src/mc/checker/CommunicationDeterminismChecker.cpp

   1 /* Copyright (c) 2008-2020. The SimGrid Team. All rights reserved.          */
   2
   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. */
   5
   6 #include "src/mc/checker/CommunicationDeterminismChecker.hpp"
   7 #include "src/kernel/activity/MailboxImpl.hpp"
   8 #include "src/mc/Session.hpp"
   9 #include "src/mc/mc_config.hpp"
  10 #include "src/mc/mc_exit.hpp"
  11 #include "src/mc/mc_private.hpp"
  12 #include "src/mc/mc_request.hpp"
  13 #include "src/mc/mc_smx.hpp"
  14 #include "src/mc/mc_api.hpp"
  15
  16 #if HAVE_SMPI
  17 #include "smpi_request.hpp"
  18 #endif
  19
  20 #include <cstdint>
  21
  22 using simgrid::mc::remote;
  23 using mcapi = simgrid::mc::mc_api;
  24
  25 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_comm_determinism, mc, "Logging specific to MC communication determinism detection");
  26
  27 /********** Global variables **********/
  28
  29 std::vector<simgrid::mc::PatternCommunicationList> initial_communications_pattern;
  30 std::vector<std::vector<simgrid::mc::PatternCommunication*>> incomplete_communications_pattern;
  31
  32 /********** Static functions ***********/
  33
  34 static simgrid::mc::CommPatternDifference compare_comm_pattern(const simgrid::mc::PatternCommunication* comm1,
  35                                                                const simgrid::mc::PatternCommunication* comm2)
  36 {
  37   using simgrid::mc::CommPatternDifference;
  38   if(comm1->type != comm2->type)
  39     return CommPatternDifference::TYPE;
  40   if (comm1->rdv != comm2->rdv)
  41     return CommPatternDifference::RDV;
  42   if (comm1->src_proc != comm2->src_proc)
  43     return CommPatternDifference::SRC_PROC;
  44   if (comm1->dst_proc != comm2->dst_proc)
  45     return CommPatternDifference::DST_PROC;
  46   if (comm1->tag != comm2->tag)
  47     return CommPatternDifference::TAG;
  48   if (comm1->data.size() != comm2->data.size())
  49     return CommPatternDifference::DATA_SIZE;
  50   if (comm1->data != comm2->data)
  51     return CommPatternDifference::DATA;
  52   return CommPatternDifference::NONE;
  53 }
  54
  55 static char* print_determinism_result(simgrid::mc::CommPatternDifference diff, int process,
  56                                       const simgrid::mc::PatternCommunication* comm, unsigned int cursor)
  57 {
  58   char* type;
  59   char* res;
  60
  61   if (comm->type == simgrid::mc::PatternCommunicationType::send)
  62     type = bprintf("The send communications pattern of the process %d is different!", process - 1);
  63   else
  64     type = bprintf("The recv communications pattern of the process %d is different!", process - 1);
  65
  66   using simgrid::mc::CommPatternDifference;
  67   switch(diff) {
  68     case CommPatternDifference::TYPE:
  69       res = bprintf("%s Different type for communication #%u", type, cursor);
  70       break;
  71     case CommPatternDifference::RDV:
  72       res = bprintf("%s Different rdv for communication #%u", type, cursor);
  73       break;
  74     case CommPatternDifference::TAG:
  75       res = bprintf("%s Different tag for communication #%u", type, cursor);
  76       break;
  77     case CommPatternDifference::SRC_PROC:
  78       res = bprintf("%s Different source for communication #%u", type, cursor);
  79       break;
  80     case CommPatternDifference::DST_PROC:
  81       res = bprintf("%s Different destination for communication #%u", type, cursor);
  82       break;
  83     case CommPatternDifference::DATA_SIZE:
  84       res = bprintf("%s Different data size for communication #%u", type, cursor);
  85       break;
  86     case CommPatternDifference::DATA:
  87       res = bprintf("%s Different data for communication #%u", type, cursor);
  88       break;
  89     default:
  90       res = nullptr;
  91       break;
  92   }
  93
  94   return res;
  95 }
  96
  97 static void update_comm_pattern(simgrid::mc::PatternCommunication* comm_pattern,
  98                                 simgrid::mc::RemotePtr<simgrid::kernel::activity::CommImpl> comm_addr)
  99 {
 100   // HACK, type punning
 101   simgrid::mc::Remote<simgrid::kernel::activity::CommImpl> temp_comm;
