1 /* Copyright (c) 2011-2023. 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 RemoteApp& remote_app)
24 : num(pair_num), prop_state_(prop_state)
26 auto& memory = mc_model_checker->get_remote_process_memory();
27 this->app_state_ = std::move(app_state);
28 if (not this->app_state_->get_system_state())
29 this->app_state_->set_system_state(std::make_shared<Snapshot>(pair_num, remote_app.get_page_store(), memory));
30 this->heap_bytes_used = memory.get_remote_heap_bytes();
31 this->actor_count_ = app_state_->get_actor_count();
33 this->atomic_propositions = std::move(atomic_propositions);
36 bool LivenessChecker::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(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 = 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)
64 auto new_pair = std::make_shared<VisitedPair>(pair->num, pair->prop_state_, pair->atomic_propositions,
65 pair->app_state_, get_remote_app());
68 res_end] = boost::range::equal_range(acceptance_pairs_, new_pair.get(), [](auto const& a, auto const& b) {
69 return std::make_pair(a->actor_count_, a->heap_bytes_used) < std::make_pair(b->actor_count_, b->heap_bytes_used);
72 if (pair->search_cycle)
73 for (auto i = res_begin; i != res_end; ++i) {
74 std::shared_ptr<simgrid::mc::VisitedPair> const& pair_test = *i;
75 if (xbt_automaton_state_compare(pair_test->prop_state_, new_pair->prop_state_) != 0 ||
76 *(pair_test->atomic_propositions) != *(new_pair->atomic_propositions) ||
77 (*pair_test->app_state_->get_system_state() != *new_pair->app_state_->get_system_state()))
79 XBT_INFO("Pair %d already reached (equal to pair %d) !", new_pair->num, pair_test->num);
80 exploration_stack_.pop_back();
81 dot_output("\"%d\" -> \"%d\" [%s];\n", this->previous_pair_, pair_test->num, 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->app_state_->get_system_state()) {
106 system_state->restore(get_remote_app().get_remote_process_memory());
111 get_remote_app().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->app_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)
142 visited_pair = std::make_shared<VisitedPair>(pair->num, pair->prop_state_, pair->atomic_propositions,
143 pair->app_state_, get_remote_app());
146 range_end] = boost::range::equal_range(visited_pairs_, visited_pair.get(), [](auto const& a, auto const& b) {
147 return std::make_pair(a->actor_count_, a->heap_bytes_used) < std::make_pair(b->actor_count_, b->heap_bytes_used);
150 for (auto i = range_begin; i != range_end; ++i) {
151 const VisitedPair* pair_test = i->get();
152 if (xbt_automaton_state_compare(pair_test->prop_state_, visited_pair->prop_state_) != 0 ||
153 *(pair_test->atomic_propositions) != *(visited_pair->atomic_propositions) ||
154 (*pair_test->app_state_->get_system_state() != *visited_pair->app_state_->get_system_state()))
156 if (pair_test->other_num == -1)
157 visited_pair->other_num = pair_test->num;
159 visited_pair->other_num = pair_test->other_num;
160 XBT_DEBUG("Pair %d already visited ! (equal to pair %d (pair %d in dot_output))", visited_pair->num, pair_test->num,
161 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(const std::vector<char*>& args) : Exploration(args) {}
182 LivenessChecker::~LivenessChecker()
184 xbt_automaton_free(property_automaton_);
187 xbt_automaton_t LivenessChecker::property_automaton_ = nullptr;
189 void LivenessChecker::automaton_load(const char* file) const
191 if (property_automaton_ == nullptr)
192 property_automaton_ = xbt_automaton_new();
194 xbt_automaton_load(property_automaton_, file);
197 std::vector<int> LivenessChecker::automaton_propositional_symbol_evaluate() const
199 unsigned int cursor = 0;
200 std::vector<int> values;
201 xbt_automaton_propositional_symbol_t ps = nullptr;
202 xbt_dynar_foreach (property_automaton_->propositional_symbols, cursor, ps)
203 values.push_back(xbt_automaton_propositional_symbol_evaluate(ps));
207 std::vector<xbt_automaton_state_t> LivenessChecker::get_automaton_state() const
209 std::vector<xbt_automaton_state_t> automaton_stack;
210 unsigned int cursor = 0;
211 xbt_automaton_state_t automaton_state;
212 xbt_dynar_foreach (property_automaton_->states, cursor, automaton_state)
213 if (automaton_state->type == -1)
