src/mc/mc_dpor.c

   1 /* Copyright (c) 2008-2013. The SimGrid Team.
   2  * All rights reserved.                                                     */
   3
   4 /* This program is free software; you can redistribute it and/or modify it
   5  * under the terms of the license (GNU LGPL) which comes with this package. */
   6
   7 #include "mc_private.h"
   8
   9 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_dpor, mc,
  10                                 "Logging specific to MC DPOR exploration");
  11
  12 /********** Global variables **********/
  13
  14 xbt_dynar_t visited_states;
  15 xbt_dict_t first_enabled_state;
  16 xbt_dynar_t initial_communications_pattern;
  17 xbt_dynar_t communications_pattern;
  18 int nb_comm_pattern;
  19
  20 /********** Static functions ***********/
  21
  22 static void comm_pattern_free(mc_comm_pattern_t p){
  23   xbt_free(p->rdv);
  24   xbt_free(p->data);
  25   xbt_free(p);
  26   p = NULL;
  27 }
  28
  29 static void comm_pattern_free_voidp( void *p){
  30   comm_pattern_free((mc_comm_pattern_t) * (void **)p);
  31 }
  32
  33 static mc_comm_pattern_t get_comm_pattern_from_idx(xbt_dynar_t pattern, unsigned int *idx, e_smx_comm_type_t type, unsigned long proc){
  34   mc_comm_pattern_t current_comm;
  35   while(*idx < xbt_dynar_length(pattern)){
  36     current_comm = (mc_comm_pattern_t)xbt_dynar_get_as(pattern, *idx, mc_comm_pattern_t);
  37     if(current_comm->type == type && type == SIMIX_COMM_SEND){
  38       if(current_comm->src_proc == proc)
  39         return current_comm;
  40     }else if(current_comm->type == type && type == SIMIX_COMM_RECEIVE){
  41       if(current_comm->dst_proc == proc)
  42         return current_comm;
  43     }
  44     (*idx)++;
  45   }
  46   return NULL;
  47 }
  48
  49 static int compare_comm_pattern(mc_comm_pattern_t comm1, mc_comm_pattern_t comm2){
  50   if(strcmp(comm1->rdv, comm2->rdv) != 0)
  51     return 1;
  52   if(comm1->src_proc != comm2->src_proc)
  53     return 1;
  54   if(comm1->dst_proc != comm2->dst_proc)
  55     return 1;
  56   if(comm1->data_size != comm2->data_size)
  57     return 1;
  58   if(memcmp(comm1->data, comm2->data, comm1->data_size) != 0)
  59     return 1;
  60   return 0;
  61 }
  62
  63 static void deterministic_pattern(xbt_dynar_t initial_pattern, xbt_dynar_t pattern){
  64   unsigned int cursor = 0, send_index = 0, recv_index = 0;
  65   mc_comm_pattern_t comm1, comm2;
  66   int comm_comparison = 0;
  67   int current_process = 0;
  68   while(current_process < simix_process_maxpid){
  69     while(cursor < xbt_dynar_length(initial_pattern)){
  70       comm1 = (mc_comm_pattern_t)xbt_dynar_get_as(initial_pattern, cursor, mc_comm_pattern_t);
  71       if(comm1->type == SIMIX_COMM_SEND && comm1->src_proc == current_process){
  72         comm2 = get_comm_pattern_from_idx(pattern, &send_index, comm1->type, current_process);
  73         comm_comparison = compare_comm_pattern(comm1, comm2);
  74         if(comm_comparison == 1){
  75           initial_state_safety->send_deterministic = 0;
  76           initial_state_safety->comm_deterministic = 0;
  77           return;
  78         }
  79         send_index++;
  80       }else if(comm1->type == SIMIX_COMM_RECEIVE && comm1->dst_proc == current_process){
  81         comm2 = get_comm_pattern_from_idx(pattern, &recv_index, comm1->type, current_process);
  82         comm_comparison = compare_comm_pattern(comm1, comm2);
  83         if(comm_comparison == 1){
  84           initial_state_safety->comm_deterministic = 0;
  85         }
  86         recv_index++;
  87       }
  88       cursor++;
  89     }
  90     cursor = 0;
  91     send_index = 0;
  92     recv_index = 0;
  93     current_process++;
  94   }
  95 }
  96
  97 static int complete_comm_pattern(xbt_dynar_t list, mc_comm_pattern_t pattern){
  98   mc_comm_pattern_t current_pattern;
  99   unsigned int cursor = 0;
 100   xbt_dynar_foreach(list, cursor, current_pattern){
