#include "src/mc/explo/udpor/Configuration.hpp"
#include "src/mc/explo/udpor/History.hpp"
#include "src/mc/explo/udpor/UnfoldingEvent.hpp"
+#include "src/mc/explo/udpor/maximal_subsets_iterator.hpp"
#include "xbt/asserts.h"
#include <algorithm>
namespace simgrid::mc::udpor {
-Configuration::Configuration(std::initializer_list<UnfoldingEvent*> events) : Configuration(EventSet(std::move(events)))
+Configuration::Configuration(std::initializer_list<const UnfoldingEvent*> events)
+ : Configuration(EventSet(std::move(events)))
{
}
}
}
-void Configuration::add_event(UnfoldingEvent* e)
+void Configuration::add_event(const UnfoldingEvent* e)
{
if (e == nullptr) {
throw std::invalid_argument("Expected a nonnull `UnfoldingEvent*` but received NULL instead");
}
}
-std::vector<UnfoldingEvent*> Configuration::get_topologically_sorted_events() const
+std::vector<const UnfoldingEvent*> Configuration::get_topologically_sorted_events() const
{
if (events_.empty()) {
- return std::vector<UnfoldingEvent*>();
+ return std::vector<const UnfoldingEvent*>();
}
- std::stack<UnfoldingEvent*> event_stack;
- std::vector<UnfoldingEvent*> topological_ordering;
+ std::stack<const UnfoldingEvent*> event_stack;
+ std::vector<const UnfoldingEvent*> topological_ordering;
EventSet unknown_events = events_;
EventSet temporarily_marked_events;
EventSet permanently_marked_events;
event_stack.push(*unknown_events.begin());
while (not event_stack.empty()) {
- UnfoldingEvent* evt = event_stack.top();
+ const UnfoldingEvent* evt = event_stack.top();
discovered_events.insert(evt);
if (not temporarily_marked_events.contains(evt)) {
event_stack.push(cause);
}
} else {
- // Mark this event as:
- // 1. discovered across all DFSs performed
- // 2. permanently marked
- // 3. part of the topological search
unknown_events.remove(evt);
temporarily_marked_events.remove(evt);
permanently_marked_events.insert(evt);
topological_ordering.push_back(evt);
// Only now do we remove the event, i.e. once
- // we've processed the same event again
+ // we've processed the same event twice
event_stack.pop();
}
}
return topological_ordering;
}
-std::vector<UnfoldingEvent*> Configuration::get_topologically_sorted_events_of_reverse_graph() const
+std::vector<const UnfoldingEvent*> Configuration::get_topologically_sorted_events_of_reverse_graph() const
{
- // The method exploits the property that
+ // The implementation exploits the property that
// a topological sorting S^R of the reverse graph G^R
// of some graph G is simply the reverse of any
// topological sorting S of G.
return topological_events;
}
+EventSet Configuration::get_minimally_reproducible_events() const
+{
+ // The implementation exploits the following observations:
+ //
+ // To select the smallest reproducible set of events, we want
+ // to pick events that "knock out" a lot of others. Furthermore,
+ // we need to ensure that the events furthest down in the
+ // causality graph are also selected. If you combine these ideas,
+ // you're basically left with traversing the set of maximal
+ // subsets of C! And we have an iterator for that already!
+ //
+ // The next observation is that the moment we don't increase in size
+ // the current maximal set (or decrease the number of events),
+ // we know that the prior set `S` covered the entire history of C and
+ // was maximal. Subsequent sets will miss events earlier in the
+ // topological ordering that appear in `S`
+ EventSet minimally_reproducible_events = EventSet();
+
+ for (const auto& maximal_set : maximal_subsets_iterator_wrapper(*this)) {
+ if (maximal_set.size() > minimally_reproducible_events.size()) {
+ minimally_reproducible_events = maximal_set;
+ } else {
+ // The moment we see the iterator generate a set of size
+ // that is not monotonically increasing, we can stop:
+ // the set prior was the minimally-reproducible one
+ return minimally_reproducible_events;
+ }
+ }
+ return minimally_reproducible_events;
+}
+
} // namespace simgrid::mc::udpor
