#include "src/mc/explo/UdporChecker.hpp"
#include "src/mc/api/State.hpp"
+#include "src/mc/explo/udpor/Comb.hpp"
+#include "src/mc/explo/udpor/ExtensionSetCalculator.hpp"
+#include "src/mc/explo/udpor/History.hpp"
+#include "src/mc/explo/udpor/maximal_subsets_iterator.hpp"
+
#include <xbt/asserts.h>
#include <xbt/log.h>
+#include <xbt/string.hpp>
XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_udpor, mc, "Logging specific to verification using UDPOR");
namespace simgrid::mc::udpor {
-UdporChecker::UdporChecker(const std::vector<char*>& args) : Exploration(args)
-{
- // Initialize the map
-}
+UdporChecker::UdporChecker(const std::vector<char*>& args) : Exploration(args, true) {}
void UdporChecker::run()
{
XBT_INFO("Starting a UDPOR exploration");
- // NOTE: `A`, `D`, and `C` are derived from the
- // original UDPOR paper [1], while `prev_exC` arises
- // from the incremental computation of ex(C) from [3]
- Configuration C_root;
-
- // TODO: Move computing the root configuration into a method on the Unfolding
- auto initial_state = get_current_state();
- auto root_event = std::make_unique<UnfoldingEvent>(EventSet(), std::make_shared<Transition>());
- auto* root_event_handle = root_event.get();
- unfolding.insert(std::move(root_event));
- C_root.add_event(root_event_handle);
-
- explore(std::move(C_root), EventSet(), EventSet(), std::move(initial_state), EventSet());
-
+ state_stack.clear();
+ state_stack.push_back(get_current_state());
+ explore(Configuration(), EventSet(), EventSet(), EventSet());
XBT_INFO("UDPOR exploration terminated -- model checking completed");
}
-void UdporChecker::explore(Configuration C, EventSet D, EventSet A, std::unique_ptr<State> stateC, EventSet prev_exC)
+void UdporChecker::explore(const Configuration& C, EventSet D, EventSet A, EventSet prev_exC)
{
- // Perform the incremental computation of exC
- //
- // TODO: This method will have side effects on
- // the unfolding, but the naming of the method
- // suggests it is doesn't have side effects. We should
- // reconcile this in the future
- auto [exC, enC] = compute_extension(C, *stateC, prev_exC);
+ auto& stateC = *state_stack.back();
+ auto exC = compute_exC(C, stateC, prev_exC);
+ const auto enC = compute_enC(C, exC);
// If enC is a subset of D, intuitively
// there aren't any enabled transitions
// exploration would lead to a so-called
// "sleep-set blocked" trace.
if (enC.is_subset_of(D)) {
-
- if (C.get_events().size() > 0) {
-
- // g_var::nb_traces++;
-
- // TODO: Log here correctly
- // XBT_DEBUG("\n Exploring executions: %d : \n", g_var::nb_traces);
- // ...
- // ...
+ if (not C.get_events().empty()) {
+ // Report information...
}
// When `en(C)` is empty, intuitively this means that there
// are no enabled transitions that can be executed from the
// state reached by `C` (denoted `state(C)`), i.e. by some
// execution of the transitions in C obeying the causality
- // relation. Here, then, we would be in a deadlock.
+ // relation. Here, then, we may be in a deadlock (the other
+ // possibility is that we've finished running everything, and
+ // we wouldn't be in deadlock then)
if (enC.empty()) {
get_remote_app().check_deadlock();
}
// TODO: Add verbose logging about which event is being explored
- UnfoldingEvent* e = select_next_unfolding_event(A, enC);
+ const UnfoldingEvent* e = select_next_unfolding_event(A, enC);
xbt_assert(e != nullptr, "\n\n****** INVARIANT VIOLATION ******\n"
"UDPOR guarantees that an event will be chosen at each point in\n"
"the search, yet no events were actually chosen\n"
"*********************************\n\n");
-
- // Move the application into stateCe and actually make note of that state
- move_to_stateCe(*stateC, *e);
- auto stateCe = record_current_state();
-
// Ce := C + {e}
Configuration Ce = C;
Ce.add_event(e);
exC.remove(e);
// Explore(C + {e}, D, A \ {e})
- explore(Ce, D, std::move(A), std::move(stateCe), std::move(exC));
+
+ // Move the application into stateCe (i.e. `state(C + {e})`) and make note of that state
+ move_to_stateCe(stateC, *e);
+ state_stack.push_back(record_current_state());
+
+ explore(Ce, D, std::move(A), std::move(exC));
+
+ // Prepare to move the application back one state.
