1 /* Copyright (c) 2007-2023. The SimGrid Team. All rights reserved. */
3 /* This program is free software; you can redistribute it and/or modify it
4 * under the terms of the license (GNU LGPL) which comes with this package. */
6 #ifndef SIMGRID_MC_UDPOR_HISTORY_HPP
7 #define SIMGRID_MC_UDPOR_HISTORY_HPP
9 #include "src/mc/explo/udpor/EventSet.hpp"
10 #include "src/mc/explo/udpor/udpor_forward.hpp"
12 namespace simgrid::mc::udpor {
15 * @brief Conceptually describes the local configuration(s) of
16 * an event or a collection of events, encoding the history of
17 * the events without needing to actually fully compute all of
18 * the events contained in the history
20 * When you create an instance of `History`, you are effectively
21 * making a "lazy" configuration whose elements are the set of
22 * causes of a given event (if the `History` constists of a single
23 * event) or the union of all causes of all events (if the
24 * `History` consists of a set of events).
26 * Using a `History` object to represent the history of a set of
27 * events is more efficient (and reads more easily) than first
28 * computing the entire history of each of the events separately
29 * and combining the results. The former can take advantage of the
30 * fact that the histories of a set of events overlap greatly, and
31 * thus only a single BFS/DFS search over the event structure needs
32 * to be performed instead of many isolated searches for each event.
34 * The same observation also allows you to compute the difference between
35 * a configuration and a history of a set of events. This is used
36 * in UDPOR, for example, when determing the difference J / C and
37 * when using K-partial alternatives (which computes J as the union
38 * of histories of events)
43 * @brief The events whose history this instance describes
49 History(const History&) = default;
50 History& operator=(History const&) = default;
51 History(History&&) = default;
53 explicit History(UnfoldingEvent* e) : events_({e}) {}
54 explicit History(EventSet event_set) : events_(std::move(event_set)) {}
57 * @brief Whether or not the given event is contained in the history
59 * @note If you only need to determine whether a few events are contained
60 * in a history, prefer this method. If, however, you wish to repeatedly
61 * determine over time (e.g. over the course of a computation) whether
62 * some event is part of the history, it may be better to first compute
63 * all events (see `History::get_all_events()`) and reuse this set
65 * @param e the event to check
66 * @returns whether or not `e` is contained in the collection
68 bool contains(UnfoldingEvent* e) const;
71 * @brief Computes all events in the history described by this instance
73 * Sometimes, it is useful to compute the entire set of events that
74 * comprise the history of some event `e` of some set of events `E`.
75 * This method performs that computation.
77 * @returns the set of all causal dependencies of all events this
78 * history represents. Equivalently, the method returns the full
79 * dependency graph for all events in this history
81 EventSet get_all_events() const;
83 EventSet get_event_diff_with(const EventSet& event_set) const;
84 EventSet get_event_diff_with(const Configuration& config) const;
87 } // namespace simgrid::mc::udpor