| 1 | % (c) 2014-2019 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(static_analysis, [dependent_actions/5, enable_analysis/6, disable_analysis/5, action_dependent_to_itself/4, tcltk_enabling_analysis/2, | |
| 6 | compute_dependendency_relation_of_all_events_in_the_model/3, | |
| 7 | enable_graph/1,dependent_act/4, | |
| 8 | syntactic_independence/3, | |
| 9 | get_conj_inv_predicate/3, % predicate used in the enabling analysis module | |
| 10 | catch_and_ignore_well_definedness_error/2, | |
| 11 | test_path_non_failing/6, | |
| 12 | test_path/6, | |
| 13 | is_timeout/1 | |
| 14 | ]). | |
| 15 | ||
| 16 | :- meta_predicate catch_enumeration_warning(0,0). | |
| 17 | :- meta_predicate catch_and_ignore_well_definedness_error(0,*). | |
| 18 | ||
| 19 | ||
| 20 | /* Modules and Infos for the code coverage analysis */ | |
| 21 | :- use_module(probsrc(module_information)). | |
| 22 | :- module_info(group,model_checker). | |
| 23 | :- module_info(description,'This module provides predicates for static analysis of Event-B and B models'). | |
| 24 | ||
| 25 | % Standard SICSTUS prolog libraries | |
| 26 | %% :- use_module(library(lists)). | |
| 27 | :- use_module(library(ordsets)). | |
| 28 | :- use_module(library(ugraphs)). | |
| 29 | ||
| 30 | % Classical B prolog modules | |
| 31 | :- use_module(probsrc(bmachine),[b_top_level_operation/1, b_get_invariant_from_machine/1, b_get_properties_from_machine/1]). | |
| 32 | :- use_module(probsrc(bsyntaxtree), [conjunct_predicates/2]). | |
| 33 | :- use_module(probsrc(b_state_model_check), [get_negated_guard/3,get_guard/2]). | |
| 34 | :- use_module(probsrc(b_interpreter),[b_get_machine_operation_for_animation/6]). % TODO: predicate used for determining whether an event is self-dependent to itself (consider whether to remove) | |
| 35 | ||
| 36 | % Event-B prolog modules | |
| 37 | ||
| 38 | % POR modules | |
| 39 | :- use_module(probporsrc(enabling_predicates),[compute_enabling_predicate/5]). | |
| 40 | ||
| 41 | % Importing predicates for using CBC | |
| 42 | :- use_module(probsrc(sap), [testcase_path_timeout/9]). | |
| 43 | :- use_module(probsrc(b_read_write_info), [b_get_read_write/3, b_get_read_write_vars/5, b_get_operation_read_guard_vars/3]). | |
| 44 | ||
| 45 | % Other modules (used mostly for debugging) | |
| 46 | %:- use_module(probsrc(dot_graph_generator),[gen_dot_graph/6]). | |
| 47 | :- use_module(probsrc(preferences),[get_preference/2]). | |
| 48 | :- use_module(probsrc(error_manager),[real_error_occurred/0, logged_error/4, reset_errors/0, | |
| 49 | call_in_fresh_error_scope_for_one_solution/1, | |
| 50 | add_internal_error/2, add_error_fail/3, | |
| 51 | enumeration_warning_occured_in_error_scope/0, clear_enumeration_warnings/0]). | |
| 52 | :- use_module(probsrc(debug),[debug_println/2, debug_mode/1, debug_format/3]). | |
| 53 | :- use_module(probsrc(tools),[cputime/1]). | |
| 54 | ||
| 55 | % Importing unit tests predicates | |
| 56 | %% :- use_module(probsrc(self_check)). | |
| 57 | ||
| 58 | is_timeout(timeout). | |
| 59 | is_timeout(time_out). | |
| 60 | is_timeout(clpfd_overflow). | |
| 61 | is_timeout(overflow). | |
| 62 | is_timeout(virtual_time_out). | |
| 63 | ||
| 64 | % --------------------------- Static analysis for determining the dependece/independence of events (Begin) -----------------------------% | |
| 65 | ||
| 66 | % check syntactically influence of executing OpName1 on OpName2's enabling and effect | |
| 67 | syntactic_independence(OpName1,OpName2,Res) :- | |
| 68 | b_top_level_operation(OpName1), | |
| 69 | b_top_level_operation(OpName2), | |
