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, std::size_t heap_bytes_used)
22 : heap_bytes_used_(heap_bytes_used), actor_count_(actor_count), num_(state_number)
24 this->system_state_ = std::make_shared<simgrid::mc::Snapshot>(state_number);
27 void VisitedStates::prune()
29 while (states_.size() > (std::size_t)_sg_mc_max_visited_states) {
30 XBT_DEBUG("Try to remove visited state (maximum number of stored states reached)");
31 auto min_element = boost::range::min_element(
32 states_, [](const std::unique_ptr<simgrid::mc::VisitedState>& a,
33 const std::unique_ptr<simgrid::mc::VisitedState>& b) { return a->num_ < b->num_; });
34 xbt_assert(min_element != states_.end());
36 states_.erase(min_element);
37 XBT_DEBUG("Remove visited state (maximum number of stored states reached)");
41 /** @brief Checks whether a given state has already been visited by the algorithm. */
42 std::unique_ptr<simgrid::mc::VisitedState>
43 VisitedStates::addVisitedState(unsigned long state_number, simgrid::mc::State* graph_state, std::size_t heap_bytes_used)
46 std::make_unique<simgrid::mc::VisitedState>(state_number, graph_state->get_actor_count(), heap_bytes_used);
48 graph_state->set_system_state(new_state->system_state_);
49 XBT_DEBUG("Snapshot %p of visited state %ld (exploration stack state %ld)", new_state->system_state_.get(),
50 new_state->num_, graph_state->get_num());
52 auto [range_begin, range_end] = boost::range::equal_range(states_, new_state.get(), [](auto const& a, auto const& b) {
53 return std::make_pair(a->actor_count_, a->heap_bytes_used_) < std::make_pair(b->actor_count_, b->heap_bytes_used_);
56 for (auto i = range_begin; i != range_end; ++i) {
57 auto& visited_state = *i;
58 if (*visited_state->system_state_.get() == *new_state->system_state_.get()) {
59 // The state has been visited:
61 std::unique_ptr<simgrid::mc::VisitedState> old_state = std::move(visited_state);
63 if (old_state->original_num_ == -1) // I'm the copy of an original process
64 new_state->original_num_ = old_state->num_;
65 else // I'm the copy of a copy
66 new_state->original_num_ = old_state->original_num_;
68 XBT_DEBUG("State %ld already visited ! (equal to state %ld (state %ld in dot_output))", new_state->num_,
69 old_state->num_, new_state->original_num_);
71 /* Replace the old state with the new one (with a bigger num)
72 (when the max number of visited states is reached, the oldest
73 one is removed according to its number (= with the min number) */
74 XBT_DEBUG("Replace visited state %ld with the new visited state %ld", old_state->num_, new_state->num_);
76 visited_state = std::move(new_state);
81 XBT_DEBUG("Insert new visited state %ld (total : %lu)", new_state->num_, (unsigned long)states_.size());
82 states_.insert(range_begin, std::move(new_state));
87 } // namespace simgrid::mc