* 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/dynar.h>
-#include <xbt/dynar.hpp>
-#include <xbt/fifo.h>
#include <xbt/sysdep.h>
#include "src/mc/mc_state.h"
#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 int is_exploration_stack_state(mc_state_t current_state){
-
- xbt_fifo_item_t item;
- mc_state_t stack_state;
- for(item = xbt_fifo_get_first_item(mc_stack); item != nullptr; item = xbt_fifo_get_next_item(item)) {
- stack_state = (mc_state_t) xbt_fifo_get_item_content(item);
- if(snapshot_compare(stack_state, current_state) == 0){
- XBT_INFO("Non-progressive cycle : state %d -> state %d", stack_state->num, current_state->num);
- return 1;
- }
- }
- return 0;
+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();
}
-/**
- * \brief Initialize the DPOR exploration algorithm
- */
-void SafetyChecker::pre()
+static int snapshot_compare(simgrid::mc::State* state1, simgrid::mc::State* state2)
{
- simgrid::mc::visited_states.clear();
-
- mc_state_t initial_state = MC_state_new();
+ 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);
+}
- XBT_DEBUG("**************************************************");
- XBT_DEBUG("Initial state");
+bool SafetyChecker::checkNonTermination(simgrid::mc::State* current_state)
+{
+ for (auto i = stack_.rbegin(); i != stack_.rend(); ++i)
+ if (snapshot_compare(i->get(), current_state) == 0){
+ XBT_INFO("Non-progressive cycle : state %d -> state %d",
+ (*i)->num, current_state->num);
+ return true;
+ }
+ return false;
+}
- /* Wait for requests (schedules processes) */
- mc_model_checker->wait_for_requests();
+RecordTrace SafetyChecker::getRecordTrace() // override
+{
+ RecordTrace res;
+ for (auto const& state : stack_)
+ res.push_back(state->getTransition());
+ return res;
+}
- /* Get an enabled process and insert it in the interleave set of the initial state */
- for (auto& p : mc_model_checker->process().simix_processes())
- if (simgrid::mc::process_is_enabled(&p.copy)) {
- MC_state_interleave_process(initial_state, &p.copy);
- if (reductionMode_ != simgrid::mc::ReductionMode::none)
- break;
- }
+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;
+}
- xbt_fifo_unshift(mc_stack, initial_state);
+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->init();
- char *req_str = nullptr;
- int value;
- smx_simcall_t req = nullptr;
- mc_state_t state = nullptr, prev_state = NULL, next_state = NULL;
- xbt_fifo_item_t item = nullptr;
- std::unique_ptr<simgrid::mc::VisitedState> visited_state = nullptr;
-
- while (xbt_fifo_size(mc_stack) > 0) {
+ while (!stack_.empty()) {
/* Get current state */
- state = (mc_state_t)xbt_fifo_get_item_content(xbt_fifo_get_first_item(mc_stack));
+ simgrid::mc::State* state = stack_.back().get();
XBT_DEBUG("**************************************************");
- XBT_DEBUG
- ("Exploration depth=%d (state=%p, num %d)(%u interleave, user_max_depth %d)",
- xbt_fifo_size(mc_stack), state, state->num,
- MC_state_interleave_size(state), user_max_depth_reached);
-
- /* Update statistics */
- mc_stats->visited_states++;
-
- /* If there are processes to interleave and the maximum depth has not been reached
- then perform one step of the exploration algorithm */
- if (xbt_fifo_size(mc_stack) <= _sg_mc_max_depth && !user_max_depth_reached
- && (req = MC_state_get_request(state, &value)) && visited_state == nullptr) {
-
- req_str = simgrid::mc::request_to_string(req, value, simgrid::mc::RequestType::simix);
- XBT_DEBUG("Execute: %s", req_str);
- xbt_free(req_str);
+ XBT_DEBUG(
+ "Exploration depth=%zi (state=%p, num %d)(%zu interleave)",
+ stack_.size(), state, state->num,
+ state->interleaveSize());
+
+ mc_model_checker->visited_states++;
+
+ // The interleave set is empty or the maximum depth is reached,
+ // let's back-track.
