(State) :-
633		state_error(State,_,invariant_violated).
634		set_invariant_violated(State) :-
635		( invariant_violated(State) -> true
636		; time_out_for_invariant(ID) -> print('Timeout for node: '), print(ID),nl,
637		print('Not setting invariant violation status'),nl
638		; store_state_error(State,invariant_violated,_)
639		).
640
641		%:- set_invariant_violated([]). % why is this ??
642
643
644		:- dynamic hash_to_id/2.
645		:- dynamic id_to_marker/2.
646		:- dynamic id_back_edge/3. % optional facts to keep track where a state was constructed from
647
648		:- dynamic hash_to_nauty_id/2. % used in nauty mode to map nauty id's to hash values
649
650		:- dynamic specialized_inv/2. /* stores whether for a node a specialized invariant
651		version could be computed */
652
653		% :- dynamic reuse_operation/4. /* when for a state and given operation name we can reuse the operation computed for another state */
654		% used to be used for OPERATION_REUSE TRUE
655
656		:- use_module(hashing).
657		state_space_startup :- % call once at startup to ensure all counters exist
658		counter_init,
659		new_counter(states), new_counter(processed_nodes), new_counter(transitions),
660		new_counter(next_state_error_id),
661		new_counter(not_interesting_nodes),
662		reset_open_ids. % also calls myheap init
663		state_space_initialise :- counter_init, reset_gennum, reset_gensym,
664		new_counter(states), new_counter(processed_nodes), new_counter(transitions),
665		new_counter(next_state_error_id), new_counter(not_interesting_nodes),
666		reset_state_counter, reset_processed_nodes_counter, reset_next_state_error_id_counter,
667		retractall_visited_expression(_),
668		reset_open_ids,
669		reset_stored_values, % state_packing
670		retractall(not_invariant_checked(_)),
671		reset_not_interesting,
672		retractall(max_reached_for_node(_)),
673		retractall(time_out_for_node(_,_,_)),
674		retractall(time_out_for_invariant(_)),
675		retractall(time_out_for_assertions(_)),
676		retractall(use_no_timeout(_)),
677		retractall(state_error(_,_,_)),
678		clear_context_state,
679		reset_transition_store,
680		retractall(operation_not_yet_covered(_)),
681		retractall(hash_to_id(_,_)),
682		retractall(id_back_edge(_,_,_)),
683		retractall(hash_to_nauty_id(_,_)),
684		retractall(id_to_marker(_,_)),
685		retractall(specialized_inv(_,_)),
686		%retractall(reuse_operation(_,_,_,_)),
687		state_space_add(root,root),
688		add_id_at_front(root),
689		my_term_hash(root,RootHash),
690		assertz(hash_to_id(RootHash,root)),
691		%assertz(not_invariant_checked(root)),
692		state_space_reset.
693
694		:- use_module(eventhandling,[register_event_listener/3]).
695		:- register_event_listener(startup_prob,state_space_startup,
696		'Initialise Statespace Counters.').
697		:- register_event_listener(reset_specification,state_space_initialise,
698		'Reset Statespace.').
699		:- register_event_listener(change_of_animation_mode,state_space_initialise,
700		'Reset Statespace.').
701		:- register_event_listener(specification_initialised,initialise_operation_not_yet_covered,
702		'Init coverage info.').
703		:- register_event_listener(reset_prob,state_space_initialise,
704		'Reset Statespace.').
705
706		/* A version of reset which checks how much memory is used by each fact */
707		/* state_space:init_with_stats */
708		state_space_initialise_with_stats :-
709		reset_gennum, reset_gensym, reset_state_counter, reset_processed_nodes_counter,
710		reset_next_state_error_id_counter,
711		retract_open_ids_with_statistics,
712		retract_with_statistics(state_space,[packed_visited_expression(_,_),
713		not_invariant_checked(_),
714		not_interesting(_),
715		max_reached_for_node(_),
716		time_out_for_node(_,_,_),
717		time_out_for_invariant(_),
718		time_out_for_assertions(_),
719		use_no_timeout(_),
720		state_error(_,_,_),
721		transition(_,_,_,_),
722		transition_info(_,_),
723		operation_not_yet_covered(_),
724		hash_to_id(_,_),
725		hash_to_nauty_id(_,_),
726		id_to_marker(_,_),
727		specialized_inv(_,_),
728		%reuse_operation(_,_,_,_),
729		history(_), forward_history(_), op_trace_ids(_)]),
730		reset_not_interesting,
731		retract_stored_values_with_statistics,
732		clear_context_state,
733		reset_transition_store,
734		state_space_add(root,root),
735		add_id_at_front(root),
736		%assertz(not_invariant_checked(root)),
737		state_space_reset,
738		initialise_operation_not_yet_covered.
