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"
13 #include "src/mc/mc_api.hpp"
15 #include <boost/range/algorithm.hpp>
18 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_liveness, mc, "Logging specific to algorithms for liveness properties verification");
20 using mcapi = simgrid::mc::mc_api;
22 /********* Static functions *********/
27 VisitedPair::VisitedPair(int pair_num, xbt_automaton_state_t automaton_state,
28 std::shared_ptr<const std::vector<int>> atomic_propositions,
29 std::shared_ptr<State> graph_state)
30 : num(pair_num), automaton_state(automaton_state)
32 RemoteSimulation* process = &(mc_model_checker->get_remote_simulation());
34 this->graph_state = std::move(graph_state);
35 if (this->graph_state->system_state_ == nullptr)
36 this->graph_state->system_state_ = std::make_shared<Snapshot>(pair_num);
37 this->heap_bytes_used = mmalloc_get_bytes_used_remote(process->get_heap()->heaplimit, process->get_malloc_info());
39 this->actors_count = mc_model_checker->get_remote_simulation().actors().size();
42 this->atomic_propositions = std::move(atomic_propositions);
45 static bool evaluate_label(const xbt_automaton_exp_label* l, std::vector<int> const& values)
48 case xbt_automaton_exp_label::AUT_OR:
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_AND:
52 return evaluate_label(l->u.or_and.left_exp, values)
53 && evaluate_label(l->u.or_and.right_exp, values);
54 case xbt_automaton_exp_label::AUT_NOT:
55 return not evaluate_label(l->u.exp_not, values);
56 case xbt_automaton_exp_label::AUT_PREDICAT:{
57 unsigned int cursor = 0;
58 xbt_automaton_propositional_symbol_t p = nullptr;
59 xbt_dynar_foreach(simgrid::mc::property_automaton->propositional_symbols, cursor, p) {
60 if (std::strcmp(xbt_automaton_propositional_symbol_get_name(p), l->u.predicat) == 0)
61 return values[cursor] != 0;
63 xbt_die("Missing predicate");
66 case xbt_automaton_exp_label::AUT_ONE:
69 xbt_die("Unexpected value for automaton");
73 Pair::Pair(unsigned long expanded_pairs) : num(expanded_pairs)
76 std::shared_ptr<const std::vector<int>> LivenessChecker::get_proposition_values() const
78 std::vector<int> values;
79 unsigned int cursor = 0;
80 xbt_automaton_propositional_symbol_t ps = nullptr;
81 xbt_dynar_foreach (mc::property_automaton->propositional_symbols, cursor, ps)
82 values.push_back(xbt_automaton_propositional_symbol_evaluate(ps));
83 return std::make_shared<const std::vector<int>>(std::move(values));
86 std::shared_ptr<VisitedPair> LivenessChecker::insert_acceptance_pair(simgrid::mc::Pair* pair)
89 std::make_shared<VisitedPair>(pair->num, pair->automaton_state, pair->atomic_propositions, pair->graph_state);
91 auto res = boost::range::equal_range(acceptance_pairs_, new_pair.get(), DerefAndCompareByActorsCountAndUsedHeap());
93 if (pair->search_cycle) for (auto i = res.first; i != res.second; ++i) {
94 std::shared_ptr<simgrid::mc::VisitedPair> const& pair_test = *i;
95 if (xbt_automaton_state_compare(pair_test->automaton_state, new_pair->automaton_state) != 0 ||
96 *(pair_test->atomic_propositions) != *(new_pair->atomic_propositions) ||
97 not snapshot_equal(pair_test->graph_state->system_state_.get(), new_pair->graph_state->system_state_.get()))
99 XBT_INFO("Pair %d already reached (equal to pair %d) !", new_pair->num, pair_test->num);
100 exploration_stack_.pop_back();
101 if (dot_output != nullptr)
102 fprintf(dot_output, "\"%d\" -> \"%d\" [%s];\n", this->previous_pair_, pair_test->num,
103 this->previous_request_.c_str());
107 acceptance_pairs_.insert(res.first, new_pair);
111 void LivenessChecker::remove_acceptance_pair(int pair_num)
113 for (auto i = acceptance_pairs_.begin(); i != acceptance_pairs_.end(); ++i)
