1 % (c) 2016-2024 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(b_operation_cache, [ %project_in_state/6,
6 %operation_computed/4,
7 compute_operation_on_expanded_store_cache/6,
8 check_invariant_violated_cache/2,
9 print_op_cache_profile/0,
10 get_op_cache_stats/1,
11 reset_b_operation_cache_with_statistics/0,
12 tcltk_op_cache_stats/1
13 ]).
14
15
16 :- use_module(probsrc(module_information)).
17 :- module_info(group,animator).
18 :- module_info(description,'This module caches B operation results on projected states. Used when preference try_operation_reuse different from false').
19
20 % TO DO:
21 % provide predecessor ID and operation to know which values are unchanged? -> reuse hash; know which ops are definitely disabled? (cf pge)
22 % Note: operation caching works better with COMPRESSION TRUE, as this way the values are pre-hashed. A simpler hash function is then used.
23 % Note: if we change the MAX_OPERATIONS preference, this will have no effect on already cached operations
24 % TODO: we could invalidate operation cache upon such a change; storing the value for each node is probably overkill
25
26 :- use_module(probsrc(self_check)).
27 :- use_module(extension('counter/counter')). % op_cache_id,... counter
28 :- use_module(probsrc(succeed_max),[succeed_max_call_id/3, reset_max_reached/1, max_reached/1, assert_max_reached/1]).
29 :- use_module(probsrc(eventhandling),[register_event_listener/3]).
30 :- use_module(probsrc(error_manager)).
31 :- use_module(probsrc(debug),[debug_println/2]).
32 :- use_module(probsrc(performance_messages),[perfmessage/2]).
33 :- use_module(library(ordsets), [ord_subtract/3]).
34 :- use_module(probsrc(tools),[retract_with_statistics/2]).
35
36 b_operation_cache_startup :- % call once at startup to ensure all counters exist
37 counter_init,
38 new_counter(op_cache_id),
39 new_counter(inv_cache_nr),
40 new_counter(op_cached_failures),
41 new_counter(op_cached_successes),
42 new_counter(inv_cached_successes),
43 new_counter(op_cached_timeouts).
44
45
46 :- register_event_listener(startup_prob,b_operation_cache_startup,
47 'Initialise Statespace Counters.').
48 :- register_event_listener(reset_specification,reset_b_operation_cache,
49 'Reset Operation Cache.').
50 :- register_event_listener(clear_specification,reset_b_operation_cache, % necessary? as reset occurs before?
51 'Reset Operation Cache.').
52 :- register_event_listener(change_of_animation_mode,reset_b_operation_cache,
53 'Reset Operation Cache.').
54 % TO DO: also reset if maxNrOfEnablingsPerOperation changed ?
55
56
57 :- dynamic operation_read_projection_cache/5, operation_read_constants/2, operation_guard_read_info/3.
58 reset_b_operation_cache :-
59 retractall(operation_read_projection_cache(_,_,_,_,_)),
60 retractall(operation_read_constants(_,_)),
61 retractall(operation_guard_read_info(_,_,_)),
62 retractall(operation_computed(_,_,_,_,_)),
63 retractall(operation_cached_results(_,_,_,_)),
64 retractall(operation_cached_max_reached(_,_)),
65 retractall(operation_cached_time_out(_,_)),
66 retractall(op_guard_fails(_,_,_)),
67 reset_counter(op_cache_id),
68 reset_counter(inv_cache_nr),
69 reset_counter(op_cached_failures),
70 reset_counter(op_cached_successes),
71 reset_counter(inv_cached_successes).
72
73
74 reset_b_operation_cache_with_statistics :-
75 retract_with_statistics(b_operation_cache,
76 [operation_read_projection_cache(_,_,_,_,_),
77 operation_read_constants(_,_),operation_guard_read_info(_,_,_),
78 operation_computed(_,_,_,_,_), operation_cached_results(_,_,_,_),
79 operation_cached_max_reached(_,_),
80 operation_cached_time_out(_,_),
81 op_guard_fails(_,_,_)
82 ]
83 ),
84 reset_b_operation_cache.
85
86
87 % -------------------------------------------------
88
89
90 % project the in-state for an operation onto the relevant variables
91 project_in_state(VarsInState,OpName,ProjectedInState) :-
92 get_opname_key(OpName,OpNameKey),
93 project_in_state_for_opname_key(VarsInState,OpNameKey,ProjectedInState).
94
95 :- use_module(probsrc(bmachine),[b_is_constant/1]).
96 :- use_module(library(lists),[exclude/3, include/3]).
97 project_in_state_for_opname_key(InState,OpNameKey,ProjectedInState) :-
98 get_operation_read_projection_infos(OpNameKey,_,InState,ProjVars,_,_),
99 (re_project_state(ProjVars,InState,Res) -> ProjectedInState=Res
100 ; add_internal_error('Re-Projection failed: ',re_project_state(ProjVars,InState,_)),
101 ProjectedInState = InState).
102
103 :- use_module(probsrc(specfile),[csp_with_bz_mode/0]).
104 :- use_module(probsrc(b_read_write_info),[b_get_operation_read_guard_vars/4]).
