funcnode.cc

   1 #include "action.h"
   2 #include "history.h"
   3 #include "funcnode.h"
   4 #include "funcinst.h"
   5 #include "predicate.h"
   6 #include "concretepredicate.h"
   7
   8 #include "model.h"
   9 #include "execution.h"
  10 #include "newfuzzer.h"
  11 #include <cmath>
  12
  13 FuncNode::FuncNode(ModelHistory * history) :
  14         history(history),
  15         inst_counter(1),
  16         marker(1),
  17         thrd_markers(),
  18         thrd_recursion_depth(),
  19         func_inst_map(),
  20         inst_list(),
  21         entry_insts(),
  22         thrd_inst_pred_maps(),
  23         thrd_inst_id_maps(),
  24         thrd_loc_inst_maps(),
  25         thrd_predicate_tree_position(),
  26         thrd_predicate_trace(),
  27         edge_table(32),
  28         out_edges()
  29 {
  30         predicate_tree_entry = new Predicate(NULL, true);
  31         predicate_tree_entry->add_predicate_expr(NOPREDICATE, NULL, true);
  32
  33         predicate_tree_exit = new Predicate(NULL, false, true);
  34         predicate_tree_exit->set_depth(MAX_DEPTH);
  35
  36         /* Snapshot data structures below */
  37         read_locations = new loc_set_t();
  38         write_locations = new loc_set_t();
  39         val_loc_map = new HashTable<uint64_t, loc_set_t *, uint64_t, 0, snapshot_malloc, snapshot_calloc, snapshot_free, int64_hash>();
  40         loc_may_equal_map = new HashTable<void *, loc_set_t *, uintptr_t, 0>();
  41
  42         //values_may_read_from = new value_set_t();
  43 }
  44
  45 /* Reallocate snapshotted memories when new executions start */
  46 void FuncNode::set_new_exec_flag()
  47 {
  48         read_locations = new loc_set_t();
  49         write_locations = new loc_set_t();
  50         val_loc_map = new HashTable<uint64_t, loc_set_t *, uint64_t, 0, snapshot_malloc, snapshot_calloc, snapshot_free, int64_hash>();
  51         loc_may_equal_map = new HashTable<void *, loc_set_t *, uintptr_t, 0>();
  52
  53         //values_may_read_from = new value_set_t();
  54 }
  55
  56 /* Check whether FuncInst with the same type, position, and location
  57  * as act has been added to func_inst_map or not. If not, add it.
  58  */
  59 void FuncNode::add_inst(ModelAction *act)
  60 {
  61         ASSERT(act);
  62         const char * position = act->get_position();
  63
  64         /* THREAD* actions, ATOMIC_LOCK, ATOMIC_TRYLOCK, and ATOMIC_UNLOCK
  65          * actions are not tagged with their source line numbers
  66          */
  67         if (position == NULL)
  68                 return;
  69
  70         FuncInst * func_inst = func_inst_map.get(position);
  71
  72         /* This position has not been inserted into hashtable before */
  73         if (func_inst == NULL) {
  74                 func_inst = create_new_inst(act);
  75                 func_inst_map.put(position, func_inst);
  76                 return;
  77         }
  78
  79         /* Volatile variables that use ++ or -- syntax may result in read and write actions with the same position */
  80         if (func_inst->get_type() != act->get_type()) {
  81                 FuncInst * collision_inst = func_inst->search_in_collision(act);
  82
  83                 if (collision_inst == NULL) {
  84                         collision_inst = create_new_inst(act);
  85                         func_inst->add_to_collision(collision_inst);
  86                         return;
  87                 } else {
  88                         func_inst = collision_inst;
  89                 }
  90         }
  91
  92         ASSERT(func_inst->get_type() == act->get_type());
  93         int curr_execution_number = model->get_execution_number();
  94
  95         /* Reset locations when new executions start */
  96         if (func_inst->get_execution_number() != curr_execution_number) {
  97                 func_inst->set_location(act->get_location());
  98                 func_inst->set_execution_number(curr_execution_number);
  99         }
 100
 101         /* Mark the memory location of such inst as not unique */
 102         if (func_inst->get_location() != act->get_location())
 103                 func_inst->not_single_location();
 104 }
 105
 106 FuncInst * FuncNode::create_new_inst(ModelAction * act)
 107 {
 108         FuncInst * func_inst = new FuncInst(act, this);
