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"
12 namespace simgrid::mc::udpor {
16 Configuration() = default;
17 Configuration(const Configuration&) = default;
18 Configuration& operator=(Configuration const&) = default;
19 Configuration(Configuration&&) = default;
21 explicit Configuration(const EventSet& events);
22 explicit Configuration(std::initializer_list<const UnfoldingEvent*> events);
24 auto begin() const { return this->events_.begin(); }
25 auto end() const { return this->events_.end(); }
26 auto cbegin() const { return this->events_.cbegin(); }
27 auto cend() const { return this->events_.cend(); }
29 bool contains(const UnfoldingEvent* e) const { return this->events_.contains(e); }
30 const EventSet& get_events() const { return this->events_; }
31 const UnfoldingEvent* get_latest_event() const { return this->newest_event; }
34 * @brief Insert a new event into the configuration
36 * When the newly added event is inserted into the configuration,
37 * an assertion is made to ensure that the configuration remains
38 * valid, i.e. that the newly added event's dependencies are contained
39 * within the configuration.
41 * @param e the event to add to the configuration. If the event is
42 * already a part of the configuration, calling this method has no
45 * @throws an invalid argument exception is raised should the event
46 * be missing one of its dependencies
48 * @note: UDPOR technically enforces the invariant that all newly-added events
49 * will ensure that the configuration is valid. We perform extra checks to ensure
50 * that UDPOR is implemented as expected. There is a performance penalty that
51 * should be noted: checking for maximality requires ensuring that all events in the
52 * configuration have their dependencies containes within the configuration, which
53 * essentially means performing a BFS/DFS over the configuration using a History object.
54 * However, since the slowest part of UDPOR involves enumerating all
55 * subsets of maximal events and computing k-partial alternatives (the
56 * latter definitively an NP-hard problem when optimal), Amdahl's law suggests
57 * we shouldn't focus so much on this (let alone the additional benefit of the
60 void add_event(const UnfoldingEvent* e);
63 * @brief Orders the events of the configuration such that
64 * "more recent" events (i.e. those that are farther down in
65 * the event structure's dependency chain) come after those
66 * that appeared "farther in the past"
68 * @returns a vector `V` with the following property:
70 * 1. Let i(e) := C -> I map events to their indices in `V`.
71 * For every pair of events e, e' in C, if e < e' then i(e) < i(e')
73 * Intuitively, events that are closer to the "bottom" of the event
74 * structure appear farther along in the list than those that appear
77 std::vector<const UnfoldingEvent*> get_topologically_sorted_events() const;
80 * @brief Orders the events of the configuration such that
81 * "more recent" events (i.e. those that are farther down in
82 * the event structure's dependency chain) come before those
83 * that appear "farther in the past"
85 * @note The events of the event structure are arranged such that
86 * e < e' implies a directed edge from e to e'. However, it is
87 * also useful to be able to traverse the *reverse* graph (for
88 * example when computing the compatibility graph of a configuration),
89 * hence the distinction between "reversed" and the method
90 * "Configuration::get_topologically_sorted_events()"
92 * @returns a vector `V` with the following property:
94 * 1. Let i(e) := C -> I map events to their indices in `V`.
95 * For every pair of events e, e' in C, if e < e' then i(e) > i(e')
97 * Intuitively, events that are closer to the "top" of the event
98 * structure appear farther along in the list than those that appear
99 * closer to the "bottom"
101 std::vector<const UnfoldingEvent*> get_topologically_sorted_events_of_reverse_graph() const;
104 * @brief Computes the smallest set of events whose collective histories
105 * capture all events of this configuration
107 * @invariant The set of all events in the collective histories
108 * of the events returned by this method is equal to the set of events
109 * in this configuration
111 * @returns the smallest set of events whose events generates this configuration
112 * (denoted `config(E)`)
114 EventSet get_minimally_reproducible_events() const;
118 * @brief The most recent event added to the configuration
120 const UnfoldingEvent* newest_event = nullptr;
123 * @brief The events which make up this configuration
125 * @invariant For each event `e` in `events_`, the set of
126 * dependencies of `e` is also contained in `events_`
131 } // namespace simgrid::mc::udpor