105 :- use_module(probsrc(bmachine),[b_definition_prefixed/5]).
106
107
108 % get infos about cached operations (and compute the first time info requested for an operation)
109 get_operation_read_projection_infos(OpNameKey,OpName,_,ProjVars,IsReadingCsts,AdditionalOutVars) :-
110 operation_read_projection_cache(OpNameKey,OpName,ProjVars,IsReadingCsts,AdditionalOutVars),!,
111 ProjVars \= no_caching.
112 get_operation_read_projection_infos(OpNameKey,OpName,_,_,_,_) :- atom(OpName),
113 b_definition_prefixed(_, 'OPERATION_REUSE_OFF_', OpName, _DefName,_),
114 !,
115 format('Ignoring operation ~w for reuse~n',[OpName]),
116 assertz(operation_read_projection_cache(OpNameKey,OpName,no_caching,no_caching,[])),
117 fail.
118 get_operation_read_projection_infos(OpNameKey,OpName,InState,ProjVarsInOrder,IsReadingCsts,AdditionalOutVars) :-
119 api_get_operation_read_write_info(OpName,ReadVariables,ReadConstants,WrittenVariables),
120 (ReadConstants=[] -> IsReadingCsts=false ; IsReadingCsts=true),
121 debug_println(19,operation_reads_vars_consts(OpName,ReadVariables,ReadConstants)),
122 (project_state_onto_vars(InState,ReadVariables,ProjVarsInOrder,_RelevantState,0,NrDeleted)
123 -> % TO DO: if we have constants in the state which are deterministic anyway, then they should not count
124 % TO DO: statically pre-compute which operations are worthwhile for this treatment
125 ((NrDeleted>0 % we project away at least one variable and thus hope to cache operation results
126 ; csp_with_bz_mode) % in CSP||B mode, the same operation may be called with different CSP controllers
127 -> ord_subtract(WrittenVariables,ReadVariables,AdditionalOutVars), % vars written but not read
128 assertz(operation_read_projection_cache(OpNameKey,OpName,ProjVarsInOrder,IsReadingCsts,AdditionalOutVars)),
129 assertz(operation_read_constants(OpNameKey,ReadConstants)),
130 % ,print(proj(OpName,ProjVarsInOrder,AdditionalOutVars)),nl,
131 (get_preference(try_operation_reuse,full),
132 b_get_operation_read_guard_vars(OpName,true,ReadVarsInGuard,precise),
133 exclude(member_ord(ReadVarsInGuard),ProjVarsInOrder,IrrelevantVars),
134 % TO DO: analyse if projection really useful
135 IrrelevantVars \= []
136 -> include(member_ord(ReadVarsInGuard),ProjVarsInOrder,ReadVarsInGuard),
137 debug_println(19,guard_reads_subset_of_vars(OpName,OpNameKey,ReadVarsInGuard,IrrelevantVars)),
138 assertz(operation_guard_read_info(OpNameKey,ReadVarsInGuard,IrrelevantVars))
139 ; true)
140 ; assertz(operation_read_projection_cache(OpNameKey,OpName,no_caching,no_caching,[])),
141 perfmessage('Not caching operation for reuse: ',OpName),
142 fail
143 )
144 ; add_internal_error('Projection failed for: ', project_state_onto_vars(InState,ReadVariables,_,_,0,_)),
145 assertz(operation_read_projection_cache(OpNameKey,OpName,no_caching,no_caching,[])),
146 fail
147 ).
148 %TODO: also compute precise guard b_get_operation_read_guard_vars(Operation,JustVariables,VarsResult,VarsPrecise) if possible and if read vars in guard << ReadVariables also store this
149 % if operation call fails -> store only precise guard
150
151 % -------------------------------
152
153 % API to abstract operations so that we can use caching also for invariants, maybe later assertions, ...
154
155 % get atomic key to store operation info
156 get_opname_key(Name,Res) :- var(Name),!,
157 add_internal_error('Variable opname: ',get_opname_key(Name,Res)), Res=Name.
158 get_opname_key(check_invariant_violated(Nr),Key) :- !, Key=Nr.
159 get_opname_key(Name,Name).
160
161 api_get_operation_read_write_info(OpName,ReadVariables,ReadConstants,WrittenVariables) :-
162 api_get_op_rw_aux(OpName,ReadIds,WrittenVariables),
163 exclude(b_is_constant,ReadIds,ReadVariables),
164 include(b_is_constant,ReadIds,ReadConstants).
165 :- use_module(probsrc(bmachine),[b_nth1_invariant/3,b_get_operation_normalized_read_write_info/3]).
166 api_get_op_rw_aux(check_invariant_violated(Nr),UsedIds,Written) :- !, Written=[],
167 b_nth1_invariant(Nr,_,UsedIds).
168 api_get_op_rw_aux(OpName,ReadVariables,WrittenVariables) :-
169 b_get_operation_normalized_read_write_info(OpName,ReadVariables,WrittenVariables).
170
171
172 :- use_module(probsrc(b_interpreter),[b_execute_top_level_operation_update/5]).