| 70 | b_get_read_write_vars(OpName1,GReads1,AReads1,Reads1,Writes1), | |
| 71 | b_get_read_write_vars(OpName2,GReads2,AReads2,Reads2,Writes2), | |
| 72 | \+ ord_intersect(Writes1,GReads2),% otherwise Op1 can influence guard of Op2 | |
| 73 | (ord_intersect(Writes1,AReads2) | |
| 74 | -> % guard not modified, but effect of OpName2 could change | |
| 75 | Res = syntactic_keep | |
| 76 | ; (\+ ord_intersect(Writes1,Writes2), % no race | |
| 77 | \+ ord_intersect(GReads1,Writes2), % no enabling/disabling of OpName1 by OpName2 | |
| 78 | \+ ord_intersect(AReads1,Writes2)) % no change of effect | |
| 79 | -> (\+ ord_intersect(Reads1,Reads2) | |
| 80 | -> Res = syntactic_fully_independent | |
| 81 | ; Res = syntactic_independent | |
| 82 | ) | |
| 83 | ; otherwise -> Res = syntactic_unchanged % guard is kept and operation effect of OpName2 unchanged; but there could be race conditions on writes or effects of OpName2 on OpName1 | |
| 84 | ). | |
| 85 | ||
| 86 | dependent_actions1(OpName1,OpName2,FindInvViolations,Timeout,Res) :- | |
| 87 | b_top_level_operation(OpName1), | |
| 88 | b_top_level_operation(OpName2), | |
| 89 | b_get_read_write_vars(OpName1,GReads1,AReads1,Reads1,Writes1), | |
| 90 | ( OpName1=OpName2 -> action_dependent_to_itself(OpName1,GReads1,Writes1,Res) % TODO: Do we really need this kind of analysis??? | |
| 91 | ; OpName2 @< OpName1 -> Res = '-' % our checking is symmetric; check only one pair | |
| 92 | ; otherwise -> | |
| 93 | b_get_read_write_vars(OpName2,GReads2,AReads2,Reads2,Writes2), | |
| 94 | ( ord_intersect(Writes1,Writes2) -> Res = race_dependent | |
| 95 | ; (\+ ord_intersect(Writes1,Reads2),\+ ord_intersect(Writes2,Reads1)) -> Res = syntactic_independent | |
| 96 | ; otherwise -> | |
| 97 | (get_preference(use_cbc_analysis,true) -> % sometimes we don't want to use the CBC | |
| 98 | (\+ord_intersect(AReads1,Writes2), | |
| 99 | \+ord_intersect(AReads2,Writes1) -> | |
| 100 | (get_preference(dependency_enable_predicates,true) -> %trace, | |
| 101 | get_dependency_enabling_predicate(OpName1,GReads1,Writes1,OpName2,GReads2,Writes2,FindInvViolations,Timeout,Res) | |
| 102 | ; otherwise -> | |
| 103 | test_enabledness_condition(OpName1,GReads1,Writes1,OpName2,GReads2,Writes2,FindInvViolations,Timeout,Res) | |
| 104 | ) | |
| 105 | ; otherwise -> Res = action_dependent | |
| 106 | ) | |
| 107 | ; otherwise -> Res = dependent % use_cbc_analysis = false | |
| 108 | ) | |
| 109 | ) | |
| 110 | ). | |
| 111 | ||
| 112 | % Testing whether it is possible that the one of the events can disable the other one | |
| 113 | test_enabledness_condition(OpName1,GReads1,Writes1,OpName2,GReads2,Writes2,FindInvViolations,Timeout,Res) :- | |
| 114 | get_negated_guard(OpName1,PosGuard1,NegGuard1), | |
| 115 | get_negated_guard(OpName2,PosGuard2,NegGuard2), | |
| 116 | %% get_conj_inv_predicate([PosGuard1,PosGuard2],FindInvViolations,GuardsConj), | |
| 117 | conjunct_predicates([PosGuard1,PosGuard2],GuardsConj), % both events are enabled | |
| 118 | ( ord_intersect(GReads1,Writes2), | |
| 119 | test_path(GuardsConj,[OpName2],NegGuard1,FindInvViolations,Timeout,_R1) | |
| 120 | -> Res = guard_dependent | |
| 121 | ; ord_intersect(Writes1,GReads2), | |
| 122 | test_path(GuardsConj,[OpName1],NegGuard2,FindInvViolations,Timeout,_R2) | |
| 123 | -> Res = guard_dependent | |
| 124 | ; otherwise -> Res = independent | |
| 125 | ). | |
| 126 | ||
| 127 | get_dependency_enabling_predicate(OpName1,GReads1,Writes1,OpName2,GReads2,Writes2,FindInvViolations,Timeout,Res) :- | |
