* under the terms of the license (GNU LGPL) which comes with this package. */
#include "src/mc/explo/DFSExplorer.hpp"
-#include "src/mc/VisitedState.hpp"
#include "src/mc/mc_config.hpp"
#include "src/mc/mc_exit.hpp"
#include "src/mc/mc_private.hpp"
#include "src/mc/mc_record.hpp"
#include "src/mc/transition/Transition.hpp"
+#if SIMGRID_HAVE_STATEFUL_MC
+#include "src/mc/VisitedState.hpp"
+#endif
+
#include "src/xbt/mmalloc/mmprivate.h"
#include "xbt/log.h"
#include "xbt/string.hpp"
void DFSExplorer::check_non_termination(const State* current_state)
{
+#if SIMGRID_HAVE_STATEFUL_MC
for (auto const& state : stack_) {
if (state->get_system_state()->equals_to(*current_state->get_system_state(),
*get_remote_app().get_remote_process_memory())) {
get_record_trace().to_string().c_str());
log_state();
- throw TerminationError();
+ throw McError(ExitStatus::NON_TERMINATION);
}
}
+#endif
}
RecordTrace DFSExplorer::get_record_trace() // override
-{
- return get_record_trace_of_stack(stack_);
-}
-
-RecordTrace DFSExplorer::get_record_trace_of_stack(stack_t stack)
{
RecordTrace res;
- for (auto const& state : stack)
- res.push_back(state->get_transition());
+ for (auto const& transition : stack_.back()->get_recipe())
+ res.push_back(transition);
+ res.push_back(stack_.back()->get_transition_out());
return res;
}
std::vector<std::string> DFSExplorer::get_textual_trace() // override
{
std::vector<std::string> trace;
- for (auto const& state : stack_) {
- const auto* t = state->get_transition();
- trace.push_back(xbt::string_printf("%ld: %s", t->aid_, t->to_string().c_str()));
+ for (auto const& transition : stack_.back()->get_recipe()) {
+ trace.push_back(xbt::string_printf("%ld: %s", transition->aid_, transition->to_string().c_str()));
}
+ if (const auto* trans = stack_.back()->get_transition_out(); trans != nullptr)
+ trace.push_back(xbt::string_printf("%ld: %s", trans->aid_, trans->to_string().c_str()));
return trace;
}
+void DFSExplorer::restore_stack(std::shared_ptr<State> state)
+{
+ stack_.clear();
+ auto current_state = state;
+ stack_.emplace_front(current_state);
+ // condition corresponds to reaching initial state
+ while (current_state->get_parent_state() != nullptr) {
+ current_state = current_state->get_parent_state();
+ stack_.emplace_front(current_state);
+ }
+ XBT_DEBUG("Replaced stack by %s", get_record_trace().to_string().c_str());
+}
+
void DFSExplorer::log_state() // override
{
on_log_state_signal(get_remote_app());
Exploration::log_state();
}
-void DFSExplorer::add_to_opened_states(stack_t stack)
-{
- stack_t tmp_stack;
- for (auto& state : stack)
- tmp_stack.push_back(std::make_shared<State>(State(*state)));
- opened_states_.emplace_back(tmp_stack);
-}
-
void DFSExplorer::run()
{
on_exploration_start_signal(get_remote_app());
while (not stack_.empty()) {
/* Get current state */
- State* state = stack_.back().get();
+ auto state = stack_.back();
XBT_DEBUG("**************************************************");
XBT_DEBUG("Exploration depth=%zu (state:#%ld; %zu interleaves todo)", stack_.size(), state->get_num(),
continue;
}
+#if SIMGRID_HAVE_STATEFUL_MC
// 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.",
this->backtrack();
continue;
}
+#endif
// Search for the next transition
- // next_transition returns a pair<aid_t, double> in case we want to consider multiple state
+ // next_transition returns a pair<aid_t, int> in case we want to consider multiple state (eg. during backtrack)
auto [next, _] = state->next_transition_guided();
if (next < 0) { // If there is no more transition in the current state, backtrack.
- XBT_VERB("There remains %lu actors, but none to interleave (depth %zu).", state->get_actor_count(),
+ XBT_VERB("%lu actors remain, but none of them need to be interleaved (depth %zu).", state->get_actor_count(),
stack_.size() + 1);
if (state->get_actor_count() == 0) {
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());
}
- // if (stack_.back()->count_todo_multiples() <= 1)
- // add_to_opened_states(stack_);
-
/* Actually answer the request: let's execute the selected request (MCed does one step) */
state->execute_next(next, get_remote_app());
- on_transition_execute_signal(state->get_transition(), get_remote_app());
+ on_transition_execute_signal(state->get_transition_out(), get_remote_app());
// If there are processes to interleave and the maximum depth has not been
// reached then perform one step of the exploration algorithm.