739
740
741
742		:- dynamic op_trace_ids/1.
743		reset_trace :- retractall(op_trace_ids(_)), assertz(op_trace_ids([])).
744		get_action_trace(T) :- trace(T).
745		get_action_term_trace(PT) :- get_action_trace_with_limit(0,T), project_on_action_term(T,PT).
746		trace(Trace) :- get_action_trace_with_limit(500,Trace).
747		get_action_trace_with_limit(Limit,Trace) :-
748		op_trace_ids(IDT), reverse(IDT,RIDT),
749		extract_trace_from_transition_ids(RIDT,root,Limit,[],Trace).
750
751		reset_op_trace_ids :- retractall(op_trace_ids(_)), assertz(op_trace_ids([])).
752		add_to_op_trace_ids(OpID) :- retract(op_trace_ids(OpIDS)), assertz(op_trace_ids([OpID|OpIDS])).
753		remove_from_op_trace_ids(OpID) :- retract(op_trace_ids(OpIDS)),
754		(OpIDS = [R|Rest]
755		-> assertz(op_trace_ids(Rest)), OpID = R
756		; assertz(op_trace_ids(OpIDS)), fail).
757
758		% translate a list of transition ids (from root) into a list of operation terms
759		extract_term_trace_from_transition_ids(TransIDListFromRoot,Trace) :-
760		extract_trace_from_transition_ids(TransIDListFromRoot,root,0,[],ActionTrace),
761		reverse_and_project_on_action_term(ActionTrace,[],Trace).
762
763		reverse_and_project_on_action_term([],A,A).
764		reverse_and_project_on_action_term([action(_,Term)|T],Acc,Res) :- !,
765		reverse_and_project_on_action_term(T,[Term|Acc],Res).
766		reverse_and_project_on_action_term([H|T],Acc,Res) :-
767		add_error(reverse_and_project_on_action_term,'Illegal action: ',H),
768		reverse_and_project_on_action_term(T,[H|Acc],Res).
769
770		project_on_action_term([],[]).
771		project_on_action_term([action(_,Term)|T],Res) :- !, Res=[Term|TR],
772		project_on_action_term(T,TR).
773		project_on_action_term([H|T],Res) :-
774		add_error(project_on_action_term,'Illegal action: ',H),
775		project_on_action_term(T,Res).
776
777		extract_trace_from_transition_ids([],_CurrentState,_,Trace,Trace).
778		extract_trace_from_transition_ids([TransId|Rest],CurrentState,Limit,AccTrace,Trace) :-
779		compute_op_string(TransId,CurrentState,Limit,OpTerm,OpString,DestState),!,
780		extract_trace_from_transition_ids(Rest,DestState,Limit,
781		[action(OpString,OpTerm)|AccTrace],Trace).
782		extract_trace_from_transition_ids([TransId|_],CurrentState,_,_,_Trace) :-
783		add_error(state_space,'Could not execute transition id: ', TransId:from(CurrentState)),fail.
784
785		:- use_module(translate,[translate_event_with_src_and_target_id/5]).
786		compute_op_string(jump(TO),_CurID,_,Term,String,DestID) :- !, Term=jump,String=jump,DestID=TO.
787		compute_op_string(TransId,CurID,Limit,Term,String,DestID) :- transition(CurID,Term,TransId,DestID),
788		translate_event_with_src_and_target_id(Term,CurID,DestID,Limit,String).
789
790		% reset history and forward history, but not state-space itself
791		state_space_reset :-
792		reset_trace,
793		retractall(history(_)),
794		retractall(forward_history(_)),
795		retractall(current_state_id(_)),
796		retractall(current_options(_)),
797		assertz(history([])),
798		assertz(current_state_id(root)).
799
800		reset_not_interesting :- retractall(not_interesting(_)), reset_counter(not_interesting_nodes).
801
802		mark_as_not_interesting(ID) :- assertz(not_interesting(ID)), inc_counter(not_interesting_nodes).
803
804		set_current_state_id(ID) :- (retract(current_state_id(_)) -> true ; true),
805		assertz(current_state_id(ID)).
