-/* Copyright (c) 2016-2022. The SimGrid Team. All rights reserved. */
+/* Copyright (c) 2016-2023. 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/xbt/mmalloc/mmprivate.h"
#include "xbt/log.h"
+#include "xbt/string.hpp"
#include "xbt/sysdep.h"
#include <cassert>
void DFSExplorer::check_non_termination(const State* current_state)
{
- for (auto state = stack_.rbegin(); state != stack_.rend(); ++state)
- if (*(*state)->get_system_state() == *current_state->get_system_state()) {
- XBT_INFO("Non-progressive cycle: state %ld -> state %ld", (*state)->get_num(), current_state->get_num());
+ for (auto const& state : stack_) {
+ if (state->get_system_state()->equals_to(*current_state->get_system_state(),
+ *get_remote_app().get_remote_process_memory())) {
+ XBT_INFO("Non-progressive cycle: state %ld -> state %ld", state->get_num(), current_state->get_num());
XBT_INFO("******************************************");
XBT_INFO("*** NON-PROGRESSIVE CYCLE DETECTED ***");
XBT_INFO("******************************************");
throw TerminationError();
}
+ }
}
RecordTrace DFSExplorer::get_record_trace() // override
void DFSExplorer::log_state() // override
{
on_log_state_signal(get_remote_app());
- XBT_INFO("DFS exploration ended. %ld unique states visited; %ld backtracks (%lu transition replays, %lu states "
+ XBT_INFO("DFS exploration ended. %ld unique states visited; %lu backtracks (%lu transition replays, %lu states "
"visited overall)",
- State::get_expanded_states(), backtrack_count_, mc_model_checker->get_visited_states(),
+ State::get_expanded_states(), backtrack_count_, visited_states_count_,
Transition::get_replayed_transitions());
+ Exploration::log_state();
}
void DFSExplorer::run()
XBT_DEBUG("Exploration depth=%zu (state:#%ld; %zu interleaves todo)", stack_.size(), state->get_num(),
state->count_todo());
- mc_model_checker->inc_visited_states();
+ visited_states_count_++;
// Backtrack if we reached the maximum depth
if (stack_.size() > (std::size_t)_sg_mc_max_depth) {
continue;
}
- // Backtrack if we are revisiting a state we saw previously
+ // Backtrack if we are revisiting a state we saw previously while applying state-equality reduction
if (visited_state_ != nullptr) {
XBT_DEBUG("State already visited (equal to state %ld), exploration stopped on this path.",
- visited_state_->original_num == -1 ? visited_state_->num : visited_state_->original_num);
+ visited_state_->original_num_ == -1 ? visited_state_->num_ : visited_state_->original_num_);
visited_state_ = nullptr;
this->backtrack();
}
// Search for the next transition
- aid_t next = state->next_transition();
+ // next_transition returns a pair<aid_t, double> in case we want to consider multiple state
+ auto [next, _] = state->next_transition_guided();
if (next < 0) { // If there is no more transition in the current state, backtrack.
XBT_DEBUG("There remains %lu actors, but none to interleave (depth %zu).", state->get_actor_count(),
stack_.size() + 1);
if (state->get_actor_count() == 0) {
- mc_model_checker->finalize_app();
+ get_remote_app().finalize_app();
XBT_VERB("Execution came to an end at %s (state: %ld, depth: %zu)", get_record_trace().to_string().c_str(),
state->get_num(), stack_.size());
}
+
this->backtrack();
continue;
}
+ if (_sg_mc_sleep_set && XBT_LOG_ISENABLED(mc_dfs, xbt_log_priority_verbose)) {
+ XBT_VERB("Sleep set actually containing:");
+ for (auto& [aid, transition] : state->get_sleep_set())
+ XBT_VERB(" <%ld,%s>", aid, transition.to_string().c_str());
+ }
+
/* Actually answer the request: let's execute the selected request (MCed does one step) */
- state->execute_next(next);
+ state->execute_next(next, get_remote_app());
on_transition_execute_signal(state->get_transition(), get_remote_app());
// If there are processes to interleave and the maximum depth has not been
state->get_transition()->to_string().c_str(), stack_.size(), state->get_num(), state->count_todo());
/* Create the new expanded state (copy the state of MCed into our MCer data) */
- auto next_state = std::make_unique<State>(get_remote_app());
+ std::unique_ptr<State> next_state;
+
+ next_state = std::make_unique<State>(get_remote_app(), state);
on_state_creation_signal(next_state.get(), get_remote_app());
+ /* Sleep set procedure:
+ * adding the taken transition to the sleep set of the original state.
