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");
28 if (_sg_mc_strategy == "none")
29 strategy_ = std::make_shared<BasicStrategy>();
30 else if (_sg_mc_strategy == "max_match_comm")
31 strategy_ = std::make_shared<MaxMatchComm>();
32 else if (_sg_mc_strategy == "min_match_comm")
33 strategy_ = std::make_shared<MinMatchComm>();
34 else if (_sg_mc_strategy == "uniform") {
35 xbt::random::set_mersenne_seed(_sg_mc_random_seed);
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)
53 if (_sg_mc_strategy == "none")
54 strategy_ = std::make_shared<BasicStrategy>();
55 else if (_sg_mc_strategy == "max_match_comm")
56 strategy_ = std::make_shared<MaxMatchComm>();
57 else if (_sg_mc_strategy == "min_match_comm")
58 strategy_ = std::make_shared<MinMatchComm>();
59 else if (_sg_mc_strategy == "uniform")
60 strategy_ = std::make_shared<UniformStrategy>();
63 strategy_->copy_from(parent_state_->strategy_.get());
65 remote_app.get_actors_status(strategy_->actors_to_run_);
67 #if SIMGRID_HAVE_STATEFUL_MC /* Stateful model checking */
68 if ((_sg_mc_checkpoint > 0 && (num_ % _sg_mc_checkpoint == 0)) || _sg_mc_termination)
69 system_state_ = std::make_shared<simgrid::mc::Snapshot>(num_, remote_app.get_page_store(),
70 *remote_app.get_remote_process_memory());
73 /* Copy the sleep set and eventually removes things from it: */
74 /* For each actor in the previous sleep set, keep it if it is not dependent with current transition.
75 * And if we kept it and the actor is enabled in this state, mark the actor as already done, so that
76 * it is not explored*/
77 for (const auto& [aid, transition] : parent_state_->get_sleep_set()) {
78 if (not incoming_transition_->depends(transition.get())) {
79 sleep_set_.try_emplace(aid, transition);
80 if (strategy_->actors_to_run_.count(aid) != 0) {
81 XBT_DEBUG("Actor %ld will not be explored, for it is in the sleep set", aid);
82 strategy_->actors_to_run_.at(aid).mark_done();
85 XBT_DEBUG("Transition >>%s<< removed from the sleep set because it was dependent with incoming >>%s<<",
86 transition->to_string().c_str(), incoming_transition_->to_string().c_str());
90 std::size_t State::count_todo() const
92 return boost::range::count_if(this->strategy_->actors_to_run_, [](auto& pair) { return pair.second.is_todo(); });
95 std::size_t State::count_todo_multiples() const
98 for (auto const& [_, actor] : strategy_->actors_to_run_)
100 count += actor.get_times_not_considered();
105 aid_t State::next_transition() const
107 XBT_DEBUG("Search for an actor to run. %zu actors to consider", strategy_->actors_to_run_.size());
108 for (auto const& [aid, actor] : strategy_->actors_to_run_) {
109 /* Only consider actors (1) marked as interleaving by the checker and (2) currently enabled in the application */
110 if (not actor.is_todo() || not actor.is_enabled() || actor.is_done()) {
111 if (not actor.is_todo())
112 XBT_DEBUG("Can't run actor %ld because it is not todo", aid);
114 if (not actor.is_enabled())
115 XBT_DEBUG("Can't run actor %ld because it is not enabled", aid);
118 XBT_DEBUG("Can't run actor %ld because it has already been done", aid);
128 std::pair<aid_t, int> State::next_transition_guided() const
130 return strategy_->next_transition();
133 aid_t State::next_odpor_transition() const
135 return wakeup_tree_.get_min_single_process_actor().value_or(-1);
138 // This should be done in GuidedState, or at least interact with it
139 std::shared_ptr<Transition> State::execute_next(aid_t next, RemoteApp& app)
141 // First, warn the guide, so it knows how to build a proper child state
142 strategy_->execute_next(next, app);
144 // This actor is ready to be executed. Execution involves three phases:
146 // 1. Identify the appropriate ActorState to prepare for execution
147 // when simcall_handle will be called on it
148 auto& actor_state = strategy_->actors_to_run_.at(next);
149 const unsigned times_considered = actor_state.do_consider();
150 const auto* expected_executed_transition = actor_state.get_transition(times_considered).get();
151 xbt_assert(expected_executed_transition != nullptr,
152 "Expected a transition with %u times considered to be noted in actor %ld", times_considered, next);
154 XBT_DEBUG("Let's run actor %ld (times_considered = %u)", next, times_considered);
156 // 2. Execute the actor according to the preparation above
157 Transition::executed_transitions_++;
158 auto* just_executed = app.handle_simcall(next, times_considered, true);
159 xbt_assert(just_executed->type_ == expected_executed_transition->type_,
160 "The transition that was just executed by actor %ld, viz:\n"
162 "is not what was purportedly scheduled to execute, which was:\n"
164 next, just_executed->to_string().c_str(), expected_executed_transition->to_string().c_str());
166 // 3. Update the state with the newest information. This means recording
168 // 1. what action was last taken from this state (viz. `executed_transition`)
169 // 2. what action actor `next` was able to take given `times_considered`
170 // The latter update is important as *more* information is potentially available
171 // about a transition AFTER it has executed.
