1 /* Copyright (c) 2011-2022. The SimGrid Team. All rights reserved. */
3 /* This program is free software; you can redistribute it and/or modify it
4 * under the terms of the license (GNU LGPL) which comes with this package. */
6 #include "src/mc/explo/LivenessChecker.hpp"
7 #include "src/mc/Session.hpp"
8 #include "src/mc/mc_config.hpp"
9 #include "src/mc/mc_exit.hpp"
10 #include "src/mc/mc_private.hpp"
12 #include <boost/range/algorithm.hpp>
15 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_liveness, mc, "Logging specific to algorithms for liveness properties verification");
17 /********* Static functions *********/
19 namespace simgrid::mc {
21 VisitedPair::VisitedPair(int pair_num, xbt_automaton_state_t prop_state,
22 std::shared_ptr<const std::vector<int>> atomic_propositions, std::shared_ptr<State> app_state)
23 : num(pair_num), prop_state_(prop_state)
25 this->app_state_ = std::move(app_state);
26 if (not this->app_state_->get_system_state())
27 this->app_state_->set_system_state(std::make_shared<Snapshot>(pair_num));
28 this->heap_bytes_used = Api::get().get_remote_heap_bytes();
29 this->actor_count_ = mc_model_checker->get_remote_process().actors().size();
31 this->atomic_propositions = std::move(atomic_propositions);
34 static bool evaluate_label(const xbt_automaton_exp_label* l, std::vector<int> const& values)
37 case xbt_automaton_exp_label::AUT_OR:
38 return evaluate_label(l->u.or_and.left_exp, values) || evaluate_label(l->u.or_and.right_exp, values);
39 case xbt_automaton_exp_label::AUT_AND:
40 return evaluate_label(l->u.or_and.left_exp, values) && evaluate_label(l->u.or_and.right_exp, values);
41 case xbt_automaton_exp_label::AUT_NOT:
42 return not evaluate_label(l->u.exp_not, values);
43 case xbt_automaton_exp_label::AUT_PREDICAT:
44 return values.at(Api::get().compare_automaton_exp_label(l)) != 0;
45 case xbt_automaton_exp_label::AUT_ONE:
48 xbt_die("Unexpected value for automaton");
52 Pair::Pair(unsigned long expanded_pairs) : num(expanded_pairs) {}
54 std::shared_ptr<const std::vector<int>> LivenessChecker::get_proposition_values() const
56 auto values = Api::get().automaton_propositional_symbol_evaluate();
57 return std::make_shared<const std::vector<int>>(std::move(values));
60 std::shared_ptr<VisitedPair> LivenessChecker::insert_acceptance_pair(simgrid::mc::Pair* pair)
63 std::make_shared<VisitedPair>(pair->num, pair->prop_state_, pair->atomic_propositions, pair->app_state_);
65 auto [res_begin, res_end] = boost::range::equal_range(acceptance_pairs_, new_pair.get(), Api::get().compare_pair());
67 if (pair->search_cycle)
68 for (auto i = res_begin; i != res_end; ++i) {
69 std::shared_ptr<simgrid::mc::VisitedPair> const& pair_test = *i;
70 if (xbt_automaton_state_compare(pair_test->prop_state_, new_pair->prop_state_) != 0 ||
71 *(pair_test->atomic_propositions) != *(new_pair->atomic_propositions) ||
72 not Api::get().snapshot_equal(pair_test->app_state_->get_system_state(),
73 new_pair->app_state_->get_system_state()))
75 XBT_INFO("Pair %d already reached (equal to pair %d) !", new_pair->num, pair_test->num);
76 exploration_stack_.pop_back();
77 if (dot_output != nullptr)
78 fprintf(dot_output, "\"%d\" -> \"%d\" [%s];\n", this->previous_pair_, pair_test->num,
79 this->previous_request_.c_str());
83 acceptance_pairs_.insert(res_begin, new_pair);
87 void LivenessChecker::remove_acceptance_pair(int pair_num)
89 for (auto i = acceptance_pairs_.begin(); i != acceptance_pairs_.end(); ++i)
90 if ((*i)->num == pair_num) {
91 acceptance_pairs_.erase(i);
96 void LivenessChecker::replay()
98 XBT_DEBUG("**** Begin Replay ****");
100 /* Intermediate backtracking */
101 if (_sg_mc_checkpoint > 0) {
102 const Pair* pair = exploration_stack_.back().get();
103 if (const auto* system_state = pair->app_state_->get_system_state()) {
104 Api::get().restore_state(system_state);
109 get_session().restore_initial_state();
111 /* Traverse the stack from the initial state and re-execute the transitions */
113 for (std::shared_ptr<Pair> const& pair : exploration_stack_) {
114 if (pair == exploration_stack_.back())
117 std::shared_ptr<State> state = pair->app_state_;
119 if (pair->exploration_started) {
120 state->get_transition()->replay();
121 XBT_DEBUG("Replay (depth = %d) : %s (%p)", depth, state->get_transition()->to_string().c_str(), state.get());
124 /* Update statistics */
125 visited_pairs_count_++;
128 XBT_DEBUG("**** End Replay ****");
132 * @brief Checks whether a given pair has already been visited by the algorithm.
