1 /* Copyright (c) 2011-2021. 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/checker/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 using api = simgrid::mc::Api;
19 /********* Static functions *********/
24 VisitedPair::VisitedPair(int pair_num, xbt_automaton_state_t automaton_state,
25 std::shared_ptr<const std::vector<int>> atomic_propositions,
26 std::shared_ptr<State> graph_state)
27 : num(pair_num), automaton_state(automaton_state)
29 this->graph_state = std::move(graph_state);
30 if (this->graph_state->system_state_ == nullptr)
31 this->graph_state->system_state_ = std::make_shared<Snapshot>(pair_num);
32 this->heap_bytes_used = api::get().get_remote_heap_bytes();
33 this->actors_count = api::get().get_actors_size();
35 this->atomic_propositions = std::move(atomic_propositions);
38 static bool evaluate_label(const xbt_automaton_exp_label* l, std::vector<int> const& values)
41 case xbt_automaton_exp_label::AUT_OR:
42 return evaluate_label(l->u.or_and.left_exp, values)
43 || evaluate_label(l->u.or_and.right_exp, values);
44 case xbt_automaton_exp_label::AUT_AND:
45 return evaluate_label(l->u.or_and.left_exp, values)
46 && evaluate_label(l->u.or_and.right_exp, values);
47 case xbt_automaton_exp_label::AUT_NOT:
48 return not evaluate_label(l->u.exp_not, values);
49 case xbt_automaton_exp_label::AUT_PREDICAT:{
50 auto cursor = api::get().compare_automaton_exp_label(l);
52 return values[cursor] != 0;
53 xbt_die("Missing predicate");
56 case xbt_automaton_exp_label::AUT_ONE:
59 xbt_die("Unexpected value for automaton");
63 Pair::Pair(unsigned long expanded_pairs) : num(expanded_pairs)
66 std::shared_ptr<const std::vector<int>> LivenessChecker::get_proposition_values() const
68 auto values = api::get().automaton_propositional_symbol_evaluate();
69 return std::make_shared<const std::vector<int>>(std::move(values));
72 std::shared_ptr<VisitedPair> LivenessChecker::insert_acceptance_pair(simgrid::mc::Pair* pair)
75 std::make_shared<VisitedPair>(pair->num, pair->automaton_state, pair->atomic_propositions, pair->graph_state);
77 auto res = boost::range::equal_range(acceptance_pairs_, new_pair.get(), api::get().compare_pair());
79 if (pair->search_cycle) for (auto i = res.first; i != res.second; ++i) {
80 std::shared_ptr<simgrid::mc::VisitedPair> const& pair_test = *i;
81 if (api::get().automaton_state_compare(pair_test->automaton_state, new_pair->automaton_state) != 0 ||
82 *(pair_test->atomic_propositions) != *(new_pair->atomic_propositions) ||
83 not api::get().snapshot_equal(pair_test->graph_state->system_state_.get(), new_pair->graph_state->system_state_.get()))
85 XBT_INFO("Pair %d already reached (equal to pair %d) !", new_pair->num, pair_test->num);
86 exploration_stack_.pop_back();
87 if (dot_output != nullptr)
88 fprintf(dot_output, "\"%d\" -> \"%d\" [%s];\n", this->previous_pair_, pair_test->num,
89 this->previous_request_.c_str());
93 acceptance_pairs_.insert(res.first, new_pair);
97 void LivenessChecker::remove_acceptance_pair(int pair_num)
99 for (auto i = acceptance_pairs_.begin(); i != acceptance_pairs_.end(); ++i)
100 if ((*i)->num == pair_num) {
101 acceptance_pairs_.erase(i);
106 void LivenessChecker::replay()
108 XBT_DEBUG("**** Begin Replay ****");
110 /* Intermediate backtracking */
111 if(_sg_mc_checkpoint > 0) {
112 const Pair* pair = exploration_stack_.back().get();
113 if (pair->graph_state->system_state_) {
114 api::get().restore_state(pair->graph_state->system_state_);
119 get_session().restore_initial_state();
121 /* Traverse the stack from the initial state and re-execute the transitions */
123 for (std::shared_ptr<Pair> const& pair : exploration_stack_) {
124 if (pair == exploration_stack_.back())
127 std::shared_ptr<State> state = pair->graph_state;
129 if (pair->exploration_started) {
130 int req_num = state->transition_.times_considered_;
131 const s_smx_simcall* saved_req = &state->executed_req_;
133 smx_simcall_t req = nullptr;
135 /* because we got a copy of the executed request, we have to fetch the
136 real one, pointed by the request field of the issuer process */
137 const smx_actor_t issuer = api::get().simcall_get_issuer(saved_req);
138 req = &issuer->simcall_;
140 /* Debug information */
141 XBT_DEBUG("Replay (depth = %d) : %s (%p)", depth, api::get().request_to_string(req, req_num).c_str(),
144 api::get().execute(state->transition_, req);
147 /* Update statistics */
148 visited_pairs_count_++;
149 api::get().mc_inc_executed_trans();
153 XBT_DEBUG("**** End Replay ****");
157 * @brief Checks whether a given pair has already been visited by the algorithm.
