1 /* Copyright (c) 2011-2020. 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"
11 #include "src/mc/mc_request.hpp"
12 #include "src/mc/mc_smx.hpp"
14 #include <boost/range/algorithm.hpp>
17 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_liveness, mc, "Logging specific to algorithms for liveness properties verification");
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 RemoteClient* process = &(mc_model_checker->process());
31 this->graph_state = std::move(graph_state);
32 if (this->graph_state->system_state_ == nullptr)
33 this->graph_state->system_state_ = std::make_shared<Snapshot>(pair_num);
34 this->heap_bytes_used = mmalloc_get_bytes_used_remote(process->get_heap()->heaplimit, process->get_malloc_info());
36 this->actors_count = mc_model_checker->process().actors().size();
39 this->atomic_propositions = std::move(atomic_propositions);
42 static bool evaluate_label(const xbt_automaton_exp_label* l, std::vector<int> const& values)
45 case xbt_automaton_exp_label::AUT_OR:
46 return evaluate_label(l->u.or_and.left_exp, values)
47 || evaluate_label(l->u.or_and.right_exp, values);
48 case xbt_automaton_exp_label::AUT_AND:
49 return evaluate_label(l->u.or_and.left_exp, values)
50 && evaluate_label(l->u.or_and.right_exp, values);
51 case xbt_automaton_exp_label::AUT_NOT:
52 return not evaluate_label(l->u.exp_not, values);
53 case xbt_automaton_exp_label::AUT_PREDICAT:{
54 unsigned int cursor = 0;
55 xbt_automaton_propositional_symbol_t p = nullptr;
56 xbt_dynar_foreach(simgrid::mc::property_automaton->propositional_symbols, cursor, p) {
57 if (std::strcmp(xbt_automaton_propositional_symbol_get_name(p), l->u.predicat) == 0)
58 return values[cursor] != 0;
60 xbt_die("Missing predicate");
63 case xbt_automaton_exp_label::AUT_ONE:
66 xbt_die("Unexpected vaue for automaton");
70 Pair::Pair(unsigned long expanded_pairs) : num(expanded_pairs)
73 std::shared_ptr<const std::vector<int>> LivenessChecker::get_proposition_values()
75 std::vector<int> values;
76 unsigned int cursor = 0;
77 xbt_automaton_propositional_symbol_t ps = nullptr;
78 xbt_dynar_foreach (mc::property_automaton->propositional_symbols, cursor, ps)
79 values.push_back(xbt_automaton_propositional_symbol_evaluate(ps));
80 return std::make_shared<const std::vector<int>>(std::move(values));
83 std::shared_ptr<VisitedPair> LivenessChecker::insert_acceptance_pair(simgrid::mc::Pair* pair)
85 std::shared_ptr<VisitedPair> new_pair = std::make_shared<VisitedPair>(
86 pair->num, pair->automaton_state, pair->atomic_propositions,
89 auto res = boost::range::equal_range(acceptance_pairs_, new_pair.get(), DerefAndCompareByActorsCountAndUsedHeap());
91 if (pair->search_cycle) for (auto i = res.first; i != res.second; ++i) {
92 std::shared_ptr<simgrid::mc::VisitedPair> const& pair_test = *i;
93 if (xbt_automaton_state_compare(pair_test->automaton_state, new_pair->automaton_state) != 0 ||
94 *(pair_test->atomic_propositions) != *(new_pair->atomic_propositions) ||
95 not snapshot_equal(pair_test->graph_state->system_state_.get(), new_pair->graph_state->system_state_.get()))
97 XBT_INFO("Pair %d already reached (equal to pair %d) !", new_pair->num, pair_test->num);
98 exploration_stack_.pop_back();
99 if (dot_output != nullptr)
100 fprintf(dot_output, "\"%d\" -> \"%d\" [%s];\n", this->previous_pair_, pair_test->num,
101 this->previous_request_.c_str());
105 acceptance_pairs_.insert(res.first, new_pair);
109 void LivenessChecker::remove_acceptance_pair(int pair_num)
111 for (auto i = acceptance_pairs_.begin(); i != acceptance_pairs_.end(); ++i)
112 if ((*i)->num == pair_num) {
113 acceptance_pairs_.erase(i);
118 void LivenessChecker::replay()