173
174 % we use a trick using a mutable to detect when a time_out or exception has been thrown
175 % during caching; we could have used assert/retract or bb_put/bb_get instead
176
177 api_compute_operation_update_max(NewID,OpName,Operation,ProjInOutState,NewState,PathInfo,MaxForCall) :-
178 create_mutable(still_computing,Done),
179 %tools:start_ms_timer(Timer),
180 call_cleanup(
181 com_op_update_max(NewID,OpName,Operation,ProjInOutState,NewState,PathInfo,MaxForCall,Done),
182 (get_mutable(still_computing,Done)
183 -> format('Timeout, exception or virtual timeout occured during caching for ~w (cache id ~w)~n',[OpName,NewID]),
184 % also happens during -execute due to cut!, hence we now disable preference in -execute
185 % stop_ms_timer_with_msg(Timer,'Runtime for computing'),
186 inc_counter(op_cached_timeouts),
187 register_op_cache_time_out(NewID,OpName)
188 ; true
189 )),
190 get_mutable(DVal,Done), DVal \= finished. % fail if we are Done;
191
192 % we could do this: but we don't know if an exception, timeout or virtual time_out occurred
193 register_op_cache_time_out(ID,OpName) :-
194 inc_counter(op_cached_timeouts),
195 assertz(operation_cached_time_out(ID,OpName)).
196 % as an alternative this removes the cached results:
197 %invalidate_operation_cache(ID,OpName) :-
198 % retractall(operation_cached_results(ID,_Operation,_,_)),
199 % retractall(operation_computed(_,OpName,_,_,ID)). % can be expensive
200
201
202
203 com_op_update_max(_,check_invariant_violated(Nr),Operation,ProjState,NewState,PathInfo,_,Done) :- !,
204 NewState =[], PathInfo=invariant, Operation=Nr, % values not used anyway for invariants
205 %print(check_invariant(Nr)),nl, bmachine:b_nth1_invariant(Nr,Inv,_UsedIds), translate:print_bexpr(Inv),nl,
206 (b_interpreter:check_nth1_invariant(Nr,ProjState )
207 -> update_mutable(finished,Done) % will lead to failure above; we store only violations
208 ; % invariant violation found
209 update_mutable(last_sol_found,Done)
210 ).
211 com_op_update_max(_,OpName,Operation,ProjInOutState,NewState,PathInfo,MaxForCall,_) :-
212 % for CSP||B: clear out any parameters; otherwise we also need to hash the parameters
213 reset_max_reached(OpName),
214 succeed_max_call_id(OpName,
215 b_execute_top_level_operation_update(OpName,Operation,ProjInOutState,NewState,PathInfo),
216 MaxForCall).
217 % TO DO: normalise_store out state values, to avoid re-normalising when storing updates
218 com_op_update_max(NewID,OpName,_,_,_,_,_,Done) :-
219 (NewID \= uncached,
220 max_reached(OpName)
221 -> assertz(operation_cached_max_reached(NewID,OpName)) % store that we reached max. nr of transitions for this node
222 ; true %format('No Timeout or virtual timeout occurred during caching for ~w leading to ~w~n',[OpName,NewID])
223 ),
224 update_mutable(finished,Done).
225
226
227
228 % entry point to cache invariant checking
229 check_invariant_violated_cache(Nr,State) :-
230 %get_store_and_info(State,FullStore,Infos),
231 compute_operation_on_expanded_store_cache(check_invariant_violated(Nr),_,State,_,_,-1).
232
233 :- use_module(probsrc(specfile),[expand_const_and_vars_to_full_store/2]).
234 %get_store_and_info(expanded_const_and_vars(_ConstID,_Vars,E,Info),FullStore,Info) :- !, FullStore=E.
235 %get_store_and_info(expanded_vars(E,Info),FullStore,Info) :- !, FullStore=E.
236 %get_store_and_info(Store,FullStore,[]) :- expand_const_and_vars_to_full_store(Store,FullStore).
237
238 % -------------------------------
239
240
241 % check if caching is worthwhile for this operation
242 %worthwhile_to_cache(OpName) :-
243 % get_read_write_info(OpName,ReadVariables,WrittenVariables),
244 % length(ReadVariables,NrRV),
245 % bmachine:b_machine_statistics(variables,NrVars),
246 % bmachine:b_machine_statistics(constants,NrConstants),
247 % Perc is (NrRV*100) // (NrVars+NrConstants),
248 % length(WrittenVariables,NrWV),
249 % format('Analyzing ~w, ~w %, read: ~w, written: ~w, tot vars: ~w, tot cst: ~w~n (read: ~w)~n',[OpName,Perc,NrRV,NrWV,NrVars,NrConstants,ReadVariables]),
250 % Perc < 95. % maybe provide as preference
251
252 :- use_module(library(ordsets),[ord_member/2]).
253 %is_read(ReadVariables,bind(Var,_)) :- ord_member(Var,ReadVariables).
254 member_ord(List,X) :- ord_member(X,List). % for maplist, exclude,...
