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 automaton_state,
22 std::shared_ptr<const std::vector<int>> atomic_propositions,
23 std::shared_ptr<State> graph_state)
24 : num(pair_num), automaton_state(automaton_state)
26 this->graph_state = std::move(graph_state);
27 if (not this->graph_state->get_system_state())
28 this->graph_state->set_system_state(std::make_shared<Snapshot>(pair_num));
29 this->heap_bytes_used = Api::get().get_remote_heap_bytes();
30 this->actors_count = Api::get().get_actors().size();
32 this->atomic_propositions = std::move(atomic_propositions);
35 static bool evaluate_label(const xbt_automaton_exp_label* l, std::vector<int> const& values)
38 case xbt_automaton_exp_label::AUT_OR:
39 return evaluate_label(l->u.or_and.left_exp, values) || evaluate_label(l->u.or_and.right_exp, values);
40 case xbt_automaton_exp_label::AUT_AND:
41 return evaluate_label(l->u.or_and.left_exp, values) && evaluate_label(l->u.or_and.right_exp, values);
42 case xbt_automaton_exp_label::AUT_NOT:
43 return not evaluate_label(l->u.exp_not, values);
44 case xbt_automaton_exp_label::AUT_PREDICAT:
45 return values.at(Api::get().compare_automaton_exp_label(l)) != 0;
46 case xbt_automaton_exp_label::AUT_ONE:
49 xbt_die("Unexpected value for automaton");
53 Pair::Pair(unsigned long expanded_pairs) : num(expanded_pairs) {}
55 std::shared_ptr<const std::vector<int>> LivenessChecker::get_proposition_values() const
57 auto values = Api::get().automaton_propositional_symbol_evaluate();
58 return std::make_shared<const std::vector<int>>(std::move(values));
61 std::shared_ptr<VisitedPair> LivenessChecker::insert_acceptance_pair(simgrid::mc::Pair* pair)
64 std::make_shared<VisitedPair>(pair->num, pair->automaton_state, pair->atomic_propositions, pair->graph_state);
66 auto [res_begin, res_end] = boost::range::equal_range(acceptance_pairs_, new_pair.get(), Api::get().compare_pair());
68 if (pair->search_cycle)
69 for (auto i = res_begin; i != res_end; ++i) {
70 std::shared_ptr<simgrid::mc::VisitedPair> const& pair_test = *i;
71 if (xbt_automaton_state_compare(pair_test->automaton_state, new_pair->automaton_state) != 0 ||
72 *(pair_test->atomic_propositions) != *(new_pair->atomic_propositions) ||
73 not Api::get().snapshot_equal(pair_test->graph_state->get_system_state(),
74 new_pair->graph_state->get_system_state()))
76 XBT_INFO("Pair %d already reached (equal to pair %d) !", new_pair->num, pair_test->num);
77 exploration_stack_.pop_back();
78 if (dot_output != nullptr)
79 fprintf(dot_output, "\"%d\" -> \"%d\" [%s];\n", this->previous_pair_, pair_test->num,
80 this->previous_request_.c_str());
84 acceptance_pairs_.insert(res_begin, new_pair);
88 void LivenessChecker::remove_acceptance_pair(int pair_num)
90 for (auto i = acceptance_pairs_.begin(); i != acceptance_pairs_.end(); ++i)
91 if ((*i)->num == pair_num) {
92 acceptance_pairs_.erase(i);
97 void LivenessChecker::replay()
99 XBT_DEBUG("**** Begin Replay ****");
101 /* Intermediate backtracking */
102 if (_sg_mc_checkpoint > 0) {
103 const Pair* pair = exploration_stack_.back().get();
104 if (const auto* system_state = pair->graph_state->get_system_state()) {
105 Api::get().restore_state(system_state);
110 get_session().restore_initial_state();
112 /* Traverse the stack from the initial state and re-execute the transitions */
114 for (std::shared_ptr<Pair> const& pair : exploration_stack_) {
115 if (pair == exploration_stack_.back())
118 std::shared_ptr<State> state = pair->graph_state;
120 if (pair->exploration_started) {
121 state->get_transition()->replay();
122 XBT_DEBUG("Replay (depth = %d) : %s (%p)", depth, state->get_transition()->to_string().c_str(), state.get());
125 /* Update statistics */
126 visited_pairs_count_++;
129 XBT_DEBUG("**** End Replay ****");
133 * @brief Checks whether a given pair has already been visited by the algorithm.
