+++ /dev/null
-/* Copyright (c) 2016. 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 <cassert>
-#include <cstdio>
-
-#include <memory>
-#include <string>
-#include <vector>
-
-#include <xbt/log.h>
-#include <xbt/sysdep.h>
-
-#include "src/mc/mc_state.h"
-#include "src/mc/mc_request.h"
-#include "src/mc/mc_safety.h"
-#include "src/mc/mc_private.h"
-#include "src/mc/mc_record.h"
-#include "src/mc/mc_smx.h"
-#include "src/mc/Client.hpp"
-#include "src/mc/mc_exit.h"
-#include "src/mc/Checker.hpp"
-#include "src/mc/SafetyChecker.hpp"
-#include "src/mc/VisitedState.hpp"
-#include "src/mc/Transition.hpp"
-#include "src/mc/Session.hpp"
-
-#include "src/xbt/mmalloc/mmprivate.h"
-
-XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_safety, mc,
- "Logging specific to MC safety verification ");
-namespace simgrid {
-namespace mc {
-
-static void MC_show_non_termination(void)
-{
- XBT_INFO("******************************************");
- XBT_INFO("*** NON-PROGRESSIVE CYCLE DETECTED ***");
- XBT_INFO("******************************************");
- XBT_INFO("Counter-example execution trace:");
- for (auto& s : mc_model_checker->getChecker()->getTextualTrace())
- XBT_INFO("%s", s.c_str());
- simgrid::mc::session->logState();
-}
-
-static int snapshot_compare(simgrid::mc::State* state1, simgrid::mc::State* state2)
-{
- simgrid::mc::Snapshot* s1 = state1->system_state.get();
- simgrid::mc::Snapshot* s2 = state2->system_state.get();
- int num1 = state1->num;
- int num2 = state2->num;
- return snapshot_compare(num1, s1, num2, s2);
-}
-
-bool SafetyChecker::checkNonTermination(simgrid::mc::State* current_state)
-{
- for (auto state = stack_.rbegin(); state != stack_.rend(); ++state)
- if (snapshot_compare(state->get(), current_state) == 0) {
- XBT_INFO("Non-progressive cycle: state %d -> state %d", (*state)->num, current_state->num);
- return true;
- }
- return false;
-}
-
-RecordTrace SafetyChecker::getRecordTrace() // override
-{
- RecordTrace res;
- for (auto const& state : stack_)
- res.push_back(state->getTransition());
- return res;
-}
-
-std::vector<std::string> SafetyChecker::getTextualTrace() // override
-{
- std::vector<std::string> trace;
- for (auto const& state : stack_) {
- int value = state->transition.argument;
- smx_simcall_t req = &state->executed_req;
- if (req)
- trace.push_back(simgrid::mc::request_to_string(
- req, value, simgrid::mc::RequestType::executed));
- }
- return trace;
-}
-
-void SafetyChecker::logState() // override
-{
- Checker::logState();
- XBT_INFO("Expanded states = %lu", expandedStatesCount_);
- XBT_INFO("Visited states = %lu", mc_model_checker->visited_states);
- XBT_INFO("Executed transitions = %lu", mc_model_checker->executed_transitions);
-}
-
-int 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 to explore the call stack when we want to. */
-
- while (!stack_.empty()) {
-
- /* Get current state */
- simgrid::mc::State* state = stack_.back().get();
-
- XBT_DEBUG("**************************************************");
- XBT_DEBUG("Exploration depth=%zi (state=%p, num %d)(%zu interleave)",
- stack_.size(), state, state->num, state->interleaveSize());
-
- mc_model_checker->visited_states++;
-
- // Backtrack if we reached the maximum depth
- if (stack_.size() > (std::size_t)_sg_mc_max_depth) {
- XBT_WARN("/!\\ Max depth reached ! /!\\ ");
- int res = this->backtrack();
- if (res)
- return res;
- else
- continue;
- }
-
- // Backtrack if we are revisiting a state we saw previously