255
256 % -------------------------------
257
258 % a variation of split_list which also returns a list of predicate results
259 % with re_project_state(L,ProjVarsInOrder,A) : we can split another list using the same pattern
260
261 :- assert_must_succeed((b_operation_cache:project_state_onto_vars([bind(x,1),bind(y,2),bind(b,3)],[b,y],
262 ProjVars,ProjState,0,NrDel),
263 ProjVars == [y,b], ProjState == [bind(y,2),bind(b,3)], NrDel==1)).
264
265 project_state_onto_vars([],_,[],[],Acc,Acc).
266 project_state_onto_vars([Elem|Rest],ReadVariables,ProjVars,ProjState,NrDelAcc,NrDel) :-
267 Elem = bind(Var,_),
268 (ord_member(Var,ReadVariables) % TO DO: we could improve performance by sorting Elements
269 -> ProjVars=[Var|PT], ProjState=[Elem|AR], ND1=NrDelAcc
270 ; ProjVars=PT, ProjState=AR, ND1 is NrDelAcc+1),
271 project_state_onto_vars(Rest,ReadVariables,PT,AR,ND1,NrDel).
272
273
274 % -------------------------------
275
276 :- assert_must_succeed((b_operation_cache:re_project_state([y,b],[bind(x,1),bind(y,2),bind(b,3)],Res),
277 Res == [bind(y,2),bind(b,3)])).
278
279 % project state(VarsInOrder,State,ProjectedState)
280 % faster than project_state_onto_vars
281 re_project_state([],_,[]).
282 re_project_state([VarToProject|PT],[Elem|Rest],A) :-
283 arg(1,Elem,Var), %Elem = bind(Var,_),
284 (VarToProject==Var
285 -> A=[Elem|AR],re_project_state(PT,Rest,AR)
286 ; re_project_state2(VarToProject,PT,Rest,A)).
287
288 re_project_state2(VarToProject,PT,[Elem|Rest],A) :-
289 arg(1,Elem,Var), %Elem = bind(Var,_),
290 (VarToProject==Var
291 -> A=[Elem|AR],re_project_state(PT,Rest,AR)
292 ; re_project_state2(VarToProject,PT,Rest,A)).
293
294 % -----------------------------
295
296 % Two utilities to optionally generate lemma facts for fast projection
297 % Does not seem to be worth it
298
299 % abstract away values, can be used to generate pre-compiled facts
300 %abstract_state([],[]).
301 %abstract_state([bind(Var,_)|T],[bind(Var,_)|AT]) :- abstract_state(T,AT).
302
303 % abstract away unused bindings, can be used to generate pre-compiled facts
304 %clear_unused_bindings([],_,_) :- !.
305 %clear_unused_bindings([VarToProject|PT],[bind(Var,V)|T],[bind(Var,V)|RT]) :-
306 % % we could clear out Variable name Var; but this creates a danger of successfully matching an erroneous state
307 % VarToProject==Var,!,
308 % clear_unused_bindings(PT,T,RT).
309 %clear_unused_bindings(Vars,[_|T],[_|RT]) :- % leave slot in result as fresh var
310 % clear_unused_bindings(Vars,T,RT).
311
312 % -------------------------------
313
314 :- use_module(probsrc(hashing)).
315 :- use_module(probsrc(state_packing)).
316
317 :- dynamic operation_computed/5, operation_cached_results/4,
318 operation_cached_max_reached/2, operation_cached_time_out/2,
319 op_guard_fails/3.
320
321 % return Hash and check if operation computed
322 % TO DO: do not hash constants if single value exists ?
323 check_if_operation_was_computed(OpName,ConstID,State,Skel,Infos,PackedValList,IsReadingCsts,
324 HashConstID,Hash,Res) :-
325 (Infos = [packed_state/PS|_]
326 -> get_packed_vars(PS,OpName,PackedState),
327 remove_bind_skeleton(PackedState,Skel,PackedValList)
328 % packing already performed in prepare_state_for_specfile_trans
329 ; write(no_packed_state_info(OpName,ConstID)),nl, % shouldn't happen hopefully
330 project_in_state(State,OpName,ProjectedInState), % State contains just variables
331 pack_bind_list(ProjectedInState,Skel,PackedValList)
332 ),
333 (IsReadingCsts = false -> HashConstID=root ; HashConstID=ConstID),
334 op_hash(OpName,HashConstID,PackedValList,Hash),
335 (operation_computed(Hash,OpName,HashConstID,PackedValList,ID)
336 -> Res = ID
337 ; % operation_guard_read_info(OpKey,GuardVars,_), re_project_state(GuardVars,Skel,PackedValList,GuardPackedVals)
338 % op_hash(OpName,HashConstID,GuardPackedVals,GuardHash), op_guard_fails(GuardHash,OpName,GuardPackedVals,ID) -> true
339 Res= false).
340
341 % project a state or packed value list onto the variables relevant for the guard (if it is a subset)
342 project_onto_guard(OpName,OpKey,HashConstID,Skel,PackedValList,GuardPackedVals,GuardHash) :-
343 operation_guard_read_info(OpKey,_,IgnoredVars),
344 remove_ignored_vars(IgnoredVars,Skel,PackedValList,GuardPackedVals),
345 op_hash(OpName,HashConstID,GuardPackedVals,GuardHash).