135 int LivenessChecker::insert_visited_pair(std::shared_ptr<VisitedPair> visited_pair, simgrid::mc::Pair* pair)
137 if (_sg_mc_max_visited_states == 0)
140 if (visited_pair == nullptr)
142 std::make_shared<VisitedPair>(pair->num, pair->automaton_state, pair->atomic_propositions, pair->graph_state);
144 auto [range_begin, range_end] =
145 boost::range::equal_range(visited_pairs_, visited_pair.get(), Api::get().compare_pair());
147 for (auto i = range_begin; i != range_end; ++i) {
148 const VisitedPair* pair_test = i->get();
149 if (xbt_automaton_state_compare(pair_test->automaton_state, visited_pair->automaton_state) != 0 ||
150 *(pair_test->atomic_propositions) != *(visited_pair->atomic_propositions) ||
151 not Api::get().snapshot_equal(pair_test->graph_state->get_system_state(),
152 visited_pair->graph_state->get_system_state()))
154 if (pair_test->other_num == -1)
155 visited_pair->other_num = pair_test->num;
157 visited_pair->other_num = pair_test->other_num;
158 if (dot_output == nullptr)
159 XBT_DEBUG("Pair %d already visited ! (equal to pair %d)", visited_pair->num, pair_test->num);
161 XBT_DEBUG("Pair %d already visited ! (equal to pair %d (pair %d in dot_output))", visited_pair->num,
162 pair_test->num, visited_pair->other_num);
163 (*i) = std::move(visited_pair);
164 return (*i)->other_num;
167 visited_pairs_.insert(range_begin, std::move(visited_pair));
168 this->purge_visited_pairs();
172 void LivenessChecker::purge_visited_pairs()
174 if (_sg_mc_max_visited_states != 0 && visited_pairs_.size() > (std::size_t)_sg_mc_max_visited_states) {
175 // Remove the oldest entry with a linear search:
176 visited_pairs_.erase(
177 boost::min_element(visited_pairs_, [](std::shared_ptr<VisitedPair> const a,
178 std::shared_ptr<VisitedPair> const& b) { return a->num < b->num; }));
182 LivenessChecker::LivenessChecker(Session* session) : Exploration(session) {}
184 RecordTrace LivenessChecker::get_record_trace() // override
187 for (std::shared_ptr<Pair> const& pair : exploration_stack_)
188 res.push_back(pair->graph_state->get_transition());
192 void LivenessChecker::log_state() // override
194 XBT_INFO("Expanded pairs = %lu", expanded_pairs_count_);
195 XBT_INFO("Visited pairs = %lu", visited_pairs_count_);
196 XBT_INFO("Executed transitions = %lu", Transition::get_executed_transitions());
199 void LivenessChecker::show_acceptance_cycle(std::size_t depth)
201 XBT_INFO("*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*");
202 XBT_INFO("| ACCEPTANCE CYCLE |");
203 XBT_INFO("*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*");
204 XBT_INFO("Counter-example that violates formula:");
205 for (auto const& s : this->get_textual_trace())
206 XBT_INFO(" %s", s.c_str());
207 XBT_INFO("Path = %s", get_record_trace().to_string().c_str());
209 XBT_INFO("Counter-example depth: %zu", depth);
212 std::vector<std::string> LivenessChecker::get_textual_trace() // override
214 std::vector<std::string> trace;
215 for (std::shared_ptr<Pair> const& pair : exploration_stack_)
216 trace.push_back(pair->graph_state->get_transition()->to_string());
221 std::shared_ptr<Pair> LivenessChecker::create_pair(const Pair* current_pair, xbt_automaton_state_t state,
222 std::shared_ptr<const std::vector<int>> propositions)
224 ++expanded_pairs_count_;
225 auto next_pair = std::make_shared<Pair>(expanded_pairs_count_);
226 next_pair->automaton_state = state;
227 next_pair->graph_state = std::make_shared<State>();
228 next_pair->atomic_propositions = std::move(propositions);
230 next_pair->depth = current_pair->depth + 1;
232 next_pair->depth = 1;
233 /* Add all enabled actors to the interleave set of the initial state */
234 for (auto& act : Api::get().get_actors()) {
235 auto actor = act.copy.get_buffer();
236 if (get_session().actor_is_enabled(actor->get_pid()))
237 next_pair->graph_state->mark_todo(actor->get_pid());
240 next_pair->requests = next_pair->graph_state->count_todo();
241 /* FIXME : get search_cycle value for each accepting state */
242 if (next_pair->automaton_state->type == 1 || (current_pair && current_pair->search_cycle))
243 next_pair->search_cycle = true;
245 next_pair->search_cycle = false;
249 void LivenessChecker::backtrack()
251 /* Traverse the stack backwards until a pair with a non empty interleave