- XBT_VERB("Execute %ld: %.60s (stack depth: %zu, state: %ld, %zu interleaves)", state->get_transition()->aid_,
- state->get_transition()->to_string().c_str(), stack_.size(), state->get_num(), state->count_todo());
+ XBT_VERB("Execute %ld: %.60s (stack depth: %zu, state: %ld, %zu interleaves)", state->get_transition_out()->aid_,
+ state->get_transition_out()->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) */
- std::shared_ptr<State> next_state;
- next_state = std::make_shared<State>(get_remote_app(), state);
+ auto next_state = std::make_shared<State>(get_remote_app(), state);
on_state_creation_signal(next_state.get(), get_remote_app());
/* Sleep set procedure:
* <!> 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
+ state->get_transition_out()->to_string().c_str(), state->get_transition_out()->aid_);
+ state->add_sleep_set(state->get_transition_out()); // 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_;
- stack_t tmp_stack = std::list(stack_);
+ aid_t issuer_id = state->get_transition_out()->aid_;
+ stack_t tmp_stack = stack_;
while (not tmp_stack.empty()) {
- State* prev_state = tmp_stack.back().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);
+ if (const State* prev_state = tmp_stack.back().get();
+ state->get_transition_out()->aid_ == prev_state->get_transition_out()->aid_) {
+ XBT_DEBUG("Simcall >>%s<< and >>%s<< with same issuer %ld", state->get_transition_out()->to_string().c_str(),
+ prev_state->get_transition_out()->to_string().c_str(), issuer_id);
tmp_stack.pop_back();
continue;
- } else if (prev_state->get_transition()->depends(state->get_transition())) {
+ } else if (prev_state->get_transition_out()->depends(state->get_transition_out())) {
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());
+ XBT_VERB(" %s (state=%ld)", prev_state->get_transition_out()->to_string().c_str(), prev_state->get_num());
+ XBT_VERB(" %s (state=%ld)", state->get_transition_out()->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);
- add_to_opened_states(tmp_stack);
+ opened_states_.emplace_back(tmp_stack.back());
} 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();
- add_to_opened_states(tmp_stack);
+ // If we ended up marking at least a transition, explore it at some point
+ if (prev_state->consider_all() > 0)
+ opened_states_.emplace_back(tmp_stack.back());
}
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());
+ XBT_VERB(" %s (state=%ld)", prev_state->get_transition_out()->to_string().c_str(), prev_state->get_num());
+ XBT_VERB(" %s (state=%ld)", state->get_transition_out()->to_string().c_str(), state->get_num());
}
tmp_stack.pop_back();
}
}
+ // Before leaving that state, if the transition we just took can be taken multiple times, we
+ // need to give it to the opened states
+ if (stack_.back()->count_todo_multiples() > 0)
+ opened_states_.emplace_back(stack_.back());
+
if (_sg_mc_termination)
this->check_non_termination(next_state.get());
+#if SIMGRID_HAVE_STATEFUL_MC
/* 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(), get_remote_app());
+#endif
- stack_.push_back(std::move(next_state));
+ stack_.emplace_back(std::move(next_state));
/* If this is a new state (or if we don't care about state-equality reduction) */
if (visited_state_ == nullptr) {
else {
stack_.back()->consider_all();
}
- if (stack_.back()->count_todo_multiples() > 1)
- add_to_opened_states(stack_);
+
dot_output("\"%ld\" -> \"%ld\" [%s];\n", state->get_num(), stack_.back()->get_num(),
- state->get_transition()->dot_string().c_str());
- } else
+ state->get_transition_out()->dot_string().c_str());
+#if SIMGRID_HAVE_STATEFUL_MC
+ } else {
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());
+ state->get_transition_out()->dot_string().c_str());
+#endif
+ }
}
-
log_state();
}
+std::shared_ptr<State> DFSExplorer::best_opened_state()
+{
+ int best_prio = 0; // cache the value for the best priority found so far (initialized to silence gcc)
+ auto best = end(opened_states_); // iterator to the state to explore having the best priority
+ auto valid = begin(opened_states_); // iterator marking the limit between states still to explore, and already
+ // explored ones
+
+ // Keep only still non-explored states (aid != -1), and record the one with the best (greater) priority.
+ for (auto current = begin(opened_states_); current != end(opened_states_); ++current) {
+ auto [aid, prio] = (*current)->next_transition_guided();
+ if (aid == -1)
+ continue;
+ if (valid != current)
+ *valid = std::move(*current);
+ if (best == end(opened_states_) || prio > best_prio) {
+ best_prio = prio;
+ best = valid;
+ }
+ ++valid;
+ }
+
+ std::shared_ptr<State> best_state;
+ if (best < valid) {
+ // There are non-explored states, and one of them has the best priority. Remove it from opened_states_ before
+ // returning.
