void maximal_subsets_iterator::increment()
{
- // Until we discover otherwise, we default to being done
- auto next_event_ref = topological_ordering.end();
+ if (current_maximal_set = std::nullopt) {
+ return;
+ }
+
+ const auto next_event_ref = continue_traversal_of_maximal_events_tree();
+ if (next_event_ref == topological_ordering.end()) {
+ current_maximal_set = std::nullopt;
+ return;
+ }
+ // We found some other event `e'` which is not in causally related with anything
+ // that currently exists in `current_maximal_set`. Add it in
+ add_element_to_current_maximal_set(*next_event_ref);
+ backtrack_points.push(next_event_ref);
+}
+
+maximal_subsets_iterator::topological_order_position
+maximal_subsets_iterator::continue_traversal_of_maximal_events_tree()
+{
while (not backtrack_points.empty()) {
// This is an iterator which points to the latest event `e` that
// was added to what is currently the maximal set
// will not change whether or not to now allow someone before `e`
// in the ordering (otherwise, they would have to be in `e`'s history
// and therefore would come after `e`)
- next_event_ref = bookkeeper.find_next_event(latest_event_ref, topological_ordering.end());
-
- // If we can't find another event to add after `e`,
- // then we retry after first removing the latest event.
- // This effectively tests "check now with all combinations that
- // exclude the latest event".
- //
- // Note: it is important to remove the element FIRST before performing
- // the second search, as removal may enable dependencies of `e` to be selected
- if (next_event_ref == topological_ordering.end()) {
+ auto next_event_ref = bookkeeper.find_next_candidate_event(latest_event_ref, topological_ordering.end());
+
+ // If we found some event, we can stop
+ if (next_event_ref != topological_ordering.end() and should_consider_event(*next_event_ref)) {
+ return next_event_ref;
+ } else {
+ // Otherwise, if we can't find another event to add after `e` that
+ // we need to consider, we retry after first removing the latest event.
+ // This effectively tests "check now with all combinations that3
+ // exclude the latest event".
+ //
+ // Note: it is important to remove the element FIRST before performing
+ // the second search, as removal may enable dependencies of `e` to be selected
remove_element_from_current_maximal_set(*latest_event_ref);
backtrack_points.pop();
// We begin the search AFTER the event we popped: we only want
// to consider those events that could be added AFTER `e` and
// not `e` itself again
- next_event_ref = bookkeeper.find_next_event(latest_event_ref + 1, topological_ordering.end());
+ next_event_ref = bookkeeper.find_next_candidate_event(latest_event_ref + 1, topological_ordering.end());
- // If we finally found some event, we can stop
- if (next_event_ref != topological_ordering.end()) {
- break;
+ // If we finally found some event AFTER removal, we can stop
+ if (next_event_ref != topological_ordering.end() and should_consider_event(*next_event_ref)) {
+ return next_event_ref;
}
}
}
+ return topological_ordering.end();
+}
- // If after all of the backtracking we still have no luck, we've finished
- if (next_event_ref == topological_ordering.end()) {
- return;
+bool maximal_subsets_iterator::should_consider_event(const UnfoldingEvent* e) const
+{
+ if (filter_function.has_value()) {
+ return filter_function.value()(e);
}
-
- // Otherwise we found some other event `e'` which is not in conflict with anything
- // that currently exists in `current_maximal_set`. Add it in and perform
- // some more bookkeeping
- add_element_to_current_maximal_set(*next_event_ref);
- backtrack_points.push(next_event_ref);
+ return true; // If nobody specified a filter, we default to considering the event
}
bool maximal_subsets_iterator::bookkeeper::is_candidate_event(const UnfoldingEvent* e) const
void maximal_subsets_iterator::add_element_to_current_maximal_set(const UnfoldingEvent* e)
{
- current_maximal_set.insert(e);
+ xbt_assert(current_maximal_set.has_value(), "Attempting to add an event to the maximal set "
+ "when iteration has completed. This indicates that "
+ "the termination condition for the iterator is broken");
+ current_maximal_set.value().insert(e);
bookkeeper.mark_included_in_maximal_set(e);
}
void maximal_subsets_iterator::remove_element_from_current_maximal_set(const UnfoldingEvent* e)
{
- current_maximal_set.remove(e);
+ xbt_assert(current_maximal_set.has_value(), "Attempting to remove an event to the maximal set "
+ "when iteration has completed. This indicates that "
+ "the termination condition for the iterator is broken");
+ current_maximal_set.value().remove(e);
bookkeeper.mark_removed_from_maximal_set(e);
}
maximal_subsets_iterator::topological_order_position
-maximal_subsets_iterator::bookkeeper::find_next_event(topological_order_position first,
- topological_order_position last) const
+maximal_subsets_iterator::bookkeeper::find_next_candidate_event(topological_order_position first,
+ topological_order_position last) const
{
return std::find_if(first, last, [&](const UnfoldingEvent* e) { return is_candidate_event(e); });
}