120 XBT_DEBUG("**** Begin Replay ****");
122 /* Intermediate backtracking */
123 if(_sg_mc_checkpoint > 0) {
124 const Pair* pair = exploration_stack_.back().get();
125 if (pair->graph_state->system_state_) {
126 pair->graph_state->system_state_->restore(&mc_model_checker->process());
131 /* Restore the initial state */
132 mc::session->restore_initial_state();
134 /* Traverse the stack from the initial state and re-execute the transitions */
136 for (std::shared_ptr<Pair> const& pair : exploration_stack_) {
137 if (pair == exploration_stack_.back())
140 std::shared_ptr<State> state = pair->graph_state;
142 if (pair->exploration_started) {
143 int req_num = state->transition_.argument_;
144 const s_smx_simcall* saved_req = &state->executed_req_;
146 smx_simcall_t req = nullptr;
148 if (saved_req != nullptr) {
149 /* because we got a copy of the executed request, we have to fetch the
150 real one, pointed by the request field of the issuer process */
151 const smx_actor_t issuer = MC_smx_simcall_get_issuer(saved_req);
152 req = &issuer->simcall;
154 /* Debug information */
155 XBT_DEBUG("Replay (depth = %d) : %s (%p)", depth,
156 request_to_string(req, req_num, simgrid::mc::RequestType::simix).c_str(), state.get());
159 this->get_session().execute(state->transition_);
162 /* Update statistics */
163 visited_pairs_count_++;
164 mc_model_checker->executed_transitions++;
168 XBT_DEBUG("**** End Replay ****");
172 * @brief Checks whether a given pair has already been visited by the algorithm.
174 int LivenessChecker::insert_visited_pair(std::shared_ptr<VisitedPair> visited_pair, simgrid::mc::Pair* pair)
176 if (_sg_mc_max_visited_states == 0)
179 if (visited_pair == nullptr)
181 std::make_shared<VisitedPair>(pair->num, pair->automaton_state, pair->atomic_propositions, pair->graph_state);
183 auto range = boost::range::equal_range(visited_pairs_, visited_pair.get(), DerefAndCompareByActorsCountAndUsedHeap());
185 for (auto i = range.first; i != range.second; ++i) {
186 const VisitedPair* pair_test = i->get();
187 if (xbt_automaton_state_compare(pair_test->automaton_state, visited_pair->automaton_state) != 0 ||
188 *(pair_test->atomic_propositions) != *(visited_pair->atomic_propositions) ||
189 not snapshot_equal(pair_test->graph_state->system_state_.get(), visited_pair->graph_state->system_state_.get()))
191 if (pair_test->other_num == -1)
192 visited_pair->other_num = pair_test->num;
194 visited_pair->other_num = pair_test->other_num;
195 if (dot_output == nullptr)
196 XBT_DEBUG("Pair %d already visited ! (equal to pair %d)", visited_pair->num, pair_test->num);
198 XBT_DEBUG("Pair %d already visited ! (equal to pair %d (pair %d in dot_output))",
199 visited_pair->num, pair_test->num, visited_pair->other_num);
200 (*i) = std::move(visited_pair);
201 return (*i)->other_num;
204 visited_pairs_.insert(range.first, std::move(visited_pair));
205 this->purge_visited_pairs();
209 void LivenessChecker::purge_visited_pairs()
211 if (_sg_mc_max_visited_states != 0 && visited_pairs_.size() > (std::size_t)_sg_mc_max_visited_states) {
212 // Remove the oldest entry with a linear search:
213 visited_pairs_.erase(
214 boost::min_element(visited_pairs_, [](std::shared_ptr<VisitedPair> const a,
215 std::shared_ptr<VisitedPair> const& b) { return a->num < b->num; }));
219 LivenessChecker::LivenessChecker(Session& s) : Checker(s)
223 RecordTrace LivenessChecker::get_record_trace() // override
226 for (std::shared_ptr<Pair> const& pair : exploration_stack_)
227 res.push_back(pair->graph_state->get_transition());
231 void LivenessChecker::log_state() // override
233 XBT_INFO("Expanded pairs = %lu", expanded_pairs_count_);
