#include "src/mc/api/ClockVector.hpp"
#include "src/mc/explo/odpor/odpor_forward.hpp"
+#include "src/mc/mc_forward.hpp"
+#include "src/mc/mc_record.hpp"
#include "src/mc/transition/Transition.hpp"
#include <list>
namespace simgrid::mc::odpor {
-using ProcessSequence = std::list<aid_t>;
-using ExecutionSequence = std::list<const State*>;
-using Hypothetical = ExecutionSequence;
+std::vector<std::string> get_textual_trace(const PartialExecution& w);
/**
* @brief The occurrence of a transition in an execution
* actor `j`
*/
class Event {
- std::pair<const Transition*, ClockVector> contents_;
+ std::pair<std::shared_ptr<Transition>, ClockVector> contents_;
public:
Event() = default;
Event(Event&&) = default;
Event(const Event&) = default;
Event& operator=(const Event&) = default;
- explicit Event(std::pair<const Transition*, ClockVector> pair) : contents_(std::move(pair)) {}
+ explicit Event(std::pair<std::shared_ptr<Transition>, ClockVector> pair) : contents_(std::move(pair)) {}
- const Transition* get_transition() const { return std::get<0>(contents_); }
+ std::shared_ptr<Transition> get_transition() const { return std::get<0>(contents_); }
const ClockVector& get_clock_vector() const { return std::get<1>(contents_); }
};
*/
class Execution {
private:
- /**
- * @brief The actual steps that are taken by the process
- * during exploration, relative to the
- */
std::vector<Event> contents_;
-
Execution(std::vector<Event>&& contents) : contents_(std::move(contents)) {}
public:
- using Handle = decltype(contents_)::const_iterator;
using EventHandle = uint32_t;
Execution() = default;
Execution(const Execution&) = default;
Execution& operator=(Execution const&) = default;
Execution(Execution&&) = default;
- Execution(ExecutionSequence&& seq);
- Execution(const ExecutionSequence& seq);
+ Execution(const PartialExecution&);
+
+ std::vector<std::string> get_textual_trace() const;
size_t size() const { return this->contents_.size(); }
bool empty() const { return this->contents_.empty(); }
* 9 | --> add some q in I_[E'](v) to backtrack(E')
*
* This method computes all of the lines simultaneously,
- * returning some actor `q` if it passes line 8 and exists.
+ * returning the set `I_[E'](v)` if condition on line 8 holds.
* The event `e` and the set `backtrack(E')` are the provided
* arguments to the method.
*
* See the SDPOR algorithm pseudocode in [1] for more
* details for the context of the function.
*
- * @invariant: This method assumes that events `e` and
- * `e' := get_latest_event_handle()` are in a *reversible* race
+ * @precondition: This method assumes that events `e` and
+ * `e' := get_latest_event_handle()` are in a *reversible* race,
* as is explicitly the case in SDPOR
*
- * @returns an actor not contained in `disqualified` which
- * can serve as an initial to reverse the race between `e`
- * and `e'`
+ * @returns a set of actors not already contained in `backtrack_set`
+ * which serve as an initials to reverse the race between `e`
+ * and `e' := get_latest_event_handle()`; that is, an initial that is
+ * not already contained in the set `backtrack_set`.
+ */
+ std::unordered_set<aid_t> get_missing_source_set_actors_from(EventHandle e,
+ const std::unordered_set<aid_t>& backtrack_set) const;
+
+ /**
+ * @brief Computes the analogous lines from the SDPOR algorithm
+ * in the ODPOR algorithm, viz. the intersection of the sleep set
+ * and the set of weak initials with respect to the given pair
+ * of racing events
+ *
+ * This method computes lines 4-6 of the ODPOR pseudocode, viz.:
+ *
+ * 4 | let E' := pre(E, e)
+ * 5 | let v := notdep(e, E).e'^
+ * 6 | if sleep(E') ∩ WI_[E'](v) = empty then
+ * 7 | --> wut(E') := insert_[E'](v, wut(E'))
+ *
+ * The sequence `v` is computed and returned as needed, based on whether
+ * the check on line 6 passes.