346
347
348 % remove_ignored_vars(VarsToIgnore,SkeletonList,ValueList,Result)
349 remove_ignored_vars([],_,PackedVals,Res) :- Res=PackedVals.
350 remove_ignored_vars([ID|T],[ID|ST],[_|PackedVals],GuardPackedVals) :- !,
351 remove_ignored_vars(T,ST,PackedVals,GuardPackedVals).
352 remove_ignored_vars(Ignored,[_|ST],[PV|PackedVals],[PV|GuardPackedVals]) :-
353 remove_ignored_vars(Ignored,ST,PackedVals,GuardPackedVals).
354
355 get_packed_vars(const_and_vars(_,Vars),OpName,PackedVars) :- !, project_in_state(Vars,OpName,PackedVars).
356 get_packed_vars(PS,OpName,PackedVars) :- !, project_in_state(PS,OpName,PackedVars).
357 :- use_module(library(terms),[term_hash/3]).
358 :- use_module(probsrc(hashing),[my_term_hash/2]).
359
360 op_hash(OpName,HashConstID,PackedValList,Hash) :- get_preference(use_state_packing,false),!,
361 my_term_hash((OpName,HashConstID,PackedValList),Hash). % will user super_hash
362 op_hash(OpName,HashConstID,PackedValList,Hash) :-
363 % we use state packing and thus replace AVL sets by identifiers, ...: a simpler hash suffices, but we get collisions for Train1_Lukas_POR (which do not seem to matter); we get an improvement for ifm18/Ref5_Switch_mch.eventb
364 term_hash((OpName,HashConstID,PackedValList),
365 [range(smallint),algorithm(sdbm),depth(infinite),if_var(ignore)], % djb2
366 Hash).
367
368
369 % remove bind/2 wrappers and variable name for faster hashing
370 remove_bind_skeleton([],[],R) :- !, R=[].
371 remove_bind_skeleton([bind(Var,Val)|T],[Var|VT],[Val|RT]) :- !,
372 remove_bind_skeleton(T,VT,RT).
373 remove_bind_skeleton(L,V,R) :- add_internal_error('Illegal store: ',remove_bind_skeleton(L,V,R)), R=L.
374
375 % we could also peel a few infos not useful for hashing:
376 %peel_val('$stored_avl_packed'(Nr),Nr).
377 %peel_val('$avl_bv'(Nr,_),Nr). % correct because if we use a bit_vector we will never also use stored_avl_packed for the same type
378
379
380 get_new_operation_computed_id(OpName,ConstID,PackedValList,Hash,ID) :-
381 inc_counter(op_cache_id,ID),
382 (OpName=check_invariant_violated(_) -> inc_counter(inv_cache_nr,_) ; true),
383 assertz(operation_computed(Hash,OpName,ConstID,PackedValList,ID)).
384 % To reduce memory consumption we could use the following clause:
385 % can be useful if there are many operations with a large number of projected variables
386 % but does lead to noticable slowdown when looking up operations
387 %get_new_operation_computed_id(OpName,ConstID,_PackedValList,Hash,[_,state_id/ReferenceStateID],ID) :- !,
388 % inc_counter(op_cache_id,ID),
389 % assertz(operation_computed(Hash,OpName,ConstID,ReferenceStateID,ID)). % storing reference ID preserves memory
390 % when looking up operation_was_computed we would need to do something like:
391 % state_space:packed_visited_expression(StoredState,PS),
392 % get_packed_b_state_with_uncompressed_lists(PS,PUS),
393 % get_state_infos(PUS,ConstID,PackedList,_,_),
394 % project_in_state(PackedList,OpName,ProjectedStoredState),
395 % remove_bind_skeleton(ProjectedStoredState,Skel,ProjectedValList),
396 % ProjectedValList = PackedValList
397
398
399 :- use_module(probsrc(runtime_profiler),[profile_failure_driven_loop/1]).
400 % this is used when get_preference(try_operation_reuse,true/full)
401 % it is only called for operations, not for setup_constants or initalise_machine
402
403 % treat expanded_const_and_vars(ConstID,Vars,FullStore,Infos)
404
405 get_state_infos(expanded_const_and_vars(ID,Vars,FullStore,I),ConstID,Vars,FullStore,Infos) :- !,ConstID=ID,Infos=I.
406 get_state_infos(expanded_vars(V,I),ConstID,Vars,FullStore,Infos) :- !, ConstID=root,Vars=V,FullStore=V,Infos=I.
407 get_state_infos(const_and_vars(ConstID,Vars),ConstID,Vars,FullStore,Infos) :- !,
408 add_warning(get_state_infos,'State not prepared for caching: ',const_and_vars(ConstID,Vars)),
409 Infos=[],
410 expand_const_and_vars_to_full_store(const_and_vars(ConstID,Vars),FullStore).
411 get_state_infos(csp_and_b(_,State),ConstID,Vars,FullStore,Infos) :- !,
412 get_state_infos(State,ConstID,Vars,FullStore,Infos).
413 get_state_infos(Vars,unknown,Vars,Vars,[]).