 109         int exec_num = model->get_execution_number();
 110         func_inst->set_execution_number(exec_num);
 111
 112         inst_list.push_back(func_inst);
 113
 114         return func_inst;
 115 }
 116
 117
 118 /* Get the FuncInst with the same type, position, and location
 119  * as act
 120  *
 121  * @return FuncInst with the same type, position, and location as act */
 122 FuncInst * FuncNode::get_inst(ModelAction *act)
 123 {
 124         ASSERT(act);
 125         const char * position = act->get_position();
 126
 127         /* THREAD* actions, ATOMIC_LOCK, ATOMIC_TRYLOCK, and ATOMIC_UNLOCK
 128          * actions are not tagged with their source line numbers
 129          */
 130         if (position == NULL)
 131                 return NULL;
 132
 133         FuncInst * inst = func_inst_map.get(position);
 134         if (inst == NULL)
 135                 return NULL;
 136
 137         action_type inst_type = inst->get_type();
 138         action_type act_type = act->get_type();
 139
 140         if (inst_type == act_type) {
 141                 return inst;
 142         }
 143         /* RMWRCAS actions are converted to RMW or READ actions */
 144         else if (inst_type == ATOMIC_RMWRCAS &&
 145                                          (act_type == ATOMIC_RMW || act_type == ATOMIC_READ)) {
 146                 return inst;
 147         }
 148         /* Return the FuncInst in the collision list */
 149         else {
 150                 return inst->search_in_collision(act);
 151         }
 152 }
 153
 154 void FuncNode::add_entry_inst(FuncInst * inst)
 155 {
 156         if (inst == NULL)
 157                 return;
 158
 159         mllnode<FuncInst *> * it;
 160         for (it = entry_insts.begin();it != NULL;it = it->getNext()) {
 161                 if (inst == it->getVal())
 162                         return;
 163         }
 164
 165         entry_insts.push_back(inst);
 166 }
 167
 168 void FuncNode::function_entry_handler(thread_id_t tid)
 169 {
 170         init_marker(tid);
 171         init_local_maps(tid);
 172         init_predicate_tree_data_structure(tid);
 173 }
 174
 175 void FuncNode::function_exit_handler(thread_id_t tid)
 176 {
 177         int thread_id = id_to_int(tid);
 178
 179         reset_local_maps(tid);
 180
 181         thrd_recursion_depth[thread_id]--;
 182         thrd_markers[thread_id]->pop_back();
 183
 184         Predicate * exit_pred = get_predicate_tree_position(tid);
 185         if (exit_pred->get_exit() == NULL) {
 186                 // Exit predicate is unset yet
 187                 exit_pred->set_exit(predicate_tree_exit);
 188         }
 189
 190         update_predicate_tree_weight(tid);
 191         reset_predicate_tree_data_structure(tid);
 192 }
 193
 194 /**
 195  * @brief Convert ModelAdtion list to FuncInst list
 196  * @param act_list A list of ModelActions
 197  */
 198 void FuncNode::update_tree(ModelAction * act)
 199 {
 200         bool should_process = act->is_read() || act->is_write();
 201         if (!should_process)
 202                 return;
 203
 204         HashTable<void *, value_set_t *, uintptr_t, 0> * write_history = history->getWriteHistory();
 205
 206         /* build inst_list from act_list for later processing */
 207 //      func_inst_list_t inst_list;
 208
 209         FuncInst * func_inst = get_inst(act);
 210         void * loc = act->get_location();
 211
 212         if (func_inst == NULL)
 213                 return;
 214
 215 //      inst_list.push_back(func_inst);
 216
 217         if (act->is_write()) {
 218                 if (!write_locations->contains(loc)) {
 219                         write_locations->add(loc);
 220                         history->update_loc_wr_func_nodes_map(loc, this);
 221                 }
 222
 223                 // Do not process writes for now
 224                 return;
 225         }
 226
 227         if (act->is_read()) {
 228
 229                 /* If func_inst may only read_from a single location, then:
 230                  *
 231                  * The first time an action reads from some location,
 232                  * import all the values that have been written to this
 233                  * location from ModelHistory and notify ModelHistory
 234                  * that this FuncNode may read from this location.