806
807		state_space_clean_all :-
808		retractall(state_space_version_in_file(_)),
809		retractall_visited_expression(_),
810		reset_open_ids,
811		retractall(not_invariant_checked(_)),
812		reset_not_interesting,
813		retractall(max_reached_for_node(_)),
814		retractall(time_out_for_node(_,_,_)),
815		retractall(time_out_for_invariant(_)),
816		retractall(time_out_for_assertions(_)),
817		retractall(use_no_timeout(_)),
818		retractall(state_error(_,_,_)),
819		clear_context_state,
820		reset_transition_store,
821		retractall(operation_not_yet_covered(_)),
822		retractall(hash_to_id(_,_)),
823		retractall(id_back_edge(_,_,_)),
824		retractall(hash_to_nauty_id(_,_)),
825		retractall(id_to_marker(_,_)),
826		retractall(specialized_inv(_,_)),
827		%retractall(reuse_operation(_,_,_,_)),
828		retractall(history(_)),
829		retractall(forward_history(_)),
830		retractall(op_trace_ids(_)),
831		retractall(current_state_id(_)),
832		retractall(current_options(_)).
833
834		% this is only used from within the Tcl/Tk animator at the moment:
835		delete_node(ID) :- print(deleting(ID)),nl,
836		retractall_visited_expression(ID),
837		retractall_invariant_violated(ID),
838		retract_open_node_and_update_processed_nodes(ID),
839		retractall(not_invariant_checked(ID)),
840		(retract(not_interesting(ID)) -> inc_counter_by(not_interesting_nodes,-1) ; true),
841		retractall(max_reached_for_node(ID)),
842		retractall(time_out_for_node(ID,_,_)),
843		retractall(time_out_for_invariant(ID)),
844		retractall(time_out_for_assertions(ID)),
845		retractall(use_no_timeout(ID)),
846		retractall(state_error(ID,_,_)),
847		retractall(transition(ID,_,_,_)),
848		% to do: check if operation_not_yet_covered(_) changes
849		retract_hash(ID),
850		retractall(id_to_marker(ID,_)).
851
852		retract_hash(ID) :- retract(hash_to_id(Hash,ID)), retractall(hash_to_nauty_id(_TermHash,Hash)),fail.
853		retract_hash(_).
854
855		% assert max_operations reachoed
856		assert_max_reached_for_node(Id) :- %print_message(max_reached_for_node(Id)),
857		(max_reached_for_node(Id) -> true ; assertz(max_reached_for_node(Id))).
858
859		:- use_module(probsrc(debug),[debug_mode/1]).
860		assert_time_out_for_node(Id,OpName,TypeOfTimeOut) :-
861		(debug_mode(off),functor(TypeOfTimeOut,virtual_time_out,_) -> true % can easily happen when parameters are unbounded
862		; print_message(time_out_for_node(Id,OpName,TypeOfTimeOut))),
863		(time_out_for_node(Id,OpName,_) -> true ; assertz(time_out_for_node(Id,OpName,TypeOfTimeOut))).
864		assert_time_out_for_invariant(Id) :- print_message(time_out_for_invariant(Id)),
865		(time_out_for_invariant(Id) -> true ; assertz(time_out_for_invariant(Id))).
866		assert_time_out_for_assertions(Id) :- print_message(time_out_for_assertions(Id)),
867		(time_out_for_assertions(Id) -> true ; assertz(time_out_for_assertions(Id))).
868
869		max_reached_or_timeout_for_node(Id) :-
870		(max_reached_for_node(Id) ; time_out_for_node(Id,_,_)).
871		/* ---------------------- */
872		/* state space saving */
873		/* ---------------------- */
874
875		:- dynamic state_space_version_in_file/1. %
876		state_space_version(1).
877
878		check_state_space_version :- state_space_version(V),
879		(state_space_version_in_file(F) -> true ; F=0),
880		(V>F -> add_message(state_space,'Warning: saved state_space may be incompatible with current version: ',F:V) ; true).
881
882		% save all infos of state space (transitions, evaluated invariants, ...)
883		tcltk_save_state_space(File) :-
884		print('% saving full state space to: '), print(File),nl,
885		open(File,write,Stream,[encoding(utf8)]),
886		print_state_space(Stream),
887		close(Stream),
888		print_message(done).
889
890
891		:- use_module(tools_printing, [print_dynamic_fact/2,print_dynamic_pred/4]).
892		print_state_space(Stream) :-
893		state_space_version(V),
894		print_dynamic_fact(Stream,state_space_version_in_file(V)),
895		% TO DO: maybe also save some important preferences, and warn user and/or propose to adapt preferences ?
