-/* Copyright (c) 2008-2022. The SimGrid Team. All rights reserved. */
+/* Copyright (c) 2008-2023. The SimGrid Team. All rights reserved. */
/* This program is free software; you can redistribute it and/or modify it
* under the terms of the license (GNU LGPL) which comes with this package. */
#include "src/mc/api/State.hpp"
-#include "src/mc/api.hpp"
+#include "src/mc/api/strategy/BasicStrategy.hpp"
+#include "src/mc/api/strategy/WaitStrategy.hpp"
+#include "src/mc/explo/Exploration.hpp"
#include "src/mc/mc_config.hpp"
+#include <algorithm>
#include <boost/range/algorithm.hpp>
XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_state, mc, "Logging specific to MC states");
long State::expended_states_ = 0;
-State::State(Session& session) : num_(++expended_states_)
+State::State(RemoteApp& remote_app) : num_(++expended_states_)
{
- auto actors = mc_model_checker->get_remote_process().actors();
+ XBT_VERB("Creating a guide for the state");
+ if (_sg_mc_strategy == "none")
+ strategy_ = std::make_shared<BasicStrategy>();
+ else if (_sg_mc_strategy == "nb_wait")
+ strategy_ = std::make_shared<WaitStrategy>();
+ else
+ THROW_IMPOSSIBLE;
- for (unsigned int i = 0; i < actors.size(); i++) {
- auto remote_actor = actors[i].copy.get_buffer();
- aid_t aid = remote_actor->get_pid();
+ remote_app.get_actors_status(strategy_->actors_to_run_);
- actor_states_.insert(
- std::make_pair(aid, ActorState(aid, session.actor_is_enabled(aid), remote_actor->simcall_.mc_max_consider_)));
- }
-
- transition_.reset(new Transition());
+#if SIMGRID_HAVE_STATEFUL_MC
/* Stateful model checking */
- if ((_sg_mc_checkpoint > 0 && (num_ % _sg_mc_checkpoint == 0)) || _sg_mc_termination) {
- auto snapshot_ptr = Api::get().take_snapshot(num_);
- system_state_ = std::shared_ptr<simgrid::mc::Snapshot>(snapshot_ptr);
+ if ((_sg_mc_checkpoint > 0 && (num_ % _sg_mc_checkpoint == 0)) || _sg_mc_termination)
+ system_state_ = std::make_shared<simgrid::mc::Snapshot>(num_, remote_app.get_page_store(),
+ *remote_app.get_remote_process_memory());
+#endif
+}
+
+State::State(RemoteApp& remote_app, std::shared_ptr<State> parent_state)
+ : incoming_transition_(parent_state->get_transition_out()), num_(++expended_states_), parent_state_(parent_state)
+{
+ if (_sg_mc_strategy == "none")
+ strategy_ = std::make_shared<BasicStrategy>();
+ else if (_sg_mc_strategy == "nb_wait")
+ strategy_ = std::make_shared<WaitStrategy>();
+ else
+ THROW_IMPOSSIBLE;
+ *strategy_ = *(parent_state->strategy_);
+
+ remote_app.get_actors_status(strategy_->actors_to_run_);
+
+#if SIMGRID_HAVE_STATEFUL_MC /* Stateful model checking */
+ if ((_sg_mc_checkpoint > 0 && (num_ % _sg_mc_checkpoint == 0)) || _sg_mc_termination)
+ system_state_ = std::make_shared<simgrid::mc::Snapshot>(num_, remote_app.get_page_store(),
+ *remote_app.get_remote_process_memory());
+#endif
+
+ /* If we want sleep set reduction, copy the sleep set and eventually removes things from it */
+ if (_sg_mc_sleep_set) {
+ /* For each actor in the previous sleep set, keep it if it is not dependent with current transition.