 101     if(current_pattern->comm == pattern->comm){
 102       if(!current_pattern->completed){
 103         current_pattern->src_proc = pattern->comm->comm.src_proc->pid;
 104         current_pattern->src_host = simcall_host_get_name(pattern->comm->comm.src_proc->smx_host);
 105         current_pattern->dst_proc = pattern->comm->comm.dst_proc->pid;
 106         current_pattern->dst_host = simcall_host_get_name(pattern->comm->comm.dst_proc->smx_host);
 107         current_pattern->data_size = pattern->comm->comm.src_buff_size;
 108         current_pattern->data = xbt_malloc0(current_pattern->data_size);
 109         current_pattern->matched_comm = pattern->num;
 110         memcpy(current_pattern->data, current_pattern->comm->comm.src_buff, current_pattern->data_size);
 111         current_pattern->completed = 1;
 112         return current_pattern->num;
 113       }
 114     }
 115   }
 116   return -1;
 117 }
 118
 119 void get_comm_pattern(xbt_dynar_t list, smx_simcall_t request, int call){
 120   mc_comm_pattern_t pattern = NULL;
 121   pattern = xbt_new0(s_mc_comm_pattern_t, 1);
 122   pattern->num = ++nb_comm_pattern;
 123   pattern->completed = 0;
 124   if(call == 1){ // ISEND
 125     pattern->comm = simcall_comm_isend__get__result(request);
 126     pattern->type = SIMIX_COMM_SEND;
 127     if(pattern->comm->comm.dst_proc != NULL){
 128       pattern->matched_comm = complete_comm_pattern(list, pattern);
 129       pattern->dst_proc = pattern->comm->comm.dst_proc->pid;
 130       pattern->completed = 1;
 131       pattern->dst_host = simcall_host_get_name(pattern->comm->comm.dst_proc->smx_host);
 132     }
 133     pattern->src_proc = pattern->comm->comm.src_proc->pid;
 134     pattern->src_host = simcall_host_get_name(request->issuer->smx_host);
 135     pattern->data_size = pattern->comm->comm.src_buff_size;
 136     pattern->data=xbt_malloc0(pattern->data_size);
 137     memcpy(pattern->data, pattern->comm->comm.src_buff, pattern->data_size);
 138   }else{ // IRECV
 139     pattern->comm = simcall_comm_irecv__get__result(request);
 140     pattern->type = SIMIX_COMM_RECEIVE;
 141     if(pattern->comm->comm.src_proc != NULL){
 142       pattern->matched_comm = complete_comm_pattern(list, pattern);
 143       pattern->src_proc = pattern->comm->comm.src_proc->pid;
 144       pattern->src_host = simcall_host_get_name(pattern->comm->comm.src_proc->smx_host);
 145       pattern->completed = 1;
 146       pattern->data_size = pattern->comm->comm.src_buff_size;
 147       pattern->data=xbt_malloc0(pattern->data_size);
 148       memcpy(pattern->data, pattern->comm->comm.src_buff, pattern->data_size);
 149     }
 150     pattern->dst_proc = pattern->comm->comm.dst_proc->pid;
 151     pattern->dst_host = simcall_host_get_name(request->issuer->smx_host);
 152   }
 153   if(pattern->comm->comm.rdv != NULL)
 154     pattern->rdv = strdup(pattern->comm->comm.rdv->name);
 155   else
 156     pattern->rdv = strdup(pattern->comm->comm.rdv_cpy->name);
 157   xbt_dynar_push(list, &pattern);
 158 }
 159
 160 static void print_communications_pattern(xbt_dynar_t comms_pattern){
 161   unsigned int cursor = 0;
 162   mc_comm_pattern_t current_comm;
 163   xbt_dynar_foreach(comms_pattern, cursor, current_comm){
 164     if(current_comm->type == SIMIX_COMM_SEND)
 165       XBT_INFO("[(%lu) %s -> %s] %s ", current_comm->src_proc, current_comm->src_host, current_comm->dst_host, "iSend");
 166     else
 167       XBT_INFO("[(%lu) %s <- %s] %s ", current_comm->dst_proc, current_comm->dst_host, current_comm->src_host, "iRecv");
 168   }
 169 }
 170
 171 static void visited_state_free(mc_visited_state_t state){
 172   if(state){
 173     MC_free_snapshot(state->system_state);
 174     xbt_free(state);
 175   }
 176 }
 177
 178 static void visited_state_free_voidp(void *s){
 179   visited_state_free((mc_visited_state_t) * (void **) s);
 180 }
 181
 182 /** \brief Save the current state
 183  *
 184  *  \return Snapshot of the current state.