- if (visitedState_ != nullptr) {
- XBT_DEBUG("State already visited (equal to state %d), exploration stopped on this path.",
- visitedState_->other_num == -1 ? visitedState_->num : visitedState_->other_num);
-
- visitedState_ = nullptr;
- int res = this->backtrack();
- if (res)
- return res;
- else
- continue;
- }
-
- smx_simcall_t req = MC_state_get_request(state);
- // Backtrack if the interleave set is empty
- if (req == nullptr) {
- XBT_DEBUG("There are no more processes to interleave. (depth %zi)", stack_.size() + 1);
-
- int res = this->backtrack();
- if (res)
- return res;
- else
- continue;
- }
-
- // 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",
- simgrid::mc::request_to_string(
- req, state->transition.argument, simgrid::mc::RequestType::simix).c_str());
-
- std::string req_str;
- if (dot_output != nullptr)
- req_str = simgrid::mc::request_get_dot_output(req, state->transition.argument);
-
- mc_model_checker->executed_transitions++;
-
- /* Answer the request */
- this->getSession().execute(state->transition);
-
- /* Create the new expanded state */
- std::unique_ptr<simgrid::mc::State> next_state =
- std::unique_ptr<simgrid::mc::State>(new simgrid::mc::State(++expandedStatesCount_));
-
- if (_sg_mc_termination && this->checkNonTermination(next_state.get())) {
- MC_show_non_termination();
- return SIMGRID_MC_EXIT_NON_TERMINATION;
- }
-
- /* Check whether we already explored next_state in the past (but only if interested in state-equality reduction) */
- if (_sg_mc_visited == true)
- visitedState_ = visitedStates_.addVisitedState(expandedStatesCount_, next_state.get(), true);
-
- /* If this is a new state (or if we don't care about state-equality reduction) */
- if (_sg_mc_visited == 0 || visitedState_ == nullptr) {
-
- /* Get an enabled process and insert it in the interleave set of the next state */
- for (auto& actor : mc_model_checker->process().actors())
- if (simgrid::mc::actor_is_enabled(actor.copy.getBuffer())) {
- next_state->interleave(actor.copy.getBuffer());
- if (reductionMode_ == simgrid::mc::ReductionMode::dpor)
- break;
- }
-
- 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,
- visitedState_->other_num == -1 ? visitedState_->num : visitedState_->other_num, req_str.c_str());
-
- stack_.push_back(std::move(next_state));
- }
-
- XBT_INFO("No property violation found.");
- simgrid::mc::session->logState();
- return SIMGRID_MC_EXIT_SUCCESS;
-}
-
-int SafetyChecker::backtrack()
-{
- stack_.pop_back();
-
- /* Check for deadlocks */
- if (mc_model_checker->checkDeadlock()) {
- MC_show_deadlock();
- return SIMGRID_MC_EXIT_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 it's 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 (!stack_.empty()) {
- std::unique_ptr<simgrid::mc::State> state = std::move(stack_.back());
- stack_.pop_back();
- if (reductionMode_ == simgrid::mc::ReductionMode::dpor) {
- smx_simcall_t req = &state->internal_req;
- if (req->call == SIMCALL_MUTEX_LOCK || req->call == SIMCALL_MUTEX_TRYLOCK)
- xbt_die("Mutex is currently not supported with DPOR, "
- "use --cfg=model-check/reduction:none");
- const smx_actor_t issuer = MC_smx_simcall_get_issuer(req);
- for (auto i = stack_.rbegin(); i != stack_.rend(); ++i) {
- simgrid::mc::State* prev_state = i->get();
- if (simgrid::mc::request_depend(req, &prev_state->internal_req)) {
- if (XBT_LOG_ISENABLED(mc_safety, xbt_log_priority_debug)) {
- XBT_DEBUG("Dependent Transitions:");
- int value = prev_state->transition.argument;