+ // We need only remove the state from the stack here: if we perform
+ // another `Explore()` after computing an alternative, at that
+ // point we'll actually create a fresh RemoteProcess
+ state_stack.pop_back();
// D <-- D + {e}
D.insert(e);
- // TODO: Determine a value of K to use or don't use it at all
constexpr unsigned K = 10;
- auto J = compute_partial_alternative(D, C, K);
- if (!J.empty()) {
- J.subtract(C.get_events());
-
+ if (auto J = C.compute_k_partial_alternative_to(D, this->unfolding, K); J.has_value()) {
// Before searching the "right half", we need to make
// sure the program actually reflects the fact
- // that we are searching again from `stateC` (the recursive
- // search moved the program into `stateCe`)
- restore_program_state_to(*stateC);
+ // that we are searching again from `state(C)`. While the
+ // stack of states is properly adjusted to represent
+ // `state(C)` all together, the RemoteApp is currently sitting
+ // at some *future* state with resepct to `state(C)` since the
+ // recursive calls have moved it there.
+ restore_program_state_with_current_stack();
// Explore(C, D + {e}, J \ C)
- explore(C, D, std::move(J), std::move(stateC), std::move(prev_exC));
+ auto J_minus_C = J.value().get_events().subtracting(C.get_events());
+ explore(C, D, std::move(J_minus_C), std::move(prev_exC));
}
// D <-- D - {e}
clean_up_explore(e, C, D);
}
-std::tuple<EventSet, EventSet> UdporChecker::compute_extension(const Configuration& C, const State& stateC,
- const EventSet& prev_exC) const
+EventSet UdporChecker::compute_exC(const Configuration& C, const State& stateC, const EventSet& prev_exC)
{
// See eqs. 5.7 of section 5.2 of [3]
// C = C' + {e_cur}, i.e. C' = C - {e_cur}
//
// Then
//
- // ex(C) = ex(C' + {e_cur}) = ex(C') / {e_cur} + U{<a, K> : K is maximal, a depends on all of K, a enabled at K }
- UnfoldingEvent* e_cur = C.get_latest_event();
- EventSet exC = prev_exC;
+ // ex(C) = ex(C' + {e_cur}) = ex(C') / {e_cur} +
+ // U{<a, K> : K is maximal, `a` depends on all of K, `a` enabled at config(K) }
+ const UnfoldingEvent* e_cur = C.get_latest_event();
+ EventSet exC = prev_exC;
exC.remove(e_cur);
for (const auto& [aid, actor_state] : stateC.get_actors_list()) {
for (const auto& transition : actor_state.get_enabled_transitions()) {
- // First check for a specialized function that can compute the extension
- // set "quickly" based on its type. Otherwise, fall back to computing
- // the set "by hand"
- const auto specialized_extension_function = incremental_extension_functions.find(transition->type_);
- if (specialized_extension_function != incremental_extension_functions.end()) {
- exC.form_union((specialized_extension_function->second)(C, *transition));
- } else {
- exC.form_union(this->compute_extension_by_enumeration(C, *transition));
- }
+ EventSet extension = ExtensionSetCalculator::partially_extend(C, &unfolding, transition);
+ exC.form_union(extension);
}
}
-
- EventSet enC;
-
- return std::tuple<EventSet, EventSet>(exC, enC);
+ return exC;
}
-EventSet UdporChecker::compute_extension_by_enumeration(const Configuration& C, const Transition& action) const
+EventSet UdporChecker::compute_enC(const Configuration& C, const EventSet& exC) const
{
- // TODO: Do something more interesting here
- return EventSet();
