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/api/RemoteApp.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 = mc_model_checker->get_remote_process().get_remote_heap_bytes();
29 this->actor_count_ = app_state_->get_actor_count();
31 this->atomic_propositions = std::move(atomic_propositions);
34 bool LivenessChecker::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(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 = 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] =
66 boost::range::equal_range(acceptance_pairs_, new_pair.get(), compare_pair_by_actor_count_and_used_heap());
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->prop_state_, new_pair->prop_state_) != 0 ||
72 *(pair_test->atomic_propositions) != *(new_pair->atomic_propositions) ||
73 (*pair_test->app_state_->get_system_state() != *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 mc_model_checker->dot_output("\"%d\" -> \"%d\" [%s];\n", this->previous_pair_, pair_test->num,
78 this->previous_request_.c_str());
82 acceptance_pairs_.insert(res_begin, new_pair);
86 void LivenessChecker::remove_acceptance_pair(int pair_num)
88 for (auto i = acceptance_pairs_.begin(); i != acceptance_pairs_.end(); ++i)
89 if ((*i)->num == pair_num) {
90 acceptance_pairs_.erase(i);
95 void LivenessChecker::replay()
97 XBT_DEBUG("**** Begin Replay ****");
99 /* Intermediate backtracking */
100 if (_sg_mc_checkpoint > 0) {
101 const Pair* pair = exploration_stack_.back().get();
102 if (const auto* system_state = pair->app_state_->get_system_state()) {
103 system_state->restore(&get_remote_app().get_remote_process());
108 get_remote_app().restore_initial_state();
110 /* Traverse the stack from the initial state and re-execute the transitions */
112 for (std::shared_ptr<Pair> const& pair : exploration_stack_) {
113 if (pair == exploration_stack_.back())
116 std::shared_ptr<State> state = pair->app_state_;
118 if (pair->exploration_started) {
119 state->get_transition()->replay();
120 XBT_DEBUG("Replay (depth = %d) : %s (%p)", depth, state->get_transition()->to_string().c_str(), state.get());
123 /* Update statistics */
124 visited_pairs_count_++;
127 XBT_DEBUG("**** End Replay ****");
131 * @brief Checks whether a given pair has already been visited by the algorithm.
133 int LivenessChecker::insert_visited_pair(std::shared_ptr<VisitedPair> visited_pair, simgrid::mc::Pair* pair)
135 if (_sg_mc_max_visited_states == 0)
138 if (visited_pair == nullptr)
140 std::make_shared<VisitedPair>(pair->num, pair->prop_state_, pair->atomic_propositions, pair->app_state_);
142 auto [range_begin, range_end] =
143 boost::range::equal_range(visited_pairs_, visited_pair.get(), compare_pair_by_actor_count_and_used_heap());
145 for (auto i = range_begin; i != range_end; ++i) {
146 const VisitedPair* pair_test = i->get();
147 if (xbt_automaton_state_compare(pair_test->prop_state_, visited_pair->prop_state_) != 0 ||
148 *(pair_test->atomic_propositions) != *(visited_pair->atomic_propositions) ||
149 (*pair_test->app_state_->get_system_state() != *visited_pair->app_state_->get_system_state()))
151 if (pair_test->other_num == -1)
152 visited_pair->other_num = pair_test->num;
154 visited_pair->other_num = pair_test->other_num;
155 XBT_DEBUG("Pair %d already visited ! (equal to pair %d (pair %d in dot_output))", visited_pair->num, pair_test->num,
156 visited_pair->other_num);
157 (*i) = std::move(visited_pair);
158 return (*i)->other_num;
161 visited_pairs_.insert(range_begin, std::move(visited_pair));
162 this->purge_visited_pairs();
166 void LivenessChecker::purge_visited_pairs()
168 if (_sg_mc_max_visited_states != 0 && visited_pairs_.size() > (std::size_t)_sg_mc_max_visited_states) {
169 // Remove the oldest entry with a linear search:
170 visited_pairs_.erase(
171 boost::min_element(visited_pairs_, [](std::shared_ptr<VisitedPair> const a,
172 std::shared_ptr<VisitedPair> const& b) { return a->num < b->num; }));
176 LivenessChecker::LivenessChecker(const std::vector<char*>& args) : Exploration(args) {}
177 LivenessChecker::~LivenessChecker()
179 if (property_automaton_ != nullptr)
180 xbt_automaton_free(property_automaton_);
183 xbt_automaton_t LivenessChecker::property_automaton_ = nullptr;
185 void LivenessChecker::automaton_load(const char* file)
187 if (property_automaton_ == nullptr)
188 property_automaton_ = xbt_automaton_new();
190 xbt_automaton_load(property_automaton_, file);
193 std::vector<int> LivenessChecker::automaton_propositional_symbol_evaluate() const
195 unsigned int cursor = 0;