114 if ((*i)->num == pair_num) {
115 acceptance_pairs_.erase(i);
120 void LivenessChecker::replay()
122 XBT_DEBUG("**** Begin Replay ****");
124 /* Intermediate backtracking */
125 if(_sg_mc_checkpoint > 0) {
126 const Pair* pair = exploration_stack_.back().get();
127 if (pair->graph_state->system_state_) {
128 pair->graph_state->system_state_->restore(&mc_model_checker->get_remote_simulation());
133 /* Restore the initial state */
134 mc::session->restore_initial_state();
136 /* Traverse the stack from the initial state and re-execute the transitions */
138 for (std::shared_ptr<Pair> const& pair : exploration_stack_) {
139 if (pair == exploration_stack_.back())
142 std::shared_ptr<State> state = pair->graph_state;
144 if (pair->exploration_started) {
145 int req_num = state->transition_.argument_;
146 const s_smx_simcall* saved_req = &state->executed_req_;
148 smx_simcall_t req = nullptr;
150 if (saved_req != nullptr) {
151 /* because we got a copy of the executed request, we have to fetch the
152 real one, pointed by the request field of the issuer process */
153 const smx_actor_t issuer = MC_smx_simcall_get_issuer(saved_req);
154 req = &issuer->simcall_;
156 /* Debug information */
157 XBT_DEBUG("Replay (depth = %d) : %s (%p)", depth,
158 request_to_string(req, req_num, simgrid::mc::RequestType::simix).c_str(), state.get());
161 this->get_session().execute(state->transition_);
164 /* Update statistics */
165 visited_pairs_count_++;
166 mc_model_checker->executed_transitions++;
170 XBT_DEBUG("**** End Replay ****");
174 * @brief Checks whether a given pair has already been visited by the algorithm.
176 int LivenessChecker::insert_visited_pair(std::shared_ptr<VisitedPair> visited_pair, simgrid::mc::Pair* pair)
178 if (_sg_mc_max_visited_states == 0)
181 if (visited_pair == nullptr)
183 std::make_shared<VisitedPair>(pair->num, pair->automaton_state, pair->atomic_propositions, pair->graph_state);
185 auto range = boost::range::equal_range(visited_pairs_, visited_pair.get(), DerefAndCompareByActorsCountAndUsedHeap());
187 for (auto i = range.first; i != range.second; ++i) {
188 const VisitedPair* pair_test = i->get();
189 if (xbt_automaton_state_compare(pair_test->automaton_state, visited_pair->automaton_state) != 0 ||
190 *(pair_test->atomic_propositions) != *(visited_pair->atomic_propositions) ||
191 not snapshot_equal(pair_test->graph_state->system_state_.get(), visited_pair->graph_state->system_state_.get()))
193 if (pair_test->other_num == -1)
194 visited_pair->other_num = pair_test->num;
196 visited_pair->other_num = pair_test->other_num;
197 if (dot_output == nullptr)
198 XBT_DEBUG("Pair %d already visited ! (equal to pair %d)", visited_pair->num, pair_test->num);
200 XBT_DEBUG("Pair %d already visited ! (equal to pair %d (pair %d in dot_output))",
201 visited_pair->num, pair_test->num, visited_pair->other_num);
202 (*i) = std::move(visited_pair);
203 return (*i)->other_num;
206 visited_pairs_.insert(range.first, std::move(visited_pair));
207 this->purge_visited_pairs();
211 void LivenessChecker::purge_visited_pairs()
213 if (_sg_mc_max_visited_states != 0 && visited_pairs_.size() > (std::size_t)_sg_mc_max_visited_states) {
214 // Remove the oldest entry with a linear search:
215 visited_pairs_.erase(
216 boost::min_element(visited_pairs_, [](std::shared_ptr<VisitedPair> const a,
217 std::shared_ptr<VisitedPair> const& b) { return a->num < b->num; }));
221 LivenessChecker::LivenessChecker(Session& s) : Checker(s)
225 RecordTrace LivenessChecker::get_record_trace() // override
228 for (std::shared_ptr<Pair> const& pair : exploration_stack_)
229 res.push_back(pair->graph_state->get_transition());
233 void LivenessChecker::log_state() // override
