}
RecordTrace DFSExplorer::get_record_trace() // override
+{
+ return get_record_trace_of_stack(stack_);
+}
+
+/* Usefull to show debug information */
+RecordTrace DFSExplorer::get_record_trace_of_stack(stack_t stack)
{
RecordTrace res;
- for (auto const& state : stack_)
+ for (auto const& state : stack)
res.push_back(state->get_transition());
return res;
}
Exploration::log_state();
}
+/* Copy a given stack by deep-copying it at the State level : this is required so we can backtrack at different
+ * points without interacting with the stacks in the opened_states_ waiting for their turn. On the other hand,
+ * the exploration of one stack in opened_states_ could only slightly modify the sleep set of another stack in
+ * opened_states_, so it is only a slight waste of performance in the exploration. */
+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(tmp_stack);
+}
+
void DFSExplorer::run()
{
on_exploration_start_signal(get_remote_app());
}
// 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, double> 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.
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) */
- std::unique_ptr<State> next_state;
- next_state = std::make_unique<State>(get_remote_app(), state);
+ std::shared_ptr<State> next_state;
+ next_state = std::make_shared<State>(get_remote_app(), state);
on_state_creation_signal(next_state.get(), get_remote_app());
/* Sleep set procedure:
* 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;
- for (auto& state : stack_)
- tmp_stack.push_back(std::make_shared<State>(State(*state)));
+ stack_t tmp_stack = std::list(stack_);
while (not tmp_stack.empty()) {
State* prev_state = tmp_stack.back().get();
if (state->get_transition()->aid_ == prev_state->get_transition()->aid_) {
if (prev_state->is_actor_enabled(issuer_id)) {
if (not prev_state->is_actor_done(issuer_id)) {
prev_state->consider_one(issuer_id);
- opened_states.emplace_back(tmp_stack);
+ add_to_opened_states(tmp_stack);
} 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();
- opened_states.emplace_back(tmp_stack);
+ if (prev_state->consider_all() >
+ 0) // If we ended up marking at least a transition, explore it at some point
+ add_to_opened_states(tmp_stack);
}
break;
} else {
}
}
+ // 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)
+ add_to_opened_states(stack_);
+
if (_sg_mc_termination)
this->check_non_termination(next_state.get());
stack_.back()->consider_best(); // Take only one transition if DPOR: others may be considered later if required
else {
stack_.back()->consider_all();
- opened_states.emplace_back(stack_);
}
+
dot_output("\"%ld\" -> \"%ld\" [%s];\n", state->get_num(), stack_.back()->get_num(),
state->get_transition()->dot_string().c_str());
} else
visited_state_->original_num_ == -1 ? visited_state_->num_ : visited_state_->original_num_,
state->get_transition()->dot_string().c_str());
}
-
log_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());
+
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) {
+ if (opened_states_.empty()) {
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& stack : opened_states) {
- auto [aid, dist] = stack.back()->next_transition_guided();
- if (aid == -1)
- continue;
- if (dist < min_dist) {
- min_dist = dist;
- min_aid = aid;
- backtrack = stack;
- }
- }
+ stack_t backtrack = opened_states_.top(); // Take the point with smallest distance
+ opened_states_.pop();
- if (min_aid == -1) {
- stack_ = std::list<std::shared_ptr<State>>();
+ // if the smallest distance corresponded to no enable actor, remove this and let the
+ // exploration ask again for a backtrack
+ if (backtrack.back()->next_transition_guided().first == -1)
return;
- }
- if (backtrack.back()->count_todo() <= 1)
- opened_states.pop_back();
+ // We found a real backtracking point, let's go to it
+ backtrack_count_++;
/* If asked to rollback on a state that has a snapshot, restore it */
State* last_state = backtrack.back().get();
stack_.back()->consider_best();
else {
stack_.back()->consider_all();
- opened_states.emplace_back(stack_);
}
+ if (stack_.back()->count_todo_multiples() > 1)
+ add_to_opened_states(stack_);
}
Exploration* create_dfs_exploration(const std::vector<char*>& args, bool with_dpor)