 235                  */
 236                 if (!read_locations->contains(loc) && func_inst->is_single_location()) {
 237                         read_locations->add(loc);
 238                         value_set_t * write_values = write_history->get(loc);
 239                         add_to_val_loc_map(write_values, loc);
 240                         history->update_loc_rd_func_nodes_map(loc, this);
 241                 }
 242         }
 243
 244 //      update_inst_tree(&inst_list); TODO
 245         update_predicate_tree(act);
 246
 247 //      print_predicate_tree();
 248 }
 249
 250 /**
 251  * @brief Link FuncInsts in inst_list  - add one FuncInst to another's predecessors and successors
 252  * @param inst_list A list of FuncInsts
 253  */
 254 void FuncNode::update_inst_tree(func_inst_list_t * inst_list)
 255 {
 256         if (inst_list == NULL)
 257                 return;
 258         else if (inst_list->size() == 0)
 259                 return;
 260
 261         /* start linking */
 262         sllnode<FuncInst *>* it = inst_list->begin();
 263         sllnode<FuncInst *>* prev;
 264
 265         /* add the first instruction to the list of entry insts */
 266         FuncInst * entry_inst = it->getVal();
 267         add_entry_inst(entry_inst);
 268
 269         it = it->getNext();
 270         while (it != NULL) {
 271                 prev = it->getPrev();
 272
 273                 FuncInst * prev_inst = prev->getVal();
 274                 FuncInst * curr_inst = it->getVal();
 275
 276                 prev_inst->add_succ(curr_inst);
 277                 curr_inst->add_pred(prev_inst);
 278
 279                 it = it->getNext();
 280         }
 281 }
 282
 283 void FuncNode::update_predicate_tree(ModelAction * next_act)
 284 {
 285         thread_id_t tid = next_act->get_tid();
 286         int thread_id = id_to_int(tid);
 287         uint32_t this_marker = thrd_markers[thread_id]->back();
 288         int recursion_depth = thrd_recursion_depth[thread_id];
 289
 290         loc_inst_map_t * loc_inst_map = thrd_loc_inst_maps[thread_id]->back();
 291         inst_pred_map_t * inst_pred_map = thrd_inst_pred_maps[thread_id]->back();
 292         inst_id_map_t * inst_id_map = thrd_inst_id_maps[thread_id]->back();
 293
 294         Predicate * curr_pred = get_predicate_tree_position(tid);
 295         NewFuzzer * fuzzer = (NewFuzzer *)model->get_execution()->getFuzzer();
 296         Predicate * selected_branch = fuzzer->get_selected_child_branch(tid);
 297
 298         while (true) {
 299                 FuncInst * next_inst = get_inst(next_act);
 300                 next_inst->set_associated_read(tid, recursion_depth, this_marker, next_act->get_reads_from_value());
 301
 302                 Predicate * unset_predicate = NULL;
 303                 bool branch_found = follow_branch(&curr_pred, next_inst, next_act, &unset_predicate);
 304
 305                 // A branch with unset predicate expression is detected
 306                 if (!branch_found && unset_predicate != NULL) {
 307                         bool amended = amend_predicate_expr(curr_pred, next_inst, next_act);
 308                         if (amended)
 309                                 continue;
 310                         else {
 311                                 curr_pred = unset_predicate;
 312                                 branch_found = true;
 313                         }
 314                 }
 315
 316                 // Detect loops
 317                 if (!branch_found && inst_id_map->contains(next_inst)) {
 318                         FuncInst * curr_inst = curr_pred->get_func_inst();
 319                         uint32_t curr_id = inst_id_map->get(curr_inst);
 320                         uint32_t next_id = inst_id_map->get(next_inst);
 321
 322                         if (curr_id >= next_id) {
 323                                 Predicate * old_pred = inst_pred_map->get(next_inst);
 324                                 Predicate * back_pred = old_pred->get_parent();
 325
 326                                 // Add to the set of backedges
 327                                 curr_pred->add_backedge(back_pred);
 328                                 curr_pred = back_pred;
 329
 330                                 continue;
 331                         }
 332                 }
 333
 334                 // Generate new branches
 335                 if (!branch_found) {
 336                         SnapVector<struct half_pred_expr *> half_pred_expressions;
 337                         infer_predicates(next_inst, next_act, &half_pred_expressions);
 338                         generate_predicates(curr_pred, next_inst, &half_pred_expressions);
 339                         continue;
 340                 }
 341
 342                 if (next_act->is_write())
 343                         curr_pred->set_write(true);
 344
 345                 if (next_act->is_read()) {
 346                         /* Only need to store the locations of read actions */
 347                         loc_inst_map->put(next_inst->get_location(), next_inst);
 348                 }
 349
 350                 inst_pred_map->put(next_inst, curr_pred);
 351                 set_predicate_tree_position(tid, curr_pred);
 352
 353                 if (!inst_id_map->contains(next_inst))
 354                         inst_id_map->put(next_inst, inst_counter++);
 355
 356                 curr_pred->incr_expl_count();
 357                 add_predicate_to_trace(tid, curr_pred);
 358                 break;
 359         }
 360
 361         // A check
 362         if (selected_branch != NULL)
 363                 ASSERT(selected_branch == curr_pred);
 364 }
 365
 366 /* Given curr_pred and next_inst, find the branch following curr_pred that
 367  * contains next_inst and the correct predicate.