 102   mc_model_checker->get_remote_simulation().read(temp_comm, comm_addr);
 103   const simgrid::kernel::activity::CommImpl* comm = temp_comm.get_buffer();
 104
 105   smx_actor_t src_proc =
 106       mc_model_checker->get_remote_simulation().resolve_actor(simgrid::mc::remote(comm->src_actor_.get()));
 107   smx_actor_t dst_proc =
 108       mc_model_checker->get_remote_simulation().resolve_actor(simgrid::mc::remote(comm->dst_actor_.get()));
 109   comm_pattern->src_proc = src_proc->get_pid();
 110   comm_pattern->dst_proc = dst_proc->get_pid();
 111   comm_pattern->src_host = MC_smx_actor_get_host_name(src_proc);
 112   comm_pattern->dst_host = MC_smx_actor_get_host_name(dst_proc);
 113   if (comm_pattern->data.empty() && comm->src_buff_ != nullptr) {
 114     size_t buff_size;
 115     mc_model_checker->get_remote_simulation().read(&buff_size, remote(comm->dst_buff_size_));
 116     comm_pattern->data.resize(buff_size);
 117     mc_model_checker->get_remote_simulation().read_bytes(comm_pattern->data.data(), comm_pattern->data.size(),
 118                                                          remote(comm->src_buff_));
 119   }
 120 }
 121
 122 namespace simgrid {
 123 namespace mc {
 124
 125 void CommunicationDeterminismChecker::deterministic_comm_pattern(int process, const PatternCommunication* comm,
 126                                                                  int backtracking)
 127 {
 128   if (not backtracking) {
 129     PatternCommunicationList& list      = initial_communications_pattern[process];
 130     CommPatternDifference diff          = compare_comm_pattern(list.list[list.index_comm].get(), comm);
 131
 132     if (diff != CommPatternDifference::NONE) {
 133       if (comm->type == PatternCommunicationType::send) {
 134         this->send_deterministic = false;
 135         if (this->send_diff != nullptr)
 136           xbt_free(this->send_diff);
 137         this->send_diff = print_determinism_result(diff, process, comm, list.index_comm + 1);
 138       } else {
 139         this->recv_deterministic = false;
 140         if (this->recv_diff != nullptr)
 141           xbt_free(this->recv_diff);
 142         this->recv_diff = print_determinism_result(diff, process, comm, list.index_comm + 1);
 143       }
 144       if (_sg_mc_send_determinism && not this->send_deterministic) {
 145         XBT_INFO("*********************************************************");
 146         XBT_INFO("***** Non-send-deterministic communications pattern *****");
 147         XBT_INFO("*********************************************************");
 148         XBT_INFO("%s", this->send_diff);
 149         xbt_free(this->send_diff);
 150         this->send_diff = nullptr;
 151         mc::session->log_state();
 152         mc_model_checker->exit(SIMGRID_MC_EXIT_NON_DETERMINISM);
 153       } else if (_sg_mc_comms_determinism && (not this->send_deterministic && not this->recv_deterministic)) {
 154         XBT_INFO("****************************************************");
 155         XBT_INFO("***** Non-deterministic communications pattern *****");
 156         XBT_INFO("****************************************************");
 157         if (this->send_diff) {
 158           XBT_INFO("%s", this->send_diff);
 159           xbt_free(this->send_diff);
 160           this->send_diff = nullptr;
 161         }
 162         if (this->recv_diff) {
 163           XBT_INFO("%s", this->recv_diff);
 164           xbt_free(this->recv_diff);
 165           this->recv_diff = nullptr;
 166         }
 167         mc::session->log_state();
 168         mc_model_checker->exit(SIMGRID_MC_EXIT_NON_DETERMINISM);
 169       }
 170     }
 171   }
 172 }
 173
 174 /********** Non Static functions ***********/
 175
 176 void CommunicationDeterminismChecker::get_comm_pattern(smx_simcall_t request, CallType call_type, int backtracking)
 177 {
 178   const smx_actor_t issuer = mcapi::get().mc_smx_simcall_get_issuer(request);
 179   const mc::PatternCommunicationList& initial_pattern          = initial_communications_pattern[issuer->get_pid()];
 180   const std::vector<PatternCommunication*>& incomplete_pattern = incomplete_communications_pattern[issuer->get_pid()];