896		print_dynamic_pred(Stream,state_space,history,1),
897		print_dynamic_pred(Stream,state_space,forward_history,1),
898		print_dynamic_pred(Stream,state_space,op_trace_ids,1),
899		print_dynamic_pred(Stream,state_space,current_state_id,1),
900		print_dynamic_pred(Stream,state_space,current_options,1),
901		print_dynamic_pred(Stream,state_space,packed_visited_expression,2),
902		print_dynamic_pred(Stream,state_space,not_invariant_checked,1),
903		print_dynamic_pred(Stream,state_space,not_interesting,1),
904		print_dynamic_pred(Stream,state_space,max_reached_for_node,1),
905		print_dynamic_pred(Stream,state_space,time_out_for_node,3),
906		print_dynamic_pred(Stream,state_space,use_no_timeout,1),
907		print_dynamic_pred(Stream,state_space,transition,4),
908		print_dynamic_pred(Stream,state_space,transition_info,2),
909		print_dynamic_pred(Stream,state_space,operation_not_yet_covered,1),
910		print_dynamic_pred(Stream,state_space,state_error,3),
911		print_state_space_open_nodes(Stream),
912		print_stored_values(Stream),
913		get_counter(states,X),
914		write_term(Stream,saved_gennum_count(X),[quoted(true)]),write(Stream,'.'),nl(Stream).
915
916		saved_gennum_count(99999).
917
918		/* ---------------------- */
919		/* state space loading */
920		/* ---------------------- */
921
922		tcltk_load_state(File) :- state_space_clean_all,
923		print('Loading: '), print(File),nl,
924		user_consult_without_redefine_warning(File), % this will read in bind_skeleton/2, ..., next_value_id/1
925		check_state_space_version,
926		print('Generating open node info'),nl,
927		transfer_open_node_info,
928		print('Transfer state packing info'),nl,
929		transfer_state_packing_info,
930		print('Recomputing hash index'),nl,
931		recompute_all_hash,
932		(saved_gennum_count(X) -> reset_state_counter(X) ; true),
933		reset_processed_nodes_counter, % TO DO: restore or save it
934		reset_next_state_error_id_counter, % DITTO
935		print('Done'),nl,!.
936		tcltk_load_state(File) :-
937		add_error(tcltk_load_state,'Could not load state from file: ',File),
938		state_space_initialise.
939
940		:- dynamic not_all_z_saved/1, not_all_transitions_added_saved/1.
941		:- dynamic bind_skeleton/2, stored_value/2, stored_value_hash_to_id/2, next_value_id/1.
942
943		% transfer facts read into state_space into other modules:
944		transfer_open_node_info :- retract(not_all_z_saved(X)), %print(not_all_z(X)),nl,
945		assert_not_all_z(X),fail.
946		transfer_open_node_info :- retract(not_all_transitions_added_saved(X)),
947		assert_not_all_transitions_added(X),fail.
948		transfer_open_node_info.
949		% now for transferring to state_packing module info generated by print_stored_values
950		transfer_state_packing_info :- retract(bind_skeleton(X,Y)), %print(skel(X)),nl,
951		assertz(state_packing:bind_skeleton(X,Y)),fail.
952		transfer_state_packing_info :- retract(stored_value(X,Y)),
953		assertz(state_packing:stored_value(X,Y)),fail.
954		transfer_state_packing_info :- retract(stored_value_hash_to_id(X,Y)),
955		assertz(state_packing:stored_value_hash_to_id(X,Y)),fail.
956		transfer_state_packing_info :- retract(next_value_id(X)),
957		state_packing:set_next_value_id(X),fail.
958		transfer_state_packing_info.
959
960		recompute_all_hash :-
961		retractall(hash_to_id(_,_)),retractall(id_to_marker(_,_)),
962		retractall(hash_to_nauty_id(_,_)),
963		visited_expression(ID,StateTemplate),
964		state_space_exploration_modes:compute_hash(StateTemplate,Hash,Marker),
965		assertz(hash_to_id(Hash,ID)),
966		assertz(id_to_marker(ID,Marker)),
967		fail.
968		recompute_all_hash.
969
970		:- use_module(hashing,[my_term_hash/2]).
971		% generates a hash for the entire state space not depending on the order in which states where added
972		compute_full_state_space_hash(Hash) :-
973		%listing(hash_to_id/2), listing(packed_visited_expression/2),
974		findall(Hash,hash_to_id(Hash,_),ListOfHashCodes),
975		sort(ListOfHashCodes,SortedList),
976		my_term_hash(SortedList,Hash).
977		% TO DO: also provide transition hashes
978
979		:- use_module(tools_meta,[safe_on_exception/3]).
980		user_consult_without_redefine_warning(File) :-
981		get_set_optional_prolog_flag(redefine_warnings, Old, off),
982		get_set_optional_prolog_flag(single_var_warnings, Old2, off),
983		(safe_on_exception(Exc,
984		%consult(File), %
985		load_files([File], [load_type(source),compilation_mode(consult),encoding(utf8)]),
986		(nl,print('Exception occurred:'),print(Exc),nl,fail))
987		-> OK=true ; OK=false),
988		get_set_optional_prolog_flag(redefine_warnings, _, Old),
989		get_set_optional_prolog_flag(single_var_warnings, _, Old2),
990		OK=true.
991
992		% execute a transition id list from current ID and update animator history,...