+ smx_simcall_t req = nullptr;
+ if (stack_.size() > (std::size_t) _sg_mc_max_depth
+ || (req = MC_state_get_request(state)) == nullptr
+ || visitedState_ != nullptr) {
+ int res = this->backtrack();
+ if (res)
+ return res;
+ else
+ continue;
+ }
- if (dot_output != nullptr)
- req_str = simgrid::mc::request_get_dot_output(req, value);
+ // 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());
- MC_state_set_executed_request(state, req, value);
- mc_stats->executed_transitions++;
+ std::string req_str;
+ if (dot_output != nullptr)
+ req_str = simgrid::mc::request_get_dot_output(req, state->transition.argument);
- // TODO, bundle both operations in a single message
- // MC_execute_transition(req, value)
+ mc_model_checker->executed_transitions++;
- /* Answer the request */
- simgrid::mc::handle_simcall(req, value);
- mc_model_checker->wait_for_requests();
+ /* Answer the request */
+ this->getSession().execute(state->transition);
- /* Create the new expanded state */
- next_state = MC_state_new();
+ /* Create the new expanded state */
+ std::unique_ptr<simgrid::mc::State> next_state =
+ std::unique_ptr<simgrid::mc::State>(MC_state_new(++expandedStatesCount_));
- if(_sg_mc_termination && is_exploration_stack_state(next_state)){
- MC_show_non_termination();
- return SIMGRID_MC_EXIT_NON_TERMINATION;
- }
+ if (_sg_mc_termination && this->checkNonTermination(next_state.get())) {
+ MC_show_non_termination();
+ return SIMGRID_MC_EXIT_NON_TERMINATION;
+ }
- if ((visited_state = simgrid::mc::is_visited_state(next_state)) == nullptr) {
+ if (_sg_mc_visited == 0
+ || (visitedState_ = visitedStates_.addVisitedState(expandedStatesCount_, next_state.get(), true)) == nullptr) {
- /* Get an enabled process and insert it in the interleave set of the next state */
- for (auto& p : mc_model_checker->process().simix_processes())
- if (simgrid::mc::process_is_enabled(&p.copy)) {
- MC_state_interleave_process(next_state, &p.copy);
- if (reductionMode_ != simgrid::mc::ReductionMode::none)
- break;
- }
+ /* Get an enabled process and insert it in the interleave set of the next state */
+ for (auto& p : mc_model_checker->process().simix_processes())
+ if (simgrid::mc::process_is_enabled(&p.copy)) {
+ next_state->interleave(&p.copy);
+ if (reductionMode_ != simgrid::mc::ReductionMode::none)
+ break;
+ }
- if (dot_output != nullptr)
- std::fprintf(dot_output, "\"%d\" -> \"%d\" [%s];\n", state->num, next_state->num, req_str);
+ 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->other_num == -1 ? visited_state->num : visited_state->other_num, req_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_fifo_unshift(mc_stack, next_state);
+ XBT_INFO("No property violation found.");
+ simgrid::mc::session->logState();
+ return SIMGRID_MC_EXIT_SUCCESS;
+}
- if (dot_output != nullptr)
- xbt_free(req_str);
+int SafetyChecker::backtrack()
+{
+ if (stack_.size() > (std::size_t) _sg_mc_max_depth
+ || visitedState_ != nullptr) {
+ if (visitedState_ == nullptr)
+ XBT_WARN("/!\\ Max depth reached ! /!\\ ");
+ else
+ XBT_DEBUG("State already visited (equal to state %d),"
+ " exploration stopped on this path.",
+ visitedState_->other_num == -1 ? visitedState_->num : visitedState_->other_num);
+ } else
+ XBT_DEBUG("There are no more processes to interleave. (depth %zi)",
+ stack_.size() + 1);
+
+ stack_.pop_back();
+
+ visitedState_ = nullptr;
+
+ /* Check for deadlocks */
+ if (mc_model_checker->checkDeadlock()) {
+ MC_show_deadlock();
+ return SIMGRID_MC_EXIT_DEADLOCK;
+ }
- /* Let's loop again */
+ /* 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 predecesor 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_process_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 (reductionMode_ != simgrid::mc::ReductionMode::none
+ && 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);
+ }
- /* The interleave set is empty or the maximum depth is reached, let's back-track */
- } else {
+ if (!prev_state->processStates[issuer->pid].isDone())
+ prev_state->interleave(issuer);
+ else
+ XBT_DEBUG("Process %p is in done set", req->issuer);
- if ((xbt_fifo_size(mc_stack) > _sg_mc_max_depth) || user_max_depth_reached || visited_state != nullptr) {
+ break;
- if (user_max_depth_reached && visited_state == nullptr)
- XBT_DEBUG("User max depth reached !");
- else if (visited_state == nullptr)
- XBT_WARN("/!\\ Max depth reached ! /!\\ ");
- else
- XBT_DEBUG("State already visited (equal to state %d), exploration stopped on this path.", visited_state->other_num == -1 ? visited_state->num : visited_state->other_num);
+ } else if (req->issuer == prev_state->internal_req.issuer) {
- } else
- XBT_DEBUG("There are no more processes to interleave. (depth %d)", xbt_fifo_size(mc_stack) + 1);
+ XBT_DEBUG("Simcall %d and %d with same issuer", req->call, prev_state->internal_req.call);