414
415 % InState is either already an expanded list or expanded_const_and_vars, expanded_vars
416 compute_operation_on_expanded_store_cache(OpName,Operation,InState,NewState,PathInfo,MaxForCall) :-
417 get_state_infos(InState,ConstID,Vars,FullStore,Infos), % extract infos from the store
418 % TO DO: check if state_id in Infos and if OpName in equivalence class with same proj. vars
419 get_opname_key(OpName,OpNameKey),
420 get_operation_read_projection_infos(OpNameKey,OpName,Vars,ProjVarsInOrder,IsReadingCsts,AdditionalOutVars),
421 !,
422 % tools_printing:print_term_summary(proj(OpName,ConstID,ProjInState,FullStore)),nl,
423 check_if_operation_was_computed(OpName,ConstID,Vars,ProjVarsInOrder,Infos,PackedValList,IsReadingCsts,
424 HashConstID,Hash,ID),
425 (ID \= false
426 -> % we can reuse the stored operation effect
427 %print('+'),
428 %hit_profiler:add_hit(operation_reused,OpName),
429 (inv_op_name(OpName) -> inc_counter(inv_cached_successes)
430 ; inc_counter(op_cached_successes)),
431 (operation_cached_results(ID,Operation,PackedNewState,PathInfo),
432 unpack_values(PackedNewState,NewState)
433 ;
434 operation_cached_max_reached(ID,OpName), % we did not compute all operations
435 assert_max_reached(OpName),
436 fail
437 ; operation_cached_time_out(ID,OpName),
438 format('Rethrowing cached time_out for ~w and cache id ~w~n',[OpName,ID]),
439 throw(time_out)
440 )
441 ; % we have not computed solutions for this operation for this projected state
442 (project_onto_guard(OpName,OpNameKey,HashConstID,ProjVarsInOrder,PackedValList,GuardPackedVals,GuardHash)
443 -> true
444 ; GuardPackedVals = none),
445 (nonvar(GuardHash),
446 op_guard_fails(GuardHash,OpName,GuardPackedVals)
447 -> % we did already compute this operation for this projected state and it failed
448 inc_counter(op_cached_failures),
449 fail % the guard is guaranteed to fail
450 ; % we have not yet computed this operation; compute it and store solutions as we go
451 get_new_operation_computed_id(OpName,HashConstID,PackedValList,Hash,NewID),
452 %print('-'),
453 %hit_profiler:add_hit(operation_cache_computation,OpName),
454 (IsReadingCsts=false
455 -> % TO DO: check if this projection is worthwhile
456 project_in_state_for_opname_key(Vars,OpNameKey,ProjInState),
457 % Note: if no packed_state this projection was already performed in check_if_operation_was_computed
458 add_new_vars(AdditionalOutVars,ProjInState,ProjInOutState)
459 ; ProjInOutState = FullStore % use full store with constants
460 ),
461 profile_failure_driven_loop(OpName),
462 if(api_compute_operation_update_max(NewID,OpName,Operation,ProjInOutState,NewState,PathInfo,MaxForCall),
463 (% Normalise here or in update_max
464 pack_values(NewState,PackedNewState),
465 (PathInfo=invariant -> StoredPathInfo=Hash
466 ; filter_transition_path_info(PathInfo,StoredPathInfo)),
467 assertz(operation_cached_results(NewID,Operation,PackedNewState,StoredPathInfo))
468 ),
469 (nonvar(GuardHash),
470 %print(op_guard_fails(GuardHash,OpName,GuardPackedVals)),nl,
471 assertz(op_guard_fails(GuardHash,OpName,GuardPackedVals)),
472 fail
473 )
474 )
475 )
476 % TO DO: if we have no successors for ID and if the operation reads less IDs in the guard
477 % we can replace remaining identifier values by a variable
478 ).
479 compute_operation_on_expanded_store_cache(OpName,Operation,InState,NewState,PathInfo,MaxForCall) :-
480 %hit_profiler:add_hit(operation_not_cached,OpName),
481 % operation is not cached
482 get_state_infos(InState,_,_,FullStore,_),
483 api_compute_operation_update_max(uncached,OpName,Operation,FullStore,NewState,PathInfo,MaxForCall).
484
485 % add written vars which are not read virtually to state to avoid error messages in store_intermediate_updates:
486 add_new_vars([],S,S).
487 add_new_vars([WrittenVar|T],State,[bind(WrittenVar,term(undefined))|ST]) :-
488 add_new_vars(T,State,ST).
489
490 :- use_module(probsrc(state_space),[keep_transition_info/1]).
491 filter_transition_path_info([],R) :- !, R=[].
492 filter_transition_path_info([H|T],Res) :- !,
493 (keep_transition_info(H) -> Res = [H|RT]
494 ; Res=RT), % by default we filter out possibly large path infos (in particular for Event-B)
495 filter_transition_path_info(T,RT).
496 filter_transition_path_info(H,Res) :-
497 (keep_transition_info(H) -> Res = H ; Res=[]).
498
499
500 invariant_op_key(OpKey,InvNr) :- operation_read_projection_cache(OpKey,check_invariant_violated(InvNr),_,_,_).
501
502 :- use_module(probsrc(bmachine),[b_nth1_invariant/3]).
