X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/fe6a4a0cfb04cbe8c0bbd93c7bf6c29ec017ddec..add8b5f44959343a150508770c76912d4886861c:/src/mc/explo/DFSExplorer.cpp diff --git a/src/mc/explo/DFSExplorer.cpp b/src/mc/explo/DFSExplorer.cpp index 9a61e128bc..edf1316724 100644 --- a/src/mc/explo/DFSExplorer.cpp +++ b/src/mc/explo/DFSExplorer.cpp @@ -1,4 +1,4 @@ -/* Copyright (c) 2016-2022. The SimGrid Team. All rights reserved. */ +/* Copyright (c) 2016-2023. The SimGrid Team. All rights reserved. */ /* This program is free software; you can redistribute it and/or modify it * under the terms of the license (GNU LGPL) which comes with this package. */ @@ -13,6 +13,7 @@ #include "src/xbt/mmalloc/mmprivate.h" #include "xbt/log.h" +#include "xbt/string.hpp" #include "xbt/sysdep.h" #include @@ -26,34 +27,37 @@ XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_dfs, mc, "DFS exploration algorithm of the mo namespace simgrid::mc { -xbt::signal DFSExplorer::on_exploration_start_signal; -xbt::signal DFSExplorer::on_backtracking_signal; +xbt::signal DFSExplorer::on_exploration_start_signal; +xbt::signal DFSExplorer::on_backtracking_signal; -xbt::signal DFSExplorer::on_state_creation_signal; +xbt::signal DFSExplorer::on_state_creation_signal; -xbt::signal DFSExplorer::on_restore_system_state_signal; -xbt::signal DFSExplorer::on_restore_initial_state_signal; -xbt::signal DFSExplorer::on_transition_replay_signal; -xbt::signal DFSExplorer::on_transition_execute_signal; +xbt::signal DFSExplorer::on_restore_system_state_signal; +xbt::signal DFSExplorer::on_restore_initial_state_signal; +xbt::signal DFSExplorer::on_transition_replay_signal; +xbt::signal DFSExplorer::on_transition_execute_signal; -xbt::signal DFSExplorer::on_log_state_signal; +xbt::signal DFSExplorer::on_log_state_signal; void DFSExplorer::check_non_termination(const State* current_state) { - for (auto state = stack_.rbegin(); state != stack_.rend(); ++state) - if (Api::get().snapshot_equal((*state)->get_system_state(), current_state->get_system_state())) { - XBT_INFO("Non-progressive cycle: state %ld -> state %ld", (*state)->get_num(), current_state->get_num()); + for (auto const& state : stack_) { + if (*state->get_system_state() == *current_state->get_system_state()) { + XBT_INFO("Non-progressive cycle: state %ld -> state %ld", state->get_num(), current_state->get_num()); XBT_INFO("******************************************"); XBT_INFO("*** NON-PROGRESSIVE CYCLE DETECTED ***"); XBT_INFO("******************************************"); XBT_INFO("Counter-example execution trace:"); for (auto const& s : get_textual_trace()) XBT_INFO(" %s", s.c_str()); - XBT_INFO("Path = %s", get_record_trace().to_string().c_str()); + XBT_INFO("You can debug the problem (and see the whole details) by rerunning out of simgrid-mc with " + "--cfg=model-check/replay:'%s'", + get_record_trace().to_string().c_str()); log_state(); throw TerminationError(); } + } } RecordTrace DFSExplorer::get_record_trace() // override @@ -76,16 +80,17 @@ std::vector DFSExplorer::get_textual_trace() // override void DFSExplorer::log_state() // override { - on_log_state_signal(); - XBT_INFO("DFS exploration ended. %ld unique states visited; %ld backtracks (%lu transition replays, %lu states " + on_log_state_signal(get_remote_app()); + XBT_INFO("DFS exploration ended. %ld unique states visited; %lu backtracks (%lu transition replays, %lu states " "visited overall)", - State::get_expanded_states(), backtrack_count_, Api::get().mc_get_visited_states(), + State::get_expanded_states(), backtrack_count_, visited_states_count_, Transition::get_replayed_transitions()); + Exploration::log_state(); } void DFSExplorer::run() { - on_exploration_start_signal(); + on_exploration_start_signal(get_remote_app()); /* This function runs the DFS algorithm the state space. * We do so iteratively