134 int LivenessChecker::insert_visited_pair(std::shared_ptr<VisitedPair> visited_pair, simgrid::mc::Pair* pair)
136 if (_sg_mc_max_visited_states == 0)
139 if (visited_pair == nullptr)
141 std::make_shared<VisitedPair>(pair->num, pair->prop_state_, pair->atomic_propositions, pair->app_state_);
143 auto [range_begin, range_end] =
144 boost::range::equal_range(visited_pairs_, visited_pair.get(), Api::get().compare_pair());
146 for (auto i = range_begin; i != range_end; ++i) {
147 const VisitedPair* pair_test = i->get();
148 if (xbt_automaton_state_compare(pair_test->prop_state_, visited_pair->prop_state_) != 0 ||
149 *(pair_test->atomic_propositions) != *(visited_pair->atomic_propositions) ||
150 not Api::get().snapshot_equal(pair_test->app_state_->get_system_state(),
151 visited_pair->app_state_->get_system_state()))
153 if (pair_test->other_num == -1)
154 visited_pair->other_num = pair_test->num;
156 visited_pair->other_num = pair_test->other_num;
157 if (dot_output == nullptr)
158 XBT_DEBUG("Pair %d already visited ! (equal to pair %d)", visited_pair->num, pair_test->num);
160 XBT_DEBUG("Pair %d already visited ! (equal to pair %d (pair %d in dot_output))", visited_pair->num,
161 pair_test->num, visited_pair->other_num);
162 (*i) = std::move(visited_pair);
163 return (*i)->other_num;
166 visited_pairs_.insert(range_begin, std::move(visited_pair));
167 this->purge_visited_pairs();
171 void LivenessChecker::purge_visited_pairs()
173 if (_sg_mc_max_visited_states != 0 && visited_pairs_.size() > (std::size_t)_sg_mc_max_visited_states) {
174 // Remove the oldest entry with a linear search:
175 visited_pairs_.erase(
176 boost::min_element(visited_pairs_, [](std::shared_ptr<VisitedPair> const a,
177 std::shared_ptr<VisitedPair> const& b) { return a->num < b->num; }));
181 LivenessChecker::LivenessChecker(Session* session) : Exploration(session) {}
183 RecordTrace LivenessChecker::get_record_trace() // override
186 for (std::shared_ptr<Pair> const& pair : exploration_stack_)
187 res.push_back(pair->app_state_->get_transition());
191 void LivenessChecker::log_state() // override
193 XBT_INFO("Expanded pairs = %lu", expanded_pairs_count_);
194 XBT_INFO("Visited pairs = %lu", visited_pairs_count_);
195 XBT_INFO("Executed transitions = %lu", Transition::get_executed_transitions());
198 void LivenessChecker::show_acceptance_cycle(std::size_t depth)
200 XBT_INFO("*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*");
201 XBT_INFO("| ACCEPTANCE CYCLE |");
202 XBT_INFO("*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*");
203 XBT_INFO("Counter-example that violates formula:");
204 for (auto const& s : this->get_textual_trace())
205 XBT_INFO(" %s", s.c_str());
206 XBT_INFO("Path = %s", get_record_trace().to_string().c_str());
208 XBT_INFO("Counter-example depth: %zu", depth);
211 std::vector<std::string> LivenessChecker::get_textual_trace() // override
213 std::vector<std::string> trace;
214 for (std::shared_ptr<Pair> const& pair : exploration_stack_)
215 trace.push_back(pair->app_state_->get_transition()->to_string());
220 std::shared_ptr<Pair> LivenessChecker::create_pair(const Pair* current_pair, xbt_automaton_state_t state,
221 std::shared_ptr<const std::vector<int>> propositions)
223 ++expanded_pairs_count_;
224 auto next_pair = std::make_shared<Pair>(expanded_pairs_count_);
225 next_pair->prop_state_ = state;
226 next_pair->app_state_ = std::make_shared<State>(get_session());
227 next_pair->atomic_propositions = std::move(propositions);
229 next_pair->depth = current_pair->depth + 1;
231 next_pair->depth = 1;
232 /* Add all enabled actors to the interleave set of the initial state */
233 for (auto const& [aid, _] : next_pair->app_state_->get_actors_list())
234 if (next_pair->app_state_->is_actor_enabled(aid))
235 next_pair->app_state_->mark_todo(aid);
237 next_pair->requests = next_pair->app_state_->count_todo();
238 /* FIXME : get search_cycle value for each accepting state */
239 if (next_pair->prop_state_->type == 1 || (current_pair && current_pair->search_cycle))
240 next_pair->search_cycle = true;
242 next_pair->search_cycle = false;
246 void LivenessChecker::backtrack()
248 /* Traverse the stack backwards until a pair with a non empty interleave
249 set is found, deleting all the pairs that have it empty in the way. */
250 while (not exploration_stack_.empty()) {
251 std::shared_ptr<simgrid::mc::Pair> current_pair = exploration_stack_.back();
252 exploration_stack_.pop_back();