 368  * @return true if branch found, false otherwise.
 369  */
 370 bool FuncNode::follow_branch(Predicate ** curr_pred, FuncInst * next_inst,
 371                                                                                                                  ModelAction * next_act, Predicate ** unset_predicate)
 372 {
 373         /* Check if a branch with func_inst and corresponding predicate exists */
 374         bool branch_found = false;
 375         thread_id_t tid = next_act->get_tid();
 376         int thread_id = id_to_int(tid);
 377         uint32_t this_marker = thrd_markers[thread_id]->back();
 378         int recursion_depth = thrd_recursion_depth[thread_id];
 379
 380         ModelVector<Predicate *> * branches = (*curr_pred)->get_children();
 381         for (uint i = 0;i < branches->size();i++) {
 382                 Predicate * branch = (*branches)[i];
 383                 if (branch->get_func_inst() != next_inst)
 384                         continue;
 385
 386                 /* Check against predicate expressions */
 387                 bool predicate_correct = true;
 388                 PredExprSet * pred_expressions = branch->get_pred_expressions();
 389
 390                 /* Only read and rmw actions my have unset predicate expressions */
 391                 if (pred_expressions->getSize() == 0) {
 392                         predicate_correct = false;
 393
 394                         if (*unset_predicate == NULL)
 395                                 *unset_predicate = branch;
 396                         else
 397                                 ASSERT(false);
 398
 399                         continue;
 400                 }
 401
 402                 PredExprSetIter * pred_expr_it = pred_expressions->iterator();
 403                 while (pred_expr_it->hasNext()) {
 404                         pred_expr * pred_expression = pred_expr_it->next();
 405                         uint64_t last_read, next_read;
 406                         bool equality;
 407
 408                         switch(pred_expression->token) {
 409                         case NOPREDICATE:
 410                                 predicate_correct = true;
 411                                 break;
 412                         case EQUALITY:
 413                                 FuncInst * to_be_compared;
 414                                 to_be_compared = pred_expression->func_inst;
 415                                 ASSERT(to_be_compared != next_inst);
 416
 417                                 last_read = to_be_compared->get_associated_read(tid, recursion_depth, this_marker);
 418                                 ASSERT(last_read != VALUE_NONE);
 419
 420                                 next_read = next_act->get_reads_from_value();
 421                                 equality = (last_read == next_read);
 422                                 if (equality != pred_expression->value)
 423                                         predicate_correct = false;
 424
 425                                 break;
 426                         case NULLITY:
 427                                 next_read = next_act->get_reads_from_value();
 428                                 // TODO: implement likely to be null
 429                                 equality = ( (void*) (next_read & 0xffffffff) == NULL);
 430                                 if (equality != pred_expression->value)
 431                                         predicate_correct = false;
 432                                 break;
 433                         default:
 434                                 predicate_correct = false;
 435                                 model_print("unkown predicate token\n");
 436                                 break;
 437                         }
 438                 }
 439
 440                 delete pred_expr_it;
 441
 442                 if (predicate_correct) {
 443                         *curr_pred = branch;
 444                         branch_found = true;
 445                         break;
 446                 }
 447         }
 448
 449         return branch_found;
 450 }
 451
 452 /* Infer predicate expressions, which are generated in FuncNode::generate_predicates */
 453 void FuncNode::infer_predicates(FuncInst * next_inst, ModelAction * next_act,
 454                                                                                                                                 SnapVector<struct half_pred_expr *> * half_pred_expressions)
 455 {
 456         void * loc = next_act->get_location();
 457         int thread_id = id_to_int(next_act->get_tid());
 458         loc_inst_map_t * loc_inst_map = thrd_loc_inst_maps[thread_id]->back();
 459
 460         if (next_inst->is_read()) {
 461                 /* read + rmw */
 462                 if ( loc_inst_map->contains(loc) ) {
 463                         FuncInst * last_inst = loc_inst_map->get(loc);
 464                         struct half_pred_expr * expression = new half_pred_expr(EQUALITY, last_inst);
 465                         half_pred_expressions->push_back(expression);
 466                 } else if ( next_inst->is_single_location() ) {
 467                         loc_set_t * loc_may_equal = loc_may_equal_map->get(loc);
 468
 469                         if (loc_may_equal != NULL) {