 185  */
 186 static mc_visited_state_t visited_state_new(){
 187
 188   mc_visited_state_t new_state = NULL;
 189   new_state = xbt_new0(s_mc_visited_state_t, 1);
 190   new_state->heap_bytes_used = mmalloc_get_bytes_used(std_heap);
 191   new_state->nb_processes = xbt_swag_size(simix_global->process_list);
 192   new_state->system_state = MC_take_snapshot(mc_stats->expanded_states);
 193   new_state->num = mc_stats->expanded_states;
 194   new_state->other_num = -1;
 195
 196   return new_state;
 197
 198 }
 199
 200 /** \brief Find a suitable subrange of candidate duplicates for a given state
 201  *
 202  *  \param all_ pairs dynamic array of states with candidate duplicates of the current state;
 203  *  \param pair current state;
 204  *  \param min (output) index of the beginning of the the subrange
 205  *  \param max (output) index of the enf of the subrange
 206  *
 207  *  Given a suitably ordered array of state, this function extracts a subrange
 208  *  (with index *min <= i <= *max) with candidate duplicates of the given state.
 209  *  This function uses only fast discriminating criterions and does not use the
 210  *  full state comparison algorithms.
 211  *
 212  *  The states in all_pairs MUST be ordered using a (given) weak order
 213  *  (based on nb_processes and heap_bytes_used).
 214  *  The subrange is the subrange of "equivalence" of the given state.
 215  */
 216 static int get_search_interval(xbt_dynar_t all_states, mc_visited_state_t state, int *min, int *max){
 217
 218   int raw_mem_set = (mmalloc_get_current_heap() == raw_heap);
 219
 220   MC_SET_RAW_MEM;
 221
 222   int cursor = 0, previous_cursor, next_cursor;
 223   mc_visited_state_t state_test;
 224   int start = 0;
 225   int end = xbt_dynar_length(all_states) - 1;
 226
 227   while(start <= end){
 228     cursor = (start + end) / 2;
 229     state_test = (mc_visited_state_t)xbt_dynar_get_as(all_states, cursor, mc_visited_state_t);
 230     if(state_test->nb_processes < state->nb_processes){
 231       start = cursor + 1;
 232     }else if(state_test->nb_processes > state->nb_processes){
 233       end = cursor - 1;
 234     }else{
 235       if(state_test->heap_bytes_used < state->heap_bytes_used){
 236         start = cursor +1;
 237       }else if(state_test->heap_bytes_used > state->heap_bytes_used){
 238         end = cursor - 1;
 239       }else{
 240         *min = *max = cursor;
 241         previous_cursor = cursor - 1;
 242         while(previous_cursor >= 0){
 243           state_test = (mc_visited_state_t)xbt_dynar_get_as(all_states, previous_cursor, mc_visited_state_t);
 244           if(state_test->nb_processes != state->nb_processes || state_test->heap_bytes_used != state->heap_bytes_used)
 245             break;
 246           *min = previous_cursor;
 247           previous_cursor--;
 248         }
 249         next_cursor = cursor + 1;
 250         while(next_cursor < xbt_dynar_length(all_states)){
 251           state_test = (mc_visited_state_t)xbt_dynar_get_as(all_states, next_cursor, mc_visited_state_t);
 252           if(state_test->nb_processes != state->nb_processes || state_test->heap_bytes_used != state->heap_bytes_used)
 253             break;
 254           *max = next_cursor;
 255           next_cursor++;
 256         }
 257         if(!raw_mem_set)
 258           MC_UNSET_RAW_MEM;
 259         return -1;
 260       }
 261      }
 262   }
 263
 264   if(!raw_mem_set)
 265     MC_UNSET_RAW_MEM;
 266
 267   return cursor;
 268 }
 269
 270 /** \brief Take a snapshot the current state and process it.