252 set is found, deleting all the pairs that have it empty in the way. */
253 while (not exploration_stack_.empty()) {
254 std::shared_ptr<simgrid::mc::Pair> current_pair = exploration_stack_.back();
255 exploration_stack_.pop_back();
256 if (current_pair->requests > 0) {
257 /* We found a backtracking point */
258 XBT_DEBUG("Backtracking to depth %d", current_pair->depth);
259 exploration_stack_.push_back(std::move(current_pair));
261 XBT_DEBUG("Backtracking done");
264 XBT_DEBUG("Delete pair %d at depth %d", current_pair->num, current_pair->depth);
265 if (current_pair->automaton_state->type == 1)
266 this->remove_acceptance_pair(current_pair->num);
271 void LivenessChecker::run()
273 XBT_INFO("Check the liveness property %s", _sg_mc_property_file.get().c_str());
274 Api::get().automaton_load(_sg_mc_property_file.get().c_str());
276 XBT_DEBUG("Starting the liveness algorithm");
277 get_session().take_initial_snapshot();
280 this->previous_pair_ = 0;
282 std::shared_ptr<const std::vector<int>> propos = this->get_proposition_values();
284 // For each initial state of the property automaton, push a
285 // (application_state, automaton_state) pair to the exploration stack:
286 auto automaton_stack = Api::get().get_automaton_state();
287 for (auto* automaton_state : automaton_stack) {
288 if (automaton_state->type == -1)
289 exploration_stack_.push_back(this->create_pair(nullptr, automaton_state, propos));
292 /* Actually run the double DFS search for counter-examples */
293 while (not exploration_stack_.empty()) {
294 std::shared_ptr<Pair> current_pair = exploration_stack_.back();
296 /* Update current state in buchi automaton */
297 Api::get().set_property_automaton(current_pair->automaton_state);
300 "********************* ( Depth = %d, search_cycle = %d, interleave size = %zu, pair_num = %d, requests = %d)",
301 current_pair->depth, current_pair->search_cycle, current_pair->graph_state->count_todo(), current_pair->num,
302 current_pair->requests);
304 if (current_pair->requests == 0) {
309 std::shared_ptr<VisitedPair> reached_pair;
310 if (current_pair->automaton_state->type == 1 && not current_pair->exploration_started) {
311 reached_pair = this->insert_acceptance_pair(current_pair.get());
312 if (reached_pair == nullptr) {
313 this->show_acceptance_cycle(current_pair->depth);
314 throw LivenessError();
318 /* Pair already visited ? stop the exploration on the current path */
319 if (not current_pair->exploration_started) {
320 int visited_num = this->insert_visited_pair(reached_pair, current_pair.get());
321 if (visited_num != -1) {
322 if (dot_output != nullptr) {
323 fprintf(dot_output, "\"%d\" -> \"%d\" [%s];\n", this->previous_pair_, visited_num,
324 this->previous_request_.c_str());
327 XBT_DEBUG("Pair already visited (equal to pair %d), exploration on the current path stopped.", visited_num);
328 current_pair->requests = 0;
334 current_pair->graph_state->execute_next(current_pair->graph_state->next_transition());
335 XBT_DEBUG("Execute: %s", current_pair->graph_state->get_transition()->to_string().c_str());
337 if (dot_output != nullptr) {
338 if (this->previous_pair_ != 0 && this->previous_pair_ != current_pair->num) {
339 fprintf(dot_output, "\"%d\" -> \"%d\" [%s];\n", this->previous_pair_, current_pair->num,
340 this->previous_request_.c_str());
341 this->previous_request_.clear();
343 this->previous_pair_ = current_pair->num;
344 this->previous_request_ = current_pair->graph_state->get_transition()->dot_string();
345 if (current_pair->search_cycle)
346 fprintf(dot_output, "%d [shape=doublecircle];\n", current_pair->num);
350 if (not current_pair->exploration_started)
351 visited_pairs_count_++;
353 current_pair->requests--;
354 current_pair->exploration_started = true;
356 /* Get values of atomic propositions (variables used in the property formula) */
357 std::shared_ptr<const std::vector<int>> prop_values = this->get_proposition_values();
359 // For each enabled transition in the property automaton, push a
360 // (application_state, automaton_state) pair to the exploration stack:
361 for (int i = xbt_dynar_length(current_pair->automaton_state->out) - 1; i >= 0; i--) {
362 const auto* transition_succ_label =
363 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);
379 } // namespace simgrid::mc