214 automaton_stack.push_back(automaton_state);
215 return automaton_stack;
218 int LivenessChecker::compare_automaton_exp_label(const xbt_automaton_exp_label* l) const
220 unsigned int cursor = 0;
221 xbt_automaton_propositional_symbol_t p = nullptr;
222 xbt_dynar_foreach (property_automaton_->propositional_symbols, cursor, p) {
223 if (std::strcmp(xbt_automaton_propositional_symbol_get_name(p), l->u.predicat) == 0)
229 void LivenessChecker::set_property_automaton(xbt_automaton_state_t const& automaton_state) const
231 property_automaton_->current_state = automaton_state;
234 xbt_automaton_exp_label_t LivenessChecker::get_automaton_transition_label(xbt_dynar_t const& dynar, int index) const
236 const xbt_automaton_transition* transition = xbt_dynar_get_as(dynar, index, xbt_automaton_transition_t);
237 return transition->label;
240 xbt_automaton_state_t LivenessChecker::get_automaton_transition_dst(xbt_dynar_t const& dynar, int index) const
242 const xbt_automaton_transition* transition = xbt_dynar_get_as(dynar, index, xbt_automaton_transition_t);
243 return transition->dst;
245 void LivenessChecker::automaton_register_symbol(RemoteProcessMemory const& remote_process, const char* name,
246 RemotePtr<int> address)
248 if (property_automaton_ == nullptr)
249 property_automaton_ = xbt_automaton_new();
251 xbt::add_proposition(property_automaton_, name,
252 [&remote_process, address]() { return remote_process.read(address); });
255 RecordTrace LivenessChecker::get_record_trace() // override
258 for (std::shared_ptr<Pair> const& pair : exploration_stack_)
259 res.push_back(pair->app_state_->get_transition());
263 void LivenessChecker::log_state() // override
265 XBT_INFO("Expanded pairs = %lu", expanded_pairs_count_);
266 XBT_INFO("Visited pairs = %lu", visited_pairs_count_);
267 XBT_INFO("Executed transitions = %lu", Transition::get_executed_transitions());
268 Exploration::log_state();
271 void LivenessChecker::show_acceptance_cycle(std::size_t depth)
273 XBT_INFO("*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*");
274 XBT_INFO("| ACCEPTANCE CYCLE |");
275 XBT_INFO("*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*");
276 XBT_INFO("Counter-example that violates formula:");
277 for (auto const& s : this->get_textual_trace())
278 XBT_INFO(" %s", s.c_str());
279 XBT_INFO("You can debug the problem (and see the whole details) by rerunning out of simgrid-mc with "
280 "--cfg=model-check/replay:'%s'",
281 get_record_trace().to_string().c_str());
283 XBT_INFO("Counter-example depth: %zu", depth);
286 std::vector<std::string> LivenessChecker::get_textual_trace() // override
288 std::vector<std::string> trace;
289 for (std::shared_ptr<Pair> const& pair : exploration_stack_)
290 trace.push_back(pair->app_state_->get_transition()->to_string());
295 std::shared_ptr<Pair> LivenessChecker::create_pair(const Pair* current_pair, xbt_automaton_state_t state,
296 std::shared_ptr<const std::vector<int>> propositions)
298 ++expanded_pairs_count_;
299 auto next_pair = std::make_shared<Pair>(expanded_pairs_count_);
300 next_pair->prop_state_ = state;
301 next_pair->app_state_ = std::make_shared<State>(get_remote_app());
302 next_pair->atomic_propositions = std::move(propositions);
304 next_pair->depth = current_pair->depth + 1;
306 next_pair->depth = 1;
307 /* Add all enabled actors to the interleave set of the initial state */
308 for (auto const& [aid, _] : next_pair->app_state_->get_actors_list())
309 if (next_pair->app_state_->is_actor_enabled(aid))
310 next_pair->app_state_->mark_todo(aid);
312 next_pair->requests = next_pair->app_state_->count_todo();
313 /* FIXME : get search_cycle value for each accepting state */
314 if (next_pair->prop_state_->type == 1 || (current_pair && current_pair->search_cycle))
315 next_pair->search_cycle = true;
317 next_pair->search_cycle = false;
321 void LivenessChecker::backtrack()
323 /* Traverse the stack backwards until a pair with a non empty interleave
324 set is found, deleting all the pairs that have it empty in the way. */
325 while (not exploration_stack_.empty()) {
326 std::shared_ptr<simgrid::mc::Pair> current_pair = exploration_stack_.back();
327 exploration_stack_.pop_back();
328 if (current_pair->requests > 0) {
329 /* We found a backtracking point */