 271  *
 272  *  \return number of the duplicate state or -1 (not visited)
 273  */
 274 static int is_visited_state(){
 275
 276   if(_sg_mc_visited == 0)
 277     return -1;
 278
 279   int raw_mem_set = (mmalloc_get_current_heap() == raw_heap);
 280
 281   MC_SET_RAW_MEM;
 282
 283   mc_visited_state_t new_state = visited_state_new();
 284
 285   if(xbt_dynar_is_empty(visited_states)){
 286
 287     xbt_dynar_push(visited_states, &new_state);
 288
 289     if(!raw_mem_set)
 290       MC_UNSET_RAW_MEM;
 291
 292     return -1;
 293
 294   }else{
 295
 296     int min = -1, max = -1, index;
 297     //int res;
 298     mc_visited_state_t state_test;
 299     int cursor;
 300
 301     index = get_search_interval(visited_states, new_state, &min, &max);
 302
 303     if(min != -1 && max != -1){
 304
 305       // Parallell implementation
 306       /*res = xbt_parmap_mc_apply(parmap, snapshot_compare, xbt_dynar_get_ptr(visited_states, min), (max-min)+1, new_state);
 307       if(res != -1){
 308         state_test = (mc_visited_state_t)xbt_dynar_get_as(visited_states, (min+res)-1, mc_visited_state_t);
 309         if(state_test->other_num == -1)
 310           new_state->other_num = state_test->num;
 311         else
 312           new_state->other_num = state_test->other_num;
 313         if(dot_output == NULL)
 314           XBT_DEBUG("State %d already visited ! (equal to state %d)", new_state->num, state_test->num);
 315         else
 316           XBT_DEBUG("State %d already visited ! (equal to state %d (state %d in dot_output))", new_state->num, state_test->num, new_state->other_num);
 317         xbt_dynar_remove_at(visited_states, (min + res) - 1, NULL);
 318         xbt_dynar_insert_at(visited_states, (min+res) - 1, &new_state);
 319         if(!raw_mem_set)
 320           MC_UNSET_RAW_MEM;
 321         return new_state->other_num;
 322         }*/
 323
 324       cursor = min;
 325       while(cursor <= max){
 326         state_test = (mc_visited_state_t)xbt_dynar_get_as(visited_states, cursor, mc_visited_state_t);
 327         if(snapshot_compare(state_test, new_state) == 0){
 328           // The state has been visited:
 329
 330           if(state_test->other_num == -1)
 331             new_state->other_num = state_test->num;
 332           else
 333             new_state->other_num = state_test->other_num;
 334           if(dot_output == NULL)
 335             XBT_DEBUG("State %d already visited ! (equal to state %d)", new_state->num, state_test->num);
 336           else
 337             XBT_DEBUG("State %d already visited ! (equal to state %d (state %d in dot_output))", new_state->num, state_test->num, new_state->other_num);
 338
 339           // Replace the old state with the new one (why?):
 340           xbt_dynar_remove_at(visited_states, cursor, NULL);
 341           xbt_dynar_insert_at(visited_states, cursor, &new_state);
 342
 343           if(!raw_mem_set)
 344             MC_UNSET_RAW_MEM;
 345           return new_state->other_num;
 346         }
 347         cursor++;
 348       }
 349
 350       // The state has not been visited, add it to the list:
 351       xbt_dynar_insert_at(visited_states, min, &new_state);
 352
 353     }else{
 354
 355       // The state has not been visited: insert the state in the dynamic array.
