X-Git-Url: http://bilbo.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/b6a2ada11480242c200660a273f4174151d0bf09..93998c2ed02609cdbf9f8039a0c6f364940df8cb:/src/mc/explo/udpor/Configuration.cpp diff --git a/src/mc/explo/udpor/Configuration.cpp b/src/mc/explo/udpor/Configuration.cpp index a05d3a7a0a..8e2cb8521e 100644 --- a/src/mc/explo/udpor/Configuration.cpp +++ b/src/mc/explo/udpor/Configuration.cpp @@ -6,15 +6,16 @@ #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 -#include #include namespace simgrid::mc::udpor { -Configuration::Configuration(std::initializer_list events) : Configuration(EventSet(std::move(events))) +Configuration::Configuration(std::initializer_list events) + : Configuration(EventSet(std::move(events))) { } @@ -25,7 +26,7 @@ Configuration::Configuration(const EventSet& events) : events_(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"); @@ -35,89 +36,62 @@ void Configuration::add_event(UnfoldingEvent* e) return; } + // Preserves the property that the configuration is conflict-free + if (e->conflicts_with(*this)) { + throw std::invalid_argument("The newly added event conflicts with the events already " + "contained in the configuration. Adding this event violates " + "the property that a configuration is conflict-free"); + } + this->events_.insert(e); this->newest_event = e; - // Preserves the property that the configuration is valid - History history(e); - if (!this->events_.contains(history)) { + // Preserves the property that the configuration is causally closed + if (auto history = History(e); !this->events_.contains(history)) { throw std::invalid_argument("The newly added event has dependencies " "which are missing from this configuration"); } } -std::vector Configuration::get_topologically_sorted_events() const +std::vector Configuration::get_topologically_sorted_events() const { - if (events_.empty()) { - return std::vector(); - } + return this->events_.get_topological_ordering(); +} - std::stack event_stack; - std::vector topological_ordering; - EventSet unknown_events = events_; - EventSet temporarily_marked_events; - EventSet permanently_marked_events; - - while (not unknown_events.empty()) { - EventSet discovered_events; - event_stack.push(*unknown_events.begin()); - - while (not event_stack.empty()) { - UnfoldingEvent* evt = event_stack.top(); - discovered_events.insert(evt); - - if (not temporarily_marked_events.contains(evt)) { - // If this event hasn't yet been marked, do - // so now so that if we see it again in a child we can - // detect a cycle and if we see it again here - // we can detect that the node is re-processed - temporarily_marked_events.insert(evt); - - EventSet immediate_causes = evt->get_immediate_causes(); - if (!immediate_causes.empty() && immediate_causes.is_subset_of(temporarily_marked_events)) { - throw std::invalid_argument("Attempted to perform a topological sort on a configuration " - "whose contents contain a cycle. The configuration (and the graph " - "connecting all of the events) is an invalid event structure"); - } - immediate_causes.subtract(discovered_events); - immediate_causes.subtract(permanently_marked_events); - const EventSet undiscovered_causes = std::move(immediate_causes); - - for (const auto cause : undiscovered_causes) { - 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); - - // In moving this event to the end of the list, - // we are saying this events "happens before" other - // events that are added later. - topological_ordering.push_back(evt); - - // Only now do we remove the event, i.e. once - // we've processed the same event again - event_stack.pop(); - } - } - } - return topological_ordering; +std::vector Configuration::get_topologically_sorted_events_of_reverse_graph() const +{ + return this->events_.get_topological_ordering_of_reverse_graph(); } -std::vector Configuration::get_topologically_sorted_events_of_reverse_graph() const +EventSet Configuration::get_minimally_reproducible_events() const { - // The method 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. - auto topological_events = get_topologically_sorted_events(); - std::reverse(topological_events.begin(), topological_events.end()); - return topological_events; + // 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