+ *
+ * @precondition: This method assumes that events `e` and
+ * `e_prime` are in a *reversible* race, as is the case
+ * in ODPOR.
+ *
+ * @returns a partial execution `v := notdep(e, E)` (where `E` refers
+ * to this execution) that should be inserted into a wakeup tree with
+ * respect to this execution if `sleep(E') ∩ WI_[E'](v) = empty`, and
+ * `std::nullopt` otherwise
+ */
+ std::optional<PartialExecution> get_odpor_extension_from(EventHandle e, EventHandle e_prime,
+ const State& state_at_e) const;
+
+ /**
+ * @brief For a given sequence of actors `v` and a sequence of transitions `w`,
+ * computes the sequence, if any, that should be inserted as a child in wakeup tree for
+ * this execution
+ *
+ * Recall that the procedure for implementing the insertion
+ * is outlined in section 6.2 of Abdulla et al. 2017 as follows:
+ *
+ * | Let `v` be the smallest (w.r.t to "<") sequence in [the tree] B
+ * | such that `v ~_[E] w`. If `v` is a leaf node, the tree can be left
+ * | unmodified.
+ * |
+ * | Otherwise let `w'` be the shortest sequence such that `w [=_[E] v.w'`
+ * | and add `v.w'` as a new leaf, ordered after all already existing nodes
+ * | of the form `v.w''`
+ *
+ * The procedure for determining whether `v ~_[E] w` is given as Lemma 4.6 of
+ * Abdulla et al. 2017:
+ *
+ * | The relation `v ~_[E] w` holds if either
+ * | (1) v = <>, or
+ * | (2) v := p.v' and either
+ * | (a) p in I_[E](w) and `v' ~_[E.p] (w \ p)`
+ * | (b) E ⊢ p ◊ w and `v' ~_[E.p] w`
+ *
+ * This method computes the result `v.w'` as needed (viz. only if `v ~_[E] w`
+ * with respect to this execution `E`). The implementation takes advantage
+ * of the fact that determining whether `v ~_[E] w` yields "for free" the
+ * the shortest such `w'` we are looking for; if we ultimately determine
+ * that `v ~_[E] w`, the work we did to do so leaves us precisely with `w'`,
+ * so we can simply prepend `v` to it and call it a day
+ *
+ * @precondition: This method assumes that `E.v` is a valid execution, viz.
+ * that the events of `E` are sufficient to enabled `v_0` and that
+ * `v_0, ..., v_{i - 1}` are sufficient to enable `v_i`. This is the
+ * case when e.g. `v := notdep(e, E).p` for example in ODPOR
+ *
+ * @returns a partial execution `v.w'` that should be inserted
+ * as a child of a wakeup tree node representing the sequence `v`
+ * if `v ~_[E] w`, or `std::nullopt` if that relation does not hold
+ * between the two sequences `v` and `w`
+ */
+ std::optional<PartialExecution> get_shortest_odpor_sq_subset_insertion(const PartialExecution& v,
+ const PartialExecution& w) const;
+
+ /**
+ * @brief For a given sequence `w`, determines whether p in I_[E](w)
+ *
+ * @note: You may notice that some of the other methods compute this
+ * value as well. What we notice, though, in those cases is that
+ * we are repeatedly asking about initials with respect to an execution.