 181
 182   auto pattern   = std::make_unique<PatternCommunication>();
 183   pattern->index = initial_pattern.index_comm + incomplete_pattern.size();
 184
 185   if (call_type == CallType::SEND) {
 186     /* Create comm pattern */
 187     pattern->type      = PatternCommunicationType::send;
 188     pattern->comm_addr = mcapi::get().get_pattern_comm_addr(request);
 189
 190     Remote<kernel::activity::CommImpl> temp_synchro;
 191     mc_model_checker->get_remote_simulation().read(temp_synchro, remote(pattern->comm_addr));
 192     const kernel::activity::CommImpl* synchro = temp_synchro.get_buffer();
 193
 194     // char* remote_name = mc_model_checker->get_remote_simulation().read<char*>(RemotePtr<char*>(
 195     //     (uint64_t)(synchro->get_mailbox() ? &synchro->get_mailbox()->name_ : &synchro->mbox_cpy->name_)));
 196     pattern->rdv      = mcapi::get().get_pattern_comm_rdv(pattern->comm_addr);
 197     pattern->src_proc = mcapi::get().get_pattern_comm_src_proc(pattern->comm_addr);
 198     pattern->src_host = mc_api::get().get_actor_host_name(issuer);
 199
 200 #if HAVE_SMPI
 201     simgrid::smpi::Request mpi_request;
 202     mc_model_checker->get_remote_simulation().read(
 203         &mpi_request, remote(static_cast<smpi::Request*>(simcall_comm_isend__get__data(request))));
 204     pattern->tag = mpi_request.tag();
 205 #endif
 206
 207     // if (synchro->src_buff_ != nullptr) {
 208     //   pattern->data.resize(synchro->src_buff_size_);
 209     //   mc_model_checker->get_remote_simulation().read_bytes(pattern->data.data(), pattern->data.size(),
 210     //                                                        remote(synchro->src_buff_));
 211     // }
 212
 213     auto pattern_data = mcapi::get().get_pattern_comm_data(pattern->comm_addr);
 214     if(pattern_data.data() != nullptr) {
 215       auto data_size = pattern_data.size();
 216       pattern->data.resize(data_size);
 217       memcpy(pattern->data.data(), pattern_data.data(), data_size);
 218     }
 219 #if HAVE_SMPI
 220     if(mpi_request.detached()){
 221       if (this->initial_communications_pattern_done) {
 222         /* Evaluate comm determinism */
 223         this->deterministic_comm_pattern(pattern->src_proc, pattern.get(), backtracking);
 224         initial_communications_pattern[pattern->src_proc].index_comm++;
 225       } else {
 226         /* Store comm pattern */
 227         initial_communications_pattern[pattern->src_proc].list.push_back(std::move(pattern));
 228       }
 229       return;
 230     }
 231 #endif
 232   } else if (call_type == CallType::RECV) {
 233     pattern->type      = PatternCommunicationType::receive;
 234     pattern->comm_addr = static_cast<kernel::activity::CommImpl*>(simcall_comm_irecv__getraw__result(request));
 235
 236 #if HAVE_SMPI
 237     smpi::Request mpi_request;
 238     mc_model_checker->get_remote_simulation().read(
 239         &mpi_request, remote(static_cast<smpi::Request*>(simcall_comm_irecv__get__data(request))));
 240     pattern->tag = mpi_request.tag();
 241 #endif
 242
 243     Remote<kernel::activity::CommImpl> temp_comm;
 244     mc_model_checker->get_remote_simulation().read(temp_comm, remote(pattern->comm_addr));
 245     const kernel::activity::CommImpl* comm = temp_comm.get_buffer();
 246
 247     char* remote_name;
 248     mc_model_checker->get_remote_simulation().read(
 249         &remote_name, remote(comm->get_mailbox() ? &xbt::string::to_string_data(comm->get_mailbox()->name_).data
 250                                                  : &xbt::string::to_string_data(comm->mbox_cpy->name_).data));
 251     pattern->rdv = mc_model_checker->get_remote_simulation().read_string(RemotePtr<char>(remote_name));
 252     pattern->dst_proc =
 253         mc_model_checker->get_remote_simulation().resolve_actor(mc::remote(comm->dst_actor_.get()))->get_pid();
 254     pattern->dst_host = MC_smx_actor_get_host_name(issuer);
 255   } else
 256     xbt_die("Unexpected call_type %i", (int) call_type);
 257
 258   XBT_DEBUG("Insert incomplete comm pattern %p for process %ld", pattern.get(), issuer->get_pid());