253 if (current_pair->requests > 0) {
254 /* We found a backtracking point */
255 XBT_DEBUG("Backtracking to depth %d", current_pair->depth);
256 exploration_stack_.push_back(std::move(current_pair));
258 XBT_DEBUG("Backtracking done");
261 XBT_DEBUG("Delete pair %d at depth %d", current_pair->num, current_pair->depth);
262 if (current_pair->prop_state_->type == 1)
263 this->remove_acceptance_pair(current_pair->num);
268 void LivenessChecker::run()
270 XBT_INFO("Check the liveness property %s", _sg_mc_property_file.get().c_str());
271 Api::get().automaton_load(_sg_mc_property_file.get().c_str());
273 XBT_DEBUG("Starting the liveness algorithm");
274 get_session().take_initial_snapshot();
277 this->previous_pair_ = 0;
279 std::shared_ptr<const std::vector<int>> propos = this->get_proposition_values();
281 // For each initial state of the property automaton, push a
282 // (application_state, automaton_state) pair to the exploration stack:
283 auto automaton_stack = Api::get().get_automaton_state();
284 for (auto* automaton_state : automaton_stack) {
285 if (automaton_state->type == -1)
286 exploration_stack_.push_back(this->create_pair(nullptr, automaton_state, propos));
289 /* Actually run the double DFS search for counter-examples */
290 while (not exploration_stack_.empty()) {
291 std::shared_ptr<Pair> current_pair = exploration_stack_.back();
293 /* Update current state in buchi automaton */
294 Api::get().set_property_automaton(current_pair->prop_state_);
297 "********************* ( Depth = %d, search_cycle = %d, interleave size = %zu, pair_num = %d, requests = %d)",
298 current_pair->depth, current_pair->search_cycle, current_pair->app_state_->count_todo(), current_pair->num,
299 current_pair->requests);
301 if (current_pair->requests == 0) {
306 std::shared_ptr<VisitedPair> reached_pair;
307 if (current_pair->prop_state_->type == 1 && not current_pair->exploration_started) {
308 reached_pair = this->insert_acceptance_pair(current_pair.get());
309 if (reached_pair == nullptr) {
310 this->show_acceptance_cycle(current_pair->depth);
311 throw LivenessError();
315 /* Pair already visited ? stop the exploration on the current path */
316 if (not current_pair->exploration_started) {
317 int visited_num = this->insert_visited_pair(reached_pair, current_pair.get());
318 if (visited_num != -1) {
319 if (dot_output != nullptr) {
320 fprintf(dot_output, "\"%d\" -> \"%d\" [%s];\n", this->previous_pair_, visited_num,
321 this->previous_request_.c_str());
324 XBT_DEBUG("Pair already visited (equal to pair %d), exploration on the current path stopped.", visited_num);
325 current_pair->requests = 0;
331 current_pair->app_state_->execute_next(current_pair->app_state_->next_transition());
332 XBT_DEBUG("Execute: %s", current_pair->app_state_->get_transition()->to_string().c_str());
334 if (dot_output != nullptr) {
335 if (this->previous_pair_ != 0 && this->previous_pair_ != current_pair->num) {
336 fprintf(dot_output, "\"%d\" -> \"%d\" [%s];\n", this->previous_pair_, current_pair->num,
337 this->previous_request_.c_str());
338 this->previous_request_.clear();
340 this->previous_pair_ = current_pair->num;
341 this->previous_request_ = current_pair->app_state_->get_transition()->dot_string();
342 if (current_pair->search_cycle)
343 fprintf(dot_output, "%d [shape=doublecircle];\n", current_pair->num);
347 if (not current_pair->exploration_started)
348 visited_pairs_count_++;
350 current_pair->requests--;
351 current_pair->exploration_started = true;
353 /* Get values of atomic propositions (variables used in the property formula) */
354 std::shared_ptr<const std::vector<int>> prop_values = this->get_proposition_values();
356 // For each enabled transition in the property automaton, push a
357 // (application_state, automaton_state) pair to the exploration stack:
358 for (int i = xbt_dynar_length(current_pair->prop_state_->out) - 1; i >= 0; i--) {
359 const auto* transition_succ_label = Api::get().get_automaton_transition_label(current_pair->prop_state_->out, i);
360 auto* transition_succ_dst = Api::get().get_automaton_transition_dst(current_pair->prop_state_->out, i);
361 if (evaluate_label(transition_succ_label, *prop_values))
362 exploration_stack_.push_back(this->create_pair(current_pair.get(), transition_succ_dst, prop_values));
366 XBT_INFO("No property violation found.");
370 Exploration* create_liveness_checker(Session* session)
372 return new LivenessChecker(session);
375 } // namespace simgrid::mc