1 /* Copyright (c) 2011-2023. 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 #include "src/mc/VisitedState.hpp"
7 #include "src/mc/explo/Exploration.hpp"
8 #include "src/mc/mc_config.hpp"
9 #include "src/mc/mc_private.hpp"
14 #include <boost/range/algorithm.hpp>
16 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_VisitedState, mc, "Logging specific to state equality detection mechanisms");
18 namespace simgrid::mc {
20 /** @brief Save the current state */
21 VisitedState::VisitedState(unsigned long state_number, unsigned int actor_count)
22 : actor_count_(actor_count), num(state_number)
24 this->heap_bytes_used = mc_model_checker->get_remote_process().get_remote_heap_bytes();
25 this->system_state = std::make_shared<simgrid::mc::Snapshot>(state_number);
28 void VisitedStates::prune()
30 while (states_.size() > (std::size_t)_sg_mc_max_visited_states) {
31 XBT_DEBUG("Try to remove visited state (maximum number of stored states reached)");
32 auto min_element = boost::range::min_element(
33 states_, [](const std::unique_ptr<simgrid::mc::VisitedState>& a,
34 const std::unique_ptr<simgrid::mc::VisitedState>& b) { return a->num < b->num; });
35 xbt_assert(min_element != states_.end());
37 states_.erase(min_element);
38 XBT_DEBUG("Remove visited state (maximum number of stored states reached)");
42 /** @brief Checks whether a given state has already been visited by the algorithm. */
43 std::unique_ptr<simgrid::mc::VisitedState> VisitedStates::addVisitedState(unsigned long state_number,
44 simgrid::mc::State* graph_state)
46 auto new_state = std::make_unique<simgrid::mc::VisitedState>(state_number, graph_state->get_actor_count());
47 graph_state->set_system_state(new_state->system_state);
48 XBT_DEBUG("Snapshot %p of visited state %ld (exploration stack state %ld)", new_state->system_state.get(),
49 new_state->num, graph_state->get_num());
51 auto [range_begin, range_end] = boost::range::equal_range(states_, new_state.get(), [](auto const& a, auto const& b) {
52 return std::make_pair(a->actor_count_, a->heap_bytes_used) < std::make_pair(b->actor_count_, b->heap_bytes_used);
55 for (auto i = range_begin; i != range_end; ++i) {
56 auto& visited_state = *i;
57 if (*visited_state->system_state.get() == *new_state->system_state.get()) {
58 // The state has been visited:
60 std::unique_ptr<simgrid::mc::VisitedState> old_state = std::move(visited_state);
62 if (old_state->original_num == -1) // I'm the copy of an original process
63 new_state->original_num = old_state->num;
64 else // I'm the copy of a copy
65 new_state->original_num = old_state->original_num;
67 XBT_DEBUG("State %ld already visited ! (equal to state %ld (state %ld in dot_output))", new_state->num,
68 old_state->num, new_state->original_num);
70 /* Replace the old state with the new one (with a bigger num)
71 (when the max number of visited states is reached, the oldest
72 one is removed according to its number (= with the min number) */
73 XBT_DEBUG("Replace visited state %ld with the new visited state %ld", old_state->num, new_state->num);
75 visited_state = std::move(new_state);
80 XBT_DEBUG("Insert new visited state %ld (total : %lu)", new_state->num, (unsigned long)states_.size());
81 states_.insert(range_begin, std::move(new_state));
86 } // namespace simgrid::mc