 259   incomplete_communications_pattern[issuer->get_pid()].push_back(pattern.release());
 260 }
 261
 262 void CommunicationDeterminismChecker::complete_comm_pattern(RemotePtr<kernel::activity::CommImpl> comm_addr,
 263                                                             unsigned int issuer, int backtracking)
 264 {
 265   /* Complete comm pattern */
 266   std::vector<PatternCommunication*>& incomplete_pattern = incomplete_communications_pattern[issuer];
 267   auto current_comm_pattern =
 268       std::find_if(begin(incomplete_pattern), end(incomplete_pattern),
 269                    [&comm_addr](const PatternCommunication* comm) { return remote(comm->comm_addr) == comm_addr; });
 270   if (current_comm_pattern == std::end(incomplete_pattern))
 271     xbt_die("Corresponding communication not found!");
 272
 273   update_comm_pattern(*current_comm_pattern, comm_addr);
 274   std::unique_ptr<PatternCommunication> comm_pattern(*current_comm_pattern);
 275   XBT_DEBUG("Remove incomplete comm pattern for process %u at cursor %zd", issuer,
 276             std::distance(begin(incomplete_pattern), current_comm_pattern));
 277   incomplete_pattern.erase(current_comm_pattern);
 278
 279   if (this->initial_communications_pattern_done) {
 280     /* Evaluate comm determinism */
 281     this->deterministic_comm_pattern(issuer, comm_pattern.get(), backtracking);
 282     initial_communications_pattern[issuer].index_comm++;
 283   } else {
 284     /* Store comm pattern */
 285     initial_communications_pattern[issuer].list.push_back(std::move(comm_pattern));
 286   }
 287 }
 288
 289 CommunicationDeterminismChecker::CommunicationDeterminismChecker(Session& s) : Checker(s)
 290 {
 291 }
 292
 293 CommunicationDeterminismChecker::~CommunicationDeterminismChecker() = default;
 294
 295 RecordTrace CommunicationDeterminismChecker::get_record_trace() // override
 296 {
 297   RecordTrace res;
 298   for (auto const& state : stack_)
 299     res.push_back(state->get_transition());
 300   return res;
 301 }
 302
 303 std::vector<std::string> CommunicationDeterminismChecker::get_textual_trace() // override
 304 {
 305   std::vector<std::string> trace;
 306   for (auto const& state : stack_) {
 307     smx_simcall_t req = &state->executed_req_;
 308     trace.push_back(mcapi::get().request_to_string(req, state->transition_.argument_, RequestType::executed));
 309   }
 310   return trace;
 311 }
 312
 313 void CommunicationDeterminismChecker::log_state() // override
 314 {
 315   if (_sg_mc_comms_determinism) {
 316     if (this->send_deterministic && not this->recv_deterministic) {
 317       XBT_INFO("*******************************************************");
 318       XBT_INFO("**** Only-send-deterministic communication pattern ****");
 319       XBT_INFO("*******************************************************");
 320       XBT_INFO("%s", this->recv_diff);
 321     }
 322     if (not this->send_deterministic && this->recv_deterministic) {
 323       XBT_INFO("*******************************************************");
 324       XBT_INFO("**** Only-recv-deterministic communication pattern ****");
 325       XBT_INFO("*******************************************************");
 326       XBT_INFO("%s", this->send_diff);
 327     }
 328   }
 329   XBT_INFO("Expanded states = %lu", expanded_states_count_);
 330   XBT_INFO("Visited states = %lu", mcapi::get().mc_get_visited_states());
 331   XBT_INFO("Executed transitions = %lu", mcapi::get().mc_get_executed_trans());
 332   XBT_INFO("Send-deterministic : %s", this->send_deterministic ? "Yes" : "No");
 333   if (_sg_mc_comms_determinism)
 334     XBT_INFO("Recv-deterministic : %s", this->recv_deterministic ? "Yes" : "No");
 335 }
 336
 337 void CommunicationDeterminismChecker::prepare()
 338 {
 339   const int maxpid = mcapi::get().get_maxpid();
 340
 341   initial_communications_pattern.resize(maxpid);
 342   incomplete_communications_pattern.resize(maxpid);
 343
 344   ++expanded_states_count_;
 345   auto initial_state = std::make_unique<State>(expanded_states_count_);
 346
 347   XBT_DEBUG("********* Start communication determinism verification *********");
 348
 349   /* Get an enabled actor and insert it in the interleave set of the initial state */