993		execute_id_trace_from_current(OperationIDList) :-
994		current_state_id(CurID),
995		get_state_list_from_opids(OperationIDList,CurID,StateIDList,NewCurID),
996		execute_id_trace_from_current(NewCurID,OperationIDList,StateIDList).
997
998		get_state_list_from_opids([],CurID,[],CurID).
999		get_state_list_from_opids([TransId|TO],CurID,[NextCurID|TS],FinalCurID) :-
1000		transition(CurID,_,TransId,NextCurID),
1001		get_state_list_from_opids(TO,NextCurID,TS,FinalCurID).
1002
1003
1004		% execute_id_trace_from_current(NewCurID,OperationIDList,StateIDList)
1005		execute_id_trace_from_current(ID,OpIDL,StateIDList) :-
1006		current_state_id(CurID),
1007		reverse([CurID|StateIDList],Rev),
1008		Rev = [Dest|TRev],
1009		(Dest==ID -> true ; print(not_eq(Dest,ID)),nl),
1010		retract(history(H)),
1011		update_forward_history(OpIDL), % check if OpIDL conforms to forward history and keep it
1012		append(TRev,H,NewH),
1013		assertz(history(NewH)),
1014		retract(op_trace_ids(OldTrace)),
1015		reverse(OpIDL,NewTrace),
1016		append(NewTrace,OldTrace,Trace),
1017		assertz(op_trace_ids(Trace)),
1018		retractall(current_state_id(_)),
1019		assertz(current_state_id(ID)).
1020		%execute_trace_to_node(OpL,StateIDList). /* <----- BOTTLENECK FOR LONG SEQUENCES */
1021		%generate_trace([],Acc,Acc).
1022		%generate_trace([OpTerm|T],Acc,Res) :-
1023		% translate:translate_event(OpTerm,OpString),
1024		% generate_trace(T,[action(OpString,OpTerm)|Acc],Res).
1025
1026		update_forward_history(TransitionIds) :-
1027		(retract(forward_history(Forward)),
1028		prune_forward_history(TransitionIds,Forward,NewForward)
1029		-> assert(forward_history(NewForward))
1030		; true).
1031		% try and prune forward history if it matches operation trace
1032		prune_forward_history([],ForwardHistory,ForwardHistory).
1033		prune_forward_history([TransID|T],[forward(_,TransID)|TF],Res) :-
1034		prune_forward_history(T,TF,Res).
1035
1036		try_set_trace_by_transition_ids(TransIds) :-
1037		(set_trace_by_transition_ids(TransIds) -> true
1038		; add_internal_error('Call failed:',set_trace_by_transition_ids(TransIds))).
1039
1040		set_trace_by_transition_ids(TransitionIds) :-
1041		extract_history_from_transition_ids(TransitionIds,root,[],[],Last,History,OpTrace),
1042		%visited_expression(Last,LastState,LastCond),
1043		retractall(history(_)),
1044		retractall(forward_history(_)), % TODO: we could try and recover a new forward history if transition ids match current history^forward history
1045		update_forward_history(TransitionIds),
1046		retractall(current_state_id(_)),
1047		retractall(op_trace_ids(_)),
1048		assertz(history(History)),
1049		assertz(op_trace_ids(OpTrace)),
1050		assertz(current_state_id(Last)).
1051
1052
1053		extract_history_from_transition_ids([],CurrentState,History,Trace,CurrentState,History,Trace).
1054		extract_history_from_transition_ids([TransId|Rest],CurrentState,AccHist,AccTrace,Last,History,Trace) :-
1055		transition(CurrentState,_,TransId,DestState),!,
1056		extract_history_from_transition_ids(Rest,DestState,[CurrentState|AccHist],
1057		[TransId|AccTrace],Last,History,Trace).
1058		extract_history_from_transition_ids([skip|Rest],CurrentState,AccHist,AccTrace,Last,History,Trace) :- !,
1059		extract_history_from_transition_ids(Rest,CurrentState,AccHist,AccTrace,Last,History,Trace).
1060		extract_history_from_transition_ids([TransId|_],CurrentState,_,_,_,_,_Trace) :-
1061		add_error(state_space,'Could not execute transition id: ', TransId:from(CurrentState)),fail.
1062
1063		% extend trace from current state
1064		extend_trace_by_transition_ids(TransitionIds) :-
1065		current_state_id(CurID),
1066		history(OldH), op_trace_ids(OldOT),
1067		extract_history_from_transition_ids(TransitionIds,CurID,OldH,OldOT,Last,History,OpTrace),
1068		retractall(history(_)), retractall(forward_history(_)),
1069		retractall(current_state_id(_)),
1070		retractall(op_trace_ids(_)),
1071		assertz(history(History)),
1072		assertz(op_trace_ids(OpTrace)),
1073		assertz(current_state_id(Last)).