+ EventSet enC;
+ for (const auto e : exC) {
+ if (not e->conflicts_with(C)) {
+ enC.insert(e);
+ }
+ }
+ return enC;
}
void UdporChecker::move_to_stateCe(State& state, const UnfoldingEvent& e)
"one transition of the state of an visited event is enabled, yet no\n"
"state was actually enabled. Please report this as a bug.\n"
"*********************************\n\n");
- state.execute_next(next_actor);
+ state.execute_next(next_actor, get_remote_app());
}
-void UdporChecker::restore_program_state_to(const State& stateC)
+void UdporChecker::restore_program_state_with_current_stack()
{
- // TODO: Perform state regeneration in the same manner as is done
- // in the DFSChecker.cpp
+ get_remote_app().restore_initial_state();
+
+ /* Traverse the stack from the state at position start and re-execute the transitions */
+ for (const std::unique_ptr<State>& state : state_stack) {
+ if (state == state_stack.back()) /* If we are arrived on the target state, don't replay the outgoing transition */
+ break;
+ state->get_transition()->replay(get_remote_app());
+ }
}
std::unique_ptr<State> UdporChecker::record_current_state()
auto next_state = this->get_current_state();
// In UDPOR, we care about all enabled transitions in a given state
- next_state->mark_all_enabled_todo();
+ next_state->consider_all();
return next_state;
}
-UnfoldingEvent* UdporChecker::select_next_unfolding_event(const EventSet& A, const EventSet& enC)
+const UnfoldingEvent* UdporChecker::select_next_unfolding_event(const EventSet& A, const EventSet& enC)
{
- if (!enC.empty()) {
+ if (enC.empty()) {
+ throw std::invalid_argument("There are no unfolding events to select. "
+ "Are you sure that you checked that en(C) was not "
+ "empty before attempting to select an event from it?");
+ }
+
+ if (A.empty()) {
return *(enC.begin());
}
return nullptr;
}
-EventSet UdporChecker::compute_partial_alternative(const EventSet& D, const Configuration& C, const unsigned k) const
-{
- // TODO: Compute k-partial alternatives using [2]
- return EventSet();
-}
-
void UdporChecker::clean_up_explore(const UnfoldingEvent* e, const Configuration& C, const EventSet& D)
{
- // TODO: Perform clean up here
+ const EventSet C_union_D = C.get_events().make_union(D);
+ const EventSet es_immediate_conflicts = this->unfolding.get_immediate_conflicts_of(e);
+ const EventSet Q_CDU = C_union_D.make_union(es_immediate_conflicts.get_local_config());
+
+ // Move {e} \ Q_CDU from U to G
+ if (Q_CDU.contains(e)) {
+ this->unfolding.remove(e);
+ }
+
+ // foreach ê in #ⁱ_U(e)
+ for (const auto* e_hat : es_immediate_conflicts) {
+ // Move [ê] \ Q_CDU from U to G
+ const EventSet to_remove = e_hat->get_history().subtracting(Q_CDU);
+ this->unfolding.remove(to_remove);
+ }
}
RecordTrace UdporChecker::get_record_trace()
{
RecordTrace res;
+ for (auto const& state : state_stack)
+ res.push_back(state->get_transition());
return res;
}
std::vector<std::string> UdporChecker::get_textual_trace()
{
- // TODO: Topologically sort the events of the latest configuration
- // and iterate through that topological sorting
std::vector<std::string> trace;
+ for (auto const& state : state_stack) {
+ const auto* t = state->get_transition();
+ trace.push_back(xbt::string_printf("%ld: %s", t->aid_, t->to_string().c_str()));
+ }
return trace;
}