| 128 | get_negated_guard(OpName1,PosGuard1,NegGuard1), | |
| 129 | get_negated_guard(OpName2,PosGuard2,NegGuard2), | |
| 130 | conjunct_predicates([PosGuard1,PosGuard2],GuardsConj), | |
| 131 | ( (ord_intersect(GReads1,Writes2),test_path(GuardsConj,[OpName2],NegGuard1,FindInvViolations,Timeout,_R1)) -> | |
| 132 | % get enabling predicate after executing OpName2 | |
| 133 | compute_enabling_predicate(OpName2,true,PosGuard1,FindInvViolations,predicate(Enable1)), | |
| 134 | ( (ord_intersect(Writes1,GReads2),test_path(GuardsConj,[OpName1],NegGuard2,FindInvViolations,Timeout,_R2)) -> | |
| 135 | % get enabling predicate after executing OpName1 | |
| 136 | compute_enabling_predicate(OpName1,true,PosGuard2,FindInvViolations,predicate(Enable2)), | |
| 137 | conjunct_predicates([Enable1,Enable2],EnablingPredicate), | |
| 138 | Res = guard_dependent(EnablingPredicate) | |
| 139 | ; otherwise -> | |
| 140 | Res = guard_dependent(Enable1) | |
| 141 | ) | |
| 142 | ; (ord_intersect(Writes1,GReads2),test_path(GuardsConj,[OpName1],NegGuard2,FindInvViolations,Timeout,_R2)) -> | |
| 143 | compute_enabling_predicate(OpName1,true,PosGuard2,FindInvViolations,predicate(Enable2)), | |
| 144 | Res = guard_dependent(Enable2) | |
| 145 | ; otherwise -> | |
| 146 | Res = independent | |
| 147 | ), | |
| 148 | (Res = guard_dependent(Pred), debug_mode(on) -> | |
| 149 | print('####### Enabling Dependency Predicate for '), print(OpName1), print('<->'), print(OpName2), print(' #######'),nl, | |
| 150 | print('Predicate: '),translate:print_bexpr(Pred),nl, | |
| 151 | print('####################################'),nl | |
| 152 | ; otherwise -> true). | |
| 153 | ||
| 154 | action_dependent_to_itself(OpName,Reads,Writes,Res) :- | |
| 155 | b_get_machine_operation_for_animation(OpName,_Res,Params,_,_,true), | |
| 156 | length(Params,Len), | |
| 157 | (Len>0,\+ord_intersect(Reads,Writes) -> | |
| 158 | Res = self_independent | |
| 159 | ; Len = 0 -> | |
| 160 | Res = '=' | |
| 161 | ; otherwise -> | |
| 162 | Res = self_dependent | |
| 163 | ). | |
| 164 | ||
| 165 | % --------------------------- Static analysis for determining the dependece/independence of events (End) -----------------------------% | |
| 166 | ||
| 167 | ||
| 168 | % --------------------------- Enabling anaysis used for the computation of ample sets (Begin) -----------------------------% | |
| 169 | ||
| 170 | enable_analysis(OpName1,OpName2,FindInvViolations,UseEnableGraph,Timeout,Enable) :- | |
| 171 | b_top_level_operation(OpName1), | |
| 172 | b_top_level_operation(OpName2), | |
| 173 | (OpName1 == OpName2 -> | |
| 174 | Enable=impossible % on top level an operation cannot enable itself | |
| 175 | ; otherwise -> | |
| 176 | b_get_read_write(OpName1,_Reads1,Writes1), | |
| 177 | b_get_operation_read_guard_vars(OpName2,true,GReads2), | |
| 178 | get_negated_guard(OpName2,PosGuard2,NegGuard2), | |
| 179 | %enabling_analysis: filter_predicate(PosGuard2,Writes1,FilteredPosGuard2), | |
| 180 | (get_preference(use_cbc_analysis,false) -> | |
| 181 | (ord_intersect(Writes1,GReads2) -> | |
| 182 | get_enabling_result(UseEnableGraph,OpName1,PosGuard2,FindInvViolations,_CBCResult,Enable) | |
| 183 | ; otherwise -> | |
| 184 | Enable=possible_keep | |
| 185 | ) | |
| 186 | ; otherwise -> | |
| 187 | get_guard(OpName1,Guard1), | |
| 188 | conjunct_predicates([Guard1,NegGuard2],StartPred), | |
| 189 | ( (ord_intersect(Writes1,GReads2),test_path(StartPred,[OpName1],PosGuard2,FindInvViolations,Timeout,R)) -> | |
| 190 | get_enabling_result(UseEnableGraph,OpName1,PosGuard2,FindInvViolations,R,Enable) | |
