* under the terms of the license (GNU LGPL) which comes with this package. */
#include "src/mc/explo/odpor/Execution.hpp"
+#include <exception>
+#include <limits>
namespace simgrid::mc::odpor {
-std::unordered_set<Execution::EventHandle> Execution::get_racing_events_of(Execution::EventHandle e1) const
+std::unordered_set<Execution::EventHandle> Execution::get_racing_events_of(Execution::EventHandle target) const
{
- return {};
+ std::unordered_set<Execution::EventHandle> racing_events;
+ std::unordered_set<Execution::EventHandle> disqualified_events;
+
+ // For each event of the execution
+ for (auto e_i = target; e_i > 0 && e_i != std::numeric_limits<Execution::EventHandle>::max(); e_i--) {
+ // We need `e_i -->_E target` as a necessary condition
+ if (not happens_before(e_i, target)) {
+ continue;
+ }
+
+ // Further, `proc(e_i) != proc(target)`
+ if (get_actor_with_handle(e_i) == get_actor_with_handle(target)) {
+ disqualified_events.insert(e_i);
+ continue;
+ }
+
+ // There could an event that "happens-between" the two events which would discount `e_i` as a race
+ for (auto e_j = e_i; e_j < target; e_j++) {
+ // If both:
+ // 1. e_i --->_E e_j; and
+ // 2. disqualified_events.count(e_j) > 0
+ // then e_i --->_E target indirectly (either through
+ // e_j directly, or transitively through e_j)
+ if (happens_before(e_i, e_j) and disqualified_events.count(e_j) > 0) {
+ disqualified_events.insert(e_i);
+ break;
+ }
+ }
+
+ // If `e_i` wasn't disqualified in the last round,
+ // it's in a race with `target`. After marking it
+ // as such, we ensure no other event `e` can happen-before
+ // it (since this would transitively make it the event
+ // which "happens-between" `target` and `e`)
+ if (disqualified_events.count(e_i) == 0) {
+ racing_events.insert(e_i);
+ disqualified_events.insert(e_i);
+ }
+ }
+
+ return racing_events;
}
-bool Execution::happens_before(Execution::EventHandle e1, Execution::EventHandle e2) const
+bool Execution::happens_before(Execution::EventHandle e1_handle, Execution::EventHandle e2_handle) const
{
- return true;
+ // 1. "happens-before" is a subset of "occurs before"
+ if (e1_handle > e2_handle) {
+ return false;
+ }
+
+ // Each execution maintains a stack of clock vectors which are updated
+ // according to the procedure outlined in section 4 of the original DPOR paper
+ const Event& e2 = get_event_with_handle(e2_handle);
+ const aid_t proc_e1 = get_actor_with_handle(e1_handle);
+ return e1_handle <= e2.get_clock_vector().get(proc_e1).value_or(0);
}
-Execution Execution::get_prefix_up_to(Execution::EventHandle)
+Execution Execution::get_prefix_up_to(Execution::EventHandle handle)
{
- return *this;
+ if (handle == static_cast<Execution::EventHandle>(0)) {
+ return Execution();
+ }
+ return Execution(std::vector<Event>{contents_.begin(), contents_.begin() + (handle - 1)});
}
-void Execution::pop_latest() {}
+void Execution::push_transition(const Transition* t)
+{
+ if (t == nullptr) {
+ throw std::invalid_argument("Unexpectedly received `nullptr`");
+ }
+ ClockVector max_clock_vector;
+ for (const Event& e : this->contents_) {
+ if (e.get_transition()->depends(t)) {
+ max_clock_vector = ClockVector::max(max_clock_vector, e.get_clock_vector());
+ }
+ }
+ // The entry in the vector for `t->aid_` is the size
+ // of the new stack, which will have a size one greater
+ // than that before we insert the new events
+ max_clock_vector[t->aid_] = this->size() + 1;
+ contents_.push_back(Event({t, max_clock_vector}));
+}
-void Execution::push_transition(const Transition*) {}
+void Execution::pop_latest()
+{
+ contents_.pop_back();
+}
} // namespace simgrid::mc::odpor
\ No newline at end of file
