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"
14 namespace simgrid::mc::udpor {
18 Configuration() = default;
19 Configuration(const Configuration&) = default;
20 Configuration& operator=(Configuration const&) = default;
21 Configuration(Configuration&&) = default;
23 explicit Configuration(const UnfoldingEvent* event);
24 explicit Configuration(const EventSet& events);
25 explicit Configuration(const History& history);
26 explicit Configuration(std::initializer_list<const UnfoldingEvent*> events);
28 auto begin() const { return this->events_.begin(); }
29 auto end() const { return this->events_.end(); }
30 auto cbegin() const { return this->events_.cbegin(); }
31 auto cend() const { return this->events_.cend(); }
33 bool contains(const UnfoldingEvent* e) const { return this->events_.contains(e); }
34 const EventSet& get_events() const { return this->events_; }
35 const UnfoldingEvent* get_latest_event() const { return this->newest_event; }
38 * @brief Insert a new event into the configuration
40 * When the newly added event is inserted into the configuration,
41 * an assertion is made to ensure that the configuration remains
42 * valid, i.e. that the newly added event's dependencies are contained
43 * within the configuration.
45 * @param e the event to add to the configuration. If the event is
46 * already a part of the configuration, calling this method has no
49 * @throws an invalid argument exception is raised should the event
50 * be missing one of its dependencies
52 * @note: UDPOR technically enforces the invariant that all newly-added events
53 * will ensure that the configuration is valid. We perform extra checks to ensure
54 * that UDPOR is implemented as expected. There is a performance penalty that
55 * should be noted: checking for maximality requires ensuring that all events in the
56 * configuration have their dependencies containes within the configuration, which
57 * essentially means performing a BFS/DFS over the configuration using a History object.
58 * However, since the slowest part of UDPOR involves enumerating all
59 * subsets of maximal events and computing k-partial alternatives (the
60 * latter definitively an NP-hard problem when optimal), Amdahl's law suggests
61 * we shouldn't focus so much on this (let alone the additional benefit of the
64 void add_event(const UnfoldingEvent* e);
67 * @brief Whether or not the given event can be added to
68 * this configuration while keeping the set of events causally closed
71 bool is_compatible_with(const UnfoldingEvent* e) const;
74 * @brief Whether or not the events in the given history can be added to
75 * this configuration while keeping the set of events causally closed
78 bool is_compatible_with(const History& history) const;
80 std::optional<Configuration> compute_alternative_to(const EventSet& D, const Unfolding& U) const;
81 std::optional<Configuration> compute_k_partial_alternative_to(const EventSet& D, const Unfolding& U, size_t k) const;
84 * @brief Orders the events of the configuration such that
85 * "more recent" events (i.e. those that are farther down in
86 * the event structure's dependency chain) come after those
87 * that appeared "farther in the past"
89 * @returns a vector `V` with the following property:
91 * 1. Let i(e) := C -> I map events to their indices in `V`.
92 * For every pair of events e, e' in C, if e < e' then i(e) < i(e')
94 * Intuitively, events that are closer to the "bottom" of the event
95 * structure appear farther along in the list than those that appear
98 std::vector<const UnfoldingEvent*> get_topologically_sorted_events() const;
101 * @brief Orders the events of the configuration such that
102 * "more recent" events (i.e. those that are farther down in
103 * the event structure's dependency chain) come before those
104 * that appear "farther in the past"
106 * @note The events of the event structure are arranged such that
107 * e < e' implies a directed edge from e to e'. However, it is
108 * also useful to be able to traverse the *reverse* graph (for
109 * example when computing the compatibility graph of a configuration),
110 * hence the distinction between "reversed" and the method
111 * "Configuration::get_topologically_sorted_events()"
113 * @returns a vector `V` with the following property:
115 * 1. Let i(e) := C -> I map events to their indices in `V`.
116 * For every pair of events e, e' in C, if e < e' then i(e) > i(e')
118 * Intuitively, events that are closer to the "top" of the event
119 * structure appear farther along in the list than those that appear
120 * closer to the "bottom"
122 std::vector<const UnfoldingEvent*> get_topologically_sorted_events_of_reverse_graph() const;
125 * @brief Computes the smallest set of events whose collective histories
126 * capture all events of this configuration
128 * @invariant The set of all events in the collective histories
129 * of the events returned by this method is equal to the set of events
130 * in this configuration
132 * @returns the smallest set of events whose events generates
133 * this configuration (denoted `config(E)`)
135 EventSet get_minimally_reproducible_events() const;
139 * @brief The most recent event added to the configuration
141 const UnfoldingEvent* newest_event = nullptr;
144 * @brief The events which make up this configuration
146 * @invariant For each event `e` in `events_`, the set of
147 * dependencies of `e` is also contained in `events_`
152 } // namespace simgrid::mc::udpor