| 191 | ; otherwise -> | |
| 192 | Enable=possible_keep_or_disable | |
| 193 | ) | |
| 194 | ) | |
| 195 | ). | |
| 196 | ||
| 197 | get_enabling_result(UseEnableGraph,OpName1,PosGuard2,FindInvViolations,CBCResult,Enable) :- | |
| 198 | (UseEnableGraph=true -> %(OpName1 = close_door, OpName2 = push_call_button -> trace;true), | |
| 199 | % check further if Enable is inconsistent, if so then we do not need to add an edge to the enable graph | |
| 200 | (compute_enabling_predicate(OpName1,true,PosGuard2,FindInvViolations,Enable) -> | |
| 201 | true | |
| 202 | ; otherwise -> | |
| 203 | add_error_fail(enable_analysis,'Error occurred while computing enabling predicate for ', OpName1/PosGuard2) | |
| 204 | ) | |
| 205 | ; otherwise -> | |
| 206 | (is_timeout(CBCResult)-> Enable=CBCResult; Enable=possible_enable) | |
| 207 | ). | |
| 208 | ||
| 209 | catch_enumeration_warning(Call,Handler) :- | |
| 210 | % throw/1 predicate raises instantiation_error | |
| 211 | on_exception(enumeration_warning(enumerating(_),_Type,_,_,critical),Call,call(Handler)). | |
| 212 | ||
| 213 | catch_and_ignore_well_definedness_error(Call,Result) :- | |
| 214 | catch_enumeration_warning(Call, true), | |
| 215 | (real_error_occurred -> | |
| 216 | ((logged_error(Error,_S,_TContext,_Span),print(error(Error)),nl,Error==well_definedness_error) -> | |
| 217 | reset_errors, | |
| 218 | print('Well definedness error occurred, but it will be ignored here.'),nl, | |
| 219 | Result=error | |
| 220 | ; otherwise -> | |
| 221 | print('No well definedness error occurred. Error will not be ignored here.'),nl, | |
| 222 | Result=unexpected_error_occurred | |
| 223 | ) | |
| 224 | ; otherwise -> | |
| 225 | Result=success | |
| 226 | ), | |
| 227 | (enumeration_warning_occured_in_error_scope -> | |
| 228 | print('Enumeration warning occurred and will be ignored here.'),nl,clear_enumeration_warnings; true). | |
| 229 | ||
| 230 | disable_analysis(OpName1,OpName2,FindInvViolations,Timeout,Result) :- | |
| 231 | b_top_level_operation(OpName1), | |
| 232 | b_top_level_operation(OpName2), | |
| 233 | b_get_read_write(OpName1,_Reads1,Writes1), | |
| 234 | b_get_operation_read_guard_vars(OpName2,true,GReads2), | |
| 235 | get_negated_guard(OpName2,PosGuard2,NegGuard2), | |
| 236 | (get_preference(use_cbc_analysis,false) -> | |
| 237 | (ord_intersect(Writes1,GReads2) -> | |
| 238 | Result=possible_disable | |
| 239 | ; otherwise -> | |
| 240 | Result=possible_keep | |
| 241 | ) | |
| 242 | ;otherwise -> | |
| 243 | get_guard(OpName1,PosGuard1), | |
| 244 | conjunct_predicates([PosGuard1,PosGuard2],StartPred), | |
| 245 | ( (ord_intersect(Writes1,GReads2),test_path(StartPred,[OpName1],NegGuard2,FindInvViolations,Timeout,CBCResult)) -> | |
| 246 | (is_timeout(CBCResult)-> Result=CBCResult; Result=possible_disable) | |
| 247 | ; otherwise -> | |
| 248 | Result=cannot_disable | |
| 249 | ) | |
| 250 | ). | |
| 251 | ||
| 252 | % test_path(+Start,+Path,+Goal,+WithInv,+Timeout,-R) | |
| 253 | % Runs the CBC to check whether there is a possible execution of sequence of events Path in the loaded model | |
| 254 | % starting at a state s satisfying Start and reaching a state s' satisfying Goal whitin Timeout milliseconds | |
| 255 | % + Start: B predicate | |
| 256 | % + Path: a list of events/operations | |
| 257 | % + Goal: B predicate | |
| 258 | % + Timeout: specifying a timeout (in milliseconds) | |
| 259 | % - R: result (result could be either 'ok', 'timeout', 'interrupt', or 'unknown') | |
| 260 | %%% pred(P) - adds P to invariant | |
