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 *********/
22 VisitedPair::VisitedPair(int pair_num, xbt_automaton_state_t automaton_state,
23 std::shared_ptr<const std::vector<int>> atomic_propositions,
24 std::shared_ptr<State> graph_state)
25 : num(pair_num), automaton_state(automaton_state)
27 this->graph_state = std::move(graph_state);
28 if (not this->graph_state->get_system_state())
29 this->graph_state->set_system_state(std::make_shared<Snapshot>(pair_num));
30 this->heap_bytes_used = Api::get().get_remote_heap_bytes();
31 this->actors_count = Api::get().get_actors().size();
33 this->atomic_propositions = std::move(atomic_propositions);
36 static bool evaluate_label(const xbt_automaton_exp_label* l, std::vector<int> const& values)
39 case xbt_automaton_exp_label::AUT_OR:
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_AND:
42 return evaluate_label(l->u.or_and.left_exp, values) && evaluate_label(l->u.or_and.right_exp, values);
43 case xbt_automaton_exp_label::AUT_NOT:
44 return not evaluate_label(l->u.exp_not, values);
45 case xbt_automaton_exp_label::AUT_PREDICAT:
46 return values.at(Api::get().compare_automaton_exp_label(l)) != 0;
47 case xbt_automaton_exp_label::AUT_ONE:
50 xbt_die("Unexpected value for automaton");
54 Pair::Pair(unsigned long expanded_pairs) : num(expanded_pairs) {}
56 std::shared_ptr<const std::vector<int>> LivenessChecker::get_proposition_values() const
58 auto values = Api::get().automaton_propositional_symbol_evaluate();
59 return std::make_shared<const std::vector<int>>(std::move(values));
62 std::shared_ptr<VisitedPair> LivenessChecker::insert_acceptance_pair(simgrid::mc::Pair* pair)
65 std::make_shared<VisitedPair>(pair->num, pair->automaton_state, pair->atomic_propositions, pair->graph_state);
67 auto [res_begin, res_end] = boost::range::equal_range(acceptance_pairs_, new_pair.get(), Api::get().compare_pair());
69 if (pair->search_cycle)
70 for (auto i = res_begin; i != res_end; ++i) {
71 std::shared_ptr<simgrid::mc::VisitedPair> const& pair_test = *i;
72 if (xbt_automaton_state_compare(pair_test->automaton_state, new_pair->automaton_state) != 0 ||
73 *(pair_test->atomic_propositions) != *(new_pair->atomic_propositions) ||
74 not Api::get().snapshot_equal(pair_test->graph_state->get_system_state(),
75 new_pair->graph_state->get_system_state()))
77 XBT_INFO("Pair %d already reached (equal to pair %d) !", new_pair->num, pair_test->num);
78 exploration_stack_.pop_back();
79 if (dot_output != nullptr)
80 fprintf(dot_output, "\"%d\" -> \"%d\" [%s];\n", this->previous_pair_, pair_test->num,
81 this->previous_request_.c_str());
85 acceptance_pairs_.insert(res_begin, new_pair);
89 void LivenessChecker::remove_acceptance_pair(int pair_num)
91 for (auto i = acceptance_pairs_.begin(); i != acceptance_pairs_.end(); ++i)
92 if ((*i)->num == pair_num) {
93 acceptance_pairs_.erase(i);
98 void LivenessChecker::replay()
100 XBT_DEBUG("**** Begin Replay ****");
102 /* Intermediate backtracking */
103 if (_sg_mc_checkpoint > 0) {
104 const Pair* pair = exploration_stack_.back().get();
105 if (const auto* system_state = pair->graph_state->get_system_state()) {
106 Api::get().restore_state(system_state);
111 get_session().restore_initial_state();
113 /* Traverse the stack from the initial state and re-execute the transitions */
115 for (std::shared_ptr<Pair> const& pair : exploration_stack_) {
116 if (pair == exploration_stack_.back())
119 std::shared_ptr<State> state = pair->graph_state;
121 if (pair->exploration_started) {
122 state->get_transition()->replay();
123 XBT_DEBUG("Replay (depth = %d) : %s (%p)", depth, state->get_transition()->to_string().c_str(), state.get());
126 /* Update statistics */
127 visited_pairs_count_++;
130 XBT_DEBUG("**** End Replay ****");
134 * @brief Checks whether a given pair has already been visited by the algorithm.
