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/MaxMatchComm.hpp"
9 #include "src/mc/api/strategy/MinMatchComm.hpp"
10 #include "src/mc/api/strategy/UniformStrategy.hpp"
11 #include "src/mc/explo/Exploration.hpp"
12 #include "src/mc/mc_config.hpp"
15 #include <boost/range/algorithm.hpp>
17 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_state, mc, "Logging specific to MC states");
19 namespace simgrid::mc {
21 long State::expended_states_ = 0;
23 State::State(RemoteApp& remote_app) : num_(++expended_states_)
25 XBT_VERB("Creating a guide for the state");
27 srand(_sg_mc_random_seed);
29 if (_sg_mc_strategy == "none")
30 strategy_ = std::make_shared<BasicStrategy>();
31 else if (_sg_mc_strategy == "max_match_comm")
32 strategy_ = std::make_shared<MaxMatchComm>();
33 else if (_sg_mc_strategy == "min_match_comm")
34 strategy_ = std::make_shared<MinMatchComm>();
35 else if (_sg_mc_strategy == "uniform")
36 strategy_ = std::make_shared<UniformStrategy>();
40 remote_app.get_actors_status(strategy_->actors_to_run_);
42 #if SIMGRID_HAVE_STATEFUL_MC
43 /* Stateful model checking */
44 if ((_sg_mc_checkpoint > 0 && (num_ % _sg_mc_checkpoint == 0)) || _sg_mc_termination)
45 system_state_ = std::make_shared<simgrid::mc::Snapshot>(num_, remote_app.get_page_store(),
46 *remote_app.get_remote_process_memory());
50 State::State(RemoteApp& remote_app, std::shared_ptr<State> parent_state)
51 : incoming_transition_(parent_state->get_transition_out()), num_(++expended_states_), parent_state_(parent_state)
54 if (_sg_mc_strategy == "none")
55 strategy_ = std::make_shared<BasicStrategy>();
56 else if (_sg_mc_strategy == "max_match_comm")
57 strategy_ = std::make_shared<MaxMatchComm>();
58 else if (_sg_mc_strategy == "min_match_comm")
59 strategy_ = std::make_shared<MinMatchComm>();
60 else if (_sg_mc_strategy == "uniform")
61 strategy_ = std::make_shared<UniformStrategy>();
64 strategy_->copy_from(parent_state_->strategy_.get());
66 remote_app.get_actors_status(strategy_->actors_to_run_);
68 #if SIMGRID_HAVE_STATEFUL_MC /* Stateful model checking */
69 if ((_sg_mc_checkpoint > 0 && (num_ % _sg_mc_checkpoint == 0)) || _sg_mc_termination)
70 system_state_ = std::make_shared<simgrid::mc::Snapshot>(num_, remote_app.get_page_store(),
71 *remote_app.get_remote_process_memory());
74 /* If we want sleep set reduction, copy the sleep set and eventually removes things from it */
75 if (_sg_mc_sleep_set) {
76 /* For each actor in the previous sleep set, keep it if it is not dependent with current transition.
77 * And if we kept it and the actor is enabled in this state, mark the actor as already done, so that
78 * it is not explored*/
79 for (auto& [aid, transition] : parent_state_->get_sleep_set()) {
80 if (not incoming_transition_->depends(transition.get())) {
81 sleep_set_.try_emplace(aid, transition);
82 if (strategy_->actors_to_run_.count(aid) != 0) {
83 XBT_DEBUG("Actor %ld will not be explored, for it is in the sleep set", aid);
84 strategy_->actors_to_run_.at(aid).mark_done();
87 XBT_DEBUG("Transition >>%s<< removed from the sleep set because it was dependent with incoming >>%s<<",
88 transition->to_string().c_str(), incoming_transition_->to_string().c_str());
93 std::size_t State::count_todo() const
95 return boost::range::count_if(this->strategy_->actors_to_run_, [](auto& pair) { return pair.second.is_todo(); });
98 std::size_t State::count_todo_multiples() const
101 for (auto const& [_, actor] : strategy_->actors_to_run_)
103 count += actor.get_times_not_considered();
108 aid_t State::next_transition() const
110 XBT_DEBUG("Search for an actor to run. %zu actors to consider", strategy_->actors_to_run_.size());
111 for (auto const& [aid, actor] : strategy_->actors_to_run_) {
112 /* Only consider actors (1) marked as interleaving by the checker and (2) currently enabled in the application */
113 if (not actor.is_todo() || not actor.is_enabled() || actor.is_done()) {
114 if (not actor.is_todo())
115 XBT_DEBUG("Can't run actor %ld because it is not todo", aid);
117 if (not actor.is_enabled())
118 XBT_DEBUG("Can't run actor %ld because it is not enabled", aid);
121 XBT_DEBUG("Can't run actor %ld because it has already been done", aid);
131 std::pair<aid_t, int> State::next_transition_guided() const
133 return strategy_->next_transition();
136 aid_t State::next_odpor_transition() const
138 return wakeup_tree_.get_min_single_process_actor().value_or(-1);
141 // This should be done in GuidedState, or at least interact with it
142 std::shared_ptr<Transition> State::execute_next(aid_t next, RemoteApp& app)
144 // First, warn the guide, so it knows how to build a proper child state
145 strategy_->execute_next(next, app);
147 // This actor is ready to be executed. Execution involves three phases:
149 // 1. Identify the appropriate ActorState to prepare for execution
150 // when simcall_handle will be called on it
151 auto& actor_state = strategy_->actors_to_run_.at(next);
152 const unsigned times_considered = actor_state.do_consider();
153 const auto* expected_executed_transition = actor_state.get_transition(times_considered).get();
154 xbt_assert(expected_executed_transition != nullptr,
155 "Expected a transition with %u times considered to be noted in actor %ld", times_considered, next);
157 XBT_DEBUG("Let's run actor %ld (times_considered = %u)", next, times_considered);
159 // 2. Execute the actor according to the preparation above
160 Transition::executed_transitions_++;
161 auto* just_executed = app.handle_simcall(next, times_considered, true);
162 xbt_assert(just_executed->type_ == expected_executed_transition->type_,
163 "The transition that was just executed by actor %ld, viz:\n"
165 "is not what was purportedly scheduled to execute, which was:\n"
167 next, just_executed->to_string().c_str(), expected_executed_transition->to_string().c_str());
169 // 3. Update the state with the newest information. This means recording
171 // 1. what action was last taken from this state (viz. `executed_transition`)
172 // 2. what action actor `next` was able to take given `times_considered`
173 // The latter update is important as *more* information is potentially available
174 // about a transition AFTER it has executed.