1074
1075		/* --------------------------------- */
1076		:- dynamic max_nr_of_new_nodes/1.
1077
1078		% negative number or non-number signifies no limit
1079		set_max_nr_of_new_impl_trans_nodes(MaxNrOfNewNodes) :-
1080		retractall(max_nr_of_new_nodes(_)),
1081		(number(MaxNrOfNewNodes), MaxNrOfNewNodes>=0
1082		-> assertz(max_nr_of_new_nodes(MaxNrOfNewNodes))
1083		; true). % no need to store limit; we will explore as much as needed
1084
1085		get_max_nr_of_new_impl_trans_nodes(MaxNrOfNewNodes) :-
1086		(max_nr_of_new_nodes(Max) -> MaxNrOfNewNodes=Max; MaxNrOfNewNodes = 0).
1087
1088		% used e.g., in refinement or ltl checker
1089		impl_trans_term(From,ActionAsTerm,TransID,To) :-
1090		compute_transitions_if_necessary_saved(From),
1091		transition(From,ActionAsTerm,TransID,To).
1092		impl_trans_term(From,ActionAsTerm,To) :-
1093		compute_transitions_if_necessary_saved(From),
1094		transition(From,ActionAsTerm,_TID,To).
1095
1096		% a variation also giving the transition id:
1097		impl_trans_id(From,ActionAsTerm,TransitionID,To) :-
1098		compute_transitions_if_necessary_saved(From),
1099		transition(From,ActionAsTerm,TransitionID,To).
1100
1101		impl_trans_term_all(From,Ops) :-
1102		compute_transitions_if_necessary_saved(From),
1103		findall(op(Id,ActionAsTerm,To),
1104		transition(From,ActionAsTerm,Id,To),
1105		Ops).
1106
1107		% true if e.g., a time-out occurred during computation of all transitions
1108		impl_trans_not_complete(From) :- max_reached_or_timeout_for_node(From).
1109
1110		compute_transitions_if_necessary_saved(From) :-
1111		catch(
1112		compute_transitions_if_necessary(From),
1113		error(forced_interrupt_error('User has interrupted the current execution'),_),
1114		user_interrupts:process_interrupted_error_message).
1115
1116		:- use_module(tcltk_interface,[compute_all_transitions_if_necessary/2]).
1117		compute_transitions_if_necessary(From) :-
1118		not_all_transitions_added(From),!,
1119		decrease_max_nr_of_new_nodes(From),
1120		compute_all_transitions_if_necessary(From,false).
1121		compute_transitions_if_necessary(_From).
1122
1123		decrease_max_nr_of_new_nodes(ID) :-
1124		retract(max_nr_of_new_nodes(Max)),!,
1125		( Max>0 ->
1126		NewMax is Max-1,
1127		assertz(max_nr_of_new_nodes(NewMax))
1128		; Max=0 -> NM is -1,
1129		assertz(max_nr_of_new_nodes(NM)),
1130		add_warning(state_space,'Maximum number of new nodes reached for CTL/LTL/refinement check, node id = ',ID),
1131		fail
1132		; % negative number: re-assert and fail
1133		assertz(max_nr_of_new_nodes(Max)),
1134		fail).
1135		decrease_max_nr_of_new_nodes(_). % no limit stored; just proceed
1136
1137		% will be called from TCL/TK side
1138		max_nr_of_new_nodes_limit_not_reached :-
1139		max_nr_of_new_nodes(N),N>0.
1140
1141		:- use_module(specfile,[b_or_z_mode/0, csp_mode/0, csp_with_bz_mode/0]).
1142		retract_open_node(NodeID) :- retract_open_node_and_update_processed_nodes(NodeID),
1143		(b_or_z_mode -> assertz(not_invariant_checked(NodeID)) ; true).
1144
1145		reset_processed_nodes_counter :- reset_counter(processed_nodes).
1146		%reset_processed_nodes_counter(Nr) :- set_counter(processed_nodes,Nr).
1147
1148		retract_open_node_and_update_processed_nodes(NodeID) :-
1149		retract_open_node_direct(NodeID),
1150		inc_processed.
1151
1152		inc_processed :-
1153		inc_counter(processed_nodes).
1154
1155		pop_id_from_front(ID) :- pop_id_from_front_direct(ID), inc_processed.
1156		pop_id_from_end(ID) :- pop_id_from_end_direct(ID), inc_processed.
