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_);
45 State::State(RemoteApp& remote_app, std::shared_ptr<State> parent_state)
46 : incoming_transition_(parent_state->get_transition_out()), num_(++expended_states_), parent_state_(parent_state)
48 if (_sg_mc_strategy == "none")
49 strategy_ = std::make_shared<BasicStrategy>();
50 else if (_sg_mc_strategy == "max_match_comm")
51 strategy_ = std::make_shared<MaxMatchComm>();
52 else if (_sg_mc_strategy == "min_match_comm")
53 strategy_ = std::make_shared<MinMatchComm>();
54 else if (_sg_mc_strategy == "uniform")
55 strategy_ = std::make_shared<UniformStrategy>();
58 strategy_->copy_from(parent_state_->strategy_.get());
60 remote_app.get_actors_status(strategy_->actors_to_run_);
62 /* Copy the sleep set and eventually removes things from it: */
63 /* For each actor in the previous sleep set, keep it if it is not dependent with current transition.
64 * And if we kept it and the actor is enabled in this state, mark the actor as already done, so that
65 * it is not explored*/
66 for (const auto& [aid, transition] : parent_state_->get_sleep_set()) {
67 if (not incoming_transition_->depends(transition.get())) {
68 sleep_set_.try_emplace(aid, transition);
69 if (strategy_->actors_to_run_.count(aid) != 0) {
70 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());
79 std::size_t State::count_todo() const
81 return boost::range::count_if(this->strategy_->actors_to_run_, [](auto& pair) { return pair.second.is_todo(); });
84 std::size_t State::count_todo_multiples() const
87 for (auto const& [_, actor] : strategy_->actors_to_run_)
89 count += actor.get_times_not_considered();
94 aid_t State::next_transition() const
96 XBT_DEBUG("Search for an actor to run. %zu actors to consider", strategy_->actors_to_run_.size());
97 for (auto const& [aid, actor] : strategy_->actors_to_run_) {
98 /* Only consider actors (1) marked as interleaving by the checker and (2) currently enabled in the application */
99 if (not actor.is_todo() || not actor.is_enabled() || actor.is_done()) {
100 if (not actor.is_todo())
101 XBT_DEBUG("Can't run actor %ld because it is not todo", aid);
103 if (not actor.is_enabled())
104 XBT_DEBUG("Can't run actor %ld because it is not enabled", aid);
107 XBT_DEBUG("Can't run actor %ld because it has already been done", aid);
117 std::pair<aid_t, int> State::next_transition_guided() const
119 return strategy_->next_transition();
122 aid_t State::next_odpor_transition() const
124 return wakeup_tree_.get_min_single_process_actor().value_or(-1);
127 // This should be done in GuidedState, or at least interact with it
128 std::shared_ptr<Transition> State::execute_next(aid_t next, RemoteApp& app)
130 // First, warn the guide, so it knows how to build a proper child state
131 strategy_->execute_next(next, app);
133 // This actor is ready to be executed. Execution involves three phases:
135 // 1. Identify the appropriate ActorState to prepare for execution
136 // when simcall_handle will be called on it
137 auto& actor_state = strategy_->actors_to_run_.at(next);
138 const unsigned times_considered = actor_state.do_consider();
139 const auto* expected_executed_transition = actor_state.get_transition(times_considered).get();
140 xbt_assert(expected_executed_transition != nullptr,
141 "Expected a transition with %u times considered to be noted in actor %ld", times_considered, next);
143 XBT_DEBUG("Let's run actor %ld (times_considered = %u)", next, times_considered);
145 // 2. Execute the actor according to the preparation above
146 Transition::executed_transitions_++;
147 auto* just_executed = app.handle_simcall(next, times_considered, true);
148 xbt_assert(just_executed->type_ == expected_executed_transition->type_,
149 "The transition that was just executed by actor %ld, viz:\n"
151 "is not what was purportedly scheduled to execute, which was:\n"
153 next, just_executed->to_string().c_str(), expected_executed_transition->to_string().c_str());
155 // 3. Update the state with the newest information. This means recording
157 // 1. what action was last taken from this state (viz. `executed_transition`)
158 // 2. what action actor `next` was able to take given `times_considered`
159 // The latter update is important as *more* information is potentially available
160 // about a transition AFTER it has executed.
