1 /* Copyright (c) 2008-2023. 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/api/State.hpp"
7 #include "src/mc/api/strategy/BasicStrategy.hpp"
8 #include "src/mc/api/strategy/WaitStrategy.hpp"
9 #include "src/mc/explo/Exploration.hpp"
10 #include "src/mc/mc_config.hpp"
13 #include <boost/range/algorithm.hpp>
15 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_state, mc, "Logging specific to MC states");
17 namespace simgrid::mc {
19 long State::expended_states_ = 0;
21 State::State(RemoteApp& remote_app) : num_(++expended_states_)
23 XBT_VERB("Creating a guide for the state");
24 if (_sg_mc_strategy == "none")
25 strategy_ = std::make_shared<BasicStrategy>();
26 else if (_sg_mc_strategy == "nb_wait")
27 strategy_ = std::make_shared<WaitStrategy>();
31 remote_app.get_actors_status(strategy_->actors_to_run_);
33 #if SIMGRID_HAVE_STATEFUL_MC
34 /* Stateful model checking */
35 if ((_sg_mc_checkpoint > 0 && (num_ % _sg_mc_checkpoint == 0)) || _sg_mc_termination)
36 system_state_ = std::make_shared<simgrid::mc::Snapshot>(num_, remote_app.get_page_store(),
37 *remote_app.get_remote_process_memory());
41 State::State(RemoteApp& remote_app, std::shared_ptr<State> parent_state)
42 : incoming_transition_(parent_state->get_transition_out()), num_(++expended_states_), parent_state_(parent_state)
44 if (_sg_mc_strategy == "none")
45 strategy_ = std::make_shared<BasicStrategy>();
46 else if (_sg_mc_strategy == "nb_wait")
47 strategy_ = std::make_shared<WaitStrategy>();
50 *strategy_ = *(parent_state->strategy_);
52 remote_app.get_actors_status(strategy_->actors_to_run_);
54 #if SIMGRID_HAVE_STATEFUL_MC /* Stateful model checking */
55 if ((_sg_mc_checkpoint > 0 && (num_ % _sg_mc_checkpoint == 0)) || _sg_mc_termination)
56 system_state_ = std::make_shared<simgrid::mc::Snapshot>(num_, remote_app.get_page_store(),
57 *remote_app.get_remote_process_memory());
60 /* If we want sleep set reduction, copy the sleep set and eventually removes things from it */
61 if (_sg_mc_sleep_set) {
62 /* For each actor in the previous sleep set, keep it if it is not dependent with current transition.
63 * And if we kept it and the actor is enabled in this state, mark the actor as already done, so that
64 * it is not explored*/
65 for (auto& [aid, transition] : parent_state_->get_sleep_set()) {
66 if (not incoming_transition_->depends(&transition)) {
67 sleep_set_.try_emplace(aid, transition);
68 if (strategy_->actors_to_run_.count(aid) != 0) {
69 XBT_DEBUG("Actor %ld will not be explored, for it is in the sleep set", aid);
71 strategy_->actors_to_run_.at(aid).mark_done();
74 XBT_DEBUG("Transition >>%s<< removed from the sleep set because it was dependent with incoming >>%s<<",
75 transition.to_string().c_str(), incoming_transition_->to_string().c_str());
80 std::size_t State::count_todo() const
82 return boost::range::count_if(this->strategy_->actors_to_run_, [](auto& pair) { return pair.second.is_todo(); });
85 std::size_t State::count_todo_multiples() const
88 for (auto const& [_, actor] : strategy_->actors_to_run_)
90 count += actor.get_times_not_considered();
95 aid_t State::next_transition() const
97 XBT_DEBUG("Search for an actor to run. %zu actors to consider", strategy_->actors_to_run_.size());
98 for (auto const& [aid, actor] : strategy_->actors_to_run_) {
99 /* Only consider actors (1) marked as interleaving by the checker and (2) currently enabled in the application */
100 if (not actor.is_todo() || not actor.is_enabled() || actor.is_done()) {
101 if (not actor.is_todo())
102 XBT_DEBUG("Can't run actor %ld because it is not todo", aid);
104 if (not actor.is_enabled())
105 XBT_DEBUG("Can't run actor %ld because it is not enabled", aid);
108 XBT_DEBUG("Can't run actor %ld because it has already been done", aid);
118 std::pair<aid_t, int> State::next_transition_guided() const
120 return strategy_->next_transition();
123 aid_t State::next_odpor_transition() const
125 return wakeup_tree_.get_min_single_process_actor().value_or(-1);
128 // This should be done in GuidedState, or at least interact with it
129 std::shared_ptr<Transition> State::execute_next(aid_t next, RemoteApp& app)
131 // First, warn the guide, so it knows how to build a proper child state
132 strategy_->execute_next(next, app);
134 // This actor is ready to be executed. Execution involves three phases:
136 // 1. Identify the appropriate ActorState to prepare for execution
137 // when simcall_handle will be called on it
138 auto& actor_state = strategy_->actors_to_run_.at(next);
139 const unsigned times_considered = actor_state.do_consider();
140 const auto* expected_executed_transition = actor_state.get_transition(times_considered).get();
141 xbt_assert(expected_executed_transition != nullptr,
142 "Expected a transition with %u times considered to be noted in actor %ld", times_considered, next);
144 XBT_DEBUG("Let's run actor %ld (times_considered = %u)", next, times_considered);
146 // 2. Execute the actor according to the preparation above
147 Transition::executed_transitions_++;
148 auto* just_executed = app.handle_simcall(next, times_considered, true);
149 xbt_assert(just_executed->type_ == expected_executed_transition->type_,
150 "The transition that was just executed by actor %ld, viz:\n"
152 "is not what was purportedly scheduled to execute, which was:\n"
154 next, just_executed->to_string().c_str(), expected_executed_transition->to_string().c_str());
156 // 3. Update the state with the newest information. This means recording
158 // 1. what action was last taken from this state (viz. `executed_transition`)
159 // 2. what action actor `next` was able to take given `times_considered`
160 // The latter update is important as *more* information is potentially available
161 // about a transition AFTER it has executed.