1157		pop_id_oldest(ID) :- pop_id_oldest_direct(ID), inc_processed.
1158
1159
1160
1161		/* --------------------------------- */
1162
1163		% find initialised states; very similar to is_initial_state_id/1
1164		% but is used by ltl/ctl/sap
1165		% TO DO: merge these two variations of the same concept
1166
1167		:- use_module(specfile,[animation_mode/1]).
1168
1169		find_initialised_states(Init) :-
1170		animation_mode(Mode),
1171		( init_states_mode_cst_init(Mode) ->
1172		findall(I,find_init1(root,I,_),Init)
1173		; init_states_mode_one_step(Mode) ->
1174		next_states_from_root(Init)
1175		;
1176		fail).
1177
1178		% find trace to some initialised state
1179		find_trace_to_initial_state(Target,Trace) :- animation_mode(Mode),
1180		find_aux(Mode,Target,Trace).
1181		find_aux(Mode,Target,[root,Target]) :-
1182		init_states_mode_one_step(Mode).
1183		find_aux(Mode,Target,[root|Trace]) :-
1184		init_states_mode_cst_init(Mode),
1185		find_init1(root,Target,Trace).
1186
1187
1188		init_states_mode_cst_init(b).
1189		init_states_mode_cst_init(z).
1190		init_states_mode_cst_init(csp_and_b).
1191
1192		init_states_mode_one_step(csp).
1193		init_states_mode_one_step(cspm).
1194		init_states_mode_one_step(xtl).
1195		%init_states_mode_one_step(promela).
1196
1197		next_states_from_root(States) :-
1198		impl_trans_term_all(root,Ops),
1199		findall(S, member(op(_Id,_,S),Ops), States).
1200
1201		find_init1(Start,Init,Trace) :- Start==Init,!,Trace=[]. % usually called with Start=Init=root
1202		find_init1(Start,Init,[State|Rest]) :-
1203		impl_trans_term(Start,O,State),
1204		find_init2(O,State,Init,Rest).
1205		find_init2(O,Init,Init,[]) :-
1206		has_functor_and_maybe_tau(O,'$initialise_machine').
1207		find_init2(O,State,Init,Path) :-
1208		has_functor_and_maybe_tau(O,F),
1209		(F='$setup_constants' ; F='$partial_setup_constants'),
1210		find_init1(State,Init,Path).
1211		find_init2(start_cspm_MAIN,State,Init,Path) :-
1212		find_init1(State,Init,Path).
1213		find_init2(start_cspm(_Proc),State,Init,Path) :-
1214		find_init1(State,Init,Path).
1215
1216		% has_functor_and_maybe_tau(Term,Functor)
1217		% checks if Term has the form "Functor(...)" or "tau(Functor(...))"
1218		% this is used for CSP||B specification where the initialisation is wrapped with
1219		% in a tau operator
1220		has_functor_and_maybe_tau(tau(Term),Functor) :-
1221		has_functor_and_maybe_tau(Term,Functor),!.
1222		has_functor_and_maybe_tau(Term,Functor) :-
1223		functor(Term,Functor,_).
1224
1225		% compute how far the state is from the root node using back_edge markers (if available)
1226		try_compute_depth_of_state_id(root,R) :- !, R=0.
1227		try_compute_depth_of_state_id(Node,Depth) :- id_back_edge(Node,Depth,_Back).
1228
1229		% optional registering of back_edges: to quickly find trace from root and to computed depth/diameter
1230		register_back_edge(ID,FromID) :-
1231		try_compute_depth_of_state_id(FromID,D),!,
1232		D1 is D+1,
1233		assertz(id_back_edge(ID,D1,FromID)).
1234		register_back_edge(ID,FromID) :- write(cannot_store_back_edge(ID,FromID)),nl.
1235
1236		/* --------------------------------- */
1237
1238		%
1239		% Code to compute equivalence classes
1240		% using the standard DFA minimization algorithm
1241
1242		:- dynamic equivalent/2.
1243		% state_space:compute_equivalence_classes
1244		:- public compute_equivalence_classes/0.
1245
1246		compute_equivalence_classes :- init_equi,
1247		split_equivalence_classes,nl,
1248		print_equi.
1249
1250		print_equi :- state_space:equivalent(A,B), visited_expression(A,State),
1251		visited_expression(B,StateB),
1252		nl,
1253		print(A), print(' : '), print(State),nl,
1254		print(B), print(' : '), print(StateB),nl,fail.
1255		print_equi.