503 print_violated_invariants :-
504 operation_cached_results(ID,Nr,[],Hash),number(Nr),
505 b_nth1_invariant(Nr,Invariant,_UsedIds),
506 format('Invariant ~w violated (op-cache-id ~w)~n ',[Nr,ID]),
507 translate:print_bexpr(Invariant),nl,
508 % now try and recover state where it was violated:
509 operation_computed(Hash,OpName,ConstID,PackedValList,ID),
510 operation_read_projection_cache(_,OpName,Skel,_,_),
511 unpack_bind_list(PackedValList,Skel,State), translate_bstate_limited(State,StateDesc),
512 format(' in state (ConstID ~w) ~w~n',[ConstID,StateDesc]),
513 fail.
514 print_violated_invariants.
515
516 % small utility code to analyze hash collisions:
517 % b_operation_cache:ahc.
518 :- public ahc/0.
519 ahc :- operation_computed(Hash,OpName,ConstID,State,ID),
520 operation_computed(Hash,OpName2,ConstID2,State2,ID2),
521 (ConstID @> ConstID2 -> true ; ConstID=ConstID2, ID2 > ID),
522 format('Hash collision: ~w~n ~w:~w:~w:~w~n ~w:~w:~w:~w~n~n',
523 [Hash,OpName,ConstID,State,ID,OpName2,ConstID2,State2,ID2]),
524 fail.
525 ahc.
526
527 :- use_module(probsrc(translate),[translate_bstate_limited/2, translate_event_with_limit/3]).
528 :- use_module(probsrc(debug),[debug_mode/1]).
529 :- use_module(probsrc(preferences),[get_preference/2]).
530 :- use_module(probsrc(specfile),[get_operation_name/2]).
531 get_op_name(Nr,check_invariant_violated(Nr)) :- number(Nr),!.
532 get_op_name(Op,OpName) :- get_operation_name(Op,OpName).
533 get_nr_next_state_calls(OpName,Nr) :- findall(1,operation_computed(_Hash,OpName,_,_,_ID),Ls), length(Ls,Nr).
534 get_nr_cache_results(OpName,RNr) :-
535 findall(1,(operation_cached_results(_ID,Op,_,_),get_op_name(Op,OpName)),Rs), length(Rs,RNr).
536 :- use_module(probsrc(bmachine),[b_get_machine_variables/1]).
537 % b_operation_cache:print_op_cache_profile
538
539 check_if_op_cache_useful :-
540 b_get_machine_variables(Var),length(Var,VLen),
541 api_get_operation_read_write_info(OpName,ReadVariables,_ReadConstants,_WrittenVariables),
542 length(ReadVariables,ReadLen),
543 ReadLen < VLen,
544 (inv_op_name(OpName) -> get_preference(use_po,false) ; true),
545 format('Operation reuse potentially useful: ~w reads ~w/~w variables~n',[OpName,ReadLen,VLen]),
546 fail.
547 check_if_op_cache_useful.
548
549 inv_op_name(check_invariant_violated(_)).
550
551 print_op_cache_profile :- \+ operation_computed(_,_,_,_,_),!, % print nothing
552 (get_preference(try_operation_reuse,false) -> format('OPERATION_REUSE preference not set to TRUE~n',[]) ; true),
553 format('No operation cached~n',[]),
554 check_if_op_cache_useful.
555 print_op_cache_profile :-
556 b_get_machine_variables(Var),length(Var,VLen),
557 operation_read_projection_cache(OpKey,OpName,ProjVars,_,WV), (ProjVars = [] ; ProjVars = [_|_]),
558 length(ProjVars,Len),
559 operation_read_constants(OpKey,ReadConstants),
560 (operation_guard_read_info(OpKey,_,IrrelevantVars)
561 -> format('Operation ~w cached onto ~w/~w variables: ~w (not relevant for guard: ~w, only written: ~w, constants read: ~w)~n',[OpName,Len,VLen,ProjVars,IrrelevantVars,WV,ReadConstants])
562 ; format('Operation ~w cached onto ~w/~w variables: ~w (only written: ~w, constants read: ~w)~n',[OpName,Len,VLen,ProjVars,WV,ReadConstants])
563 ),fail.
564 print_op_cache_profile :- findall(OpName,operation_read_projection_cache(_,OpName,no_caching,_,_),Ls),
565 format('Operations not cached: ~w~n',[Ls]),fail.
566 print_op_cache_profile :- operation_read_projection_cache(OpKey,OpName,ProjVars,_,_), ProjVars = [_|_],
567 get_nr_next_state_calls(OpName,Nr),
568 get_nr_cache_results(OpName,RNr),
569 (inv_op_name(OpName) -> Results='violations' ; Results = 'results'),
570 format('Next-state-calls for ~w: ~w (~w ~w)~n',[OpName,Nr,RNr,Results]),
571 operation_guard_read_info(OpKey,RelVars,_),
572 findall(1,op_guard_fails(_,OpName,_),Fails), length(Fails,NrFails),
573 format(' projected-failures (on ~w): ~w~n',[RelVars,NrFails]),
574 fail.