 470                                 loc_set_iter * loc_it = loc_may_equal->iterator();
 471                                 while (loc_it->hasNext()) {
 472                                         void * neighbor = loc_it->next();
 473                                         if (loc_inst_map->contains(neighbor)) {
 474                                                 FuncInst * last_inst = loc_inst_map->get(neighbor);
 475
 476                                                 struct half_pred_expr * expression = new half_pred_expr(EQUALITY, last_inst);
 477                                                 half_pred_expressions->push_back(expression);
 478                                         }
 479                                 }
 480
 481                                 delete loc_it;
 482                         }
 483                 } else {
 484                         // next_inst is not single location
 485                         uint64_t read_val = next_act->get_reads_from_value();
 486
 487                         // only infer NULLITY predicate when it is actually NULL.
 488                         if ( (void*)read_val == NULL) {
 489                                 struct half_pred_expr * expression = new half_pred_expr(NULLITY, NULL);
 490                                 half_pred_expressions->push_back(expression);
 491                         }
 492                 }
 493         } else {
 494                 /* Pure writes */
 495                 // TODO: do anything here?
 496         }
 497 }
 498
 499 /* Able to generate complex predicates when there are multiple predciate expressions */
 500 void FuncNode::generate_predicates(Predicate * curr_pred, FuncInst * next_inst,
 501                                                                                                                                          SnapVector<struct half_pred_expr *> * half_pred_expressions)
 502 {
 503         if (half_pred_expressions->size() == 0) {
 504                 Predicate * new_pred = new Predicate(next_inst);
 505                 curr_pred->add_child(new_pred);
 506                 new_pred->set_parent(curr_pred);
 507
 508                 /* entry predicates and predicates containing pure write actions
 509                  * have no predicate expressions */
 510                 if ( curr_pred->is_entry_predicate() )
 511                         new_pred->add_predicate_expr(NOPREDICATE, NULL, true);
 512                 else if (next_inst->is_write()) {
 513                         /* next_inst->is_write() <==> pure writes */
 514                         new_pred->add_predicate_expr(NOPREDICATE, NULL, true);
 515                 }
 516
 517                 return;
 518         }
 519
 520         SnapVector<Predicate *> predicates;
 521
 522         struct half_pred_expr * half_expr = (*half_pred_expressions)[0];
 523         predicates.push_back(new Predicate(next_inst));
 524         predicates.push_back(new Predicate(next_inst));
 525
 526         predicates[0]->add_predicate_expr(half_expr->token, half_expr->func_inst, true);
 527         predicates[1]->add_predicate_expr(half_expr->token, half_expr->func_inst, false);
 528
 529         for (uint i = 1;i < half_pred_expressions->size();i++) {
 530                 half_expr = (*half_pred_expressions)[i];
 531
 532                 uint old_size = predicates.size();
 533                 for (uint j = 0;j < old_size;j++) {
 534                         Predicate * pred = predicates[j];
 535                         Predicate * new_pred = new Predicate(next_inst);
 536                         new_pred->copy_predicate_expr(pred);
 537
 538                         pred->add_predicate_expr(half_expr->token, half_expr->func_inst, true);
 539                         new_pred->add_predicate_expr(half_expr->token, half_expr->func_inst, false);
 540
 541                         predicates.push_back(new_pred);
 542                 }
 543         }
 544
 545         for (uint i = 0;i < predicates.size();i++) {
 546                 Predicate * pred= predicates[i];
 547                 curr_pred->add_child(pred);
 548                 pred->set_parent(curr_pred);
 549         }
 550
 551         /* Free memories allocated by infer_predicate */
 552         for (uint i = 0;i < half_pred_expressions->size();i++) {
 553                 struct half_pred_expr * tmp = (*half_pred_expressions)[i];
 554                 snapshot_free(tmp);
 555         }
 556 }
 557
 558 /* Amend predicates that contain no predicate expressions. Currenlty only amend with NULLITY predicates */
 559 bool FuncNode::amend_predicate_expr(Predicate * curr_pred, FuncInst * next_inst, ModelAction * next_act)
 560 {
 561         ModelVector<Predicate *> * children = curr_pred->get_children();
 562
 563         Predicate * unset_pred = NULL;
 564         for (uint i = 0;i < children->size();i++) {
 565                 Predicate * child = (*children)[i];
 566                 if (child->get_func_inst() == next_inst) {
 567                         unset_pred = child;
 568                         break;
 569                 }
 570         }
 571
 572         uint64_t read_val = next_act->get_reads_from_value();
 573
 574         // only generate NULLITY predicate when it is actually NULL.