235 XBT_INFO("Expanded pairs = %lu", expanded_pairs_count_);
236 XBT_INFO("Visited pairs = %lu", visited_pairs_count_);
237 XBT_INFO("Executed transitions = %lu", mc_model_checker->executed_transitions);
240 void LivenessChecker::show_acceptance_cycle(std::size_t depth)
242 XBT_INFO("*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*");
243 XBT_INFO("| ACCEPTANCE CYCLE |");
244 XBT_INFO("*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*");
245 XBT_INFO("Counter-example that violates formula:");
246 for (auto const& s : this->get_textual_trace())
247 XBT_INFO(" %s", s.c_str());
248 mc::dumpRecordPath();
249 mc::session->log_state();
250 XBT_INFO("Counter-example depth: %zu", depth);
253 std::vector<std::string> LivenessChecker::get_textual_trace() // override
255 std::vector<std::string> trace;
256 for (std::shared_ptr<Pair> const& pair : exploration_stack_) {
257 int req_num = pair->graph_state->transition_.argument_;
258 smx_simcall_t req = &pair->graph_state->executed_req_;
259 if (req && req->call_ != SIMCALL_NONE)
260 trace.push_back(request_to_string(req, req_num, RequestType::executed));
265 std::shared_ptr<Pair> LivenessChecker::create_pair(const Pair* current_pair, xbt_automaton_state_t state,
266 std::shared_ptr<const std::vector<int>> propositions)
268 ++expanded_pairs_count_;
269 ++expanded_states_count_;
270 auto next_pair = std::make_shared<Pair>(expanded_pairs_count_);
271 next_pair->automaton_state = state;
272 next_pair->graph_state = std::make_shared<State>(expanded_states_count_);
273 next_pair->atomic_propositions = std::move(propositions);
275 next_pair->depth = current_pair->depth + 1;
277 next_pair->depth = 1;
278 /* Get enabled actors and insert them in the interleave set of the next graph_state */
279 for (auto& actor : mc_model_checker->get_remote_simulation().actors())
280 if (mc::actor_is_enabled(actor.copy.get_buffer()))
281 next_pair->graph_state->add_interleaving_set(actor.copy.get_buffer());
282 next_pair->requests = next_pair->graph_state->interleave_size();
283 /* FIXME : get search_cycle value for each accepting state */
284 if (next_pair->automaton_state->type == 1 || (current_pair && current_pair->search_cycle))
285 next_pair->search_cycle = true;
287 next_pair->search_cycle = false;
291 void LivenessChecker::backtrack()
293 /* Traverse the stack backwards until a pair with a non empty interleave
294 set is found, deleting all the pairs that have it empty in the way. */
295 while (not exploration_stack_.empty()) {
296 std::shared_ptr<simgrid::mc::Pair> current_pair = exploration_stack_.back();
297 exploration_stack_.pop_back();
298 if (current_pair->requests > 0) {
299 /* We found a backtracking point */
300 XBT_DEBUG("Backtracking to depth %d", current_pair->depth);
301 exploration_stack_.push_back(std::move(current_pair));
303 XBT_DEBUG("Backtracking done");
306 XBT_DEBUG("Delete pair %d at depth %d", current_pair->num, current_pair->depth);
307 if (current_pair->automaton_state->type == 1)
308 this->remove_acceptance_pair(current_pair->num);
313 void LivenessChecker::run()
315 XBT_INFO("Check the liveness property %s", _sg_mc_property_file.get().c_str());
316 MC_automaton_load(_sg_mc_property_file.get().c_str());
318 XBT_DEBUG("Starting the liveness algorithm");
319 mc::session->initialize();
322 this->previous_pair_ = 0;
324 std::shared_ptr<const std::vector<int>> propos = this->get_proposition_values();
326 // For each initial state of the property automaton, push a
327 // (application_state, automaton_state) pair to the exploration stack:
328 unsigned int cursor = 0;
329 xbt_automaton_state_t automaton_state;
330 xbt_dynar_foreach (mc::property_automaton->states, cursor, automaton_state)