 350   auto actors = mcapi::get().get_actors();
 351   for (auto& actor : actors)
 352     if (mcapi::get().actor_is_enabled(actor.copy.get_buffer()->get_pid()))
 353       initial_state->add_interleaving_set(actor.copy.get_buffer());
 354
 355   stack_.push_back(std::move(initial_state));
 356 }
 357
 358 static inline bool all_communications_are_finished()
 359 {
 360   auto maxpid = mcapi::get().get_maxpid();
 361   for (size_t current_actor = 1; current_actor < maxpid; current_actor++) {
 362     if (not incomplete_communications_pattern[current_actor].empty()) {
 363       XBT_DEBUG("Some communications are not finished, cannot stop the exploration! State not visited.");
 364       return false;
 365     }
 366   }
 367   return true;
 368 }
 369
 370 void CommunicationDeterminismChecker::restoreState()
 371 {
 372   /* Intermediate backtracking */
 373   State* last_state = stack_.back().get();
 374   if (last_state->system_state_) {
 375     last_state->system_state_->restore(&mcapi::get().mc_get_remote_simulation());
 376     MC_restore_communications_pattern(last_state);
 377     return;
 378   }
 379
 380   /* Restore the initial state */
 381   mcapi::get().s_restore_initial_state();
 382
 383   unsigned n = mcapi::get().get_maxpid();
 384   assert(n == incomplete_communications_pattern.size());
 385   assert(n == initial_communications_pattern.size());
 386   for (unsigned j=0; j < n ; j++) {
 387     incomplete_communications_pattern[j].clear();
 388     initial_communications_pattern[j].index_comm = 0;
 389   }
 390
 391   /* Traverse the stack from the state at position start and re-execute the transitions */
 392   for (std::unique_ptr<simgrid::mc::State> const& state : stack_) {
 393     if (state == stack_.back())
 394       break;
 395
 396     int req_num             = state->transition_.argument_;
 397     const s_smx_simcall* saved_req = &state->executed_req_;
 398     xbt_assert(saved_req);
 399
 400     /* because we got a copy of the executed request, we have to fetch the
 401        real one, pointed by the request field of the issuer process */
 402
 403     const smx_actor_t issuer = mcapi::get().mc_smx_simcall_get_issuer(saved_req);
 404     smx_simcall_t req        = &issuer->simcall_;
 405
 406     /* TODO : handle test and testany simcalls */
 407     CallType call = MC_get_call_type(req);
 408     mcapi::get().handle_simcall(state->transition_);
 409     MC_handle_comm_pattern(call, req, req_num, 1);
 410     mcapi::get().mc_wait_for_requests();
 411
 412     /* Update statistics */
 413     mcapi::get().mc_inc_visited_states();
 414     mcapi::get().mc_inc_executed_trans();
 415   }
 416 }
 417
 418 void CommunicationDeterminismChecker::real_run()
 419 {
 420   std::unique_ptr<VisitedState> visited_state = nullptr;
 421   smx_simcall_t req = nullptr;
 422
 423   while (not stack_.empty()) {
 424     /* Get current state */
 425     State* cur_state = stack_.back().get();
 426
 427     XBT_DEBUG("**************************************************");
 428     XBT_DEBUG("Exploration depth = %zu (state = %d, interleaved processes = %zu)", stack_.size(), cur_state->num_,
 429               cur_state->interleave_size());
 430
 431     /* Update statistics */
 432     mcapi::get().mc_inc_visited_states();
 433
 434     if (stack_.size() <= (std::size_t)_sg_mc_max_depth)
 435       req = mcapi::get().mc_state_choose_request(cur_state);
 436     else
 437       req = nullptr;
 438
 439     if (req != nullptr && visited_state == nullptr) {
 440       int req_num = cur_state->transition_.argument_;
 441
 442       XBT_DEBUG("Execute: %s", mcapi::get().request_to_string(req, req_num, RequestType::simix).c_str());
 443
 444       std::string req_str;
 445       if (dot_output != nullptr)
 446         req_str = mcapi::get().request_get_dot_output(req, req_num);
 447
 448       mcapi::get().mc_inc_executed_trans();
 449
 450       /* TODO : handle test and testany simcalls */
 451       CallType call = CallType::NONE;
 452       if (_sg_mc_comms_determinism || _sg_mc_send_determinism)
 453         call = MC_get_call_type(req);
 454
 455       /* Answer the request */