 575         if ( !next_inst->is_single_location() && (void*)read_val == NULL ) {
 576                 Predicate * new_pred = new Predicate(next_inst);
 577
 578                 curr_pred->add_child(new_pred);
 579                 new_pred->set_parent(curr_pred);
 580
 581                 unset_pred->add_predicate_expr(NULLITY, NULL, false);
 582                 new_pred->add_predicate_expr(NULLITY, NULL, true);
 583
 584                 return true;
 585         }
 586
 587         return false;
 588 }
 589
 590 void FuncNode::add_to_val_loc_map(uint64_t val, void * loc)
 591 {
 592         loc_set_t * locations = val_loc_map->get(val);
 593
 594         if (locations == NULL) {
 595                 locations = new loc_set_t();
 596                 val_loc_map->put(val, locations);
 597         }
 598
 599         update_loc_may_equal_map(loc, locations);
 600         locations->add(loc);
 601         // values_may_read_from->add(val);
 602 }
 603
 604 void FuncNode::add_to_val_loc_map(value_set_t * values, void * loc)
 605 {
 606         if (values == NULL)
 607                 return;
 608
 609         value_set_iter * it = values->iterator();
 610         while (it->hasNext()) {
 611                 uint64_t val = it->next();
 612                 add_to_val_loc_map(val, loc);
 613         }
 614
 615         delete it;
 616 }
 617
 618 void FuncNode::update_loc_may_equal_map(void * new_loc, loc_set_t * old_locations)
 619 {
 620         if ( old_locations->contains(new_loc) )
 621                 return;
 622
 623         loc_set_t * neighbors = loc_may_equal_map->get(new_loc);
 624
 625         if (neighbors == NULL) {
 626                 neighbors = new loc_set_t();
 627                 loc_may_equal_map->put(new_loc, neighbors);
 628         }
 629
 630         loc_set_iter * loc_it = old_locations->iterator();
 631         while (loc_it->hasNext()) {
 632                 // new_loc: { old_locations, ... }
 633                 void * member = loc_it->next();
 634                 neighbors->add(member);
 635
 636                 // for each i in old_locations, i : { new_loc, ... }
 637                 loc_set_t * _neighbors = loc_may_equal_map->get(member);
 638                 if (_neighbors == NULL) {
 639                         _neighbors = new loc_set_t();
 640                         loc_may_equal_map->put(member, _neighbors);
 641                 }
 642                 _neighbors->add(new_loc);
 643         }
 644
 645         delete loc_it;
 646 }
 647
 648 void FuncNode::set_predicate_tree_position(thread_id_t tid, Predicate * pred)
 649 {
 650         int thread_id = id_to_int(tid);
 651         ModelVector<Predicate *> * stack = thrd_predicate_tree_position[thread_id];
 652         (*stack)[stack->size() - 1] = pred;
 653 }
 654
 655 /* @return The position of a thread in a predicate tree */
 656 Predicate * FuncNode::get_predicate_tree_position(thread_id_t tid)
 657 {
 658         int thread_id = id_to_int(tid);
 659         return thrd_predicate_tree_position[thread_id]->back();
 660 }
 661
 662 void FuncNode::add_predicate_to_trace(thread_id_t tid, Predicate * pred)
 663 {
 664         int thread_id = id_to_int(tid);
 665         thrd_predicate_trace[thread_id]->back()->push_back(pred);
 666 }
 667
 668 void FuncNode::init_marker(thread_id_t tid)
 669 {
 670         marker++;
 671
 672         int thread_id = id_to_int(tid);
 673         int old_size = thrd_markers.size();
 674
 675         if (old_size < thread_id + 1) {
 676                 thrd_markers.resize(thread_id + 1);
 677
 678                 for (int i = old_size; i < thread_id + 1; i++) {
 679                         thrd_markers[i] = new ModelVector<uint32_t>();
 680                         thrd_recursion_depth.push_back(-1);
 681                 }
 682         }
 683
 684         thrd_markers[thread_id]->push_back(marker);
 685         thrd_recursion_depth[thread_id]++;
 686 }
 687
 688 uint32_t FuncNode::get_marker(thread_id_t tid)
 689 {