234 XBT_INFO("Visited pairs = %lu", visited_pairs_count_);
235 XBT_INFO("Executed transitions = %lu", mc_model_checker->executed_transitions);
238 void LivenessChecker::show_acceptance_cycle(std::size_t depth)
240 XBT_INFO("*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*");
241 XBT_INFO("| ACCEPTANCE CYCLE |");
242 XBT_INFO("*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*");
243 XBT_INFO("Counter-example that violates formula:");
244 for (auto const& s : this->get_textual_trace())
245 XBT_INFO(" %s", s.c_str());
246 mc::dumpRecordPath();
247 mc::session->log_state();
248 XBT_INFO("Counter-example depth: %zu", depth);
251 std::vector<std::string> LivenessChecker::get_textual_trace() // override
253 std::vector<std::string> trace;
254 for (std::shared_ptr<Pair> const& pair : exploration_stack_) {
255 int req_num = pair->graph_state->transition_.argument_;
256 smx_simcall_t req = &pair->graph_state->executed_req_;
257 if (req && req->call_ != SIMCALL_NONE)
258 trace.push_back(request_to_string(req, req_num, RequestType::executed));
263 std::shared_ptr<Pair> LivenessChecker::create_pair(const Pair* current_pair, xbt_automaton_state_t state,
264 std::shared_ptr<const std::vector<int>> propositions)
266 expanded_pairs_count_++;
267 std::shared_ptr<Pair> next_pair = std::make_shared<Pair>(expanded_pairs_count_);
268 next_pair->automaton_state = state;
269 next_pair->graph_state = std::shared_ptr<State>(new State(++expanded_states_count_));
270 next_pair->atomic_propositions = std::move(propositions);
272 next_pair->depth = current_pair->depth + 1;
274 next_pair->depth = 1;
275 /* Get enabled actors and insert them in the interleave set of the next graph_state */
276 for (auto& actor : mc_model_checker->process().actors())
277 if (mc::actor_is_enabled(actor.copy.get_buffer()))
278 next_pair->graph_state->add_interleaving_set(actor.copy.get_buffer());
279 next_pair->requests = next_pair->graph_state->interleave_size();
280 /* FIXME : get search_cycle value for each accepting state */
281 if (next_pair->automaton_state->type == 1 || (current_pair && current_pair->search_cycle))
282 next_pair->search_cycle = true;
284 next_pair->search_cycle = false;
288 void LivenessChecker::backtrack()
290 /* Traverse the stack backwards until a pair with a non empty interleave
291 set is found, deleting all the pairs that have it empty in the way. */
292 while (not exploration_stack_.empty()) {
293 std::shared_ptr<simgrid::mc::Pair> current_pair = exploration_stack_.back();
294 exploration_stack_.pop_back();
295 if (current_pair->requests > 0) {
296 /* We found a backtracking point */
297 XBT_DEBUG("Backtracking to depth %d", current_pair->depth);
298 exploration_stack_.push_back(std::move(current_pair));
300 XBT_DEBUG("Backtracking done");
303 XBT_DEBUG("Delete pair %d at depth %d", current_pair->num, current_pair->depth);
304 if (current_pair->automaton_state->type == 1)
305 this->remove_acceptance_pair(current_pair->num);
310 void LivenessChecker::run()
312 XBT_INFO("Check the liveness property %s", _sg_mc_property_file.get().c_str());
313 MC_automaton_load(_sg_mc_property_file.get().c_str());
315 XBT_DEBUG("Starting the liveness algorithm");
316 mc::session->initialize();
319 this->previous_pair_ = 0;
321 std::shared_ptr<const std::vector<int>> propos = this->get_proposition_values();
323 // For each initial state of the property automaton, push a
324 // (application_state, automaton_state) pair to the exploration stack:
325 unsigned int cursor = 0;
326 xbt_automaton_state_t automaton_state;
327 xbt_dynar_foreach (mc::property_automaton->states, cursor, automaton_state)