| 261 | %%% typing(P) - just use typing from invariant and add P | |
| 262 | ||
| 263 | test_path(Start,Path,Goal,WithInv,Timeout,Res) :- | |
| 264 | (Start=init -> | |
| 265 | Start1 = init | |
| 266 | ; otherwise -> | |
| 267 | (WithInv=1 -> | |
| 268 | Start1 = pred(Start), | |
| 269 | get_conj_inv_predicate([Goal],WithInv,Goal_Inv) | |
| 270 | ; Start1=typing(Start), | |
| 271 | Goal_Inv = Goal) | |
| 272 | ), | |
| 273 | catch_and_ignore_well_definedness_error(testcase_path_timeout(Start1,Timeout,Path,Goal_Inv,_,_,_,_,R),ER), | |
| 274 | check_result(R,ER,Res). | |
| 275 | ||
| 276 | test_path_non_failing(Start,Path,Goal,WithInv,Timeout,R) :- | |
| 277 | (test_path(Start,Path,Goal,WithInv,Timeout,R) -> true; R = false). | |
| 278 | ||
| 279 | check_result(R,ER,Res) :- | |
| 280 | (nonvar(R) -> Res=R | |
| 281 | ; ER = success -> Res = 'ok' | |
| 282 | ; Res = 'unknown'). | |
| 283 | ||
| 284 | % conjoin a predicate with invariant and properties if specified | |
| 285 | get_conj_inv_predicate(Preds,FindInvViolations,StartPred) :- | |
| 286 | (FindInvViolations==1 -> | |
| 287 | b_get_invariant_from_machine(Inv), | |
| 288 | b_get_properties_from_machine(Prop), | |
| 289 | conjunct_predicates([Prop,Inv|Preds],StartPred) % TO DO: project away | |
| 290 | ; otherwise -> | |
| 291 | (FindInvViolations==0 -> | |
| 292 | true | |
| 293 | ; otherwise -> | |
| 294 | add_internal_error('Illegal flag: ',get_conj_inv_predicate(Preds,FindInvViolations,StartPred)) | |
| 295 | ), | |
| 296 | conjunct_predicates(Preds,StartPred) | |
| 297 | ). | |
| 298 | ||
| 299 | %reads_writes_intersection(Writes, Reads, ComputedResult, PositiveResult, Res) :- | |
| 300 | % (ord_intersect(Writes,Reads) -> Res=PositiveResult | |
| 301 | % ; otherwise -> Res=ComputedResult ). | |
| 302 | ||
| 303 | tcltk_enabling_analysis(list([list(['Origin'|Ops])|Result]),POR) :- | |
| 304 | get_preference(timeout_cbc_analysis,Timeout), | |
| 305 | %% compute_dependendency_relation_of_all_events_in_the_model(1,por(ample_sets,0,0,0),EnableGraph), | |
| 306 | %% suitable_for_por(EnableGraph,POR), | |
| 307 | POR = option_disabled, | |
| 308 | findall(Op, b_top_level_operation(Op), Ops), | |
| 309 | findall(list([OpName1|EnableList]), | |
| 310 | (b_top_level_operation(OpName1), | |
| 311 | findall(Enable,enable_analysis(OpName1,_OpName2,1,1,Timeout,Enable),EnableList)), | |
| 312 | Result) | |
| 313 | . %,print_enable_table([list(['Origin'|Ops])|Result]). | |
| 314 | ||
| 315 | %% suitable_for_por(EnGraph,Result) :- | |
| 316 | %% (not_all_reachable(EnGraph) -> | |
| 317 | %% Result=true | |
| 318 | %% ; Result=false | |
| 319 | %% ). | |
| 320 | ||
| 321 | %% not_all_reachable(EnGraph) :- | |
| 322 | %% ample_sets: vertices(EnGraph,Vertices), | |
| 323 | %% member(V,Vertices), | |
| 324 | %% \+ (ample_sets: reachable(V,EnGraph,Reachable),Reachable=Vertices). | |
| 325 | % --------------------------- Used for the ample sets (End) -----------------------------% | |
| 326 | ||
| 327 | ||
| 328 | ||
| 329 | ||
| 330 | /************************** DEPENDENCY RELATION (BEGIN) ******************************/ | |
| 331 | ||
| 332 | /* predicate which determines the dependency relations between all actions in the model, | |
| 333 | it should be called only once (prior to the model checking) */ | |
| 334 | ||
| 335 | :- dynamic enable_graph/1, dependent_act/4. | |
| 336 | ||
| 337 | compute_dependendency_relation_of_all_events_in_the_model(FindInvViolations,por(_TYPE,UseEnableGraph,Depth,_PGE),EnableGraph) :- | |
| 338 | (enable_graph(EnableGraph) -> | |
