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_STATE_HPP
7 #define SIMGRID_MC_STATE_HPP
9 #include "src/mc/api/ActorState.hpp"
10 #include "src/mc/api/ClockVector.hpp"
11 #include "src/mc/api/RemoteApp.hpp"
12 #include "src/mc/api/strategy/Strategy.hpp"
13 #include "src/mc/explo/odpor/WakeupTree.hpp"
14 #include "src/mc/transition/Transition.hpp"
16 namespace simgrid::mc {
18 /* A node in the exploration graph (kind-of) */
19 class XBT_PRIVATE State : public xbt::Extendable<State> {
20 static long expended_states_; /* Count total amount of states, for stats */
22 /** @brief The outgoing transition is the last transition that we took to leave this state. */
23 std::shared_ptr<Transition> outgoing_transition_ = nullptr;
25 /** @brief The incoming transition is what led to this state, coming from its parent */
26 std::shared_ptr<Transition> incoming_transition_ = nullptr;
28 /** Sequential state ID (used for debugging) */
31 /** Unique parent of this state. Required both for sleep set computation
32 and for guided model-checking */
33 std::shared_ptr<State> parent_state_ = nullptr;
35 std::shared_ptr<Strategy> strategy_;
37 /* Sleep sets are composed of the actor and the corresponding transition that made it being added to the sleep
38 * set. With this information, it is check whether it should be removed from it or not when exploring a new
40 std::map<aid_t, std::shared_ptr<Transition>> sleep_set_;
43 * The wakeup tree with respect to the execution represented
44 * by the totality of all states before and including this one
45 * and with respect to this state's sleep set
47 odpor::WakeupTree wakeup_tree_;
48 bool has_initialized_wakeup_tree = false;
51 explicit State(RemoteApp& remote_app);
52 explicit State(RemoteApp& remote_app, std::shared_ptr<State> parent_state);
53 /* Returns a positive number if there is another transition to pick, or -1 if not */
54 aid_t next_transition() const; // this function should disapear as it is redundant with the next one
56 /* Same as next_transition(), but choice is now guided, and an integer corresponding to the
57 internal cost of the transition is returned */
58 std::pair<aid_t, int> next_transition_guided() const;
61 * Same as next_transition(), but the choice is not based off the ODPOR
62 * wakeup tree associated with this state
64 aid_t next_odpor_transition() const;
67 * @brief Explore a new path on the remote app; the parameter 'next' must be the result of a previous call to
70 std::shared_ptr<Transition> execute_next(aid_t next, RemoteApp& app);
72 long get_num() const { return num_; }
73 std::size_t count_todo() const;
74 std::size_t count_todo_multiples() const;
76 /* Marking as TODO some actor in this state:
77 * + consider_one mark aid actor (and assert it is possible)
78 * + consider_best ensure one actor is marked by eventually marking the best regarding its guiding method
79 * + consider_all mark all enabled actor that are not done yet */
80 void consider_one(aid_t aid) const { strategy_->consider_one(aid); }
81 void consider_best() const { strategy_->consider_best(); }
82 unsigned long consider_all() const { return strategy_->consider_all(); }
84 bool is_actor_done(aid_t actor) const { return strategy_->actors_to_run_.at(actor).is_done(); }
85 std::shared_ptr<Transition> get_transition_out() const { return outgoing_transition_; }
86 std::shared_ptr<Transition> get_transition_in() const { return incoming_transition_; }
87 std::shared_ptr<State> get_parent_state() const { return parent_state_; }
89 std::map<aid_t, ActorState> const& get_actors_list() const { return strategy_->actors_to_run_; }
91 unsigned long get_actor_count() const { return strategy_->actors_to_run_.size(); }
92 bool is_actor_enabled(aid_t actor) const { return strategy_->actors_to_run_.at(actor).is_enabled(); }
95 * @brief Computes the backtrack set for this state
96 * according to its definition in SimGrid.
98 * The backtrack set as it appears in DPOR, SDPOR, and ODPOR
99 * in SimGrid consists of those actors marked as `todo`
100 * (i.e. those that have yet to be explored) as well as those
101 * marked `done` (i.e. those that have already been explored)
102 * since the pseudocode in none of the above algorithms explicitly
103 * removes elements from the backtrack set. DPOR makes use
104 * explicitly of the `done` set, but we again note that the
105 * backtrack set still contains processes added to the done set.
107 std::unordered_set<aid_t> get_backtrack_set() const;
108 std::unordered_set<aid_t> get_sleeping_actors() const;
109 std::unordered_set<aid_t> get_enabled_actors() const;
110 std::map<aid_t, std::shared_ptr<Transition>> const& get_sleep_set() const { return sleep_set_; }
111 void add_sleep_set(std::shared_ptr<Transition> t) { sleep_set_.insert_or_assign(t->aid_, std::move(t)); }
112 bool is_actor_sleeping(aid_t actor) const
114 return std::find_if(sleep_set_.begin(), sleep_set_.end(), [=](const auto& pair) { return pair.first == actor; }) !=
119 * @brief Inserts an arbitrary enabled actor into the wakeup tree
120 * associated with this state, if such an actor exists and if
121 * the wakeup tree is already not empty
123 * @param prior The sequence of steps leading up to this state
124 * with respec to which the tree associated with this state should be
125 * a wakeup tree (wakeup trees are defined relative to an execution)
127 * @invariant: You should not manipulate a wakeup tree with respect
128 * to more than one execution; doing so will almost certainly lead to
129 * unexpected results as wakeup trees are defined relative to a single
132 void seed_wakeup_tree_if_needed(const odpor::Execution& prior);
135 * @brief Initializes the wakeup_tree_ instance by taking the subtree rooted at the
136 * single-process node `N` running actor `p := "actor taken by parent to form this state"`
137 * of the *parent's* wakeup tree
139 void sprout_tree_from_parent_state();
142 * @brief Removes the subtree rooted at the single-process node
143 * `N` running actor `p` of this state's wakeup tree
145 void remove_subtree_using_current_out_transition();
146 void remove_subtree_at_aid(aid_t proc);
147 bool has_empty_tree() const { return this->wakeup_tree_.empty(); }
148 std::string string_of_wut() const { return this->wakeup_tree_.string_of_whole_tree(); }
153 odpor::WakeupTree::InsertionResult insert_into_wakeup_tree(const odpor::PartialExecution&, const odpor::Execution&);
155 /** @brief Prepares the state for re-exploration following
156 * another after having followed ODPOR from this state with
157 * the current out transition
159 * After ODPOR has completed searching a maximal trace, it
160 * finds the first point in the execution with a nonempty wakeup
161 * tree. This method corresponds to lines 20 and 21 in the ODPOR
164 void do_odpor_unwind();
166 /* Returns the total amount of states created so far (for statistics) */
167 static long get_expanded_states() { return expended_states_; }
169 } // namespace simgrid::mc