330 XBT_DEBUG("Backtracking to depth %d", current_pair->depth);
331 exploration_stack_.push_back(std::move(current_pair));
333 XBT_DEBUG("Backtracking done");
336 XBT_DEBUG("Delete pair %d at depth %d", current_pair->num, current_pair->depth);
337 if (current_pair->prop_state_->type == 1)
338 this->remove_acceptance_pair(current_pair->num);
343 void LivenessChecker::run()
345 XBT_INFO("Check the liveness property %s", _sg_mc_property_file.get().c_str());
346 automaton_load(_sg_mc_property_file.get().c_str());
348 XBT_DEBUG("Starting the liveness algorithm");
351 this->previous_pair_ = 0;
353 std::shared_ptr<const std::vector<int>> propos = this->get_proposition_values();
355 // For each initial state of the property automaton, push a
356 // (application_state, automaton_state) pair to the exploration stack:
357 auto automaton_stack = get_automaton_state();
358 for (auto* automaton_state : automaton_stack) {
359 if (automaton_state->type == -1)
360 exploration_stack_.push_back(this->create_pair(nullptr, automaton_state, propos));
363 /* Actually run the double DFS search for counter-examples */
364 while (not exploration_stack_.empty()) {
365 std::shared_ptr<Pair> current_pair = exploration_stack_.back();
367 /* Update current state in buchi automaton */
368 set_property_automaton(current_pair->prop_state_);
371 "********************* ( Depth = %d, search_cycle = %d, interleave size = %zu, pair_num = %d, requests = %d)",
372 current_pair->depth, current_pair->search_cycle, current_pair->app_state_->count_todo(), current_pair->num,
373 current_pair->requests);
375 if (current_pair->requests == 0) {
380 std::shared_ptr<VisitedPair> reached_pair;
381 if (current_pair->prop_state_->type == 1 && not current_pair->exploration_started) {
382 reached_pair = this->insert_acceptance_pair(current_pair.get());
383 if (reached_pair == nullptr) {
384 this->show_acceptance_cycle(current_pair->depth);
385 throw LivenessError();
389 /* Pair already visited ? stop the exploration on the current path */
390 if (not current_pair->exploration_started) {
391 int visited_num = this->insert_visited_pair(reached_pair, current_pair.get());
392 if (visited_num != -1) {
393 dot_output("\"%d\" -> \"%d\" [%s];\n", this->previous_pair_, visited_num, this->previous_request_.c_str());
395 XBT_DEBUG("Pair already visited (equal to pair %d), exploration on the current path stopped.", visited_num);
396 current_pair->requests = 0;
402 current_pair->app_state_->execute_next(current_pair->app_state_->next_transition());
403 XBT_DEBUG("Execute: %s", current_pair->app_state_->get_transition()->to_string().c_str());
405 /* Update the dot output */
406 if (this->previous_pair_ != 0 && this->previous_pair_ != current_pair->num) {
407 dot_output("\"%d\" -> \"%d\" [%s];\n", this->previous_pair_, current_pair->num, this->previous_request_.c_str());
408 this->previous_request_.clear();
410 this->previous_pair_ = current_pair->num;
411 this->previous_request_ = current_pair->app_state_->get_transition()->dot_string();
412 if (current_pair->search_cycle)
413 dot_output("%d [shape=doublecircle];\n", current_pair->num);
415 if (not current_pair->exploration_started)
416 visited_pairs_count_++;
418 current_pair->requests--;
419 current_pair->exploration_started = true;
421 /* Get values of atomic propositions (variables used in the property formula) */
422 std::shared_ptr<const std::vector<int>> prop_values = this->get_proposition_values();
424 // For each enabled transition in the property automaton, push a
425 // (application_state, automaton_state) pair to the exploration stack:
426 for (int i = xbt_dynar_length(current_pair->prop_state_->out) - 1; i >= 0; i--) {
427 const auto* transition_succ_label = get_automaton_transition_label(current_pair->prop_state_->out, i);
428 auto* transition_succ_dst = get_automaton_transition_dst(current_pair->prop_state_->out, i);
429 if (evaluate_label(transition_succ_label, *prop_values))
430 exploration_stack_.push_back(this->create_pair(current_pair.get(), transition_succ_dst, prop_values));
434 XBT_INFO("No property violation found.");
438 Exploration* create_liveness_checker(const std::vector<char*>& args)
440 return new LivenessChecker(args);
443 } // namespace simgrid::mc