+ * <!> Since the parent sleep set is used to compute the child sleep set, this need to be
+ * done after next_state creation */
+ XBT_DEBUG("Marking Transition >>%s<< of process %ld done and adding it to the sleep set",
+ state->get_transition()->to_string().c_str(), state->get_transition()->aid_);
+ state->add_sleep_set(state->get_transition()); // Actors are marked done when they are considerd in ActorState
+
+ /* DPOR persistent set procedure:
+ * for each new transition considered, check if it depends on any other previous transition executed before it
+ * on another process. If there exists one, find the more recent, and add its process to the interleave set.
+ * If the process is not enabled at this point, then add every enabled process to the interleave */
+ if (reduction_mode_ == ReductionMode::dpor) {
+ aid_t issuer_id = state->get_transition()->aid_;
+ for (auto i = stack_.rbegin(); i != stack_.rend(); ++i) {
+ State* prev_state = i->get();
+ if (state->get_transition()->aid_ == prev_state->get_transition()->aid_) {
+ XBT_DEBUG("Simcall >>%s<< and >>%s<< with same issuer %ld", state->get_transition()->to_string().c_str(),
+ prev_state->get_transition()->to_string().c_str(), issuer_id);
+ continue;
+ } else if (prev_state->get_transition()->depends(state->get_transition())) {
+ XBT_VERB("Dependent Transitions:");
+ XBT_VERB(" %s (state=%ld)", prev_state->get_transition()->to_string().c_str(), prev_state->get_num());
+ XBT_VERB(" %s (state=%ld)", state->get_transition()->to_string().c_str(), state->get_num());
+
+ if (prev_state->is_actor_enabled(issuer_id)) {
+ if (not prev_state->is_actor_done(issuer_id))
+ prev_state->consider_one(issuer_id);
+ else
+ XBT_DEBUG("Actor %ld is already in done set: no need to explore it again", issuer_id);
+ } else {
+ XBT_DEBUG("Actor %ld is not enabled: DPOR may be failing. To stay sound, we are marking every enabled "
+ "transition as todo",
+ issuer_id);
+ prev_state->consider_all();
+ }
+ break;
+ } else {
+ XBT_VERB("INDEPENDENT Transitions:");
+ XBT_VERB(" %s (state=%ld)", prev_state->get_transition()->to_string().c_str(), prev_state->get_num());
+ XBT_VERB(" %s (state=%ld)", state->get_transition()->to_string().c_str(), state->get_num());
+ }
+ }
+ }
+
if (_sg_mc_termination)
this->check_non_termination(next_state.get());
/* Check whether we already explored next_state in the past (but only if interested in state-equality reduction) */
if (_sg_mc_max_visited_states > 0)
- visited_state_ = visited_states_.addVisitedState(next_state->get_num(), next_state.get());
+ visited_state_ = visited_states_.addVisitedState(next_state->get_num(), next_state.get(), get_remote_app());
/* If this is a new state (or if we don't care about state-equality reduction) */
if (visited_state_ == nullptr) {
/* Get an enabled process and insert it in the interleave set of the next state */
- for (auto const& [aid, _] : next_state->get_actors_list()) {
- if (next_state->is_actor_enabled(aid)) {
- next_state->mark_todo(aid);
- if (reduction_mode_ == ReductionMode::dpor)
- break; // With DPOR, we take the first enabled transition
- }
- }
+ if (reduction_mode_ == ReductionMode::dpor)
+ next_state->consider_best(); // Take only one transition if DPOR: others may be considered later if required
+ else
+ next_state->consider_all();
- mc_model_checker->dot_output("\"%ld\" -> \"%ld\" [%s];\n", state->get_num(), next_state->get_num(),
- state->get_transition()->dot_string().c_str());
+ dot_output("\"%ld\" -> \"%ld\" [%s];\n", state->get_num(), next_state->get_num(),
+ state->get_transition()->dot_string().c_str());
} else
- mc_model_checker->dot_output("\"%ld\" -> \"%ld\" [%s];\n", state->get_num(),
- visited_state_->original_num == -1 ? visited_state_->num
- : visited_state_->original_num,
- state->get_transition()->dot_string().c_str());
+ dot_output("\"%ld\" -> \"%ld\" [%s];\n", state->get_num(),
+ visited_state_->original_num_ == -1 ? visited_state_->num_ : visited_state_->original_num_,
+ state->get_transition()->dot_string().c_str());
stack_.push_back(std::move(next_state));
}
backtrack_count_++;
XBT_VERB("Backtracking from %s", get_record_trace().to_string().c_str());
on_backtracking_signal(get_remote_app());
- stack_.pop_back();
-
get_remote_app().check_deadlock();
+ /* We may backtrack from somewhere either because it's leaf, or because every enabled process are in done/sleep set.