172 outgoing_transition_ = std::shared_ptr<Transition>(just_executed);
174 actor_state.set_transition(outgoing_transition_, times_considered);
175 app.wait_for_requests();
177 return outgoing_transition_;
180 std::unordered_set<aid_t> State::get_backtrack_set() const
182 std::unordered_set<aid_t> actors;
183 for (const auto& [aid, state] : get_actors_list()) {
184 if (state.is_todo() || state.is_done()) {
191 std::unordered_set<aid_t> State::get_sleeping_actors() const
193 std::unordered_set<aid_t> actors;
194 for (const auto& [aid, _] : get_sleep_set()) {
200 std::unordered_set<aid_t> State::get_enabled_actors() const
202 std::unordered_set<aid_t> actors;
203 for (const auto& [aid, state] : get_actors_list()) {
204 if (state.is_enabled()) {
211 void State::seed_wakeup_tree_if_needed(const odpor::Execution& prior)
213 // TODO: It would be better not to have such a flag.
214 if (has_initialized_wakeup_tree) {
215 XBT_DEBUG("Reached a node with the following initialized WuT:");
216 XBT_DEBUG("\n%s", wakeup_tree_.string_of_whole_tree().c_str());
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()
244 XBT_DEBUG("Initializing Wut with parent one:");
245 XBT_DEBUG("\n%s", parent_state_->wakeup_tree_.string_of_whole_tree().c_str());
248 xbt_assert(parent_state_ != nullptr, "Attempting to construct a wakeup tree for the root state "
249 "(or what appears to be, rather for state without a parent defined)");
250 const auto min_process_node = parent_state_->wakeup_tree_.get_min_single_process_node();
251 xbt_assert(min_process_node.has_value(), "Attempting to construct a subtree for a substate from a "
252 "parent with an empty wakeup tree. This indicates either that ODPOR "
253 "actor selection in State.cpp is incorrect, or that the code "
254 "deciding when to make subtrees in ODPOR is incorrect");
255 xbt_assert((get_transition_in()->aid_ == min_process_node.value()->get_actor()) &&
256 (get_transition_in()->type_ == min_process_node.value()->get_action()->type_),
257 "We tried to make a subtree from a parent state who claimed to have executed `%s` on actor %ld "
258 "but whose wakeup tree indicates it should have executed `%s` on actor %ld. This indicates "
259 "that exploration is not following ODPOR. Are you sure you're choosing actors "
260 "to schedule from the wakeup tree?",
261 get_transition_in()->to_string(false).c_str(), get_transition_in()->aid_,
262 min_process_node.value()->get_action()->to_string(false).c_str(), min_process_node.value()->get_actor());
263 this->wakeup_tree_ = odpor::WakeupTree::make_subtree_rooted_at(min_process_node.value());
266 void State::remove_subtree_using_current_out_transition()
268 if (auto out_transition = get_transition_out(); out_transition != nullptr) {
269 if (const auto min_process_node = wakeup_tree_.get_min_single_process_node(); min_process_node.has_value()) {
270 xbt_assert((out_transition->aid_ == min_process_node.value()->get_actor()) &&
271 (out_transition->type_ == min_process_node.value()->get_action()->type_),
272 "We tried to make a subtree from a parent state who claimed to have executed `%s` "
273 "but whose wakeup tree indicates it should have executed `%s`. This indicates "
274 "that exploration is not following ODPOR. Are you sure you're choosing actors "
275 "to schedule from the wakeup tree?",
276 out_transition->to_string(false).c_str(),
277 min_process_node.value()->get_action()->to_string(false).c_str());
280 wakeup_tree_.remove_min_single_process_subtree();
283 odpor::WakeupTree::InsertionResult State::insert_into_wakeup_tree(const odpor::PartialExecution& pe,
284 const odpor::Execution& E)
286 return this->wakeup_tree_.insert(E, pe);
289 void State::do_odpor_unwind()
291 if (auto out_transition = get_transition_out(); out_transition != nullptr) {
292 remove_subtree_using_current_out_transition();
294 // Only when we've exhausted all variants of the transition which
295 // can be chosen from this state do we finally add the actor to the
296 // sleep set. This ensures that the current logic handling sleep sets
297 // works with ODPOR in the way we intend it to work. There is not a
298 // good way to perform transition equality in SimGrid; instead, we
299 // effectively simply check for the presence of an actor in the sleep set.
300 if (not get_actors_list().at(out_transition->aid_).has_more_to_consider())
301 add_sleep_set(std::move(out_transition));
305 } // namespace simgrid::mc