-/* 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/Session.hpp"
-#include "src/mc/api.hpp"
+#include "src/mc/api/strategy/BasicStrategy.hpp"
+#include "src/mc/api/strategy/MaxMatchComm.hpp"
+#include "src/mc/api/strategy/MinMatchComm.hpp"
+#include "src/mc/api/strategy/UniformStrategy.hpp"
+#include "src/mc/explo/Exploration.hpp"
#include "src/mc/mc_config.hpp"
+#include "xbt/random.hpp"
+#include <algorithm>
#include <boost/range/algorithm.hpp>
XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_state, mc, "Logging specific to MC states");
-using simgrid::mc::remote;
-using api = simgrid::mc::Api;
-
-namespace simgrid {
-namespace mc {
+namespace simgrid::mc {
long State::expended_states_ = 0;
-State::State() : num_(++expended_states_)
-{
- const unsigned long maxpid = api::get().get_maxpid();
- actor_states_.resize(maxpid);
- transition_.reset(new Transition());
- /* 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_comms_determinism || _sg_mc_send_determinism) {
- copy_incomplete_comm_pattern();
- copy_index_comm_pattern();
- }
+State::State(RemoteApp& remote_app) : num_(++expended_states_)
+{
+ XBT_VERB("Creating a guide for the state");
+
+ if (_sg_mc_strategy == "none")
+ strategy_ = std::make_shared<BasicStrategy>();
+ else if (_sg_mc_strategy == "max_match_comm")
+ strategy_ = std::make_shared<MaxMatchComm>();
+ else if (_sg_mc_strategy == "min_match_comm")
+ strategy_ = std::make_shared<MinMatchComm>();
+ else if (_sg_mc_strategy == "uniform") {
+ xbt::random::set_mersenne_seed(_sg_mc_random_seed);
+ strategy_ = std::make_shared<UniformStrategy>();
+ } else
+ THROW_IMPOSSIBLE;
+
+ remote_app.get_actors_status(strategy_->actors_to_run_);
+}
+
+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 == "max_match_comm")
+ strategy_ = std::make_shared<MaxMatchComm>();
+ else if (_sg_mc_strategy == "min_match_comm")
+ strategy_ = std::make_shared<MinMatchComm>();
+ else if (_sg_mc_strategy == "uniform")
+ strategy_ = std::make_shared<UniformStrategy>();
+ else
+ THROW_IMPOSSIBLE;
+ strategy_->copy_from(parent_state_->strategy_.get());
+
+ remote_app.get_actors_status(strategy_->actors_to_run_);
+
+ /* Copy the sleep set and eventually removes things from it: */
+ /* 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 (const auto& [aid, transition] : parent_state_->get_sleep_set()) {
+ if (not incoming_transition_->depends(transition.get())) {
+ 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_, [](simgrid::mc::ActorState const& a) { return a.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;
}
-int State::next_transition() const
+aid_t State::next_transition() const
{
- std::vector<ActorInformation>& actors = mc_model_checker->get_remote_process().actors();
- XBT_DEBUG("Search for an actor to run. %zu actors to consider", actors.size());
- for (unsigned int i = 0; i < actors.size(); i++) {
- aid_t aid = actors[i].copy.get_buffer()->get_pid();
- const ActorState* actor_state = &actor_states_[aid];
+ 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() || 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);
- /* Only consider actors (1) marked as interleaving by the checker and (2) currently enabled in the application*/
- if (not actor_state->is_todo() || not simgrid::mc::session_singleton->actor_is_enabled(aid))
continue;
+ }
- return i;
+ return aid;
}
return -1;
}
-void State::execute_next(int next)
+
+std::pair<aid_t, int> State::next_transition_guided() const
+{
+ return strategy_->next_transition();
+}
+
+aid_t State::next_odpor_transition() const
{
- std::vector<ActorInformation>& actors = mc_model_checker->get_remote_process().actors();
+ return wakeup_tree_.get_min_single_process_actor().value_or(-1);
+}
- const kernel::actor::ActorImpl* actor = actors[next].copy.get_buffer();
- aid_t aid = actor->get_pid();
- int times_considered;
+// 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);
- simgrid::mc::ActorState* actor_state = &actor_states_[aid];
- /* This actor is ready to be executed. Prepare its execution when simcall_handle will be called on it */
- if (actor->simcall_.observer_ != nullptr) {
- times_considered = actor_state->get_times_considered_and_inc();
- if (actor->simcall_.mc_max_consider_ <= actor_state->get_times_considered())
- actor_state->set_done();
- } else {
- times_considered = 0;
- actor_state->set_done();
- }
+ // This actor is ready to be executed. Execution involves three phases:
- executed_req_ = actor->simcall_;
+ // 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 = %d)", aid, times_considered);
+ 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());
+
+ // 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();
- transition_.reset(mc_model_checker->handle_simcall(aid, times_considered, true));
- mc_model_checker->wait_for_requests();
+ return outgoing_transition_;
}
-void State::copy_incomplete_comm_pattern()
+std::unordered_set<aid_t> State::get_backtrack_set() const
{
- incomplete_comm_pattern_.clear();
- const unsigned long maxpid = api::get().get_maxpid();
- for (unsigned long i = 0; i < maxpid; i++) {
- std::vector<simgrid::mc::PatternCommunication> res;
- for (auto const& comm : incomplete_communications_pattern[i])
- res.push_back(comm->dup());
- incomplete_comm_pattern_.push_back(std::move(res));
+ std::unordered_set<aid_t> actors;
+ for (const auto& [aid, state] : get_actors_list()) {
+ if (state.is_todo() || state.is_done()) {
+ actors.insert(aid);
+ }
}
+ return actors;
}
-void State::copy_index_comm_pattern()
+std::unordered_set<aid_t> State::get_sleeping_actors() const
{
- communication_indices_.clear();
- for (auto const& list_process_comm : initial_communications_pattern)
- this->communication_indices_.push_back(list_process_comm.index_comm);
+ 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) {
+ XBT_DEBUG("Reached a node with the following initialized WuT:");
+ XBT_DEBUG("\n%s", wakeup_tree_.string_of_whole_tree().c_str());
+
+ 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()) {
+ // Find an enabled transition to pick
+ for (const auto& [_, actor] : get_actors_list()) {
+ if (actor.is_enabled()) {
+ // For each variant of the transition that is enabled, we want to insert the action into the tree.