328 if (automaton_state->type == -1)
329 exploration_stack_.push_back(this->create_pair(nullptr, automaton_state, propos));
331 /* Actually run the double DFS search for counter-examples */
332 while (not exploration_stack_.empty()) {
333 std::shared_ptr<Pair> current_pair = exploration_stack_.back();
335 /* Update current state in buchi automaton */
336 mc::property_automaton->current_state = current_pair->automaton_state;
339 "********************* ( Depth = %d, search_cycle = %d, interleave size = %zu, pair_num = %d, requests = %d)",
340 current_pair->depth, current_pair->search_cycle, current_pair->graph_state->interleave_size(),
341 current_pair->num, current_pair->requests);
343 if (current_pair->requests == 0) {
348 std::shared_ptr<VisitedPair> reached_pair;
349 if (current_pair->automaton_state->type == 1 && not current_pair->exploration_started) {
350 reached_pair = this->insert_acceptance_pair(current_pair.get());
351 if (reached_pair == nullptr) {
352 this->show_acceptance_cycle(current_pair->depth);
353 throw LivenessError();
357 /* Pair already visited ? stop the exploration on the current path */
358 if (not current_pair->exploration_started) {
359 int visited_num = this->insert_visited_pair(reached_pair, current_pair.get());
360 if (visited_num != -1) {
361 if (dot_output != nullptr) {
362 fprintf(dot_output, "\"%d\" -> \"%d\" [%s];\n", this->previous_pair_, visited_num,
363 this->previous_request_.c_str());
366 XBT_DEBUG("Pair already visited (equal to pair %d), exploration on the current path stopped.", visited_num);
367 current_pair->requests = 0;
373 smx_simcall_t req = MC_state_choose_request(current_pair->graph_state.get());
374 int req_num = current_pair->graph_state->transition_.argument_;
376 if (dot_output != nullptr) {
377 if (this->previous_pair_ != 0 && this->previous_pair_ != current_pair->num) {
378 fprintf(dot_output, "\"%d\" -> \"%d\" [%s];\n", this->previous_pair_, current_pair->num,
379 this->previous_request_.c_str());
380 this->previous_request_.clear();
382 this->previous_pair_ = current_pair->num;
383 this->previous_request_ = request_get_dot_output(req, req_num);
384 if (current_pair->search_cycle)
385 fprintf(dot_output, "%d [shape=doublecircle];\n", current_pair->num);
389 XBT_DEBUG("Execute: %s", request_to_string(req, req_num, RequestType::simix).c_str());
392 mc_model_checker->executed_transitions++;
393 if (not current_pair->exploration_started)
394 visited_pairs_count_++;
396 /* Answer the request */
397 mc_model_checker->handle_simcall(current_pair->graph_state->transition_);
399 /* Wait for requests (schedules processes) */
400 mc_model_checker->wait_for_requests();
402 current_pair->requests--;
403 current_pair->exploration_started = true;
405 /* Get values of atomic propositions (variables used in the property formula) */
406 std::shared_ptr<const std::vector<int>> prop_values = this->get_proposition_values();
408 // For each enabled transition in the property automaton, push a
409 // (application_state, automaton_state) pair to the exploration stack:
410 for (int i = xbt_dynar_length(current_pair->automaton_state->out) - 1; i >= 0; i--) {
411 const xbt_automaton_transition* transition_succ = (xbt_automaton_transition_t)xbt_dynar_get_as(
412 current_pair->automaton_state->out, i, xbt_automaton_transition_t);
413 if (evaluate_label(transition_succ->label, *prop_values))
414 exploration_stack_.push_back(this->create_pair(current_pair.get(), transition_succ->dst, prop_values));
418 XBT_INFO("No property violation found.");
419 mc::session->log_state();
422 Checker* createLivenessChecker(Session& s)
424 return new LivenessChecker(s);
428 } // namespace simgrid