 356       state_test = (mc_visited_state_t)xbt_dynar_get_as(visited_states, index, mc_visited_state_t);
 357       if(state_test->nb_processes < new_state->nb_processes){
 358         xbt_dynar_insert_at(visited_states, index+1, &new_state);
 359       }else{
 360         if(state_test->heap_bytes_used < new_state->heap_bytes_used)
 361           xbt_dynar_insert_at(visited_states, index + 1, &new_state);
 362         else
 363           xbt_dynar_insert_at(visited_states, index, &new_state);
 364       }
 365
 366     }
 367
 368     // We have reached the maximum number of stored states;
 369     if(xbt_dynar_length(visited_states) > _sg_mc_visited){
 370
 371       // Find the (index of the) older state:
 372       int min2 = mc_stats->expanded_states;
 373       unsigned int cursor2 = 0;
 374       unsigned int index2 = 0;
 375       xbt_dynar_foreach(visited_states, cursor2, state_test){
 376         if(state_test->num < min2){
 377           index2 = cursor2;
 378           min2 = state_test->num;
 379         }
 380       }
 381
 382       // and drop it:
 383       xbt_dynar_remove_at(visited_states, index2, NULL);
 384     }
 385
 386     if(!raw_mem_set)
 387       MC_UNSET_RAW_MEM;
 388
 389     return -1;
 390
 391   }
 392 }
 393
 394 /**
 395  *  \brief Initialize the DPOR exploration algorithm
 396  */
 397 void MC_dpor_init()
 398 {
 399
 400   int raw_mem_set = (mmalloc_get_current_heap() == raw_heap);
 401
 402   mc_state_t initial_state = NULL;
 403   smx_process_t process;
 404
 405   /* Create the initial state and push it into the exploration stack */
 406   MC_SET_RAW_MEM;
 407
 408   if(_sg_mc_visited > 0)
 409     visited_states = xbt_dynar_new(sizeof(mc_visited_state_t), visited_state_free_voidp);
 410
 411   first_enabled_state = xbt_dict_new_homogeneous(&xbt_free_f);
 412
 413   initial_communications_pattern = xbt_dynar_new(sizeof(mc_comm_pattern_t), comm_pattern_free_voidp);
 414   communications_pattern = xbt_dynar_new(sizeof(mc_comm_pattern_t), comm_pattern_free_voidp);
 415   nb_comm_pattern = 0;
 416
 417   initial_state = MC_state_new();
 418
 419   MC_UNSET_RAW_MEM;
 420
 421   XBT_DEBUG("**************************************************");
 422   XBT_DEBUG("Initial state");
 423
 424   /* Wait for requests (schedules processes) */
 425   MC_wait_for_requests();
 426
 427   MC_ignore_heap(simix_global->process_to_run->data, 0);
 428   MC_ignore_heap(simix_global->process_that_ran->data, 0);
 429
 430   MC_SET_RAW_MEM;
 431
 432   /* Get an enabled process and insert it in the interleave set of the initial state */
 433   xbt_swag_foreach(process, simix_global->process_list){
 434     if(MC_process_is_enabled(process)){
 435       MC_state_interleave_process(initial_state, process);
 436       if(mc_reduce_kind != e_mc_reduce_none)
 437         break;
 438     }
 439   }
 440
 441   xbt_fifo_unshift(mc_stack_safety, initial_state);
 442
 443   /* To ensure the soundness of DPOR, we have to keep a list of
 444      processes which are still enabled at each step of the exploration.
 445      If max depth is reached, we interleave them in the state in which they have
 446      been enabled for the first time. */
 447   xbt_swag_foreach(process, simix_global->process_list){
 448     if(MC_process_is_enabled(process)){
 449       char *key = bprintf("%lu", process->pid);
 450       char *data = bprintf("%d", xbt_fifo_size(mc_stack_safety));
 451       xbt_dict_set(first_enabled_state, key, data, NULL);
 452       xbt_free(key);
 453     }
 454   }
 455
 456   MC_UNSET_RAW_MEM;
 457
 458   if(raw_mem_set)
 459     MC_SET_RAW_MEM;
 460   else
 461     MC_UNSET_RAW_MEM;
 462
 463 }
 464
 465
 466 /** \brief Model-check the application using a DFS exploration
 467  *         with DPOR (Dynamic Partial Order Reductions)
 468  */
 469 void MC_dpor(void)
 470 {
 471
 472   char *req_str = NULL;
 473   int value;
 474   smx_simcall_t req = NULL, prev_req = NULL;
 475   mc_state_t state = NULL, prev_state = NULL, next_state = NULL, restored_state=NULL;
 476   smx_process_t process = NULL;
 477   xbt_fifo_item_t item = NULL;
 478   mc_state_t state_test = NULL;
 479   int pos;
 480   int visited_state = -1;
 481   int enabled = 0;
 482   int interleave_size = 0;
 483   int comm_pattern = 0;
 484
 485   while (xbt_fifo_size(mc_stack_safety) > 0) {
 486
 487     /* Get current state */
 488     state = (mc_state_t)