575 print_op_cache_profile :-
576 get_total_number_of_next_state_calls(Nr,InvNr),
577 format('Total Number of Next-state-calls for Operations: ~w~n',[Nr]),
578 get_counter(op_cached_failures,FailCalls),
579 format(' - Reused guard failures: ~w~n',[FailCalls]),
580 get_counter(op_cached_successes,SuccCalls),
581 format(' - Reused successful operation call results: ~w~n',[SuccCalls]),
582 format('Total Number of Invariant-check-calls: ~w~n',[InvNr]),
583 get_counter(inv_cached_successes,SuccInvCalls),
584 format(' - Reused invariant check results: ~w~n',[SuccInvCalls]),
585 fail.
586 print_op_cache_profile :- debug_mode(on), nl,
587 operation_read_projection_cache(_,OpName,Skel,_,_),
588 format('~n** Local Operation Cache Info for ~w ** (projected on ~w):~n',[OpName,Skel]),
589 operation_computed(_Hash,OpName,ConstID,PackedValList,ID),
590 (operation_cached_max_reached(ID,OpName) -> MaxR='(max reached, not all transitions computed)'
591 ; MaxR=''),
592 format('~nNode ID = ~w, Operation = ~w ~w~n',[ID,OpName,MaxR]),
593 unpack_bind_list(PackedValList,Skel,State), translate_bstate_limited(State,NodeDesc),
594 format(' projected state : (ConstID ~w) ~w~n',[ConstID,NodeDesc]),
595 operation_cached_results(ID,Operation,PackedNewState,_PathInfo),
596 translate_event_with_limit(Operation,100,OpStr),
597 unpack_values(PackedNewState,NewState), translate:translate_bstate_limited(NewState,UpdateStr),
598 format(' ~w -upd-> ~w~n',[OpStr,UpdateStr]),
599 fail.
600 print_op_cache_profile :- print_violated_invariants,fail.
601 print_op_cache_profile :- ahc,print('----------'),nl.
602
603 get_total_number_of_next_state_calls(OpNr,InvNr) :-
604 get_counter(op_cache_id,TotNr),
605 get_counter(inv_cache_nr,InvNr),
606 OpNr is TotNr-InvNr.
607 %findall(0,b_operation_cache:operation_computed(_Hash,_Op,_,_,_ID),Ls), length(Ls,Nr).
608
609 get_op_cache_stats([next_state_calls-NrN, % actual calls to the B interpreter to compute next state
610 operations_cached-NrC, % number of operations whose calls are cached
611 invariants_cached-NrI, % number of invariants whose evaluation is cached
612 next_state_guard_failures-NrFails, % number of next-state_call failures stored (disabled operation)
613 reused_next_state_calls-SuccCalls,
614 reused_next_state_failures-FailCalls,
615 inv_check_calls-InvNr, % actual calls to check individual invariants in a state
616 reused_inv_check_calls-SuccInvCalls
617 ]) :-
618 findall(OpKey,(operation_read_projection_cache(OpKey,OpName,_,_,_),atomic(OpName)),OK1),
619 length(OK1,NrC),
620 findall(OpKey,invariant_op_key(OpKey,_),OK2),
621 length(OK2,NrI),
622 findall(OpKey,(op_guard_fails(OpKey,_,_)),OK3),
623 length(OK3,NrFails),
624 get_total_number_of_next_state_calls(NrN,InvNr),
625 get_counter(op_cached_failures,FailCalls),
626 get_counter(op_cached_successes,SuccCalls),
627 get_counter(inv_cached_successes,SuccInvCalls).
628
629 % ----------------------
630
631 :- use_module(probsrc(tools_strings),[ajoin/2]).
632 tcltk_op_cache_stats(list([list(['Operation','#Next-State', '#Results',
633 '# Proj.Vars','Proj.Vars', 'ReadCsts', 'OnlyWritten'])|SEntries])) :-
634 %b_get_machine_variables(Var),length(Var,VLen),
635 findall(list([OP,NrCalls,RNr,NrProjVars,ProjVars,ReadConstants,AdditionalOutVars]),
636 (operation_read_projection_cache(OpKey,OpName,ProjVars,_,AdditionalOutVars),
637 (OpName = check_invariant_violated(Nr) -> ajoin(['Invariant',Nr],OP) ; OP=OpName),
638 length(ProjVars,NrProjVars),
639 operation_read_constants(OpKey,ReadConstants),
640 get_nr_next_state_calls(OpName,NrCalls),
641 get_nr_cache_results(OpName,RNr)
642 ), Entries), sort(Entries,SEntries).
643
644 % ----------------------
645 % DOT RENDERING (not yet finished)
646
647 %op_cache_node(ID,OpName,NodeDesc,Shape,Style,Color) :- Shape=box, Style=solid, Color=blue,
648 % operation_computed(_Hash,OpName,_,PackedState,ID),
649 % unpack_values(PackedState,State), translate_bstate_limited(State,NodeDesc).
650 %:- use_module(probsrc(dotsrc(dot_graph_generator)),[gen_dot_graph/3]).
651 % Predicates for creating a dependency graph
652 %tcltk_operation_cache_graph(File) :- gen_dot_graph(File,op_cache_node,cbc_dependence_trans_predicate).
653