+ // This ensures that all variants are searched
+ for (unsigned times = 0; times < actor.get_max_considered(); ++times) {
+ wakeup_tree_.insert(prior, odpor::PartialExecution{actor.get_transition(times)});
+ }
+ break; // Only one actor gets inserted (see pseudocode)
+ }
+ }
+ }
+ has_initialized_wakeup_tree = true;
+}
+
+void State::sprout_tree_from_parent_state()
+{
+
+ XBT_DEBUG("Initializing Wut with parent one:");
+ XBT_DEBUG("\n%s", parent_state_->wakeup_tree_.string_of_whole_tree().c_str());
+
+ 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 min_process_node = parent_state_->wakeup_tree_.get_min_single_process_node();
+ xbt_assert(min_process_node.has_value(), "Attempting to construct a subtree for a substate from a "
+ "parent with an empty wakeup tree. This indicates either that ODPOR "
+ "actor selection in State.cpp is incorrect, or that the code "
+ "deciding when to make subtrees in ODPOR is incorrect");
+ if (not(get_transition_in()->aid_ == min_process_node.value()->get_actor() &&
+ get_transition_in()->type_ == min_process_node.value()->get_action()->type_)) {
+ XBT_ERROR("We tried to make a subtree from a parent state who claimed to have executed `%s` on actor %ld "
+ "but whose wakeup tree indicates it should have executed `%s` on actor %ld. This indicates "
+ "that exploration is not following ODPOR. Are you sure you're choosing actors "
+ "to schedule from the wakeup tree? Trace so far:",
+ get_transition_in()->to_string(false).c_str(), get_transition_in()->aid_,
+ min_process_node.value()->get_action()->to_string(false).c_str(), min_process_node.value()->get_actor());
+ for (auto const& elm : Exploration::get_instance()->get_textual_trace())
+ XBT_ERROR("%s", elm.c_str());
+ xbt_abort();
+ }
+ this->wakeup_tree_ = odpor::WakeupTree::make_subtree_rooted_at(min_process_node.value());
+}
+
+void State::remove_subtree_using_current_out_transition()
+{
+ if (auto out_transition = get_transition_out(); out_transition != nullptr) {
+ if (const auto min_process_node = wakeup_tree_.get_min_single_process_node(); min_process_node.has_value()) {
+ xbt_assert((out_transition->aid_ == min_process_node.value()->get_actor()) &&
+ (out_transition->type_ == min_process_node.value()->get_action()->type_),
+ "We tried to make a subtree from a parent state who claimed to have executed `%s` "
+ "but whose wakeup tree indicates it should have executed `%s`. This indicates "
+ "that exploration is not following ODPOR. Are you sure you're choosing actors "
+ "to schedule from the wakeup tree?",
+ out_transition->to_string(false).c_str(),
+ min_process_node.value()->get_action()->to_string(false).c_str());
+ }
+ }
+ wakeup_tree_.remove_min_single_process_subtree();
+}
+
+void State::remove_subtree_at_aid(const aid_t proc)
+{
+ wakeup_tree_.remove_subtree_at_aid(proc);
+}
+
+odpor::WakeupTree::InsertionResult State::insert_into_wakeup_tree(const odpor::PartialExecution& pe,
+ const odpor::Execution& E)
+{
+ return this->wakeup_tree_.insert(E, pe);
+}
+
+void State::do_odpor_unwind()
+{
+ if (auto out_transition = get_transition_out(); out_transition != nullptr) {
+ remove_subtree_using_current_out_transition();
+
+ // Only when we've exhausted all variants of the transition which
+ // can be chosen from this state do we finally add the actor to the
+ // sleep set. This ensures that the current logic handling sleep sets
+ // works with ODPOR in the way we intend it to work. There is not a
+ // good way to perform transition equality in SimGrid; instead, we
+ // effectively simply check for the presence of an actor in the sleep set.
+ if (not get_actors_list().at(out_transition->aid_).has_more_to_consider())
+ add_sleep_set(std::move(out_transition));
+ }
}
-} // namespace mc
-} // namespace simgrid
+} // namespace simgrid::mc