+ * And if we kept it and the actor is enabled in this state, mark the actor as already done, so that
+ * it is not explored*/
+ for (auto& [aid, transition] : parent_state_->get_sleep_set()) {
+ if (not incoming_transition_->depends(&transition)) {
+ sleep_set_.try_emplace(aid, transition);
+ if (strategy_->actors_to_run_.count(aid) != 0) {
+ XBT_DEBUG("Actor %ld will not be explored, for it is in the sleep set", aid);
+
+ strategy_->actors_to_run_.at(aid).mark_done();
+ }
+ } else
+ XBT_DEBUG("Transition >>%s<< removed from the sleep set because it was dependent with incoming >>%s<<",
+ transition.to_string().c_str(), incoming_transition_->to_string().c_str());
+ }
}
}
std::size_t State::count_todo() const
{
- return boost::range::count_if(this->actor_states_, [](auto& pair) { return pair.second.is_todo(); });
+ return boost::range::count_if(this->strategy_->actors_to_run_, [](auto& pair) { return pair.second.is_todo(); });
}
-Transition* State::get_transition() const
+std::size_t State::count_todo_multiples() const
{
- return transition_.get();
+ size_t count = 0;
+ for (auto const& [_, actor] : strategy_->actors_to_run_)
+ if (actor.is_todo())
+ count += actor.get_times_not_considered();
+
+ return count;
}
aid_t State::next_transition() const
{
- XBT_DEBUG("Search for an actor to run. %zu actors to consider", actor_states_.size());
- for (auto const& [aid, actor] : actor_states_) {
+ XBT_DEBUG("Search for an actor to run. %zu actors to consider", strategy_->actors_to_run_.size());
+ for (auto const& [aid, actor] : strategy_->actors_to_run_) {
/* Only consider actors (1) marked as interleaving by the checker and (2) currently enabled in the application */
- if (not actor.is_todo() || not actor.is_enabled())
+ if (not actor.is_todo() || not actor.is_enabled() || actor.is_done()) {
+ if (not actor.is_todo())
+ XBT_DEBUG("Can't run actor %ld because it is not todo", aid);
+
+ if (not actor.is_enabled())
+ XBT_DEBUG("Can't run actor %ld because it is not enabled", aid);
+
+ if (actor.is_done())
+ XBT_DEBUG("Can't run actor %ld because it has already been done", aid);
+
continue;
+ }
return aid;
}
return -1;
}
-void State::execute_next(aid_t next)
+
+std::pair<aid_t, int> State::next_transition_guided() const
{
- /* This actor is ready to be executed. Prepare its execution when simcall_handle will be called on it */
- const unsigned times_considered = actor_states_.at(next).do_consider();
+ return strategy_->next_transition();
+}
+
+aid_t State::next_odpor_transition() const
+{
+ const auto first_single_process_branch =
+ std::find_if(wakeup_tree_.begin(), wakeup_tree_.end(),
+ [=](const odpor::WakeupTreeNode* node) { return node->is_single_process(); });
+ if (first_single_process_branch != wakeup_tree_.end()) {
+ const auto* wakeup_tree_node = *first_single_process_branch;
+ xbt_assert(wakeup_tree_node->get_sequence().size() == 1, "We claimed that the selected branch "
+ "contained only a single process, yet more "
+ "than one process was actually contained in it :(");
+ return wakeup_tree_node->get_first_actor();
+ }
+ return -1;
+}
+
+// This should be done in GuidedState, or at least interact with it
+std::shared_ptr<Transition> State::execute_next(aid_t next, RemoteApp& app)
+{
+ // First, warn the guide, so it knows how to build a proper child state
+ strategy_->execute_next(next, app);
+
+ // This actor is ready to be executed. Execution involves three phases:
+
+ // 1. Identify the appropriate ActorState to prepare for execution
+ // when simcall_handle will be called on it
+ auto& actor_state = strategy_->actors_to_run_.at(next);
+ const unsigned times_considered = actor_state.do_consider();
+ const auto* expected_executed_transition = actor_state.get_transition(times_considered).get();
+ xbt_assert(expected_executed_transition != nullptr,
+ "Expected a transition with %u times considered to be noted in actor %ld", times_considered, next);
XBT_DEBUG("Let's run actor %ld (times_considered = %u)", next, times_considered);
+ // 2. Execute the actor according to the preparation above
Transition::executed_transitions_++;
+ auto* just_executed = app.handle_simcall(next, times_considered, true);
+ xbt_assert(just_executed->type_ == expected_executed_transition->type_,
+ "The transition that was just executed by actor %ld, viz:\n"
+ "%s\n"
+ "is not what was purportedly scheduled to execute, which was:\n"
+ "%s\n",
+ next, just_executed->to_string().c_str(), expected_executed_transition->to_string().c_str());
- transition_.reset(mc_model_checker->handle_simcall(next, times_considered, true));
- mc_model_checker->wait_for_requests();
+ // 3. Update the state with the newest information. This means recording
+ // both
+ // 1. what action was last taken from this state (viz. `executed_transition`)
+ // 2. what action actor `next` was able to take given `times_considered`
+ // The latter update is important as *more* information is potentially available
+ // about a transition AFTER it has executed.
