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_CONFIGURATION_HPP
7 #define SIMGRID_MC_UDPOR_CONFIGURATION_HPP
9 #include "src/mc/explo/udpor/EventSet.hpp"
10 #include "src/mc/explo/udpor/udpor_forward.hpp"
13 #include <initializer_list>
16 namespace simgrid::mc::udpor {
20 Configuration() = default;
21 Configuration(const Configuration&) = default;
22 Configuration& operator=(Configuration const&) = default;
23 Configuration(Configuration&&) = default;
25 explicit Configuration(const EventSet& events);
26 explicit Configuration(std::initializer_list<UnfoldingEvent*> events);
28 auto begin() const { return this->events_.begin(); }
29 auto end() const { return this->events_.end(); }
31 bool contains(UnfoldingEvent* e) const { return this->events_.contains(e); }
32 const EventSet& get_events() const { return this->events_; }
33 UnfoldingEvent* get_latest_event() const { return this->newest_event; }
36 * @brief Insert a new event into the configuration
38 * When the newly added event is inserted into the configuration,
39 * an assertion is made to ensure that the configuration remains
40 * valid, i.e. that the newly added event's dependencies are contained
41 * within the configuration.
43 * @param e the event to add to the configuration. If the event is
44 * already a part of the configuration, calling this method has no
47 * @throws an invalid argument exception is raised should the event
48 * be missing one of its dependencies
50 * @note: UDPOR technically enforces the invariant that all newly-added events
51 * will ensure that the configuration is valid. We perform extra checks to ensure
52 * that UDPOR is implemented as expected. There is a performance penalty that
53 * should be noted: checking for maximality requires ensuring that all events in the
54 * configuration have their dependencies containes within the configuration, which
55 * essentially means performing a BFS/DFS over the configuration using a History object.
56 * However, since the slowest part of UDPOR involves enumerating all
57 * subsets of maximal events and computing k-partial alternatives (the
58 * latter definitively an NP-hard problem when optimal), Amdahl's law suggests
59 * we shouldn't focus so much on this (let alone the additional benefit of the
62 void add_event(UnfoldingEvent* e);
65 * @brief Orders the events of the configuration such that
66 * "more recent" events (i.e. those that are farther down in
67 * the event structure's dependency chain) come after those
68 * that appeared "farther in the past"
70 * @returns a vector `V` with the following property:
72 * 1. Let i(e) := C -> I map events to their indices in `V`.
73 * For every pair of events e, e' in C, if e < e' then i(e) < i(e')
75 * Intuitively, events that are closer to the "bottom" of the event
76 * structure appear farther along in the list than those that appear
79 std::vector<UnfoldingEvent*> get_topologically_sorted_events() const;
82 * @brief Orders the events of the configuration such that
83 * "more recent" events (i.e. those that are farther down in
84 * the event structure's dependency chain) come before those
85 * that appear "farther in the past"
87 * @note The events of the event structure are arranged such that
88 * e < e' implies a directed edge from e to e'. However, it is
89 * also useful to be able to traverse the *reverse* graph (for
90 * example when computing the compatibility graph of a configuration),
91 * hence the distinction between "reversed" and the method
92 * "Configuration::get_topologically_sorted_events()"
94 * @returns a vector `V` with the following property:
96 * 1. Let i(e) := C -> I map events to their indices in `V`.
97 * For every pair of events e, e' in C, if e < e' then i(e) > i(e')
99 * Intuitively, events that are closer to the "top" of the event
100 * structure appear farther along in the list than those that appear
101 * closer to the "bottom"
103 std::vector<UnfoldingEvent*> get_topologically_sorted_events_of_reverse_graph() const;
107 * @brief The most recent event added to the configuration
109 UnfoldingEvent* newest_event = nullptr;
112 * @brief The events which make up this configuration
114 * @invariant For each event `e` in `events_`, the set of
115 * dependencies of `e` is also contained in `events_`
120 } // namespace simgrid::mc::udpor