136 int LivenessChecker::insert_visited_pair(std::shared_ptr<VisitedPair> visited_pair, simgrid::mc::Pair* pair)
138 if (_sg_mc_max_visited_states == 0)
141 if (visited_pair == nullptr)
143 std::make_shared<VisitedPair>(pair->num, pair->automaton_state, pair->atomic_propositions, pair->graph_state);
145 auto [range_begin, range_end] =
146 boost::range::equal_range(visited_pairs_, visited_pair.get(), Api::get().compare_pair());
148 for (auto i = range_begin; i != range_end; ++i) {
149 const VisitedPair* pair_test = i->get();
150 if (xbt_automaton_state_compare(pair_test->automaton_state, visited_pair->automaton_state) != 0 ||
151 *(pair_test->atomic_propositions) != *(visited_pair->atomic_propositions) ||
152 not Api::get().snapshot_equal(pair_test->graph_state->get_system_state(),
153 visited_pair->graph_state->get_system_state()))
155 if (pair_test->other_num == -1)
156 visited_pair->other_num = pair_test->num;
158 visited_pair->other_num = pair_test->other_num;
159 if (dot_output == nullptr)
160 XBT_DEBUG("Pair %d already visited ! (equal to pair %d)", visited_pair->num, pair_test->num);
162 XBT_DEBUG("Pair %d already visited ! (equal to pair %d (pair %d in dot_output))", visited_pair->num,
163 pair_test->num, visited_pair->other_num);
164 (*i) = std::move(visited_pair);
165 return (*i)->other_num;
168 visited_pairs_.insert(range_begin, std::move(visited_pair));
169 this->purge_visited_pairs();
173 void LivenessChecker::purge_visited_pairs()
175 if (_sg_mc_max_visited_states != 0 && visited_pairs_.size() > (std::size_t)_sg_mc_max_visited_states) {
176 // Remove the oldest entry with a linear search:
177 visited_pairs_.erase(
178 boost::min_element(visited_pairs_, [](std::shared_ptr<VisitedPair> const a,
179 std::shared_ptr<VisitedPair> const& b) { return a->num < b->num; }));
183 LivenessChecker::LivenessChecker(Session* session) : Exploration(session) {}
185 RecordTrace LivenessChecker::get_record_trace() // override
188 for (std::shared_ptr<Pair> const& pair : exploration_stack_)
189 res.push_back(pair->graph_state->get_transition());
193 void LivenessChecker::log_state() // override
195 XBT_INFO("Expanded pairs = %lu", expanded_pairs_count_);
196 XBT_INFO("Visited pairs = %lu", visited_pairs_count_);
197 XBT_INFO("Executed transitions = %lu", Transition::get_executed_transitions());
200 void LivenessChecker::show_acceptance_cycle(std::size_t depth)
202 XBT_INFO("*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*");
203 XBT_INFO("| ACCEPTANCE CYCLE |");
204 XBT_INFO("*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*");
205 XBT_INFO("Counter-example that violates formula:");
206 for (auto const& s : this->get_textual_trace())
207 XBT_INFO(" %s", s.c_str());
208 XBT_INFO("Path = %s", get_record_trace().to_string().c_str());
210 XBT_INFO("Counter-example depth: %zu", depth);
213 std::vector<std::string> LivenessChecker::get_textual_trace() // override
215 std::vector<std::string> trace;
216 for (std::shared_ptr<Pair> const& pair : exploration_stack_)
217 trace.push_back(pair->graph_state->get_transition()->to_string());
222 std::shared_ptr<Pair> LivenessChecker::create_pair(const Pair* current_pair, xbt_automaton_state_t state,
223 std::shared_ptr<const std::vector<int>> propositions)
225 ++expanded_pairs_count_;
226 auto next_pair = std::make_shared<Pair>(expanded_pairs_count_);
227 next_pair->automaton_state = state;
228 next_pair->graph_state = std::make_shared<State>();
229 next_pair->atomic_propositions = std::move(propositions);
231 next_pair->depth = current_pair->depth + 1;
233 next_pair->depth = 1;
234 /* Add all enabled actors to the interleave set of the initial state */
235 for (auto& act : Api::get().get_actors()) {
236 auto actor = act.copy.get_buffer();
237 if (get_session().actor_is_enabled(actor->get_pid()))
238 next_pair->graph_state->mark_todo(actor->get_pid());
241 next_pair->requests = next_pair->graph_state->count_todo();
242 /* FIXME : get search_cycle value for each accepting state */
243 if (next_pair->automaton_state->type == 1 || (current_pair && current_pair->search_cycle))
244 next_pair->search_cycle = true;
246 next_pair->search_cycle = false;
250 void LivenessChecker::backtrack()
252 /* Traverse the stack backwards until a pair with a non empty interleave
253 set is found, deleting all the pairs that have it empty in the way. */
254 while (not exploration_stack_.empty()) {
255 std::shared_ptr<simgrid::mc::Pair> current_pair = exploration_stack_.back();
256 exploration_stack_.pop_back();