instead of recursively, dealing with the call stack manually. * This allows one to explore the call stack at will. */ @@ -95,14 +100,14 @@ void DFSExplorer::run() State* state = stack_.back().get(); XBT_DEBUG("**************************************************"); - XBT_DEBUG("Exploration depth=%zu (state:%ld; %zu interleaves)", stack_.size(), state->get_num(), + XBT_DEBUG("Exploration depth=%zu (state:#%ld; %zu interleaves todo)", stack_.size(), state->get_num(), state->count_todo()); - Api::get().mc_inc_visited_states(); + visited_states_count_++; // Backtrack if we reached the maximum depth if (stack_.size() > (std::size_t)_sg_mc_max_depth) { - if (reductionMode_ == ReductionMode::dpor) { + if (reduction_mode_ == ReductionMode::dpor) { XBT_ERROR("/!\\ Max depth of %d reached! THIS WILL PROBABLY BREAK the dpor reduction /!\\", _sg_mc_max_depth.get()); XBT_ERROR("/!\\ If bad things happen, disable dpor with --cfg=model-check/reduction:none /!\\"); @@ -112,10 +117,10 @@ void DFSExplorer::run() continue; } - // Backtrack if we are revisiting a state we saw previously + // Backtrack if we are revisiting a state we saw previously while applying state-equality reduction if (visited_state_ != nullptr) { XBT_DEBUG("State already visited (equal to state %ld), exploration stopped on this path.", - visited_state_->original_num == -1 ? visited_state_->num : visited_state_->original_num); + visited_state_->original_num_ == -1 ? visited_state_->num_ : visited_state_->original_num_); visited_state_ = nullptr; this->backtrack(); @@ -123,24 +128,32 @@ void DFSExplorer::run() } // Search for the next transition - int next = state->next_transition(); + // next_transition returns a pair in case we want to consider multiple state + auto [next, _] = state->next_transition_guided(); if (next < 0) { // If there is no more transition in the current state, backtrack. - XBT_DEBUG("There remains %d actors, but none to interleave (depth %zu).", state->get_actor_count(), + XBT_DEBUG("There remains %lu actors, but none to interleave (depth %zu).", state->get_actor_count(), stack_.size() + 1); if (state->get_actor_count() == 0) { - mc_model_checker->finalize_app(); + get_remote_app().finalize_app(); XBT_VERB("Execution came to an end at %s (state: %ld, depth: %zu)", get_record_trace().to_string().c_str(), state->get_num(), stack_.size()); } + this->backtrack(); continue; } + if (_sg_mc_sleep_set && XBT_LOG_ISENABLED(mc_dfs, xbt_log_priority_verbose)) { + XBT_VERB("Sleep set actually containing:"); + for (auto& [aid, transition] : state->get_sleep_set()) + XBT_VERB(" <%ld,%s>", aid, transition.to_string().c_str()); + } + /* Actually answer the request: let's execute the selected request (MCed does one step) */ - state->execute_next(next); - on_transition_execute_signal(state->get_transition()); + state->execute_next(next, get_remote_app()); + on_transition_execute_signal(state->get_transition(), get_remote_app()); // If there are processes to interleave and the maximum depth has not been // reached then perform one step of the exploration algorithm. @@ -148,35 +161,77 @@ void DFSExplorer::run() state->get_transition()->to_string().c_str(), stack_.size(), state->get_num(), state->count_todo()); /* Create the new expanded state (copy the state of MCed into our MCer data) */ - auto next_state = std::make_unique(get_remote_app()); - on_state_creation_signal(next_state.get()); + std::unique_ptr next_state; + + next_state = std::make_unique(get_remote_app(), state); + on_state_creation_signal(next_state.get(), get_remote_app()); + + /* Sleep set procedure: + * adding the taken transition to the sleep set of the original state. + * Since the parent sleep set is used to compute the child sleep set, this need to be + * done after next_state creation */ + XBT_DEBUG("Marking Transition >>%s<< of process %ld done and adding it to the