162 outgoing_transition_ = std::shared_ptr<Transition>(just_executed);
164 actor_state.set_transition(outgoing_transition_, times_considered);
165 app.wait_for_requests();
167 return outgoing_transition_;
170 std::unordered_set<aid_t> State::get_backtrack_set() const
172 std::unordered_set<aid_t> actors;
173 for (const auto& [aid, state] : get_actors_list()) {
174 if (state.is_todo() or state.is_done()) {
181 std::unordered_set<aid_t> State::get_sleeping_actors() const
183 std::unordered_set<aid_t> actors;
184 for (const auto& [aid, _] : get_sleep_set()) {
190 std::unordered_set<aid_t> State::get_enabled_actors() const
192 std::unordered_set<aid_t> actors;
193 for (const auto& [aid, state] : get_actors_list()) {
194 if (state.is_enabled()) {
201 void State::seed_wakeup_tree_if_needed(const odpor::Execution& prior)
203 // TODO: It would be better not to have such a flag.
204 if (has_initialized_wakeup_tree) {
207 // TODO: Note that the next action taken by the actor may be updated
208 // after it executes. But we will have already inserted it into the
209 // tree and decided upon "happens-before" at that point for different
211 if (wakeup_tree_.empty()) {
212 // Find an enabled transition to pick
213 for (const auto& [_, actor] : get_actors_list()) {
214 if (actor.is_enabled()) {
215 // For each variant of the transition, we want
216 // to insert the action into the tree. This ensures
217 // that all variants are searched?
219 // TODO: How do we modify sleep sets then?
220 for (unsigned times = 0; times < actor.get_max_considered(); ++times) {
221 wakeup_tree_.insert(prior, odpor::PartialExecution{actor.get_transition(times)});
226 has_initialized_wakeup_tree = true;
229 void State::sprout_tree_from_parent_state()
231 xbt_assert(parent_state_ != nullptr, "Attempting to construct a wakeup tree for the root state "
232 "(or what appears to be, rather for state without a parent defined)");
233 const auto min_process_node = parent_state_->wakeup_tree_.get_min_single_process_node();
234 xbt_assert(min_process_node.has_value(), "Attempting to construct a subtree for a substate from a "
235 "parent with an empty wakeup tree. This indicates either that ODPOR "
236 "actor selection in State.cpp is incorrect, or that the code "
237 "deciding when to make subtrees in ODPOR is incorrect");
239 // TODO: This assert should even be bolstered to check that the
240 // the transitions themselves are identical -- not only just
241 // that the actors are the same. When we have to consider
242 // multiple paths for a transition, things get trickier
243 xbt_assert(parent_state_->get_transition_out()->aid_ == min_process_node.value()->get_actor(),
244 "We tried to make a subtree from a parent state who claimed to have executed %ld "
245 "but whose wakeup tree indicates it should have executed %ld. This indicates "
246 "that exploration is not following ODPOR. Are you sure you're choosing actors "
247 "to schedule from the wakeup tree?",
248 parent_state_->get_transition_out()->aid_, min_process_node.value()->get_actor());
249 this->wakeup_tree_ = odpor::WakeupTree::make_subtree_rooted_at(min_process_node.value());
252 void State::remove_subtree_using_current_out_transition()
254 if (auto out_transition = get_transition_out(); out_transition != nullptr) {
255 // TODO: Add invariant check here
258 wakeup_tree_.remove_min_single_process_subtree();
261 void State::mark_path_interesting_for_odpor(const odpor::PartialExecution& pe, const odpor::Execution& E)
263 this->wakeup_tree_.insert(E, pe);
266 void State::do_odpor_backtrack_cleanup()
268 if (auto out_transition = get_transition_out(); out_transition != nullptr) {
269 remove_subtree_using_current_out_transition();
270 add_sleep_set(std::move(out_transition));
274 } // namespace simgrid::mc