 690         int thread_id = id_to_int(tid);
 691         return thrd_markers[thread_id]->back();
 692 }
 693
 694 int FuncNode::get_recursion_depth(thread_id_t tid)
 695 {
 696         return thrd_recursion_depth[id_to_int(tid)];
 697 }
 698
 699 /* Make sure elements of maps are initialized properly when threads enter functions */
 700 void FuncNode::init_local_maps(thread_id_t tid)
 701 {
 702         int thread_id = id_to_int(tid);
 703         int old_size = thrd_loc_inst_maps.size();
 704
 705         if (old_size < thread_id + 1) {
 706                 int new_size = thread_id + 1;
 707
 708                 thrd_loc_inst_maps.resize(new_size);
 709                 thrd_inst_id_maps.resize(new_size);
 710                 thrd_inst_pred_maps.resize(new_size);
 711
 712                 for (int i = old_size; i < new_size; i++) {
 713                         thrd_loc_inst_maps[i] = new ModelVector<loc_inst_map_t *>;
 714                         thrd_inst_id_maps[i] = new ModelVector<inst_id_map_t *>;
 715                         thrd_inst_pred_maps[i] = new ModelVector<inst_pred_map_t *>;
 716                 }
 717         }
 718
 719         ModelVector<loc_inst_map_t *> * map = thrd_loc_inst_maps[thread_id];
 720         int index = thrd_recursion_depth[thread_id];
 721
 722         // If there are recursive calls, push more hashtables into the vector.
 723         if (map->size() < (uint) index + 1) {
 724                 thrd_loc_inst_maps[thread_id]->push_back(new loc_inst_map_t(64));
 725                 thrd_inst_id_maps[thread_id]->push_back(new inst_id_map_t(64));
 726                 thrd_inst_pred_maps[thread_id]->push_back(new inst_pred_map_t(64));
 727         }
 728
 729         ASSERT(map->size() == (uint) index + 1);
 730 }
 731
 732 /* Reset elements of maps when threads exit functions */
 733 void FuncNode::reset_local_maps(thread_id_t tid)
 734 {
 735         int thread_id = id_to_int(tid);
 736         int index = thrd_recursion_depth[thread_id];
 737
 738         // When recursive call ends, keep only one hashtable in the vector
 739         if (index > 0) {
 740                 delete thrd_loc_inst_maps[thread_id]->back();
 741                 delete thrd_inst_id_maps[thread_id]->back();
 742                 delete thrd_inst_pred_maps[thread_id]->back();
 743
 744                 thrd_loc_inst_maps[thread_id]->pop_back();
 745                 thrd_inst_id_maps[thread_id]->pop_back();
 746                 thrd_inst_pred_maps[thread_id]->pop_back();
 747         } else {
 748                 thrd_loc_inst_maps[thread_id]->back()->reset();
 749                 thrd_inst_id_maps[thread_id]->back()->reset();
 750                 thrd_inst_pred_maps[thread_id]->back()->reset();
 751         }
 752 }
 753
 754 void FuncNode::init_predicate_tree_data_structure(thread_id_t tid)
 755 {
 756         int thread_id = id_to_int(tid);
 757         int old_size = thrd_predicate_tree_position.size();
 758
 759         if (old_size < thread_id + 1) {
 760                 thrd_predicate_tree_position.resize(thread_id + 1);
 761                 thrd_predicate_trace.resize(thread_id + 1);
 762
 763                 for (int i = old_size; i < thread_id + 1; i++) {
 764                         thrd_predicate_tree_position[i] = new ModelVector<Predicate *>();
 765                         thrd_predicate_trace[i] = new ModelVector<predicate_trace_t *>();
 766                 }
 767         }
 768
 769         thrd_predicate_tree_position[thread_id]->push_back(predicate_tree_entry);
 770         thrd_predicate_trace[thread_id]->push_back(new predicate_trace_t());
 771 }
 772
 773 void FuncNode::reset_predicate_tree_data_structure(thread_id_t tid)
 774 {
 775         int thread_id = id_to_int(tid);
 776         thrd_predicate_tree_position[thread_id]->pop_back();
 777
 778         // Free memories allocated in init_predicate_tree_data_structure
 779         predicate_trace_t * trace = thrd_predicate_trace[thread_id]->back();