159 int LivenessChecker::insert_visited_pair(std::shared_ptr<VisitedPair> visited_pair, simgrid::mc::Pair* pair)
161 if (_sg_mc_max_visited_states == 0)
164 if (visited_pair == nullptr)
166 std::make_shared<VisitedPair>(pair->num, pair->automaton_state, pair->atomic_propositions, pair->graph_state);
168 auto range = boost::range::equal_range(visited_pairs_, visited_pair.get(), api::get().compare_pair());
170 for (auto i = range.first; i != range.second; ++i) {
171 const VisitedPair* pair_test = i->get();
172 if (api::get().automaton_state_compare(pair_test->automaton_state, visited_pair->automaton_state) != 0 ||
173 *(pair_test->atomic_propositions) != *(visited_pair->atomic_propositions) ||
174 not api::get().snapshot_equal(pair_test->graph_state->system_state_.get(), visited_pair->graph_state->system_state_.get()))
176 if (pair_test->other_num == -1)
177 visited_pair->other_num = pair_test->num;
179 visited_pair->other_num = pair_test->other_num;
180 if (dot_output == nullptr)
181 XBT_DEBUG("Pair %d already visited ! (equal to pair %d)", visited_pair->num, pair_test->num);
183 XBT_DEBUG("Pair %d already visited ! (equal to pair %d (pair %d in dot_output))",
184 visited_pair->num, pair_test->num, visited_pair->other_num);
185 (*i) = std::move(visited_pair);
186 return (*i)->other_num;
189 visited_pairs_.insert(range.first, std::move(visited_pair));
190 this->purge_visited_pairs();
194 void LivenessChecker::purge_visited_pairs()
196 if (_sg_mc_max_visited_states != 0 && visited_pairs_.size() > (std::size_t)_sg_mc_max_visited_states) {
197 // Remove the oldest entry with a linear search:
198 visited_pairs_.erase(
199 boost::min_element(visited_pairs_, [](std::shared_ptr<VisitedPair> const a,
200 std::shared_ptr<VisitedPair> const& b) { return a->num < b->num; }));
204 LivenessChecker::LivenessChecker(Session* session) : Checker(session) {}
206 RecordTrace LivenessChecker::get_record_trace() // override
209 for (std::shared_ptr<Pair> const& pair : exploration_stack_)
210 res.push_back(pair->graph_state->get_transition());
214 void LivenessChecker::log_state() // override
216 XBT_INFO("Expanded pairs = %lu", expanded_pairs_count_);
217 XBT_INFO("Visited pairs = %lu", visited_pairs_count_);
218 XBT_INFO("Executed transitions = %lu", api::get().mc_get_executed_trans());
221 void LivenessChecker::show_acceptance_cycle(std::size_t depth)
223 XBT_INFO("*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*");
224 XBT_INFO("| ACCEPTANCE CYCLE |");
225 XBT_INFO("*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*");
226 XBT_INFO("Counter-example that violates formula:");
227 for (auto const& s : this->get_textual_trace())
228 XBT_INFO(" %s", s.c_str());
229 api::get().dump_record_path();
230 api::get().log_state();
231 XBT_INFO("Counter-example depth: %zu", depth);
234 std::vector<std::string> LivenessChecker::get_textual_trace() // override
236 std::vector<std::string> trace;
237 for (std::shared_ptr<Pair> const& pair : exploration_stack_) {
238 int req_num = pair->graph_state->transition_.times_considered_;
239 smx_simcall_t req = &pair->graph_state->executed_req_;
240 if (req->call_ != simix::Simcall::NONE)
241 trace.push_back(api::get().request_to_string(req, req_num));
246 std::shared_ptr<Pair> LivenessChecker::create_pair(const Pair* current_pair, xbt_automaton_state_t state,
247 std::shared_ptr<const std::vector<int>> propositions)
249 ++expanded_pairs_count_;
250 ++expanded_states_count_;
251 auto next_pair = std::make_shared<Pair>(expanded_pairs_count_);
252 next_pair->automaton_state = state;
253 next_pair->graph_state = std::make_shared<State>(expanded_states_count_);
254 next_pair->atomic_propositions = std::move(propositions);
256 next_pair->depth = current_pair->depth + 1;
258 next_pair->depth = 1;
259 /* Add all enabled actors to the interleave set of the initial state */
260 for (auto& act : api::get().get_actors()) {
261 auto actor = act.copy.get_buffer();
262 if (get_session().actor_is_enabled(actor->get_pid()))
263 next_pair->graph_state->mark_todo(actor);
266 next_pair->requests = next_pair->graph_state->count_todo();
267 /* FIXME : get search_cycle value for each accepting state */
268 if (next_pair->automaton_state->type == 1 || (current_pair && current_pair->search_cycle))
269 next_pair->search_cycle = true;
271 next_pair->search_cycle = false;
275 void LivenessChecker::backtrack()
277 /* Traverse the stack backwards until a pair with a non empty interleave
278 set is found, deleting all the pairs that have it empty in the way. */
279 while (not exploration_stack_.empty()) {
280 std::shared_ptr<simgrid::mc::Pair> current_pair = exploration_stack_.back();
281 exploration_stack_.pop_back();
282 if (current_pair->requests > 0) {