175 outgoing_transition_ = std::shared_ptr<Transition>(just_executed);
177 actor_state.set_transition(outgoing_transition_, times_considered);
178 app.wait_for_requests();
180 return outgoing_transition_;
183 std::unordered_set<aid_t> State::get_backtrack_set() const
185 std::unordered_set<aid_t> actors;
186 for (const auto& [aid, state] : get_actors_list()) {
187 if (state.is_todo() or state.is_done()) {
194 std::unordered_set<aid_t> State::get_sleeping_actors() const
196 std::unordered_set<aid_t> actors;
197 for (const auto& [aid, _] : get_sleep_set()) {
203 std::unordered_set<aid_t> State::get_enabled_actors() const
205 std::unordered_set<aid_t> actors;
206 for (const auto& [aid, state] : get_actors_list()) {
207 if (state.is_enabled()) {
214 void State::seed_wakeup_tree_if_needed(const odpor::Execution& prior)
216 // TODO: It would be better not to have such a flag.
217 if (has_initialized_wakeup_tree) {
220 // TODO: Note that the next action taken by the actor may be updated
221 // after it executes. But we will have already inserted it into the
222 // tree and decided upon "happens-before" at that point for different
224 if (wakeup_tree_.empty()) {
225 // Find an enabled transition to pick
226 for (const auto& [_, actor] : get_actors_list()) {
227 if (actor.is_enabled()) {
228 // For each variant of the transition, we want
229 // to insert the action into the tree. This ensures
230 // that all variants are searched
231 for (unsigned times = 0; times < actor.get_max_considered(); ++times) {
232 wakeup_tree_.insert(prior, odpor::PartialExecution{actor.get_transition(times)});
234 break; // Only one actor gets inserted (see pseudocode)
238 has_initialized_wakeup_tree = true;
241 void State::sprout_tree_from_parent_state()
243 xbt_assert(parent_state_ != nullptr, "Attempting to construct a wakeup tree for the root state "
244 "(or what appears to be, rather for state without a parent defined)");
245 const auto min_process_node = parent_state_->wakeup_tree_.get_min_single_process_node();
246 xbt_assert(min_process_node.has_value(), "Attempting to construct a subtree for a substate from a "
247 "parent with an empty wakeup tree. This indicates either that ODPOR "
248 "actor selection in State.cpp is incorrect, or that the code "
249 "deciding when to make subtrees in ODPOR is incorrect");
250 xbt_assert((get_transition_in()->aid_ == min_process_node.value()->get_actor()) &&
251 (get_transition_in()->type_ == min_process_node.value()->get_action()->type_),
252 "We tried to make a subtree from a parent state who claimed to have executed `%s` "
253 "but whose wakeup tree indicates it should have executed `%s`. This indicates "
254 "that exploration is not following ODPOR. Are you sure you're choosing actors "
255 "to schedule from the wakeup tree?",
256 get_transition_in()->to_string(false).c_str(),
257 min_process_node.value()->get_action()->to_string(false).c_str());
258 this->wakeup_tree_ = odpor::WakeupTree::make_subtree_rooted_at(min_process_node.value());
261 void State::remove_subtree_using_current_out_transition()
263 if (auto out_transition = get_transition_out(); out_transition != nullptr) {
264 if (const auto min_process_node = wakeup_tree_.get_min_single_process_node(); min_process_node.has_value()) {
265 xbt_assert((out_transition->aid_ == min_process_node.value()->get_actor()) &&
266 (out_transition->type_ == min_process_node.value()->get_action()->type_),
267 "We tried to make a subtree from a parent state who claimed to have executed `%s` "
268 "but whose wakeup tree indicates it should have executed `%s`. This indicates "
269 "that exploration is not following ODPOR. Are you sure you're choosing actors "
270 "to schedule from the wakeup tree?",
271 out_transition->to_string(false).c_str(),
272 min_process_node.value()->get_action()->to_string(false).c_str());
275 wakeup_tree_.remove_min_single_process_subtree();
278 odpor::WakeupTree::InsertionResult State::insert_into_wakeup_tree(const odpor::PartialExecution& pe,
279 const odpor::Execution& E)
281 return this->wakeup_tree_.insert(E, pe);
284 void State::do_odpor_unwind()
286 if (auto out_transition = get_transition_out(); out_transition != nullptr) {
287 remove_subtree_using_current_out_transition();
289 // Only when we've exhausted all variants of the transition which
290 // can be chosen from this state do we finally add the actor to the
291 // sleep set. This ensures that the current logic handling sleep sets
292 // works with ODPOR in the way we intend it to work. There is not a
293 // good way to perform transition equality in SimGrid; instead, we
294 // effectively simply check for the presence of an actor in the sleep set.
295 if (!get_actors_list().at(out_transition->aid_).has_more_to_consider())
296 add_sleep_set(std::move(out_transition));
300 } // namespace simgrid::mc