 780         delete trace;
 781         thrd_predicate_trace[thread_id]->pop_back();
 782 }
 783
 784 /* Add FuncNodes that this node may follow */
 785 void FuncNode::add_out_edge(FuncNode * other)
 786 {
 787         if ( !edge_table.contains(other) ) {
 788                 edge_table.put(other, OUT_EDGE);
 789                 out_edges.push_back(other);
 790                 return;
 791         }
 792
 793         edge_type_t edge = edge_table.get(other);
 794         if (edge == IN_EDGE) {
 795                 edge_table.put(other, BI_EDGE);
 796                 out_edges.push_back(other);
 797         }
 798 }
 799
 800 /* Compute the distance between this FuncNode and the target node.
 801  * Return -1 if the target node is unreachable or the actual distance
 802  * is greater than max_step.
 803  */
 804 int FuncNode::compute_distance(FuncNode * target, int max_step)
 805 {
 806         if (target == NULL)
 807                 return -1;
 808         else if (target == this)
 809                 return 0;
 810
 811         SnapList<FuncNode *> queue;
 812         HashTable<FuncNode *, int, uintptr_t, 0> distances(128);
 813
 814         queue.push_back(this);
 815         distances.put(this, 0);
 816
 817         while (!queue.empty()) {
 818                 FuncNode * curr = queue.front();
 819                 queue.pop_front();
 820                 int dist = distances.get(curr);
 821
 822                 if (max_step <= dist)
 823                         return -1;
 824
 825                 ModelList<FuncNode *> * outEdges = curr->get_out_edges();
 826                 mllnode<FuncNode *> * it;
 827                 for (it = outEdges->begin();it != NULL;it = it->getNext()) {
 828                         FuncNode * out_node = it->getVal();
 829
 830                         /* This node has not been visited before */
 831                         if ( !distances.contains(out_node) ) {
 832                                 if (out_node == target)
 833                                         return dist + 1;
 834
 835                                 queue.push_back(out_node);
 836                                 distances.put(out_node, dist + 1);
 837                         }
 838                 }
 839         }
 840
 841         /* Target node is unreachable */
 842         return -1;
 843 }
 844
 845 void FuncNode::update_predicate_tree_weight(thread_id_t tid)
 846 {
 847         predicate_trace_t * trace = thrd_predicate_trace[id_to_int(tid)]->back();
 848
 849         // Update predicate weights based on prediate trace
 850         for (mllnode<Predicate *> * rit = trace->end(); rit != NULL; rit = rit->getPrev()) {
 851                 Predicate * node = rit->getVal();
 852                 ModelVector<Predicate *> * children = node->get_children();
 853
 854                 if (children->size() == 0) {
 855                         double weight = 100.0 / sqrt(node->get_expl_count() + node->get_fail_count() + 1);
 856                         node->set_weight(weight);
 857                 } else {
 858                         double weight_sum = 0.0;
 859                         for (uint i = 0;i < children->size();i++) {
 860                                 Predicate * child = (*children)[i];
 861                                 double weight = child->get_weight();
 862                                 weight_sum += weight;
 863                         }
 864
 865                         double average_weight = (double) weight_sum / (double) children->size();
 866                         double weight = average_weight * pow(0.9, node->get_depth());
 867                         node->set_weight(weight);
 868                 }
 869         }
 870 }
 871
 872 void FuncNode::print_predicate_tree()
 873 {
 874         model_print("digraph function_%s {\n", func_name);
 875         predicate_tree_entry->print_pred_subtree();
 876         predicate_tree_exit->print_predicate();
 877         model_print("}\n");     // end of graph
 878 }