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"
13 #include "xbt/random.hpp"
16 #include <boost/range/algorithm.hpp>
18 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_state, mc, "Logging specific to MC states");
20 namespace simgrid::mc {
22 long State::expended_states_ = 0;
24 State::State(RemoteApp& remote_app) : num_(++expended_states_)
26 XBT_VERB("Creating a guide for the state");
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 xbt::random::set_mersenne_seed(_sg_mc_random_seed);
37 strategy_ = std::make_shared<UniformStrategy>();
42 remote_app.get_actors_status(strategy_->actors_to_run_);
44 #if SIMGRID_HAVE_STATEFUL_MC
45 /* Stateful model checking */
46 if ((_sg_mc_checkpoint > 0 && (num_ % _sg_mc_checkpoint == 0)) || _sg_mc_termination)
47 system_state_ = std::make_shared<simgrid::mc::Snapshot>(num_, remote_app.get_page_store(),
48 *remote_app.get_remote_process_memory());
52 State::State(RemoteApp& remote_app, std::shared_ptr<State> parent_state)
53 : incoming_transition_(parent_state->get_transition_out()), num_(++expended_states_), parent_state_(parent_state)
55 if (_sg_mc_strategy == "none")
56 strategy_ = std::make_shared<BasicStrategy>();
57 else if (_sg_mc_strategy == "max_match_comm")
58 strategy_ = std::make_shared<MaxMatchComm>();
59 else if (_sg_mc_strategy == "min_match_comm")
60 strategy_ = std::make_shared<MinMatchComm>();
61 else if (_sg_mc_strategy == "uniform")
62 strategy_ = std::make_shared<UniformStrategy>();
65 strategy_->copy_from(parent_state_->strategy_.get());
67 remote_app.get_actors_status(strategy_->actors_to_run_);
69 #if SIMGRID_HAVE_STATEFUL_MC /* Stateful model checking */
70 if ((_sg_mc_checkpoint > 0 && (num_ % _sg_mc_checkpoint == 0)) || _sg_mc_termination)
71 system_state_ = std::make_shared<simgrid::mc::Snapshot>(num_, remote_app.get_page_store(),
72 *remote_app.get_remote_process_memory());
75 /* Copy the sleep set and eventually removes things from it: */
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 (const 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());
92 std::size_t State::count_todo() const
94 return boost::range::count_if(this->strategy_->actors_to_run_, [](auto& pair) { return pair.second.is_todo(); });
97 std::size_t State::count_todo_multiples() const
100 for (auto const& [_, actor] : strategy_->actors_to_run_)
102 count += actor.get_times_not_considered();
107 aid_t State::next_transition() const
109 XBT_DEBUG("Search for an actor to run. %zu actors to consider", strategy_->actors_to_run_.size());
110 for (auto const& [aid, actor] : strategy_->actors_to_run_) {
111 /* Only consider actors (1) marked as interleaving by the checker and (2) currently enabled in the application */
112 if (not actor.is_todo() || not actor.is_enabled() || actor.is_done()) {
113 if (not actor.is_todo())
114 XBT_DEBUG("Can't run actor %ld because it is not todo", aid);
116 if (not actor.is_enabled())
117 XBT_DEBUG("Can't run actor %ld because it is not enabled", aid);
120 XBT_DEBUG("Can't run actor %ld because it has already been done", aid);
130 std::pair<aid_t, int> State::next_transition_guided() const
132 return strategy_->next_transition();
135 aid_t State::next_odpor_transition() const
137 return wakeup_tree_.get_min_single_process_actor().value_or(-1);
140 // This should be done in GuidedState, or at least interact with it
141 std::shared_ptr<Transition> State::execute_next(aid_t next, RemoteApp& app)
143 // First, warn the guide, so it knows how to build a proper child state
144 strategy_->execute_next(next, app);
146 // This actor is ready to be executed. Execution involves three phases:
148 // 1. Identify the appropriate ActorState to prepare for execution
149 // when simcall_handle will be called on it
150 auto& actor_state = strategy_->actors_to_run_.at(next);
151 const unsigned times_considered = actor_state.do_consider();
152 const auto* expected_executed_transition = actor_state.get_transition(times_considered).get();
153 xbt_assert(expected_executed_transition != nullptr,
154 "Expected a transition with %u times considered to be noted in actor %ld", times_considered, next);
156 XBT_DEBUG("Let's run actor %ld (times_considered = %u)", next, times_considered);
158 // 2. Execute the actor according to the preparation above
159 Transition::executed_transitions_++;
160 auto* just_executed = app.handle_simcall(next, times_considered, true);
161 xbt_assert(just_executed->type_ == expected_executed_transition->type_,
162 "The transition that was just executed by actor %ld, viz:\n"
164 "is not what was purportedly scheduled to execute, which was:\n"
166 next, just_executed->to_string().c_str(), expected_executed_transition->to_string().c_str());
168 // 3. Update the state with the newest information. This means recording
170 // 1. what action was last taken from this state (viz. `executed_transition`)
171 // 2. what action actor `next` was able to take given `times_considered`
172 // The latter update is important as *more* information is potentially available
173 // about a transition AFTER it has executed.