| 339 | % In case the dependency relations and the enable graph are already computed. | |
| 340 | % Case possible if the user stopped the model checking for a while (and meanwhile didn't reloaded the model) | |
| 341 | % and in case that he wants to continue the verification of the model the enable graph don't have | |
| 342 | % to be computed again. | |
| 343 | true | |
| 344 | ; otherwise -> | |
| 345 | findall(Action, b_top_level_operation(Action),Actions), | |
| 346 | sort(Actions,AllActions), | |
| 347 | retractall(enable_graph(_)), | |
| 348 | debug_println(19,'********** DETERMINE ACTION DEPENDENCIES AND ENABLE GRAPH *************'), | |
| 349 | get_preference(timeout_cbc_analysis,Timeout), | |
| 350 | cputime(T1), | |
| 351 | call_in_fresh_error_scope_for_one_solution( | |
| 352 | determine_dependency_enabling_relations(AllActions,Timeout,FindInvViolations,UseEnableGraph,Depth,EnableGraph)), | |
| 353 | cputime(T2), | |
| 354 | debug_println(19,'********** FINISHED ANALYSIS *************'), | |
| 355 | D is T2-T1, debug_format(19,'Dependency Analysis Time: ~w ms~n',[D]), | |
| 356 | assert(enable_graph(EnableGraph)) | |
| 357 | ), | |
| 358 | debug_println(9,enable_graph(EnableGraph)). | |
| 359 | ||
| 360 | determine_dependency_enabling_relations(AllActions,Timeout,FindInvViolations,UseEnableGraph,Depth,EnableGraph) :- | |
| 361 | determine_dependency_enabling_relations(AllActions,AllActions,Timeout,FindInvViolations,UseEnableGraph,Depth,Edges), | |
| 362 | (UseEnableGraph = true -> | |
| 363 | enable_graph: vertices_edges_predicates_to_egraph(AllActions,Edges,EnableGraph) | |
| 364 | ; otherwise -> % to be removed later (here we just want to compare the graph implementation's performances of enable_graph and ugraph) | |
| 365 | vertices_edges_to_ugraph(AllActions,Edges,EnableGraph) | |
| 366 | ). | |
| 367 | ||
| 368 | ||
| 369 | %determine_dependency_enabling_relations(AllActions,Timeout,FindInvViolations,Depth,EnableGraph) :- | |
| 370 | % determine_dependency_enabling_relations(AllActions,AllActions,Timeout,FindInvViolations,Depth,Edges), | |
| 371 | % enable_graph: vertices_edges_predicates_to_egraph(AllActions,Edges,EnableGraph). | |
| 372 | ||
| 373 | determine_dependency_enabling_relations([],_AllActions,_Timeout,_FindInvViolations,_UseEnableGraph,_Depth,[]). | |
| 374 | determine_dependency_enabling_relations([Act|Actions],AllActions,Timeout,FindInvViolations,UseEnableGraph,Depth,Edges) :- | |
| 375 | determine_dependency_enabling_relations1(AllActions,Act,Timeout,FindInvViolations,UseEnableGraph,Depth,Edges1), | |
| 376 | append(Edges1,Rest,Edges), | |
| 377 | determine_dependency_enabling_relations(Actions,AllActions,Timeout,FindInvViolations,UseEnableGraph,Depth,Rest). | |
| 378 | ||
| 379 | determine_dependency_enabling_relations1([],_Act,_Timeout,_FindInvViolations,_UseEnableGraph,_Depth,[]). | |
| 380 | determine_dependency_enabling_relations1([Act2|Acts],Act1,Timeout,FindInvViolations,UseEnableGraph,Depth,Result) :- | |
| 381 | ( (Act1==Act2,\+dependent_act(Act1,Act1,_Status,_)) -> | |
| 382 | assert(dependent_act(Act1,Act1,self,true)), | |
| 383 | debug_println(9,dependent_act(Act1,Act1,self,true)) | |
| 384 | ; dependent_actions_symm(Act1,Act2,FindInvViolations,Timeout,Status,Coenabled) -> | |
| 385 | assert(dependent_act(Act1,Act2,Status,Coenabled)), % the dependency relation is symmetric | |
| 386 | assert(dependent_act(Act2,Act1,Status,Coenabled)), | |
| 387 | debug_println(9,dependent_act(Act1,Act2,Status,Coenabled)) | |
| 388 | ; otherwise -> | |
| 389 | true % no new dependencies have been discovered | |