196 std::vector<int> values;
197 xbt_automaton_propositional_symbol_t ps = nullptr;
198 xbt_dynar_foreach (property_automaton_->propositional_symbols, cursor, ps)
199 values.push_back(xbt_automaton_propositional_symbol_evaluate(ps));
203 std::vector<xbt_automaton_state_t> LivenessChecker::get_automaton_state() const
205 std::vector<xbt_automaton_state_t> automaton_stack;
206 unsigned int cursor = 0;
207 xbt_automaton_state_t automaton_state;
208 xbt_dynar_foreach (property_automaton_->states, cursor, automaton_state)
209 if (automaton_state->type == -1)
210 automaton_stack.push_back(automaton_state);
211 return automaton_stack;
214 int LivenessChecker::compare_automaton_exp_label(const xbt_automaton_exp_label* l) const
216 unsigned int cursor = 0;
217 xbt_automaton_propositional_symbol_t p = nullptr;
218 xbt_dynar_foreach (property_automaton_->propositional_symbols, cursor, p) {
219 if (std::strcmp(xbt_automaton_propositional_symbol_get_name(p), l->u.predicat) == 0)
225 void LivenessChecker::set_property_automaton(xbt_automaton_state_t const& automaton_state) const
227 property_automaton_->current_state = automaton_state;
230 xbt_automaton_exp_label_t LivenessChecker::get_automaton_transition_label(xbt_dynar_t const& dynar, int index) const
232 const xbt_automaton_transition* transition = xbt_dynar_get_as(dynar, index, xbt_automaton_transition_t);
233 return transition->label;
236 xbt_automaton_state_t LivenessChecker::get_automaton_transition_dst(xbt_dynar_t const& dynar, int index) const
238 const xbt_automaton_transition* transition = xbt_dynar_get_as(dynar, index, xbt_automaton_transition_t);
239 return transition->dst;
241 void LivenessChecker::automaton_register_symbol(RemoteProcess& remote_process, const char* name, RemotePtr<int> address)
243 if (property_automaton_ == nullptr)
244 property_automaton_ = xbt_automaton_new();
246 xbt::add_proposition(property_automaton_, name,
247 [&remote_process, address]() { return remote_process.read(address); });
250 RecordTrace LivenessChecker::get_record_trace() // override
253 for (std::shared_ptr<Pair> const& pair : exploration_stack_)
254 res.push_back(pair->app_state_->get_transition());
258 void LivenessChecker::log_state() // override
260 XBT_INFO("Expanded pairs = %lu", expanded_pairs_count_);
261 XBT_INFO("Visited pairs = %lu", visited_pairs_count_);
262 XBT_INFO("Executed transitions = %lu", Transition::get_executed_transitions());
263 Exploration::log_state();
266 void LivenessChecker::show_acceptance_cycle(std::size_t depth)
268 XBT_INFO("*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*");
269 XBT_INFO("| ACCEPTANCE CYCLE |");
270 XBT_INFO("*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*");
271 XBT_INFO("Counter-example that violates formula:");
272 for (auto const& s : this->get_textual_trace())
273 XBT_INFO(" %s", s.c_str());
274 XBT_INFO("Path = %s", get_record_trace().to_string().c_str());
276 XBT_INFO("Counter-example depth: %zu", depth);
279 std::vector<std::string> LivenessChecker::get_textual_trace() // override
281 std::vector<std::string> trace;
282 for (std::shared_ptr<Pair> const& pair : exploration_stack_)
283 trace.push_back(pair->app_state_->get_transition()->to_string());
288 std::shared_ptr<Pair> LivenessChecker::create_pair(const Pair* current_pair, xbt_automaton_state_t state,
289 std::shared_ptr<const std::vector<int>> propositions)
291 ++expanded_pairs_count_;
292 auto next_pair = std::make_shared<Pair>(expanded_pairs_count_);
293 next_pair->prop_state_ = state;
294 next_pair->app_state_ = std::make_shared<State>(get_remote_app());
295 next_pair->atomic_propositions = std::move(propositions);
297 next_pair->depth = current_pair->depth + 1;
299 next_pair->depth = 1;
300 /* Add all enabled actors to the interleave set of the initial state */
301 for (auto const& [aid, _] : next_pair->app_state_->get_actors_list())
302 if (next_pair->app_state_->is_actor_enabled(aid))
303 next_pair->app_state_->mark_todo(aid);
305 next_pair->requests = next_pair->app_state_->count_todo();
306 /* FIXME : get search_cycle value for each accepting state */
307 if (next_pair->prop_state_->type == 1 || (current_pair && current_pair->search_cycle))
308 next_pair->search_cycle = true;
310 next_pair->search_cycle = false;
314 void LivenessChecker::backtrack()
316 /* Traverse the stack backwards until a pair with a non empty interleave
317 set is found, deleting all the pairs that have it empty in the way. */
318 while (not exploration_stack_.empty()) {
319 std::shared_ptr<simgrid::mc::Pair> current_pair = exploration_stack_.back();