174 outgoing_transition_ = std::shared_ptr<Transition>(just_executed);
176 actor_state.set_transition(outgoing_transition_, times_considered);
177 app.wait_for_requests();
179 return outgoing_transition_;
182 std::unordered_set<aid_t> State::get_backtrack_set() const
184 std::unordered_set<aid_t> actors;
185 for (const auto& [aid, state] : get_actors_list()) {
186 if (state.is_todo() || state.is_done()) {
193 std::unordered_set<aid_t> State::get_sleeping_actors() const
195 std::unordered_set<aid_t> actors;
196 for (const auto& [aid, _] : get_sleep_set()) {
202 std::unordered_set<aid_t> State::get_enabled_actors() const
204 std::unordered_set<aid_t> actors;
205 for (const auto& [aid, state] : get_actors_list()) {
206 if (state.is_enabled()) {
213 void State::seed_wakeup_tree_if_needed(const odpor::Execution& prior)
215 // TODO: It would be better not to have such a flag.
216 if (has_initialized_wakeup_tree) {
219 // TODO: Note that the next action taken by the actor may be updated
220 // after it executes. But we will have already inserted it into the
221 // tree and decided upon "happens-before" at that point for different
223 if (wakeup_tree_.empty()) {
224 // Find an enabled transition to pick
225 for (const auto& [_, actor] : get_actors_list()) {
226 if (actor.is_enabled()) {
227 // For each variant of the transition, we want
228 // to insert the action into the tree. This ensures
229 // that all variants are searched
230 for (unsigned times = 0; times < actor.get_max_considered(); ++times) {
231 wakeup_tree_.insert(prior, odpor::PartialExecution{actor.get_transition(times)});
233 break; // Only one actor gets inserted (see pseudocode)
237 has_initialized_wakeup_tree = true;
240 void State::sprout_tree_from_parent_state()
242 xbt_assert(parent_state_ != nullptr, "Attempting to construct a wakeup tree for the root state "
243 "(or what appears to be, rather for state without a parent defined)");
244 const auto min_process_node = parent_state_->wakeup_tree_.get_min_single_process_node();
245 xbt_assert(min_process_node.has_value(), "Attempting to construct a subtree for a substate from a "
246 "parent with an empty wakeup tree. This indicates either that ODPOR "
247 "actor selection in State.cpp is incorrect, or that the code "
248 "deciding when to make subtrees in ODPOR is incorrect");
249 xbt_assert((get_transition_in()->aid_ == min_process_node.value()->get_actor()) &&
250 (get_transition_in()->type_ == min_process_node.value()->get_action()->type_),
251 "We tried to make a subtree from a parent state who claimed to have executed `%s` "
252 "but whose wakeup tree indicates it should have executed `%s`. This indicates "
253 "that exploration is not following ODPOR. Are you sure you're choosing actors "
254 "to schedule from the wakeup tree?",
255 get_transition_in()->to_string(false).c_str(),
256 min_process_node.value()->get_action()->to_string(false).c_str());
257 this->wakeup_tree_ = odpor::WakeupTree::make_subtree_rooted_at(min_process_node.value());
260 void State::remove_subtree_using_current_out_transition()
262 if (auto out_transition = get_transition_out(); out_transition != nullptr) {
263 if (const auto min_process_node = wakeup_tree_.get_min_single_process_node(); min_process_node.has_value()) {
264 xbt_assert((out_transition->aid_ == min_process_node.value()->get_actor()) &&
265 (out_transition->type_ == min_process_node.value()->get_action()->type_),
266 "We tried to make a subtree from a parent state who claimed to have executed `%s` "
267 "but whose wakeup tree indicates it should have executed `%s`. This indicates "
268 "that exploration is not following ODPOR. Are you sure you're choosing actors "
269 "to schedule from the wakeup tree?",
270 out_transition->to_string(false).c_str(),
271 min_process_node.value()->get_action()->to_string(false).c_str());
274 wakeup_tree_.remove_min_single_process_subtree();
277 odpor::WakeupTree::InsertionResult State::insert_into_wakeup_tree(const odpor::PartialExecution& pe,
278 const odpor::Execution& E)
280 return this->wakeup_tree_.insert(E, pe);
283 void State::do_odpor_unwind()
285 if (auto out_transition = get_transition_out(); out_transition != nullptr) {
286 remove_subtree_using_current_out_transition();
288 // Only when we've exhausted all variants of the transition which
289 // can be chosen from this state do we finally add the actor to the
290 // sleep set. This ensures that the current logic handling sleep sets
291 // works with ODPOR in the way we intend it to work. There is not a
292 // good way to perform transition equality in SimGrid; instead, we
293 // effectively simply check for the presence of an actor in the sleep set.
294 if (not get_actors_list().at(out_transition->aid_).has_more_to_consider())
295 add_sleep_set(std::move(out_transition));
299 } // namespace simgrid::mc