+++ /dev/null
-/* Copyright (c) 2016-2022. 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. */
-
-#include "src/mc/Session.hpp"
-#include "src/mc/Transition.hpp"
-#include "src/mc/VisitedState.hpp"
-#include "src/mc/checker/SafetyChecker.hpp"
-#include "src/mc/mc_config.hpp"
-#include "src/mc/mc_exit.hpp"
-#include "src/mc/mc_private.hpp"
-#include "src/mc/mc_record.hpp"
-
-#include "src/xbt/mmalloc/mmprivate.h"
-#include "xbt/log.h"
-#include "xbt/sysdep.h"
-
-#include <cassert>
-#include <cstdio>
-
-#include <memory>
-#include <string>
-#include <vector>
-
-using api = simgrid::mc::Api;
-
-XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_safety, mc, "Logging specific to MC safety verification ");
-
-namespace simgrid {
-namespace mc {
-
-void SafetyChecker::check_non_termination(const State* current_state)
-{
- for (auto state = stack_.rbegin(); state != stack_.rend(); ++state)
- if (api::get().snapshot_equal((*state)->system_state_.get(), current_state->system_state_.get())) {
- XBT_INFO("Non-progressive cycle: state %d -> state %d", (*state)->num_, current_state->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());
- api::get().dump_record_path();
- api::get().log_state();
-
- throw TerminationError();
- }
-}
-
-RecordTrace SafetyChecker::get_record_trace() // override
-{
- RecordTrace res;
- for (auto const& state : stack_)
- res.push_back(state->get_transition());
- return res;
-}
-
-std::vector<std::string> SafetyChecker::get_textual_trace() // override
-{
- std::vector<std::string> trace;
- for (auto const& state : stack_)
- trace.push_back(state->transition_.textual);
- return trace;
-}
-
-void SafetyChecker::log_state() // override
-{
- XBT_INFO("Expanded states = %lu", expanded_states_count_);
- XBT_INFO("Visited states = %lu", api::get().mc_get_visited_states());
- XBT_INFO("Executed transitions = %lu", api::get().mc_get_executed_trans());
-}
-
-void SafetyChecker::run()
-{
- /* 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. */
-
- while (not stack_.empty()) {
- /* Get current state */
- State* state = stack_.back().get();
-
- XBT_DEBUG("**************************************************");
- XBT_VERB("Exploration depth=%zu (state=%p, num %d)(%zu interleave)", stack_.size(), state, state->num_,
- state->count_todo());
-
- api::get().mc_inc_visited_states();
-
- // Backtrack if we reached the maximum depth
- if (stack_.size() > (std::size_t)_sg_mc_max_depth) {
- if (reductionMode_ == 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 /!\\");
- } else
- XBT_WARN("/!\\ Max depth reached ! /!\\ ");
- this->backtrack();
- continue;
- }
-
- // Backtrack if we are revisiting a state we saw previously
- if (visited_state_ != nullptr) {
- XBT_DEBUG("State already visited (equal to state %d), exploration stopped on this path.",
- visited_state_->original_num == -1 ? visited_state_->num : visited_state_->original_num);
-
- visited_state_ = nullptr;
- this->backtrack();
- continue;
- }
-
- // Search for the next transition. If found, state is modified accordingly (transition and executed_req are set)
- // If there is no more transition in the current state, backtrack.
-
- if (not api::get().mc_state_choose_request(state)) {
-
- XBT_DEBUG("There remains %zu actors, but none to interleave (depth %zu).",
- mc_model_checker->get_remote_process().actors().size(), stack_.size() + 1);
-
- if (mc_model_checker->get_remote_process().actors().empty())
- mc_model_checker->finalize_app();
- this->backtrack();
- continue;
- }
-
- /* Actually answer the request: let execute the selected request (MCed does one step) */
- auto remote_observer = api::get().execute(state->transition_);
-
- // If there are processes to interleave and the maximum depth has not been
- // reached then perform one step of the exploration algorithm.