257 if (current_pair->requests > 0) {
258 /* We found a backtracking point */
259 XBT_DEBUG("Backtracking to depth %d", current_pair->depth);
260 exploration_stack_.push_back(std::move(current_pair));
262 XBT_DEBUG("Backtracking done");
265 XBT_DEBUG("Delete pair %d at depth %d", current_pair->num, current_pair->depth);
266 if (current_pair->automaton_state->type == 1)
267 this->remove_acceptance_pair(current_pair->num);
272 void LivenessChecker::run()
274 XBT_INFO("Check the liveness property %s", _sg_mc_property_file.get().c_str());
275 Api::get().automaton_load(_sg_mc_property_file.get().c_str());
277 XBT_DEBUG("Starting the liveness algorithm");
278 get_session().take_initial_snapshot();
281 this->previous_pair_ = 0;
283 std::shared_ptr<const std::vector<int>> propos = this->get_proposition_values();
285 // For each initial state of the property automaton, push a
286 // (application_state, automaton_state) pair to the exploration stack:
287 auto automaton_stack = Api::get().get_automaton_state();
288 for (auto* automaton_state : automaton_stack) {
289 if (automaton_state->type == -1)
290 exploration_stack_.push_back(this->create_pair(nullptr, automaton_state, propos));
293 /* Actually run the double DFS search for counter-examples */
294 while (not exploration_stack_.empty()) {
295 std::shared_ptr<Pair> current_pair = exploration_stack_.back();
297 /* Update current state in buchi automaton */
298 Api::get().set_property_automaton(current_pair->automaton_state);
301 "********************* ( Depth = %d, search_cycle = %d, interleave size = %zu, pair_num = %d, requests = %d)",
302 current_pair->depth, current_pair->search_cycle, current_pair->graph_state->count_todo(), current_pair->num,
303 current_pair->requests);
305 if (current_pair->requests == 0) {
310 std::shared_ptr<VisitedPair> reached_pair;
311 if (current_pair->automaton_state->type == 1 && not current_pair->exploration_started) {
312 reached_pair = this->insert_acceptance_pair(current_pair.get());
313 if (reached_pair == nullptr) {
314 this->show_acceptance_cycle(current_pair->depth);
315 throw LivenessError();
319 /* Pair already visited ? stop the exploration on the current path */
320 if (not current_pair->exploration_started) {
321 int visited_num = this->insert_visited_pair(reached_pair, current_pair.get());
322 if (visited_num != -1) {
323 if (dot_output != nullptr) {
324 fprintf(dot_output, "\"%d\" -> \"%d\" [%s];\n", this->previous_pair_, visited_num,
325 this->previous_request_.c_str());
328 XBT_DEBUG("Pair already visited (equal to pair %d), exploration on the current path stopped.", visited_num);
329 current_pair->requests = 0;
335 current_pair->graph_state->execute_next(current_pair->graph_state->next_transition());
336 XBT_DEBUG("Execute: %s", current_pair->graph_state->get_transition()->to_string().c_str());
338 if (dot_output != nullptr) {
339 if (this->previous_pair_ != 0 && this->previous_pair_ != current_pair->num) {
340 fprintf(dot_output, "\"%d\" -> \"%d\" [%s];\n", this->previous_pair_, current_pair->num,
341 this->previous_request_.c_str());
342 this->previous_request_.clear();
344 this->previous_pair_ = current_pair->num;
345 this->previous_request_ = current_pair->graph_state->get_transition()->dot_string();
346 if (current_pair->search_cycle)
347 fprintf(dot_output, "%d [shape=doublecircle];\n", current_pair->num);
351 if (not current_pair->exploration_started)
352 visited_pairs_count_++;
354 current_pair->requests--;
355 current_pair->exploration_started = true;
357 /* Get values of atomic propositions (variables used in the property formula) */
358 std::shared_ptr<const std::vector<int>> prop_values = this->get_proposition_values();
360 // For each enabled transition in the property automaton, push a
361 // (application_state, automaton_state) pair to the exploration stack:
362 for (int i = xbt_dynar_length(current_pair->automaton_state->out) - 1; i >= 0; i--) {
363 auto transition_succ_label = Api::get().get_automaton_transition_label(current_pair->automaton_state->out, i);
364 auto transition_succ_dst = Api::get().get_automaton_transition_dst(current_pair->automaton_state->out, i);
365 if (evaluate_label(transition_succ_label, *prop_values))
366 exploration_stack_.push_back(this->create_pair(current_pair.get(), transition_succ_dst, prop_values));
370 XBT_INFO("No property violation found.");
374 Exploration* create_liveness_checker(Session* session)
376 return new LivenessChecker(session);
380 } // namespace simgrid