320 exploration_stack_.pop_back();
321 if (current_pair->requests > 0) {
322 /* We found a backtracking point */
323 XBT_DEBUG("Backtracking to depth %d", current_pair->depth);
324 exploration_stack_.push_back(std::move(current_pair));
326 XBT_DEBUG("Backtracking done");
329 XBT_DEBUG("Delete pair %d at depth %d", current_pair->num, current_pair->depth);
330 if (current_pair->prop_state_->type == 1)
331 this->remove_acceptance_pair(current_pair->num);
336 void LivenessChecker::run()
338 XBT_INFO("Check the liveness property %s", _sg_mc_property_file.get().c_str());
339 automaton_load(_sg_mc_property_file.get().c_str());
341 XBT_DEBUG("Starting the liveness algorithm");
344 this->previous_pair_ = 0;
346 std::shared_ptr<const std::vector<int>> propos = this->get_proposition_values();
348 // For each initial state of the property automaton, push a
349 // (application_state, automaton_state) pair to the exploration stack:
350 auto automaton_stack = get_automaton_state();
351 for (auto* automaton_state : automaton_stack) {
352 if (automaton_state->type == -1)
353 exploration_stack_.push_back(this->create_pair(nullptr, automaton_state, propos));
356 /* Actually run the double DFS search for counter-examples */
357 while (not exploration_stack_.empty()) {
358 std::shared_ptr<Pair> current_pair = exploration_stack_.back();
360 /* Update current state in buchi automaton */
361 set_property_automaton(current_pair->prop_state_);
364 "********************* ( Depth = %d, search_cycle = %d, interleave size = %zu, pair_num = %d, requests = %d)",
365 current_pair->depth, current_pair->search_cycle, current_pair->app_state_->count_todo(), current_pair->num,
366 current_pair->requests);
368 if (current_pair->requests == 0) {
373 std::shared_ptr<VisitedPair> reached_pair;
374 if (current_pair->prop_state_->type == 1 && not current_pair->exploration_started) {
375 reached_pair = this->insert_acceptance_pair(current_pair.get());
376 if (reached_pair == nullptr) {
377 this->show_acceptance_cycle(current_pair->depth);
378 throw LivenessError();
382 /* Pair already visited ? stop the exploration on the current path */
383 if (not current_pair->exploration_started) {
384 int visited_num = this->insert_visited_pair(reached_pair, current_pair.get());
385 if (visited_num != -1) {
386 mc_model_checker->dot_output("\"%d\" -> \"%d\" [%s];\n", this->previous_pair_, visited_num,
387 this->previous_request_.c_str());
388 mc_model_checker->dot_output_flush();
390 XBT_DEBUG("Pair already visited (equal to pair %d), exploration on the current path stopped.", visited_num);
391 current_pair->requests = 0;
397 current_pair->app_state_->execute_next(current_pair->app_state_->next_transition());
398 XBT_DEBUG("Execute: %s", current_pair->app_state_->get_transition()->to_string().c_str());
400 /* Update the dot output */
401 if (this->previous_pair_ != 0 && this->previous_pair_ != current_pair->num) {
402 mc_model_checker->dot_output("\"%d\" -> \"%d\" [%s];\n", this->previous_pair_, current_pair->num,
403 this->previous_request_.c_str());
404 this->previous_request_.clear();
406 this->previous_pair_ = current_pair->num;
407 this->previous_request_ = current_pair->app_state_->get_transition()->dot_string();
408 if (current_pair->search_cycle)
409 mc_model_checker->dot_output("%d [shape=doublecircle];\n", current_pair->num);
410 mc_model_checker->dot_output_flush();
412 if (not current_pair->exploration_started)
413 visited_pairs_count_++;
415 current_pair->requests--;
416 current_pair->exploration_started = true;
418 /* Get values of atomic propositions (variables used in the property formula) */
419 std::shared_ptr<const std::vector<int>> prop_values = this->get_proposition_values();
421 // For each enabled transition in the property automaton, push a
422 // (application_state, automaton_state) pair to the exploration stack:
423 for (int i = xbt_dynar_length(current_pair->prop_state_->out) - 1; i >= 0; i--) {
424 const auto* transition_succ_label = get_automaton_transition_label(current_pair->prop_state_->out, i);
425 auto* transition_succ_dst = get_automaton_transition_dst(current_pair->prop_state_->out, i);
426 if (evaluate_label(transition_succ_label, *prop_values))
427 exploration_stack_.push_back(this->create_pair(current_pair.get(), transition_succ_dst, prop_values));
431 XBT_INFO("No property violation found.");
435 Exploration* create_liveness_checker(const std::vector<char*>& args)
437 return new LivenessChecker(args);
440 } // namespace simgrid::mc