- XBT_DEBUG("Execute: %s", state->transition_.textual.c_str());
-
- std::string req_str;
- if (dot_output != nullptr)
- req_str = api::get().request_get_dot_output(state->transition_.aid_, state->transition_.times_considered_);
-
- api::get().mc_inc_executed_trans();
-
- /* Create the new expanded state (copy the state of MCed into our MCer data) */
- ++expanded_states_count_;
- auto next_state = std::make_unique<State>(expanded_states_count_);
- next_state->remote_observer_ = remote_observer;
-
- 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(expanded_states_count_, next_state.get(), true);
-
- /* 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 */
- auto actors = api::get().get_actors();
- for (auto& remoteActor : actors) {
- auto actor = remoteActor.copy.get_buffer();
- if (get_session().actor_is_enabled(actor->get_pid())) {
- next_state->mark_todo(actor->get_pid());
- if (reductionMode_ == ReductionMode::dpor)
- break; // With DPOR, we take the first enabled transition
- }
- }
-
- if (dot_output != nullptr)
- std::fprintf(dot_output, "\"%d\" -> \"%d\" [%s];\n", state->num_, next_state->num_, req_str.c_str());
-
- } else if (dot_output != nullptr)
- std::fprintf(dot_output, "\"%d\" -> \"%d\" [%s];\n", state->num_,
- visited_state_->original_num == -1 ? visited_state_->num : visited_state_->original_num,
- req_str.c_str());
-
- stack_.push_back(std::move(next_state));
- }
-
- XBT_INFO("No property violation found.");
- api::get().log_state();
-}
-
-void SafetyChecker::backtrack()
-{
- stack_.pop_back();
-
- api::get().mc_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. */
-
- while (not stack_.empty()) {
- std::unique_ptr<State> state = std::move(stack_.back());
- stack_.pop_back();
- if (reductionMode_ == ReductionMode::dpor) {
- aid_t issuer_id = state->transition_.aid_;
- for (auto i = stack_.rbegin(); i != stack_.rend(); ++i) {
- State* prev_state = i->get();
- if (state->transition_.aid_ == prev_state->transition_.aid_) {
- XBT_DEBUG("Simcall >>%s<< and >>%s<< with same issuer %ld", state->transition_.textual.c_str(),
- prev_state->transition_.textual.c_str(), issuer_id);
- break;
- } else if (api::get().requests_are_dependent(prev_state->remote_observer_, state->remote_observer_)) {
- if (XBT_LOG_ISENABLED(mc_safety, xbt_log_priority_debug)) {
- XBT_DEBUG("Dependent Transitions:");
- XBT_DEBUG(" %s (state=%d)", prev_state->transition_.textual.c_str(), prev_state->num_);
- XBT_DEBUG(" %s (state=%d)", state->transition_.textual.c_str(), state->num_);
- }
-
- if (not prev_state->actor_states_[issuer_id].is_done())
- prev_state->mark_todo(issuer_id);
- else
- XBT_DEBUG("Actor %ld is in done set", issuer_id);
- break;
- } else {
- if (XBT_LOG_ISENABLED(mc_safety, xbt_log_priority_debug)) {
- XBT_DEBUG("INDEPENDENT Transitions:");
- XBT_DEBUG(" %s (state=%d)", prev_state->transition_.textual.c_str(), prev_state->num_);
- XBT_DEBUG(" %s (state=%d)", state->transition_.textual.c_str(), state->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 %d at depth %zu", state->num_, stack_.size() + 1);
- stack_.push_back(std::move(state));
- this->restore_state();
- XBT_DEBUG("Back-tracking to state %d at depth %zu done", stack_.back()->num_, stack_.size());
- break;
- } else {
- XBT_DEBUG("Delete state %d at depth %zu", state->num_, stack_.size() + 1);
- }
- }
-}
-
-void SafetyChecker::restore_state()
-{
- /* Intermediate backtracking */
- const State* last_state = stack_.back().get();
- if (last_state->system_state_) {
- api::get().restore_state(last_state->system_state_);
- return;
- }
-
- get_session().restore_initial_state();
-
- /* Traverse the stack from the state at position start and re-execute the transitions */
- for (std::unique_ptr<State> const& state : stack_) {
- if (state == stack_.back())
- break;
- api::get().execute(state->transition_);
- /* Update statistics */
- api::get().mc_inc_visited_states();
- api::get().mc_inc_executed_trans();
- }
-}
-
-SafetyChecker::SafetyChecker(Session* session) : Checker(session)
-{
- 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");
- else
- XBT_INFO("Check a safety property. Reduction is: %s.",
- (reductionMode_ == ReductionMode::none ? "none"
- : (reductionMode_ == ReductionMode::dpor ? "dpor" : "unknown")));
-
- get_session().take_initial_snapshot();
-
- XBT_DEBUG("Starting the safety algorithm");
-
- ++expanded_states_count_;
- auto initial_state = std::make_unique<State>(expanded_states_count_);
-
- XBT_DEBUG("**************************************************");
-
- /* Get an enabled actor and insert it in the interleave set of the initial state */
- auto actors = api::get().get_actors();
- XBT_DEBUG("Initial state. %zu actors to consider", actors.size());
- for (auto& actor : actors) {
- aid_t aid = actor.copy.get_buffer()->get_pid();
- if (get_session().actor_is_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);
- }
- }
-
- stack_.push_back(std::move(initial_state));
-}
-
-Checker* create_safety_checker(Session* session)
-{
- return new SafetyChecker(session);
-}
-
-} // namespace mc
-} // namespace simgrid