+ outgoing_transition_ = std::shared_ptr<Transition>(just_executed);
+
+ actor_state.set_transition(outgoing_transition_, times_considered);
+ app.wait_for_requests();
+
+ return outgoing_transition_;
}
+
+std::unordered_set<aid_t> State::get_backtrack_set() const
+{
+ std::unordered_set<aid_t> actors;
+ for (const auto& [aid, state] : get_actors_list()) {
+ if (state.is_todo() or state.is_done()) {
+ actors.insert(aid);
+ }
+ }
+ return actors;
+}
+
+std::unordered_set<aid_t> State::get_sleeping_actors() const
+{
+ std::unordered_set<aid_t> actors;
+ for (const auto& [aid, _] : get_sleep_set()) {
+ actors.insert(aid);
+ }
+ return actors;
+}
+
+std::unordered_set<aid_t> State::get_enabled_actors() const
+{
+ std::unordered_set<aid_t> actors;
+ for (const auto& [aid, state] : get_actors_list()) {
+ if (state.is_enabled()) {
+ actors.insert(aid);
+ }
+ }
+ return actors;
+}
+
+void State::seed_wakeup_tree_if_needed(const odpor::Execution& prior)
+{
+ // TODO: It would be better not to have such a flag.
+ if (has_initialized_wakeup_tree) {
+ return;
+ }
+ // TODO: Note that the next action taken by the actor may be updated
+ // after it executes. But we will have already inserted it into the
+ // tree and decided upon "happens-before" at that point for different
+ // executions :(
+ if (wakeup_tree_.empty()) {
+ strategy_->consider_best();
+ if (const aid_t next = std::get<0>(strategy_->next_transition()); next >= 0) {
+ wakeup_tree_.insert(prior, odpor::PartialExecution{strategy_->actors_to_run_.at(next).get_transition()});
+ }
+ }
+ has_initialized_wakeup_tree = true;
+}
+
+void State::sprout_tree_from_parent_state()
+{
+ xbt_assert(parent_state_ != nullptr, "Attempting to construct a wakeup tree for the root state "
+ "(or what appears to be, rather for state without a parent defined)");
+ const auto p = parent_state_->get_transition_out()->aid_;
+ const auto branch = std::find_if(
+ parent_state_->wakeup_tree_.begin(), parent_state_->wakeup_tree_.end(),
+ [=](const odpor::WakeupTreeNode* node) { return node->is_single_process() && node->get_first_actor() == p; });
+ xbt_assert(branch != parent_state_->wakeup_tree_.end(),
+ "Attempted to create a subtree from the wakeup tree of the parent "
+ "state using actor `%ld`, but no such subtree could be found. "
+ "This implies that the wakeup tree management is broken, "
+ "and more specifically that subtree formation is not working "
+ "as intended; for if this state was generated by the parent "
+ "having taken an action by actor `%ld`, this implies that "
+ "ODPOR found `%ld` as a candidate branch prior",
+ p, p, p);
+ this->wakeup_tree_ = odpor::WakeupTree::make_subtree_rooted_at(*branch);
+}
+
+void State::remove_subtree_starting_with(aid_t p)
+{
+ const auto branch = std::find_if(wakeup_tree_.begin(), wakeup_tree_.end(), [=](const odpor::WakeupTreeNode* node) {
+ return node->is_single_process() && node->get_first_actor() == p;
+ });
+ xbt_assert(branch != wakeup_tree_.end(), "Attempted to remove a subtree of this state's "
+ "wakeup tree that does not exist");
+ this->wakeup_tree_.remove_subtree_rooted_at(*branch);
+}
+
+void State::mark_path_interesting_for_odpor(const odpor::PartialExecution& pe, const odpor::Execution& E)
+{
+ this->wakeup_tree_.insert(E, pe);
+}
+
} // namespace simgrid::mc