+ * In the first case, we need to remove the last transition corresponding to the Finalize */
+ if (stack_.back()->get_transition()->aid_ == 0)
+ stack_.pop_back();
+
/* Traverse the stack backwards until a state with a non empty interleave set is found, deleting all the states that
- * have it empty in the way. For each deleted state, check if the request that has generated it (from its
- * predecessor state), depends on any other previous request executed before it. If it does then add it to the
- * interleave set of the state that executed that previous request. */
+ * have it empty in the way. */
bool found_backtracking_point = false;
while (not stack_.empty() && not found_backtracking_point) {
std::unique_ptr<State> state = std::move(stack_.back());
+
stack_.pop_back();
- if (reduction_mode_ == ReductionMode::dpor) {
- aid_t issuer_id = state->get_transition()->aid_;
- for (auto i = stack_.rbegin(); i != stack_.rend(); ++i) {
- State* prev_state = i->get();
- if (state->get_transition()->aid_ == prev_state->get_transition()->aid_) {
- XBT_DEBUG("Simcall >>%s<< and >>%s<< with same issuer %ld", state->get_transition()->to_string().c_str(),
- prev_state->get_transition()->to_string().c_str(), issuer_id);
- break;
- } else if (prev_state->get_transition()->depends(state->get_transition())) {
- XBT_VERB("Dependent Transitions:");
- XBT_VERB(" %s (state=%ld)", prev_state->get_transition()->to_string().c_str(), prev_state->get_num());
- XBT_VERB(" %s (state=%ld)", state->get_transition()->to_string().c_str(), state->get_num());
- if (not prev_state->is_done(issuer_id))
- prev_state->mark_todo(issuer_id);
- else
- XBT_DEBUG("Actor %ld is in done set", issuer_id);
- break;
- } else {
- XBT_VERB("INDEPENDENT Transitions:");
- XBT_VERB(" %s (state=%ld)", prev_state->get_transition()->to_string().c_str(), prev_state->get_num());
- XBT_VERB(" %s (state=%ld)", state->get_transition()->to_string().c_str(), state->get_num());
- }
- }
- }
- if (state->count_todo() == 0) { // Empty interleaving set
+ if (state->count_todo() == 0) { // Empty interleaving set: exploration at this level is over
XBT_DEBUG("Delete state %ld at depth %zu", state->get_num(), stack_.size() + 1);
} else {
- XBT_DEBUG("Back-tracking to state %ld at depth %zu", state->get_num(), stack_.size() + 1);
- stack_.push_back(std::move(state)); // Put it back on the stack
+ XBT_DEBUG("Back-tracking to state %ld at depth %zu: %lu transitions left to be explored", state->get_num(),
+ stack_.size() + 1, state->count_todo());
+ stack_.push_back(
+ std::move(state)); // Put it back on the stack so we can explore the next transition of the interleave
found_backtracking_point = true;
}
}
/* If asked to rollback on a state that has a snapshot, restore it */
State* last_state = stack_.back().get();
if (const auto* system_state = last_state->get_system_state()) {
- system_state->restore(&get_remote_app().get_remote_process());
+ system_state->restore(*get_remote_app().get_remote_process_memory());
on_restore_system_state_signal(last_state, get_remote_app());
return;
}
for (std::unique_ptr<State> const& state : stack_) {
if (state == stack_.back()) /* If we are arrived on the target state, don't replay the outgoing transition */
break;
- state->get_transition()->replay();
+ state->get_transition()->replay(get_remote_app());
on_transition_replay_signal(state->get_transition(), get_remote_app());
- /* Update statistics */
- mc_model_checker->inc_visited_states();
+ visited_states_count_++;
}
} // If no backtracing point, then the stack is empty and the exploration is over
}
-DFSExplorer::DFSExplorer(const std::vector<char*>& args, bool with_dpor) : Exploration(args)
+DFSExplorer::DFSExplorer(const std::vector<char*>& args, bool with_dpor) : Exploration(args, _sg_mc_termination)
{
if (with_dpor)
reduction_mode_ = ReductionMode::dpor;
/* Get an enabled actor and insert it in the interleave set of the initial state */
XBT_DEBUG("Initial state. %lu actors to consider", initial_state->get_actor_count());
- for (auto const& [aid, _] : initial_state->get_actors_list()) {
- if (initial_state->is_actor_enabled(aid)) {
- initial_state->mark_todo(aid);
- if (reduction_mode_ == ReductionMode::dpor) {
- XBT_DEBUG("Actor %ld is TODO, DPOR is ON so let's go for this one.", aid);
- break;
- }
- XBT_DEBUG("Actor %ld is TODO", aid);
- }
- }
+ if (reduction_mode_ == ReductionMode::dpor)
+ initial_state->consider_best();
+ else
+ initial_state->consider_all();
stack_.push_back(std::move(initial_state));
}