331 if (automaton_state->type == -1)
332 exploration_stack_.push_back(this->create_pair(nullptr, automaton_state, propos));
334 /* Actually run the double DFS search for counter-examples */
335 while (not exploration_stack_.empty()) {
336 std::shared_ptr<Pair> current_pair = exploration_stack_.back();
338 /* Update current state in buchi automaton */
339 mc::property_automaton->current_state = current_pair->automaton_state;
342 "********************* ( Depth = %d, search_cycle = %d, interleave size = %zu, pair_num = %d, requests = %d)",
343 current_pair->depth, current_pair->search_cycle, current_pair->graph_state->interleave_size(),
344 current_pair->num, current_pair->requests);
346 if (current_pair->requests == 0) {
351 std::shared_ptr<VisitedPair> reached_pair;
352 if (current_pair->automaton_state->type == 1 && not current_pair->exploration_started) {
353 reached_pair = this->insert_acceptance_pair(current_pair.get());
354 if (reached_pair == nullptr) {
355 this->show_acceptance_cycle(current_pair->depth);
356 throw LivenessError();
360 /* Pair already visited ? stop the exploration on the current path */
361 if (not current_pair->exploration_started) {
362 int visited_num = this->insert_visited_pair(reached_pair, current_pair.get());
363 if (visited_num != -1) {
364 if (dot_output != nullptr) {
365 fprintf(dot_output, "\"%d\" -> \"%d\" [%s];\n", this->previous_pair_, visited_num,
366 this->previous_request_.c_str());
369 XBT_DEBUG("Pair already visited (equal to pair %d), exploration on the current path stopped.", visited_num);
370 current_pair->requests = 0;
376 smx_simcall_t req = mcapi::get().mc_state_choose_request(current_pair->graph_state.get());
377 int req_num = current_pair->graph_state->transition_.argument_;
379 if (dot_output != nullptr) {
380 if (this->previous_pair_ != 0 && this->previous_pair_ != current_pair->num) {
381 fprintf(dot_output, "\"%d\" -> \"%d\" [%s];\n", this->previous_pair_, current_pair->num,
382 this->previous_request_.c_str());
383 this->previous_request_.clear();
385 this->previous_pair_ = current_pair->num;
386 this->previous_request_ = request_get_dot_output(req, req_num);
387 if (current_pair->search_cycle)
388 fprintf(dot_output, "%d [shape=doublecircle];\n", current_pair->num);
392 XBT_DEBUG("Execute: %s", request_to_string(req, req_num, RequestType::simix).c_str());
395 mc_model_checker->executed_transitions++;
396 if (not current_pair->exploration_started)
397 visited_pairs_count_++;
399 /* Answer the request */
400 mc_model_checker->handle_simcall(current_pair->graph_state->transition_);
402 /* Wait for requests (schedules processes) */
403 mc_model_checker->wait_for_requests();
405 current_pair->requests--;
406 current_pair->exploration_started = true;
408 /* Get values of atomic propositions (variables used in the property formula) */
409 std::shared_ptr<const std::vector<int>> prop_values = this->get_proposition_values();
411 // For each enabled transition in the property automaton, push a
412 // (application_state, automaton_state) pair to the exploration stack:
413 for (int i = xbt_dynar_length(current_pair->automaton_state->out) - 1; i >= 0; i--) {
414 const xbt_automaton_transition* transition_succ =
415 xbt_dynar_get_as(current_pair->automaton_state->out, i, xbt_automaton_transition_t);
416 if (evaluate_label(transition_succ->label, *prop_values))
417 exploration_stack_.push_back(this->create_pair(current_pair.get(), transition_succ->dst, prop_values));
421 XBT_INFO("No property violation found.");
422 mc::session->log_state();
425 Checker* createLivenessChecker(Session& s)
427 return new LivenessChecker(s);
431 } // namespace simgrid