 489       xbt_fifo_get_item_content(xbt_fifo_get_first_item(mc_stack_safety));
 490
 491     XBT_DEBUG("**************************************************");
 492     XBT_DEBUG("Exploration depth=%d (state=%p, num %d)(%u interleave, user_max_depth %d, first_enabled_state size : %d)",
 493               xbt_fifo_size(mc_stack_safety), state, state->num,
 494               MC_state_interleave_size(state), user_max_depth_reached, xbt_dict_size(first_enabled_state));
 495
 496     interleave_size = MC_state_interleave_size(state);
 497
 498     /* Update statistics */
 499     mc_stats->visited_states++;
 500
 501     /* If there are processes to interleave and the maximum depth has not been reached
 502        then perform one step of the exploration algorithm */
 503     if (xbt_fifo_size(mc_stack_safety) <= _sg_mc_max_depth && !user_max_depth_reached &&
 504         (req = MC_state_get_request(state, &value)) && visited_state == -1) {
 505
 506       /* Debug information */
 507       if(XBT_LOG_ISENABLED(mc_dpor, xbt_log_priority_debug)){
 508         req_str = MC_request_to_string(req, value);
 509         XBT_DEBUG("Execute: %s", req_str);
 510         xbt_free(req_str);
 511       }
 512
 513       MC_SET_RAW_MEM;
 514       if(dot_output != NULL)
 515         req_str = MC_request_get_dot_output(req, value);
 516       MC_UNSET_RAW_MEM;
 517
 518       MC_state_set_executed_request(state, req, value);
 519       mc_stats->executed_transitions++;
 520
 521       MC_SET_RAW_MEM;
 522       char *key = bprintf("%lu", req->issuer->pid);
 523       xbt_dict_remove(first_enabled_state, key);
 524       xbt_free(key);
 525       MC_UNSET_RAW_MEM;
 526
 527       if(_sg_mc_comms_determinism || _sg_mc_send_determinism){
 528         if(req->call == SIMCALL_COMM_ISEND)
 529           comm_pattern = 1;
 530         else if(req->call == SIMCALL_COMM_IRECV)
 531           comm_pattern = 2;
 532       }
 533
 534       /* Answer the request */
 535       SIMIX_simcall_pre(req, value); /* After this call req is no longer usefull */
 536
 537       if(_sg_mc_comms_determinism || _sg_mc_send_determinism){
 538         MC_SET_RAW_MEM;
 539         if(comm_pattern != 0){
 540           if(!initial_state_safety->initial_communications_pattern_done)
 541             get_comm_pattern(initial_communications_pattern, req, comm_pattern);
 542           else
 543             get_comm_pattern(communications_pattern, req, comm_pattern);
 544         }
 545         MC_UNSET_RAW_MEM;
 546         comm_pattern = 0;
 547       }
 548
 549       /* Wait for requests (schedules processes) */
 550       MC_wait_for_requests();
 551
 552       /* Create the new expanded state */
 553       MC_SET_RAW_MEM;
 554
 555       next_state = MC_state_new();
 556
 557       if((visited_state = is_visited_state()) == -1){
 558
 559         /* Get an enabled process and insert it in the interleave set of the next state */
 560         xbt_swag_foreach(process, simix_global->process_list){
 561           if(MC_process_is_enabled(process)){
 562             MC_state_interleave_process(next_state, process);
 563             if(mc_reduce_kind != e_mc_reduce_none)
 564               break;
 565           }
 566         }
 567
 568         if(_sg_mc_checkpoint && ((xbt_fifo_size(mc_stack_safety) + 1) % _sg_mc_checkpoint == 0)){
 569           next_state->system_state = MC_take_snapshot(next_state->num);
 570         }
 571
 572         if(dot_output != NULL)
 573           fprintf(dot_output, "\"%d\" -> \"%d\" [%s];\n", state->num, next_state->num, req_str);
 574
 575       }else{
 576
 577         if(dot_output != NULL)
 578           fprintf(dot_output, "\"%d\" -> \"%d\" [%s];\n", state->num, visited_state, req_str);
 579
 580       }
 581
 582       xbt_fifo_unshift(mc_stack_safety, next_state);
 583
 584       /* Insert in dict all enabled processes, if not included yet */
 585       xbt_swag_foreach(process, simix_global->process_list){
 586         if(MC_process_is_enabled(process)){
 587           char *key = bprintf("%lu", process->pid);
 588           if(xbt_dict_get_or_null(first_enabled_state, key) == NULL){
 589             char *data = bprintf("%d", xbt_fifo_size(mc_stack_safety));
 590             xbt_dict_set(first_enabled_state, key, data, NULL);
 591           }
 592           xbt_free(key);
 593         }
 594       }
 595
 596       if(dot_output != NULL)
 597         xbt_free(req_str);
 598
 599       MC_UNSET_RAW_MEM;
 600