 456       mcapi::get().handle_simcall(cur_state->transition_);
 457       /* After this call req is no longer useful */
 458
 459       MC_handle_comm_pattern(call, req, req_num, 0);
 460
 461
 462       /* Wait for requests (schedules processes) */
 463       mcapi::get().mc_wait_for_requests();
 464
 465       /* Create the new expanded state */
 466       ++expanded_states_count_;
 467       auto next_state = std::make_unique<State>(expanded_states_count_);
 468
 469       /* If comm determinism verification, we cannot stop the exploration if some communications are not finished (at
 470        * least, data are transferred). These communications  are incomplete and they cannot be analyzed and compared
 471        * with the initial pattern. */
 472       bool compare_snapshots = this->initial_communications_pattern_done && all_communications_are_finished();
 473
 474       if (_sg_mc_max_visited_states != 0)
 475         visited_state = visited_states_.addVisitedState(expanded_states_count_, next_state.get(), compare_snapshots);
 476       else
 477         visited_state = nullptr;
 478
 479       if (visited_state == nullptr) {
 480         /* Get enabled actors and insert them in the interleave set of the next state */
 481         auto actors = mcapi::get().mc_get_remote_simulation().actors();
 482         for (auto& actor : actors)
 483           if (mcapi::get().actor_is_enabled(actor.copy.get_buffer()->get_pid()))
 484             next_state->add_interleaving_set(actor.copy.get_buffer());
 485
 486         if (dot_output != nullptr)
 487           fprintf(dot_output, "\"%d\" -> \"%d\" [%s];\n", cur_state->num_, next_state->num_, req_str.c_str());
 488
 489       } else if (dot_output != nullptr)
 490         fprintf(dot_output, "\"%d\" -> \"%d\" [%s];\n", cur_state->num_,
 491                 visited_state->original_num == -1 ? visited_state->num : visited_state->original_num, req_str.c_str());
 492
 493       stack_.push_back(std::move(next_state));
 494     } else {
 495       if (stack_.size() > (std::size_t) _sg_mc_max_depth)
 496         XBT_WARN("/!\\ Max depth reached! /!\\ ");
 497       else if (visited_state != nullptr)
 498         XBT_DEBUG("State already visited (equal to state %d), exploration stopped on this path.",
 499             visited_state->original_num == -1 ? visited_state->num : visited_state->original_num);
 500       else
 501         XBT_DEBUG("There are no more processes to interleave. (depth %zu)", stack_.size());
 502
 503       this->initial_communications_pattern_done = true;
 504
 505       /* Trash the current state, no longer needed */
 506       XBT_DEBUG("Delete state %d at depth %zu", cur_state->num_, stack_.size());
 507       stack_.pop_back();
 508
 509       visited_state = nullptr;
 510
 511       /* Check for deadlocks */
 512       if (mcapi::get().mc_check_deadlock()) {
 513         mcapi::get().mc_show_deadlock();
 514         throw simgrid::mc::DeadlockError();
 515       }
 516
 517       while (not stack_.empty()) {
 518         std::unique_ptr<State> state(std::move(stack_.back()));
 519         stack_.pop_back();
 520         if (state->interleave_size() && stack_.size() < (std::size_t)_sg_mc_max_depth) {
 521           /* We found a back-tracking point, let's loop */
 522           XBT_DEBUG("Back-tracking to state %d at depth %zu", state->num_, stack_.size() + 1);
 523           stack_.push_back(std::move(state));
 524
 525           this->restoreState();
 526
 527           XBT_DEBUG("Back-tracking to state %d at depth %zu done", stack_.back()->num_, stack_.size());
 528
 529           break;
 530         } else {
 531           XBT_DEBUG("Delete state %d at depth %zu", state->num_, stack_.size() + 1);
 532         }
 533       }
 534     }
 535   }
 536
 537   mcapi::get().s_log_state();
 538 }
 539
 540 void CommunicationDeterminismChecker::run()
 541 {
 542   XBT_INFO("Check communication determinism");
 543   mcapi::get().s_initialize();
 544
 545   this->prepare();
 546   this->real_run();
 547 }
 548
 549 Checker* createCommunicationDeterminismChecker(Session& s)
 550 {
 551   return new CommunicationDeterminismChecker(s);
 552 }
 553
 554 } // namespace mc
 555 } // namespace simgrid