+ break;
- /* Trash the current state, no longer needed */
- xbt_fifo_shift(mc_stack);
- XBT_DEBUG("Delete state %d at depth %d", state->num, xbt_fifo_size(mc_stack) + 1);
- MC_state_delete(state, !state->in_visited_states ? 1 : 0);
+ } else {
- visited_state = nullptr;
+ const smx_process_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);
- /* Check for deadlocks */
- if (mc_model_checker->checkDeadlock()) {
- MC_show_deadlock(nullptr);
- 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 predecesor 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 ((state = (mc_state_t) xbt_fifo_shift(mc_stack))) {
- if (reductionMode_ == simgrid::mc::ReductionMode::dpor) {
- req = MC_state_get_internal_request(state);
- 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_process_t issuer = MC_smx_simcall_get_issuer(req);
- xbt_fifo_foreach(mc_stack, item, prev_state, mc_state_t) {
- if (reductionMode_ != simgrid::mc::ReductionMode::none
- && simgrid::mc::request_depend(req, MC_state_get_internal_request(prev_state))) {
- if (XBT_LOG_ISENABLED(mc_safety, xbt_log_priority_debug)) {
- XBT_DEBUG("Dependent Transitions:");
- smx_simcall_t prev_req = MC_state_get_executed_request(prev_state, &value);
- req_str = simgrid::mc::request_to_string(prev_req, value, simgrid::mc::RequestType::internal);
- XBT_DEBUG("%s (state=%d)", req_str, prev_state->num);
- xbt_free(req_str);
- prev_req = MC_state_get_executed_request(state, &value);
- req_str = simgrid::mc::request_to_string(prev_req, value, simgrid::mc::RequestType::executed);
- XBT_DEBUG("%s (state=%d)", req_str, state->num);
- xbt_free(req_str);
- }
-
- if (!MC_state_process_is_done(prev_state, issuer))
- MC_state_interleave_process(prev_state, issuer);
- else
- XBT_DEBUG("Process %p is in done set", req->issuer);
-
- break;
-
- } else if (req->issuer == MC_state_get_internal_request(prev_state)->issuer) {
-
- XBT_DEBUG("Simcall %d and %d with same issuer", req->call, MC_state_get_internal_request(prev_state)->call);
- break;
-
- } else {
-
- const smx_process_t previous_issuer = MC_smx_simcall_get_issuer(MC_state_get_internal_request(prev_state));
- XBT_DEBUG("Simcall %d, process %lu (state %d) and simcall %d, process %lu (state %d) are independant",
- req->call, issuer->pid, state->num,
- MC_state_get_internal_request(prev_state)->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;
+}
- if (MC_state_interleave_size(state) && xbt_fifo_size(mc_stack) < _sg_mc_max_depth) {
- /* We found a back-tracking point, let's loop */
- XBT_DEBUG("Back-tracking to state %d at depth %d", state->num, xbt_fifo_size(mc_stack) + 1);
- xbt_fifo_unshift(mc_stack, state);
- MC_replay(mc_stack);
- XBT_DEBUG("Back-tracking to state %d at depth %d done", state->num, xbt_fifo_size(mc_stack));
- break;
- } else {
- XBT_DEBUG("Delete state %d at depth %d", state->num, xbt_fifo_size(mc_stack) + 1);
- MC_state_delete(state, !state->in_visited_states ? 1 : 0);
- }
- }
+void SafetyChecker::restoreState()
+{
+ /* Intermediate backtracking */
+ {
+ simgrid::mc::State* state = stack_.back().get();
+ if (state->system_state) {
+ simgrid::mc::restore_snapshot(state->system_state);
+ return;
}
}
- XBT_INFO("No property violation found.");
- MC_print_statistics(mc_stats);
- return SIMGRID_MC_EXIT_SUCCESS;
+ /* 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++;
+ }
}
void SafetyChecker::init()
else if (reductionMode_ == simgrid::mc::ReductionMode::unset)
reductionMode_ = simgrid::mc::ReductionMode::dpor;
- _sg_mc_safety = 1;
-
if (_sg_mc_termination)
XBT_INFO("Check non progressive cycles");
else
XBT_INFO("Check a safety property");
- mc_model_checker->wait_for_requests();
+ simgrid::mc::session->initialize();
XBT_DEBUG("Starting the safety algorithm");
- /* Create exploration stack */
- mc_stack = xbt_fifo_new();
+ std::unique_ptr<simgrid::mc::State> initial_state =
+ std::unique_ptr<simgrid::mc::State>(MC_state_new(++expandedStatesCount_));
+
+ XBT_DEBUG("**************************************************");
+ XBT_DEBUG("Initial state");
- this->pre();
+ /* Get an enabled process and insert it in the interleave set of the initial state */
+ for (auto& p : mc_model_checker->process().simix_processes())
+ if (simgrid::mc::process_is_enabled(&p.copy)) {
+ initial_state->interleave(&p.copy);
+ if (reductionMode_ != simgrid::mc::ReductionMode::none)
+ break;
+ }
- /* Save the initial state */
- initial_global_state = xbt_new0(s_mc_global_t, 1);
- initial_global_state->snapshot = simgrid::mc::take_snapshot(0);
+ stack_.push_back(std::move(initial_state));
}
SafetyChecker::SafetyChecker(Session& session) : Checker(session)
SafetyChecker::~SafetyChecker()
{
}
+
+Checker* createSafetyChecker(Session& session)
+{
+ return new SafetyChecker(session);
+}
}
}