 601       /* Let's loop again */
 602
 603       /* The interleave set is empty or the maximum depth is reached, let's back-track */
 604     } else {
 605
 606       if((xbt_fifo_size(mc_stack_safety) > _sg_mc_max_depth) || user_max_depth_reached || visited_state != -1){
 607
 608         if(user_max_depth_reached && visited_state == -1)
 609           XBT_DEBUG("User max depth reached !");
 610         else if(visited_state == -1)
 611           XBT_WARN("/!\\ Max depth reached ! /!\\ ");
 612
 613         visited_state = -1;
 614
 615         /* Interleave enabled processes in the state in which they have been enabled for the first time */
 616         xbt_swag_foreach(process, simix_global->process_list){
 617           if(MC_process_is_enabled(process)){
 618             char *key = bprintf("%lu", process->pid);
 619             enabled = (int)strtoul(xbt_dict_get_or_null(first_enabled_state, key), 0, 10);
 620             xbt_free(key);
 621             int cursor = xbt_fifo_size(mc_stack_safety);
 622             xbt_fifo_foreach(mc_stack_safety, item, state_test, mc_state_t){
 623               if(cursor-- == enabled){
 624                 if(!MC_state_process_is_done(state_test, process) && state_test->num != state->num){
 625                   XBT_DEBUG("Interleave process %lu in state %d", process->pid, state_test->num);
 626                   MC_state_interleave_process(state_test, process);
 627                   break;
 628                 }
 629               }
 630             }
 631           }
 632         }
 633
 634       }else{
 635
 636         XBT_DEBUG("There are no more processes to interleave. (depth %d)", xbt_fifo_size(mc_stack_safety) + 1);
 637
 638       }
 639
 640       MC_SET_RAW_MEM;
 641
 642       if(_sg_mc_comms_determinism || _sg_mc_send_determinism){
 643         if(initial_state_safety->initial_communications_pattern_done){
 644           if(interleave_size == 0){ /* if (interleave_size > 0), process interleaved but not enabled => "incorrect" path, determinism not evaluated */
 645             //print_communications_pattern(communications_pattern);
 646             deterministic_pattern(initial_communications_pattern, communications_pattern);
 647             if(initial_state_safety->comm_deterministic == 0 && _sg_mc_comms_determinism){
 648               XBT_INFO("****************************************************");
 649               XBT_INFO("***** Non-deterministic communications pattern *****");
 650               XBT_INFO("****************************************************");
 651               XBT_INFO("Initial communications pattern:");
 652               print_communications_pattern(initial_communications_pattern);
 653               XBT_INFO("Communications pattern counter-example:");
 654               print_communications_pattern(communications_pattern);
 655               MC_print_statistics(mc_stats);
 656               return;
 657             }else if(initial_state_safety->send_deterministic == 0 && _sg_mc_send_determinism){
 658               XBT_INFO("****************************************************");
 659               XBT_INFO("***** Non-send-deterministic communications pattern *****");
 660               XBT_INFO("****************************************************");
 661               XBT_INFO("Initial communications pattern:");
 662               print_communications_pattern(initial_communications_pattern);
 663               XBT_INFO("Communications pattern counter-example:");
 664               print_communications_pattern(communications_pattern);
 665               MC_print_statistics(mc_stats);
 666               return;
 667             }
 668           }
 669         }else{
 670           initial_state_safety->initial_communications_pattern_done = 1;
 671         }
 672       }
 673
 674       /* Trash the current state, no longer needed */
 675       xbt_fifo_shift(mc_stack_safety);
 676       MC_state_delete(state);
 677       XBT_DEBUG("Delete state %d at depth %d", state->num, xbt_fifo_size(mc_stack_safety) + 1);
 678
 679       MC_UNSET_RAW_MEM;
 680
 681       /* Check for deadlocks */
 682       if(MC_deadlock_check()){
 683         MC_show_deadlock(NULL);
 684         return;
 685       }
 686
 687       MC_SET_RAW_MEM;
 688       /* Traverse the stack backwards until a state with a non empty interleave
 689          set is found, deleting all the states that have it empty in the way.