161 outgoing_transition_ = std::shared_ptr<Transition>(just_executed);
163 actor_state.set_transition(outgoing_transition_, times_considered);
164 app.wait_for_requests();
166 return outgoing_transition_;
169 std::unordered_set<aid_t> State::get_backtrack_set() const
171 std::unordered_set<aid_t> actors;
172 for (const auto& [aid, state] : get_actors_list()) {
173 if (state.is_todo() || state.is_done()) {
180 std::unordered_set<aid_t> State::get_sleeping_actors() const
182 std::unordered_set<aid_t> actors;
183 for (const auto& [aid, _] : get_sleep_set()) {
189 std::unordered_set<aid_t> State::get_enabled_actors() const
191 std::unordered_set<aid_t> actors;
192 for (const auto& [aid, state] : get_actors_list()) {
193 if (state.is_enabled()) {
200 void State::seed_wakeup_tree_if_needed(const odpor::Execution& prior)
202 // TODO: It would be better not to have such a flag.
203 if (has_initialized_wakeup_tree) {
206 // TODO: Note that the next action taken by the actor may be updated
207 // after it executes. But we will have already inserted it into the
208 // tree and decided upon "happens-before" at that point for different
210 if (wakeup_tree_.empty()) {
211 // Find an enabled transition to pick
212 for (const auto& [_, actor] : get_actors_list()) {
213 if (actor.is_enabled()) {
214 // For each variant of the transition that is enabled, we want to insert the action into the tree.
215 // This ensures that all variants are searched
216 for (unsigned times = 0; times < actor.get_max_considered(); ++times) {
217 wakeup_tree_.insert(prior, odpor::PartialExecution{actor.get_transition(times)});
219 break; // Only one actor gets inserted (see pseudocode)
223 has_initialized_wakeup_tree = true;
226 void State::sprout_tree_from_parent_state()
228 xbt_assert(parent_state_ != nullptr, "Attempting to construct a wakeup tree for the root state "
229 "(or what appears to be, rather for state without a parent defined)");
230 const auto min_process_node = parent_state_->wakeup_tree_.get_min_single_process_node();
231 xbt_assert(min_process_node.has_value(), "Attempting to construct a subtree for a substate from a "
232 "parent with an empty wakeup tree. This indicates either that ODPOR "
233 "actor selection in State.cpp is incorrect, or that the code "
234 "deciding when to make subtrees in ODPOR is incorrect");
235 if (not(get_transition_in()->aid_ == min_process_node.value()->get_actor() &&
236 get_transition_in()->type_ == min_process_node.value()->get_action()->type_)) {
237 XBT_ERROR("We tried to make a subtree from a parent state who claimed to have executed `%s` on actor %ld "
238 "but whose wakeup tree indicates it should have executed `%s` on actor %ld. This indicates "
239 "that exploration is not following ODPOR. Are you sure you're choosing actors "
240 "to schedule from the wakeup tree? Trace so far:",
241 get_transition_in()->to_string(false).c_str(), get_transition_in()->aid_,
242 min_process_node.value()->get_action()->to_string(false).c_str(), min_process_node.value()->get_actor());
243 for (auto elm : Exploration::get_instance()->get_textual_trace())
244 XBT_ERROR("%s", elm.c_str());
247 this->wakeup_tree_ = odpor::WakeupTree::make_subtree_rooted_at(min_process_node.value());
250 void State::remove_subtree_using_current_out_transition()
252 if (auto out_transition = get_transition_out(); out_transition != nullptr) {
253 if (const auto min_process_node = wakeup_tree_.get_min_single_process_node(); min_process_node.has_value()) {
254 xbt_assert((out_transition->aid_ == min_process_node.value()->get_actor()) &&
255 (out_transition->type_ == min_process_node.value()->get_action()->type_),
256 "We tried to make a subtree from a parent state who claimed to have executed `%s` "
257 "but whose wakeup tree indicates it should have executed `%s`. This indicates "
258 "that exploration is not following ODPOR. Are you sure you're choosing actors "
259 "to schedule from the wakeup tree?",
260 out_transition->to_string(false).c_str(),
261 min_process_node.value()->get_action()->to_string(false).c_str());
264 wakeup_tree_.remove_min_single_process_subtree();
267 odpor::WakeupTree::InsertionResult State::insert_into_wakeup_tree(const odpor::PartialExecution& pe,
268 const odpor::Execution& E)
270 return this->wakeup_tree_.insert(E, pe);
273 void State::do_odpor_unwind()
275 if (auto out_transition = get_transition_out(); out_transition != nullptr) {
276 remove_subtree_using_current_out_transition();
278 // Only when we've exhausted all variants of the transition which
279 // can be chosen from this state do we finally add the actor to the
280 // sleep set. This ensures that the current logic handling sleep sets
281 // works with ODPOR in the way we intend it to work. There is not a
282 // good way to perform transition equality in SimGrid; instead, we
283 // effectively simply check for the presence of an actor in the sleep set.
284 if (not get_actors_list().at(out_transition->aid_).has_more_to_consider())
285 add_sleep_set(std::move(out_transition));
289 } // namespace simgrid::mc