1256
1257		init_equi :- retractall(equivalent(_,_)),
1258		packed_visited_expression(ID,_State),
1259		\+ not_all_transitions_added(ID),
1260		findall(Action,transition(ID,Action,_,_),List),
1261		packed_visited_expression(ID2,_S2), ID2 @> ID,
1262		\+ not_all_transitions_added(ID2),
1263		findall(Action,transition(ID2,Action,_,_),List),
1264		assertz(equivalent(ID,ID2)), % they have the same signature
1265		%print(equivalent(ID,ID2)),nl,
1266		fail.
1267		init_equi :- print(finished_initialising),nl.
1268
1269		split_equivalence_classes :- retractall(echange),
1270		equivalent(ID1,ID2),
1271		transition(ID1,A,_,Dest1),
1272		transition(ID2,A,_,Dest2),
1273		\+ check_equi(Dest1,Dest2),
1274		retract(equivalent(ID1,ID2)), % splitting class
1275		% print(diff(ID1,ID2, A, Dest1, Dest2)),nl,
1276		assert_echange,
1277		fail.
1278		split_equivalence_classes :- echange -> split_equivalence_classes ; true.
1279
1280		:- dynamic echange/0.
1281		assert_echange :- echange -> true ; assertz(echange),print('.'),flush_output.
1282
1283		check_equi(A,B) :- A=B -> true ; A @<B -> equivalent(A,B) ; equivalent(B,A).
1284
1285		/*
1286		% benchmark how much time it takes to copy the state space state_space:bench_state_space.
1287		bench_state_space :-
1288		statistics(walltime,_),
1289		(state_space:packed_visited_expression(ID,S), assertz(pve(ID,S)),fail ; true),
1290		statistics(walltime,[_,Delta]), format('Time to copy packed_visited_expression: ~w ms~n',[Delta]),
1291		(state_space:transition(A,B,C,D), assertz(tr(A,B,C,D)),fail ; true),
1292		statistics(walltime,[_,Delta2]), format('Time to copy transition: ~w ms~n',[Delta2]),
1293		(state_packing:stored_value(A,B), assertz(sv(A,B)),fail ; true),
1294		(state_packing:stored_value_hash_to_id(A,B), assertz(svhi(A,B)),fail ; true),
1295		statistics(walltime,[_,Delta3]), format('Time to copy stored_value: ~w ms~n',[Delta3]).
1296		*/
1297
1298		:- public portray_state_space/0.
1299		portray_state_space :- packed_visited_expression(ID,S), functor(S,F,N),
1300		format('State ~w : ~w/~w~n',[ID,F,N]), fail.
1301		portray_state_space :- transition(ID,Action,TransID,DestID),
1302		format(' ~w: ~w -- ~w --> ~w~n',[TransID,ID,Action,DestID]),fail.
1303		portray_state_space.
1304
1305		bench_state_space :- statistics(walltime,[W1,_]),
1306		(packed_visited_expression(_,_), fail ; true),
1307		statistics(walltime,[W2,_]), T1 is W2-W1,
1308		format('Time to inspect all states: ~w ms walltime~n',[T1]),
1309		(visited_expression(_,_), fail ; true),
1310		statistics(walltime,[W3,_]), T2 is W3-W2,
1311		format('Time to inspect and unpack all states: ~w ms walltime~n',[T2]),
1312		(transition(_,_,_,_), fail ; true),
1313		statistics(walltime,[W4,_]), T3 is W4-W3,
1314		format('Time to inspect all transitions: ~w ms walltime~n',[T3]),
1315		(visited_expression(_,E), my_term_hash(E,_), fail ; true),
1316		statistics(walltime,[W5,_]), T4 is W5-W4,
1317		format('Time to inspect, unpack and hash all states: ~w ms walltime~n',[T4]).
1318
1319		% ----------------------------
1320		% COUNTER EXAMPLE MANAGEMENT
1321
1322		% store counter example nodes and transition ids; used by LTL model checking for example
1323
1324
1325		:- dynamic counterexample_node/1.
1326		:- dynamic counterexample_op/1.
1327
1328		add_counterexample_node(NodeID) :- assertz(counterexample_node(NodeID)).
1329		add_counterexample_op(TransID) :-
1330		(counterexample_op(TransID) -> true ; assertz(counterexample_op(TransID))).
1331
1332
1333		reset_counterexample :-
1334		retractall(counterexample_node(_)),
1335		retractall(counterexample_op(_)).
1336
1337		:- register_event_listener(play_counterexample,reset_counterexample,
1338		'Reset marked nodes from previous counterexamples.').
1339
1340		set_counterexample_by_transition_ids(TransIds) :-
1341		set_trace_by_transition_ids(TransIds),
1342		maplist(add_counterexample_op,TransIds),
1343		extract_history_from_transition_ids(TransIds,root,[],[],_Last,History,_OpTrace),
1344		maplist(add_counterexample_node,History).