| 390 | ), | |
| 391 | (may_enable(Act1,Act2,FindInvViolations,Timeout,UseEnableGraph,Depth,Edge) -> | |
| 392 | Result = [Edge|Res1] | |
| 393 | ; otherwise -> | |
| 394 | Result = Res1 | |
| 395 | ), | |
| 396 | %compute_if_coenabled(Act1,Act2,FindInvViolations,Timeout), | |
| 397 | determine_dependency_enabling_relations1(Acts,Act1,Timeout,FindInvViolations,UseEnableGraph,Depth,Res1). | |
| 398 | ||
| 399 | may_enable(Act1,Act2,FindInvViolations,Timeout,UseEnableGraph,_Depth,Edge) :- | |
| 400 | enable_analysis(Act1,Act2,FindInvViolations,UseEnableGraph,Timeout,Enable), | |
| 401 | (memberchk(Enable,[guaranteed,possible,possible_enable]) -> | |
| 402 | (UseEnableGraph = true -> | |
| 403 | Edge = Act1-b(truth,pred,[])-Act2 | |
| 404 | ; otherwise -> | |
| 405 | Edge = Act1-Act2 | |
| 406 | ) | |
| 407 | ; Enable = predicate(Expr) -> Edge = Act1-Expr-Act2 | |
| 408 | ; is_timeout(Enable) -> Edge = Act1-Act2 % assume it is possible to enable Act2 | |
| 409 | ; otherwise -> fail | |
| 410 | ). | |
| 411 | ||
| 412 | /* | |
| 413 | dependent_actions/2 determine statically or dynamically if two actions are dependent | |
| 414 | two events/actions are syntactically dependent in the following three cases: | |
| 415 | 1. If both events modify at least one common variable. | |
| 416 | 2. Act1 modifies a variable in the guard of Act2. (Act1 can enable or disable Act2) | |
| 417 | 3. Act2 modifies a variable in the guard of Act1. (Act2 can enable or disable Act1) | |
| 418 | */ | |
| 419 | ||
| 420 | %%% Act1 and Act2 are enabled in current state State, | |
| 421 | %%% we don't have to check if both actions are enabled in | |
| 422 | %%% some state | |
| 423 | dependent_actions_symm(Act1,Act2,_FindInvViolations,_Timeout,Status,Coenabled) :- | |
| 424 | dependent_act(Act1,Act2,Status,Coenabled),!,fail. % dependent relation is already computed | |
| 425 | dependent_actions_symm(Act1,Act2,FindInvViolations,Timeout,Status,Coenabled) :- | |
| 426 | dependent_actions_coenabled(Act1,Act2,FindInvViolations,Timeout,Status,Coenabled). | |
| 427 | ||
| 428 | dependent_actions_coenabled(Act1,Act2,FindInvViolations,Timeout,Status,Coenabled) :- | |
| 429 | dependent_actions1(Act1,Act2,FindInvViolations,Timeout,Res), | |
| 430 | ( Res == '-' -> dependent_actions_coenabled(Act2,Act1,FindInvViolations,Timeout,Status,Coenabled) % Res = '-' : not checked due to symmetry | |
| 431 | ; Res == syntactic_independent -> fail | |
| 432 | ; Res == independent -> fail | |
| 433 | ; Res == self_independent -> fail | |
| 434 | ; otherwise -> | |
| 435 | get_dependency_status(Res,Status), | |
| 436 | check_if_coenabled_nonfailing(Act1,Act2,FindInvViolations,Timeout,Coenabled) | |
| 437 | ). | |
| 438 | ||
| 439 | dependent_actions(Act1,Act2,FindInvViolations,Timeout,Status) :- | |
| 440 | dependent_actions1(Act1,Act2,FindInvViolations,Timeout,Res), | |
| 441 | ( Res == '-' -> dependent_actions(Act2,Act1,FindInvViolations,Timeout,Status) % Res = '-' : not checked due to symmetry | |
| 442 | ; Res == syntactic_independent -> fail | |
| 443 | ; Res == independent -> fail | |
| 444 | ; Res == self_independent -> fail | |
| 445 | ; otherwise -> | |
| 446 | get_dependency_status(Res,Status)). | |
| 447 | ||
| 448 | ||
| 449 | get_dependency_status(race_dependent,Status) :- !,Status=race. | |
| 450 | get_dependency_status(action_dependent,Status) :- !,Status=action. | |
| 451 | get_dependency_status(guard_dependent,Status) :- !,Status=guard. | |
| 452 | get_dependency_status(guard_dependent(Pred),Status) :- !,Status=predicate(Pred). | |