- smx_simcall_t prev_req = &prev_state->executed_req;
- XBT_DEBUG("%s (state=%d)",
- simgrid::mc::request_to_string(
- prev_req, value, simgrid::mc::RequestType::internal).c_str(),
- prev_state->num);
- value = state->transition.argument;
- prev_req = &state->executed_req;
- XBT_DEBUG("%s (state=%d)",
- simgrid::mc::request_to_string(
- prev_req, value, simgrid::mc::RequestType::executed).c_str(),
- state->num);
- }
-
- if (!prev_state->processStates[issuer->pid].isDone())
- prev_state->interleave(issuer);
- else
- XBT_DEBUG("Process %p is in done set", req->issuer);
-
- break;
-
- } else if (req->issuer == prev_state->internal_req.issuer) {
-
- XBT_DEBUG("Simcall %d and %d with same issuer", req->call, prev_state->internal_req.call);
- break;
-
- } else {
-
- const smx_actor_t previous_issuer = MC_smx_simcall_get_issuer(&prev_state->internal_req);
- XBT_DEBUG("Simcall %d, process %lu (state %d) and simcall %d, process %lu (state %d) are independant",
- req->call, issuer->pid, state->num,
- prev_state->internal_req.call,
- previous_issuer->pid,
- prev_state->num);
-
- }
- }
- }
-
- if (state->interleaveSize()
- && 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 %zi",
- state->num, stack_.size() + 1);
- stack_.push_back(std::move(state));
- this->restoreState();
- XBT_DEBUG("Back-tracking to state %d at depth %zi done",
- stack_.back()->num, stack_.size());
- break;
- } else {
- XBT_DEBUG("Delete state %d at depth %zi",
- state->num, stack_.size() + 1);
- }
- }
- return SIMGRID_MC_EXIT_SUCCESS;
-}
-
-void SafetyChecker::restoreState()
-{
- /* Intermediate backtracking */
- simgrid::mc::State* state = stack_.back().get();
- if (state->system_state) {
- simgrid::mc::restore_snapshot(state->system_state);
- return;
- }
-
- /* Restore the initial state */
- simgrid::mc::session->restoreInitialState();
-
- /* Traverse the stack from the state at position start and re-execute the transitions */
- for (std::unique_ptr<simgrid::mc::State> const& state : stack_) {
- if (state == stack_.back())
- break;
- session->execute(state->transition);
- /* Update statistics */
- mc_model_checker->visited_states++;
- mc_model_checker->executed_transitions++;
- }
-}
-
-SafetyChecker::SafetyChecker(Session& session) : Checker(session)
-{
- reductionMode_ = simgrid::mc::reduction_mode;
- if (_sg_mc_termination)
- reductionMode_ = simgrid::mc::ReductionMode::none;
- else if (reductionMode_ == simgrid::mc::ReductionMode::unset)
- reductionMode_ = simgrid::mc::ReductionMode::dpor;
-
- if (_sg_mc_termination)
- XBT_INFO("Check non progressive cycles");
- else
- XBT_INFO("Check a safety property");
- simgrid::mc::session->initialize();
-
- XBT_DEBUG("Starting the safety algorithm");
-
- std::unique_ptr<simgrid::mc::State> initial_state =
- std::unique_ptr<simgrid::mc::State>(new simgrid::mc::State(++expandedStatesCount_));
-
- XBT_DEBUG("**************************************************");
- XBT_DEBUG("Initial state");
-
- /* Get an enabled actor and insert it in the interleave set of the initial state */
- for (auto& actor : mc_model_checker->process().actors())
- if (simgrid::mc::actor_is_enabled(actor.copy.getBuffer())) {
- initial_state->interleave(actor.copy.getBuffer());
- if (reductionMode_ != simgrid::mc::ReductionMode::none)
- break;
- }
-
- stack_.push_back(std::move(initial_state));
-}
-
-SafetyChecker::~SafetyChecker()
-{
-}
-
-Checker* createSafetyChecker(Session& session)
-{
- return new SafetyChecker(session);
-}
-
-}
-}