+ best_state = std::move(*best);
+ --valid;
+ if (best != valid)
+ *best = std::move(*valid);
+ }
+ opened_states_.erase(valid, end(opened_states_));
+
+ return best_state;
+}
+
void DFSExplorer::backtrack()
{
- backtrack_count_++;
XBT_VERB("Backtracking from %s", get_record_trace().to_string().c_str());
XBT_DEBUG("%lu alternatives are yet to be explored:", opened_states_.size());
- for (auto& stack : opened_states_)
- XBT_DEBUG("--> %s", get_record_trace_of_stack(stack).to_string().c_str());
+
on_backtracking_signal(get_remote_app());
get_remote_app().check_deadlock();
- // if no backtracking point, then set the stack_ to empty so we can end the exploration
- if (opened_states_.size() == 0) {
- stack_ = std::list<std::shared_ptr<State>>();
- return;
- }
-
- /* 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();
-
- stack_t backtrack;
- double min_dist = std::numeric_limits<double>::infinity();
- aid_t min_aid = -1;
- for (auto iter = opened_states_.begin(); iter != opened_states_.end();) {
- auto [aid, dist] = (*iter).back()->next_transition_guided();
- if (aid == -1) { // happens if no actors are todo anymore in this transition
- iter = opened_states_.erase(iter);
- continue;
- }
- if (dist < min_dist) {
- min_dist = dist;
- min_aid = aid;
- backtrack = (*iter);
- }
- iter++;
- }
+ // Take the point with smallest distance
+ auto backtracking_point = best_opened_state();
- if (min_aid == -1) {
- stack_ = std::list<std::shared_ptr<State>>();
+ // if no backtracking point, then set the stack_ to empty so we can end the exploration
+ if (not backtracking_point) {
+ XBT_DEBUG("No more opened point of exploration, the search will end");
+ stack_.clear();
return;
}
- if (backtrack.back()->count_todo_multiples() <= 1)
- opened_states_.remove(backtrack);
+ // We found a backtracking point, let's go to it
+ backtrack_count_++;
+ XBT_DEBUG("Backtracking to state#%ld", backtracking_point->get_num());
+#if SIMGRID_HAVE_STATEFUL_MC
/* If asked to rollback on a state that has a snapshot, restore it */
- State* last_state = backtrack.back().get();
- if (const auto* system_state = last_state->get_system_state()) {
+ if (const auto* system_state = backtracking_point->get_system_state()) {
system_state->restore(*get_remote_app().get_remote_process_memory());
- on_restore_system_state_signal(last_state, get_remote_app());
- stack_ = backtrack;
+ on_restore_system_state_signal(backtracking_point.get(), get_remote_app());
+ this->restore_stack(backtracking_point);
return;
}
+#endif
/* if no snapshot, we need to restore the initial state and replay the transitions */
get_remote_app().restore_initial_state();
on_restore_initial_state_signal(get_remote_app());
/* Traverse the stack from the state at position start and re-execute the transitions */
- for (std::shared_ptr<State> const& state : backtrack) {
- if (state == backtrack.back()) /* If we are arrived on the target state, don't replay the outgoing transition */
- break;
- state->get_transition()->replay(get_remote_app());
- on_transition_replay_signal(state->get_transition(), get_remote_app());
+ for (auto& state : backtracking_point->get_recipe()) {
+ state->replay(get_remote_app());
+ on_transition_replay_signal(state, get_remote_app());
visited_states_count_++;
}
- stack_ = backtrack;
- XBT_DEBUG(">> Backtracked to %s", get_record_trace().to_string().c_str());
+ this->restore_stack(backtracking_point);
}
DFSExplorer::DFSExplorer(const std::vector<char*>& args, bool with_dpor, bool need_memory_info)
} else
XBT_INFO("Start a DFS exploration. Reduction is: %s.", to_c_str(reduction_mode_));
- auto initial_state = std::make_unique<State>(get_remote_app());
+ auto initial_state = std::make_shared<State>(get_remote_app());
XBT_DEBUG("**************************************************");
- stack_.push_back(std::move(initial_state));
+ stack_.emplace_back(std::move(initial_state));
/* 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());
+ XBT_DEBUG("Initial state. %lu actors to consider", stack_.back()->get_actor_count());
if (reduction_mode_ == ReductionMode::dpor)
stack_.back()->consider_best();
else {
stack_.back()->consider_all();
}
if (stack_.back()->count_todo_multiples() > 1)
- add_to_opened_states(stack_);
+ opened_states_.emplace_back(stack_.back());
}
Exploration* create_dfs_exploration(const std::vector<char*>& args, bool with_dpor)