| 453 | get_dependency_status(dependent,Status) :- !,Status=general. | |
| 454 | get_dependency_status(self_dependent,Status) :- !,Status=general. % not sure this is correct | |
| 455 | get_dependency_status('=',Status) :- !, Status=general. | |
| 456 | get_dependency_status(DStatus,_) :- add_error_fail(get_dependency_status, 'Unknown dependency status: ', DStatus). | |
| 457 | ||
| 458 | % currently unused | |
| 459 | % computes which events are co-enabled | |
| 460 | % co-enabled relations is reflexive and symmetric | |
| 461 | %:- dynamic coenabled/2. | |
| 462 | %compute_if_coenabled(OpName1,OpName2,FindInvViolations,Timeout) :- | |
| 463 | % (OpName1 == OpName2 -> | |
| 464 | % assert(coenabled(OpName1,OpName1)) | |
| 465 | % ;OpName2 @< OpName1 -> | |
| 466 | % true % due symmetry we skip the computation of coenabled events in that case | |
| 467 | % ;check_if_coenabled(OpName1,OpName2,FindInvViolations,Timeout) -> | |
| 468 | % assert(coenabled(OpName1,OpName2)), | |
| 469 | % assert(coenabled(OpName2,OpName1)) | |
| 470 | % ; otherwise -> % both events cannot be co-enabled | |
| 471 | % true). | |
| 472 | ||
| 473 | check_if_coenabled_nonfailing(OpName1,OpName2,FindInvViolations,Timeout,Result) :- | |
| 474 | (check_if_coenabled(OpName1,OpName2,FindInvViolations,Timeout) -> | |
| 475 | Result = true | |
| 476 | ; Result = false). | |
| 477 | ||
| 478 | check_if_coenabled(OpName1,OpName2,FindInvViolations,Timeout) :- | |
| 479 | get_guard(OpName1,PosGuard1), | |
| 480 | get_guard(OpName2,PosGuard2), | |
| 481 | conjunct_predicates([PosGuard1,PosGuard2],GuardsConj), % both events are enabled | |
| 482 | (FindInvViolations=1 -> Pred = pred(GuardsConj) ; Pred=typing(GuardsConj)), | |
| 483 | sap:testcase_predicate_timeout(Pred,Timeout,_R). | |
| 484 | ||
| 485 | /************************** DEPENDENCY RELATION (END) ******************************/ | |
| 486 | ||
| 487 | ||
| 488 | /* | |
| 489 | ||
| 490 | The meaning of the following comments here is to give an idea how to validate the results from the Enabling analysis. | |
| 491 | We use here the Linear Time Logic (proposed by Amir Pnueli) in order to give LTL-formulas to each possible table entry result that can prove that | |
| 492 | the relation results between the operations of machine M produced by the Enabling analysis are correct. For instance, | |
| 493 | if the Enabling analysis says that it is impossible operation B to be preceded by operation A in the state space of M (i.e. the result in | |
| 494 | cell (A,B) of the table is 'impossible') then this property can be expressed by the LTL-formula "G ([a] => not X e(b))" and checked by | |
| 495 | the LTL model checker of ProB. | |
| 496 | ||
| 497 | * impossible: | |
| 498 | The impossibility an action 'a' to enable action 'b' can be expressed by means of LTL-formulas as follows: | |
| 499 | "G ([a] => not X e(b))" (dis) | |
| 500 | ||
| 501 | If a disables b then (dis) should be satisfied by the model. The result of the enabling analysis | |
| 502 | returns 'impossible' in cell (a,b) of the Enabling analysis table. | |
| 503 | ||
| 504 | * guaranteed: | |
| 505 | Action 'a' guaranteed enables action 'b' if there is an execution in the state space where after 'a' follows 'b' and | |
| 506 | 'a' and 'b' are never enabled simultaneously in the same state: | |
| 507 | "G ( ([a] => X e(b)) & (not (e(a) & e(b))) )" (en) | |
| 508 | ||
| 509 | * keep: | |
| 510 | Action 'a' keeps action 'b' enabled: | |
| 511 | "(G ((e(b) & [a]) => X e(b))) or (G ((not e(b) & [a]) => X not e(b)))" (keep) | |
| 512 | */ |