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 const auto first_single_process_branch =
126 std::find_if(wakeup_tree_.begin(), wakeup_tree_.end(),
127 [=](const odpor::WakeupTreeNode* node) { return node->is_single_process(); });
128 if (first_single_process_branch != wakeup_tree_.end()) {
129 const auto* wakeup_tree_node = *first_single_process_branch;
130 xbt_assert(wakeup_tree_node->get_sequence().size() == 1, "We claimed that the selected branch "
131 "contained only a single process, yet more "
132 "than one process was actually contained in it :(");
133 return wakeup_tree_node->get_first_actor();
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() or state.is_done()) {
191 void State::seed_wakeup_tree_if_needed(const odpor::Execution& prior)
193 // TODO: It would be better not to have such a flag.
194 if (has_initialized_wakeup_tree) {
197 // TODO: Note that the next action taken by the actor may be updated
198 // after it executes. But we will have already inserted it into the
199 // tree and decided upon "happens-before" at that point for different
201 if (wakeup_tree_.empty()) {
202 if (const aid_t next = std::get<0>(next_transition_guided()); next >= 0) {
203 wakeup_tree_.insert(prior, odpor::PartialExecution{strategy_->actors_to_run_.at(next).get_transition()});
206 has_initialized_wakeup_tree = true;
209 void State::sprout_tree_from_parent_state()
211 xbt_assert(parent_state_ != nullptr, "Attempting to construct a wakeup tree for the root state "
212 "(or what appears to be, rather for state without a parent defined)");
213 const auto p = parent_state_->get_transition_out()->aid_;
214 const auto branch = std::find_if(
215 parent_state_->wakeup_tree_.begin(), parent_state_->wakeup_tree_.end(),
216 [=](const odpor::WakeupTreeNode* node) { return node->is_single_process() && node->get_first_actor() == p; });
217 xbt_assert(branch != parent_state_->wakeup_tree_.end(),
218 "Attempted to create a subtree from the wakeup tree of the parent "
219 "state using actor `%ld`, but no such subtree could be found. "
220 "This implies that the wakeup tree management is broken, "
221 "and more specifically that subtree formation is not working "
222 "as intended; for if this state was generated by the parent "
223 "having taken an action by actor `%ld`, this implies that "
224 "ODPOR found `%ld` as a candidate branch prior",
226 this->wakeup_tree_ = odpor::WakeupTree::make_subtree_rooted_at(*branch);
229 void State::remove_subtree_starting_with(aid_t p)
231 const auto branch = std::find_if(wakeup_tree_.begin(), wakeup_tree_.end(), [=](const odpor::WakeupTreeNode* node) {
232 return node->is_single_process() && node->get_first_actor() == p;
234 xbt_assert(branch != wakeup_tree_.end(), "Attempted to remove a subtree of this state's "
235 "wakeup tree that does not exist");
236 this->wakeup_tree_.remove_subtree_rooted_at(*branch);
239 } // namespace simgrid::mc