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, RemoteApp& remote_app)
22 : heap_bytes_used_(remote_app.get_remote_process_memory()->get_remote_heap_bytes())
23 , actor_count_(actor_count)
26 this->system_state_ = std::make_shared<simgrid::mc::Snapshot>(state_number, remote_app.get_page_store(),
27 *remote_app.get_remote_process_memory());
30 void VisitedStates::prune()
32 while (states_.size() > (std::size_t)_sg_mc_max_visited_states) {
33 XBT_DEBUG("Try to remove visited state (maximum number of stored states reached)");
34 auto min_element = boost::range::min_element(
35 states_, [](const std::unique_ptr<simgrid::mc::VisitedState>& a,
36 const std::unique_ptr<simgrid::mc::VisitedState>& b) { return a->num_ < b->num_; });
37 xbt_assert(min_element != states_.end());
39 states_.erase(min_element);
40 XBT_DEBUG("Remove visited state (maximum number of stored states reached)");
44 /** @brief Checks whether a given state has already been visited by the algorithm. */
45 std::unique_ptr<simgrid::mc::VisitedState>
46 VisitedStates::addVisitedState(unsigned long state_number, simgrid::mc::State* graph_state, RemoteApp& remote_app)
49 std::make_unique<simgrid::mc::VisitedState>(state_number, graph_state->get_actor_count(), remote_app);
51 graph_state->set_system_state(new_state->system_state_);
52 XBT_DEBUG("Snapshot %p of visited state %ld (exploration stack state %ld)", new_state->system_state_.get(),
53 new_state->num_, graph_state->get_num());
55 auto [range_begin, range_end] = boost::range::equal_range(states_, new_state.get(), [](auto const& a, auto const& b) {
56 return std::make_pair(a->actor_count_, a->heap_bytes_used_) < std::make_pair(b->actor_count_, b->heap_bytes_used_);
59 for (auto i = range_begin; i != range_end; ++i) {
60 auto& visited_state = *i;
61 if (visited_state->system_state_->equals_to(*new_state->system_state_.get(),
62 *remote_app.get_remote_process_memory())) {
63 // The state has been visited:
65 std::unique_ptr<simgrid::mc::VisitedState> old_state = std::move(visited_state);
67 if (old_state->original_num_ == -1) // I'm the copy of an original process
68 new_state->original_num_ = old_state->num_;
69 else // I'm the copy of a copy
70 new_state->original_num_ = old_state->original_num_;
72 XBT_DEBUG("State %ld already visited ! (equal to state %ld (state %ld in dot_output))", new_state->num_,
73 old_state->num_, new_state->original_num_);
75 /* Replace the old state with the new one (with a bigger num)
76 (when the max number of visited states is reached, the oldest
77 one is removed according to its number (= with the min number) */
78 XBT_DEBUG("Replace visited state %ld with the new visited state %ld", old_state->num_, new_state->num_);
80 visited_state = std::move(new_state);
85 XBT_DEBUG("Insert new visited state %ld (total : %lu)", new_state->num_, (unsigned long)states_.size());
86 states_.insert(range_begin, std::move(new_state));
91 } // namespace simgrid::mc