283 /* We found a backtracking point */
284 XBT_DEBUG("Backtracking to depth %d", current_pair->depth);
285 exploration_stack_.push_back(std::move(current_pair));
287 XBT_DEBUG("Backtracking done");
290 XBT_DEBUG("Delete pair %d at depth %d", current_pair->num, current_pair->depth);
291 if (current_pair->automaton_state->type == 1)
292 this->remove_acceptance_pair(current_pair->num);
297 void LivenessChecker::run()
299 XBT_INFO("Check the liveness property %s", _sg_mc_property_file.get().c_str());
300 api::get().automaton_load(_sg_mc_property_file.get().c_str());
302 XBT_DEBUG("Starting the liveness algorithm");
303 get_session().take_initial_snapshot();
306 this->previous_pair_ = 0;
308 std::shared_ptr<const std::vector<int>> propos = this->get_proposition_values();
310 // For each initial state of the property automaton, push a
311 // (application_state, automaton_state) pair to the exploration stack:
312 auto automaton_stack = api::get().get_automaton_state();
313 for (auto* automaton_state : automaton_stack) {
314 if (automaton_state->type == -1)
315 exploration_stack_.push_back(this->create_pair(nullptr, automaton_state, propos));
318 /* Actually run the double DFS search for counter-examples */
319 while (not exploration_stack_.empty()) {
320 std::shared_ptr<Pair> current_pair = exploration_stack_.back();
322 /* Update current state in buchi automaton */
323 api::get().set_property_automaton(current_pair->automaton_state);
326 "********************* ( Depth = %d, search_cycle = %d, interleave size = %zu, pair_num = %d, requests = %d)",
327 current_pair->depth, current_pair->search_cycle, current_pair->graph_state->count_todo(), current_pair->num,
328 current_pair->requests);
330 if (current_pair->requests == 0) {
335 std::shared_ptr<VisitedPair> reached_pair;
336 if (current_pair->automaton_state->type == 1 && not current_pair->exploration_started) {
337 reached_pair = this->insert_acceptance_pair(current_pair.get());
338 if (reached_pair == nullptr) {
339 this->show_acceptance_cycle(current_pair->depth);
340 throw LivenessError();
344 /* Pair already visited ? stop the exploration on the current path */
345 if (not current_pair->exploration_started) {
346 int visited_num = this->insert_visited_pair(reached_pair, current_pair.get());
347 if (visited_num != -1) {
348 if (dot_output != nullptr) {
349 fprintf(dot_output, "\"%d\" -> \"%d\" [%s];\n", this->previous_pair_, visited_num,
350 this->previous_request_.c_str());
353 XBT_DEBUG("Pair already visited (equal to pair %d), exploration on the current path stopped.", visited_num);
354 current_pair->requests = 0;
360 smx_simcall_t req = api::get().mc_state_choose_request(current_pair->graph_state.get());
361 int req_num = current_pair->graph_state->transition_.times_considered_;
363 if (dot_output != nullptr) {
364 if (this->previous_pair_ != 0 && this->previous_pair_ != current_pair->num) {
365 fprintf(dot_output, "\"%d\" -> \"%d\" [%s];\n", this->previous_pair_, current_pair->num,
366 this->previous_request_.c_str());
367 this->previous_request_.clear();
369 this->previous_pair_ = current_pair->num;
370 this->previous_request_ = api::get().request_get_dot_output(req, req_num);
371 if (current_pair->search_cycle)
372 fprintf(dot_output, "%d [shape=doublecircle];\n", current_pair->num);
376 XBT_DEBUG("Execute: %s", api::get().request_to_string(req, req_num).c_str());
379 api::get().mc_inc_executed_trans();
381 if (not current_pair->exploration_started)
382 visited_pairs_count_++;
384 /* Answer the request */
385 api::get().handle_simcall(current_pair->graph_state->transition_);
387 /* Wait for requests (schedules processes) */
388 api::get().mc_wait_for_requests();
390 current_pair->requests--;
391 current_pair->exploration_started = true;
393 /* Get values of atomic propositions (variables used in the property formula) */
394 std::shared_ptr<const std::vector<int>> prop_values = this->get_proposition_values();
396 // For each enabled transition in the property automaton, push a
397 // (application_state, automaton_state) pair to the exploration stack:
398 for (int i = api::get().get_dynar_length(current_pair->automaton_state->out) - 1; i >= 0; i--) {
399 auto transition_succ_label = api::get().get_automaton_transition_label(current_pair->automaton_state->out, i);
400 auto transition_succ_dst = api::get().get_automaton_transition_dst(current_pair->automaton_state->out, i);
401 if (evaluate_label(transition_succ_label, *prop_values))
402 exploration_stack_.push_back(this->create_pair(current_pair.get(), transition_succ_dst, prop_values));
406 XBT_INFO("No property violation found.");
407 api::get().log_state();
410 Checker* createLivenessChecker(Session* session)
412 return new LivenessChecker(session);
416 } // namespace simgrid