sleep set", + state->get_transition()->to_string().c_str(), state->get_transition()->aid_); + state->add_sleep_set(state->get_transition()); // Actors are marked done when they are considerd in ActorState + + /* DPOR persistent set procedure: + * for each new transition considered, check if it depends on any other previous transition executed before it + * on another process. If there exists one, find the more recent, and add its process to the interleave set. + * If the process is not enabled at this point, then add every enabled process to the interleave */ + if (reduction_mode_ == ReductionMode::dpor) { + aid_t issuer_id = state->get_transition()->aid_; + for (auto i = stack_.rbegin(); i != stack_.rend(); ++i) { + State* prev_state = i->get(); + if (state->get_transition()->aid_ == prev_state->get_transition()->aid_) { + XBT_DEBUG("Simcall >>%s<< and >>%s<< with same issuer %ld", state->get_transition()->to_string().c_str(), + prev_state->get_transition()->to_string().c_str(), issuer_id); + continue; + } else if (prev_state->get_transition()->depends(state->get_transition())) { + XBT_VERB("Dependent Transitions:"); + XBT_VERB(" %s (state=%ld)", prev_state->get_transition()->to_string().c_str(), prev_state->get_num()); + XBT_VERB(" %s (state=%ld)", state->get_transition()->to_string().c_str(), state->get_num()); + + if (prev_state->is_actor_enabled(issuer_id)) { + if (not prev_state->is_actor_done(issuer_id)) + prev_state->consider_one(issuer_id); + else + XBT_DEBUG("Actor %ld is already in done set: no need to explore it again", issuer_id); + } else { + XBT_DEBUG("Actor %ld is not enabled: DPOR may be failing. To stay sound, we are marking every enabled " + "transition as todo", + issuer_id); + prev_state->consider_all(); + } + break; + } else { + XBT_VERB("INDEPENDENT Transitions:"); + XBT_VERB(" %s (state=%ld)", prev_state->get_transition()->to_string().c_str(), prev_state->get_num()); + XBT_VERB(" %s (state=%ld)", state->get_transition()->to_string().c_str(), state->get_num()); + } + } + } if (_sg_mc_termination) this->check_non_termination(next_state.get()); /* Check whether we already explored next_state in the past (but only if interested in state-equality reduction) */ if (_sg_mc_max_visited_states > 0) - visited_state_ = visited_states_.addVisitedState(next_state->get_num(), next_state.get(), true); + visited_state_ = visited_states_.addVisitedState(next_state->get_num(), next_state.get(), get_remote_app()); /* If this is a new state (or if we don't care about state-equality reduction) */ if (visited_state_ == nullptr) { /* Get an enabled process and insert it in the interleave set of the next state */ - for (auto const& [aid, _] : next_state->get_actors_list()) { - if (next_state->is_actor_enabled(aid)) { - next_state->mark_todo(aid); - if (reductionMode_ == ReductionMode::dpor) - break; // With DPOR, we take the first enabled transition - } - } - - if (dot_output != nullptr) - std::fprintf(dot_output, "\"%ld\" -> \"%ld\" [%s];\n", state->get_num(), next_state->get_num(), - state->get_transition()->dot_string().c_str()); - - } else if (dot_output != nullptr) - std::fprintf(dot_output, "\"%ld\" -> \"%ld\" [%s];\n", state->get_num(), - visited_state_->original_num == -1 ? visited_state_->num : visited_state_->original_num, - state->get_transition()->dot_string().c_str()); + if (reduction_mode_ == ReductionMode::dpor) + next_state->consider_best(); // Take only one transition if DPOR: others may be considered later if required + else + next_state->consider_all(); + + dot_output("\"%ld\" -> \"%ld\" [%s];\n", state->get_num(), next_state->get_num(), + state->get_transition()->dot_string().c_str()); + } else + dot_output("\"%ld\" -> \"%ld\" [%s];\n", state->get_num(), + visited_state_->original_num_ == -1 ? visited_state_->num_ : visited_state_->original_num_, + state->get_transition()->dot_string().c_str()); stack_.push_back(std::move(next_state)); } @@ -188,124 +243,93 @@ void DFSExplorer::backtrack() { backtrack_count_++; XBT_VERB("Backtracking from %s", get_record_trace().to_string().c_str()); - on_backtracking_signal(); - stack_.pop_back(); - + on_backtracking_signal(get_remote_app()); get_remote_app().check_deadlock(); - /* Traverse the stack backwards until a state with a non empty interleave set is found, deleting all the states that - * have it empty in the way. For each deleted state, check if the request that has generated it (from its - * predecessor state), depends on any other previous request executed before it. If it does then add it to the - * interleave set of the state that executed that previous request. */ + /* We may backtrack from somewhere either because it's leaf, or because every enabled process are in done/sleep set. + * In the first case, we need to remove the last transition corresponding to the Finalize */ + if (stack_.back()->get_transition()->aid_ == 0) + stack_.pop_back(); - while (not stack_.empty()) { + /* Traverse the stack backwards until a state with a non empty interleave set is found, deleting all the states that + * have it empty in the way. */ + bool found_backtracking_point = false; + while (not stack_.empty() && not found_backtracking_point) { std::unique_ptr state = std::move(stack_.back()); + stack_.pop_back(); - if (reductionMode_ == ReductionMode::dpor) { - aid_t issuer_id = state->get_transition()->aid_; - for (auto i = stack_.rbegin(); i != stack_.rend(); ++i) { - State* prev_state = i->get(); - if (state->get_transition()->aid_ == prev_state->get_transition()->aid_) { - XBT_DEBUG("Simcall >>%s<< and >>%s<< with same issuer %ld", state->get_transition()->to_string().c_str(), - prev_state->get_transition()->to_string().c_str(), issuer_id); - break; - } else if (prev_state->get_transition()->depends(state->get_transition())) { - XBT_VERB("Dependent Transitions:"); - XBT_VERB(" %s (state=%ld)", prev_state->get_transition()->to_string().c_str(), prev_state->get_num()); - XBT_VERB(" %s (state=%ld)", state->get_transition()->to_string().c_str(), state->get_num()); - if (not prev_state->is_done(issuer_id)) - prev_state->mark_todo(issuer_id); - else - XBT_DEBUG("Actor %ld is in done set", issuer_id); - break; - } else { - XBT_VERB("INDEPENDENT Transitions:"); - XBT_VERB(" %s (state=%ld)", prev_state->get_transition()->to_string().c_str(), prev_state->get_num()); - XBT_VERB(" %s (state=%ld)", state->get_transition()->to_string().c_str(), state->get_num()); - } - } - } - if (state->count_todo() && stack_.size() < (std::size_t)_sg_mc_max_depth) { - /* We found a back-tracking point, let's loop */ - XBT_DEBUG("Back-tracking to state %ld at depth %zu", state->get_num(), stack_.size() + 1); - stack_.push_back( - std::move(state)); // Put it back on the stack from which it was removed earlier in this while loop - this->restore_state(); - XBT_DEBUG("Back-tracking to state %ld at depth %zu done", stack_.back()->get_num(), stack_.size()); - break; - } else { + if (state->count_todo() == 0) { // Empty interleaving set: exploration at this level is over XBT_DEBUG("Delete state %ld at depth %zu", state->get_num(), stack_.size() + 1); + + } else { + XBT_DEBUG("Back-tracking to state %ld at depth %zu: %lu transitions left to be explored", state->get_num(), + stack_.size() + 1, state->count_todo()); + stack_.push_back( + std::move(state)); // Put it back on the stack so we can explore the next transition of the interleave + found_backtracking_point = true; } } -} -void DFSExplorer::restore_state() -{ - /* If asked to rollback on a state that has a snapshot, restore it */ - State* last_state = stack_.back().get(); - if (const auto* system_state = last_state->get_system_state()) { - Api::get().restore_state(system_state); - on_restore_system_state_signal(last_state); - return; - } + if (found_backtracking_point) { + /* If asked to rollback on a state that has a snapshot, restore it */ + State* last_state = stack_.back().get(); + if (const auto* system_state = last_state->get_system_state()) { + system_state->restore(get_remote_app().get_remote_process_memory()); + on_restore_system_state_signal(last_state, get_remote_app()); + return; + } - /* if no snapshot, we need to restore the initial state and replay the transitions */ - get_remote_app().restore_initial_state(); - on_restore_initial_state_signal(); - - /* Traverse the stack from the state at position start and re-execute the transitions */ - for (std::unique_ptr const& state : stack_) { - if (state == stack_.back()) /* If we are arrived on the target state, don't replay the outgoing transition */ - break; - state->get_transition()->replay(); - on_transition_replay_signal(state->get_transition()); - /* Update statistics */ - Api::get().mc_inc_visited_states(); - } + /* if no snapshot, we need to restore the initial state and replay the transitions */ + get_remote_app().restore_initial_state(); + on_restore_initial_state_signal(get_remote_app()); + + /* Traverse the stack from the state at position start and re-execute the transitions */ + for (std::unique_ptr const& state : stack_) { + if (state == stack_.back()) /* If we are arrived on the target state, don't replay the outgoing transition */ + break; + state->get_transition()->replay(); + on_transition_replay_signal(state->get_transition(), get_remote_app()); + visited_states_count_++; + } + } // If no backtracing point, then the stack is empty and the exploration is over } -DFSExplorer::DFSExplorer(RemoteApp& remote_app) : Exploration(remote_app) +DFSExplorer::DFSExplorer(const std::vector& args, bool with_dpor) : Exploration(args) { - reductionMode_ = reduction_mode; - if (_sg_mc_termination) - reductionMode_ = ReductionMode::none; - else if (reductionMode_ == ReductionMode::unset) - reductionMode_ = ReductionMode::dpor; - - if (_sg_mc_termination) - XBT_INFO("Check non progressive cycles"); + if (with_dpor) + reduction_mode_ = ReductionMode::dpor; else - XBT_INFO("Start a DFS exploration. Reduction is: %s.", - (reductionMode_ == ReductionMode::none ? "none" - : (reductionMode_ == ReductionMode::dpor ? "dpor" : "unknown"))); + reduction_mode_ = ReductionMode::none; - XBT_DEBUG("Starting the DFS exploration"); + if (_sg_mc_termination) { + if (with_dpor) { + XBT_INFO("Check non progressive cycles (turning DPOR off)"); + reduction_mode_ = ReductionMode::none; + } else { + XBT_INFO("Check non progressive cycles"); + } + } else + XBT_INFO("Start a DFS exploration. Reduction is: %s.", to_c_str(reduction_mode_)); auto initial_state = std::make_unique(get_remote_app()); XBT_DEBUG("**************************************************"); /* Get an enabled actor and insert it in the interleave set of the initial state */ - XBT_DEBUG("Initial state. %d actors to consider", initial_state->get_actor_count()); - for (auto const& [aid, _] : initial_state->get_actors_list()) { - if (initial_state->is_actor_enabled(aid)) { - initial_state->mark_todo(aid); - if (reductionMode_ == ReductionMode::dpor) { - XBT_DEBUG("Actor %ld is TODO, DPOR is ON so let's go for this one.", aid); - break; - } - XBT_DEBUG("Actor %ld is TODO", aid); - } - } + XBT_DEBUG("Initial state. %lu actors to consider", initial_state->get_actor_count()); + if (reduction_mode_ == ReductionMode::dpor) + initial_state->consider_best(); + else + initial_state->consider_all(); stack_.push_back(std::move(initial_state)); } -Exploration* create_dfs_exploration(RemoteApp& remote_app) +Exploration* create_dfs_exploration(const std::vector& args, bool with_dpor) { - return new DFSExplorer(remote_app); + return new DFSExplorer(args, with_dpor); } } // namespace simgrid::mc