+ * It is better, then, to bunch the work together in those cases to
+ * get asymptotically better results (e.g. instead of calling with all
+ * `N` actors, we can process them "in-parallel" as is done with the
+ * computation of SDPOR initials)
+ */
+ bool is_initial_after_execution_of(const PartialExecution& w, aid_t p) const;
+
+ /**
+ * @brief Determines whether `E ⊢ p ◊ w` given the next action taken by `p`
*/
- std::optional<aid_t> get_first_sdpor_initial_from(EventHandle e, std::unordered_set<aid_t> backtrack_set) const;
+ bool is_independent_with_execution_of(const PartialExecution& w, std::shared_ptr<Transition> next_E_p) const;
/**
- * @brief Determines the event associated with
- * the given handle `handle`
+ * @brief Determines the event associated with the given handle `handle`
*/
const Event& get_event_with_handle(EventHandle handle) const { return contents_[handle]; }
/**
- * @brief Determines the actor associated with
- * the given event handle `handle`
+ * @brief Determines the actor associated with the given event handle `handle`
*/
aid_t get_actor_with_handle(EventHandle handle) const { return get_event_with_handle(handle).get_transition()->aid_; }
+ /**
+ * @brief Determines the transition associated with the given handle `handle`
+ */
+ const Transition* get_transition_for_handle(EventHandle handle) const
+ {
+ return get_event_with_handle(handle).get_transition().get();
+ }
+
+ /**
+ * @brief Returns a handle to the newest event of the execution, if such an event exists
+ *
+ * @returns the handle to the last event of the execution.
+ * If the sequence is empty, no such handle exists and the
+ * method returns `std::nullopt`
+ */
+ std::optional<EventHandle> get_latest_event_handle() const
+ {
+ return contents_.empty() ? std::nullopt : std::optional<EventHandle>{static_cast<EventHandle>(size() - 1)};
+ }
+
/**
* @brief Returns a set of events which are in
* "immediate conflict" (according to the definition given
* in the ODPOR paper) with the given event
*
* Two events `e` and `e'` in an execution `E` are said to
- * race iff
+ * *race* iff
*
* 1. `proc(e) != proc(e')`; that is, the events correspond to
* the execution of different actors
*
* @param handle the event with respect to which races are
* computed
- * @returns a set of event handles from which race with `handle`
+ * @returns a set of event handles, each element of which is an
+ * event in this execution which is in a *race* with event `handle`
*/
std::unordered_set<EventHandle> get_racing_events_of(EventHandle handle) const;
/**
- * @brief Returns a handle to the newest event of the execution,
- * if such an event exists
+ * @brief Returns a set of events which are in a reversible
+ * race with the given event handle `handle`
+ *
+ * Two events `e` and `e'` in an execution `E` are said to
+ * be in a *reversible race* iff
+ *
+ * 1. `e` and `e'` race
+ * 2. In any equivalent execution sequence `E'` to `E`
+ * where `e` occurs immediately before `e'`, the actor
+ * running `e'` was enabled in the state prior to `e`
+ *
+ * @param handle the event with respect to which
+ * reversible races are computed
+ * @returns a set of event handles, each element of which is an event
+ * in this execution which is in a *reversible race* with event `handle`
*/
- std::optional<EventHandle> get_latest_event_handle() const
- {
- return contents_.empty() ? std::nullopt : std::optional<EventHandle>{static_cast<EventHandle>(size() - 1)};
- }
+ std::unordered_set<EventHandle> get_reversible_races_of(EventHandle handle) const;
/**
* @brief Computes `pre(e, E)` as described in ODPOR [1]
*
* The execution `pre(e, E)` for an event `e` in an
* execution `E` is the contiguous prefix of events
- * `E' <= E` up to by excluding the event `e` itself.
- * The prefix intuitively represents the "history" of
- * causes that permitted event `e` to exist (roughly
- * speaking)
+ * `E' <= E` up to but excluding the event `e` itself.
+ * Roughly speaking, the prefix intuitively represents
+ * the "history" of causes which permitted event `e`
+ * to exist
*/
- Execution get_prefix_up_to(EventHandle) const;
+ Execution get_prefix_before(EventHandle) const;
/**
* @brief Whether the event represented by `e1`
* notation of [1]) `E.proc(t)` where `proc(t)` is the
* actor which executed transition `t`.
*/
- void push_transition(const Transition*);
+ void push_transition(std::shared_ptr<Transition>);
+
+ /**
+ * @brief Extends the execution by a sequence of steps
+ *
+ * This method has the equivalent effect of pushing the
+ * transitions of the partial execution one-by-one onto
+ * the execution
+ */
+ void push_partial_execution(const PartialExecution&);
};
} // namespace simgrid::mc::odpor