 690          For each deleted state, check if the request that has generated it
 691          (from it's predecesor state), depends on any other previous request
 692          executed before it. If it does then add it to the interleave set of the
 693          state that executed that previous request. */
 694
 695       while ((state = xbt_fifo_shift(mc_stack_safety)) != NULL) {
 696         if(mc_reduce_kind != e_mc_reduce_none){
 697           req = MC_state_get_internal_request(state);
 698           xbt_fifo_foreach(mc_stack_safety, item, prev_state, mc_state_t) {
 699             if(MC_request_depend(req, MC_state_get_internal_request(prev_state))){
 700               if(XBT_LOG_ISENABLED(mc_dpor, xbt_log_priority_debug)){
 701                 XBT_DEBUG("Dependent Transitions:");
 702                 prev_req = MC_state_get_executed_request(prev_state, &value);
 703                 req_str = MC_request_to_string(prev_req, value);
 704                 XBT_DEBUG("%s (state=%d)", req_str, prev_state->num);
 705                 xbt_free(req_str);
 706                 prev_req = MC_state_get_executed_request(state, &value);
 707                 req_str = MC_request_to_string(prev_req, value);
 708                 XBT_DEBUG("%s (state=%d)", req_str, state->num);
 709                 xbt_free(req_str);
 710               }
 711
 712               if(!MC_state_process_is_done(prev_state, req->issuer))
 713                 MC_state_interleave_process(prev_state, req->issuer);
 714               else
 715                 XBT_DEBUG("Process %p is in done set", req->issuer);
 716
 717               break;
 718
 719             }else if(req->issuer == MC_state_get_internal_request(prev_state)->issuer){
 720
 721               XBT_DEBUG("Simcall %d and %d with same issuer", req->call, MC_state_get_internal_request(prev_state)->call);
 722               break;
 723
 724             }else{
 725
 726               XBT_DEBUG("Simcall %d, process %lu (state %d) and simcall %d, process %lu (state %d) are independant", req->call, req->issuer->pid, state->num, MC_state_get_internal_request(prev_state)->call, MC_state_get_internal_request(prev_state)->issuer->pid, prev_state->num);
 727
 728             }
 729           }
 730         }
 731
 732         if (MC_state_interleave_size(state) && xbt_fifo_size(mc_stack_safety) < _sg_mc_max_depth) {
 733           /* We found a back-tracking point, let's loop */
 734           XBT_DEBUG("Back-tracking to state %d at depth %d", state->num, xbt_fifo_size(mc_stack_safety) + 1);
 735           if(_sg_mc_checkpoint){
 736             if(state->system_state != NULL){
 737               MC_restore_snapshot(state->system_state);
 738               xbt_fifo_unshift(mc_stack_safety, state);
 739               MC_UNSET_RAW_MEM;
 740             }else{
 741               pos = xbt_fifo_size(mc_stack_safety);
 742               item = xbt_fifo_get_first_item(mc_stack_safety);
 743               while(pos>0){
 744                 restored_state = (mc_state_t) xbt_fifo_get_item_content(item);
 745                 if(restored_state->system_state != NULL){
 746                   break;
 747                 }else{
 748                   item = xbt_fifo_get_next_item(item);
 749                   pos--;
 750                 }
 751               }
 752               MC_restore_snapshot(restored_state->system_state);
 753               xbt_fifo_unshift(mc_stack_safety, state);
 754               MC_UNSET_RAW_MEM;
 755               MC_replay(mc_stack_safety, pos);
 756             }
 757           }else{
 758             xbt_fifo_unshift(mc_stack_safety, state);
 759             MC_UNSET_RAW_MEM;
 760             MC_replay(mc_stack_safety, -1);
 761           }
 762           XBT_DEBUG("Back-tracking to state %d at depth %d done", state->num, xbt_fifo_size(mc_stack_safety));
 763           break;
 764         } else {
 765           req = MC_state_get_internal_request(state);
 766           if(_sg_mc_comms_determinism){
 767             if(req->call == SIMCALL_COMM_ISEND || req->call == SIMCALL_COMM_IRECV){
 768               if(!xbt_dynar_is_empty(communications_pattern))
 769                 xbt_dynar_remove_at(communications_pattern, xbt_dynar_length(communications_pattern) - 1, NULL);
 770             }
 771           }
 772           XBT_DEBUG("Delete state %d at depth %d", state->num, xbt_fifo_size(mc_stack_safety) + 1);
 773           MC_state_delete(state);
 774         }
 775       }
 776       MC_UNSET_RAW_MEM;
 777     }
 778   }
 779   MC_print_statistics(mc_stats);
 780   MC_UNSET_RAW_MEM;
 781
 782   return;
 783 }
 784
 785
 786
 787