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
 224         if (act->is_read()) {
 225
 226                 /* If func_inst may only read_from a single location, then:
 227                  *
 228                  * The first time an action reads from some location,
 229                  * import all the values that have been written to this
 230                  * location from ModelHistory and notify ModelHistory
 231                  * that this FuncNode may read from this location.
 232                  */
 233                 if (!read_locations->contains(loc) && func_inst->is_single_location()) {
 234                         read_locations->add(loc);
 235                         value_set_t * write_values = write_history->get(loc);
 236                         add_to_val_loc_map(write_values, loc);
 237                         history->update_loc_rd_func_nodes_map(loc, this);
 238                 }
 239         }
 240
 241 //      update_inst_tree(&inst_list); TODO
 242
 243         update_predicate_tree(act);
 244
 245 //      print_predicate_tree();
 246 }
 247
 248 /**
 249  * @brief Link FuncInsts in inst_list  - add one FuncInst to another's predecessors and successors
 250  * @param inst_list A list of FuncInsts
 251  */
 252 void FuncNode::update_inst_tree(func_inst_list_t * inst_list)
 253 {
 254         if (inst_list == NULL)
 255                 return;
 256         else if (inst_list->size() == 0)
 257                 return;
 258
 259         /* start linking */
 260         sllnode<FuncInst *>* it = inst_list->begin();
 261         sllnode<FuncInst *>* prev;
 262
 263         /* add the first instruction to the list of entry insts */
 264         FuncInst * entry_inst = it->getVal();
 265         add_entry_inst(entry_inst);
 266
 267         it = it->getNext();
 268         while (it != NULL) {
 269                 prev = it->getPrev();
 270
 271                 FuncInst * prev_inst = prev->getVal();
 272                 FuncInst * curr_inst = it->getVal();
 273
 274                 prev_inst->add_succ(curr_inst);
 275                 curr_inst->add_pred(prev_inst);
 276
 277                 it = it->getNext();
 278         }
 279 }
 280
 281 void FuncNode::update_predicate_tree(ModelAction * next_act)
 282 {
 283         thread_id_t tid = next_act->get_tid();
 284         int thread_id = id_to_int(tid);
 285         uint32_t this_marker = thrd_markers[thread_id]->back();
 286         int recursion_depth = thrd_recursion_depth[thread_id];
 287
 288         loc_inst_map_t * loc_inst_map = thrd_loc_inst_maps[thread_id]->back();
 289         inst_pred_map_t * inst_pred_map = thrd_inst_pred_maps[thread_id]->back();
 290         inst_id_map_t * inst_id_map = thrd_inst_id_maps[thread_id]->back();
 291
 292         Predicate * curr_pred = get_predicate_tree_position(tid);
 293         NewFuzzer * fuzzer = (NewFuzzer *)model->get_execution()->getFuzzer();
 294         Predicate * selected_branch = fuzzer->get_selected_child_branch(tid);
 295
 296         bool amended;
 297         while (true) {
 298                 FuncInst * next_inst = get_inst(next_act);
 299
 300                 Predicate * unset_predicate = NULL;
 301                 bool branch_found = follow_branch(&curr_pred, next_inst, next_act, &unset_predicate);
 302
 303                 // A branch with unset predicate expression is detected
 304                 if (!branch_found && unset_predicate != NULL) {
 305                         amended = amend_predicate_expr(curr_pred, next_inst, next_act);
 306                         if (amended)
 307                                 continue;
 308                         else {
 309                                 curr_pred = unset_predicate;
 310                                 branch_found = true;
 311                         }
 312                 }
 313
 314                 // Detect loops
 315                 if (!branch_found && inst_id_map->contains(next_inst)) {
 316                         FuncInst * curr_inst = curr_pred->get_func_inst();
 317                         uint32_t curr_id = inst_id_map->get(curr_inst);
 318                         uint32_t next_id = inst_id_map->get(next_inst);
 319
 320                         if (curr_id >= next_id) {
 321                                 Predicate * old_pred = inst_pred_map->get(next_inst);
 322                                 Predicate * back_pred = old_pred->get_parent();
 323
 324                                 // Add to the set of backedges
 325                                 curr_pred->add_backedge(back_pred);
 326                                 curr_pred = back_pred;
 327
 328                                 continue;
 329                         }
 330                 }
 331
 332                 // Generate new branches
 333                 if (!branch_found) {
 334                         SnapVector<struct half_pred_expr *> half_pred_expressions;
 335                         infer_predicates(next_inst, next_act, &half_pred_expressions);
 336                         generate_predicates(curr_pred, next_inst, &half_pred_expressions);
 337                         continue;
 338                 }
 339
 340                 if (next_act->is_write()) {
 341                         curr_pred->set_write(true);
 342                 }
 343
 344                 if (next_act->is_read()) {
 345                         /* Only need to store the locations of read actions */
 346                         loc_inst_map->put(next_act->get_location(), next_inst);
 347                 }
 348
 349                 inst_pred_map->put(next_inst, curr_pred);
 350                 set_predicate_tree_position(tid, curr_pred);
 351
 352                 if (!inst_id_map->contains(next_inst))
 353                         inst_id_map->put(next_inst, inst_counter++);
 354
 355                 curr_pred->incr_expl_count();
 356                 add_predicate_to_trace(tid, curr_pred);
 357                 if (next_act->is_read())
 358                         next_inst->set_associated_read(tid, recursion_depth, this_marker, next_act->get_reads_from_value());
 359
 360                 break;
 361         }
 362
 363         // A check
 364         if (next_act->is_read()) {
 365                 if (selected_branch != NULL && !amended)
 366                         ASSERT(selected_branch == curr_pred);
 367         }
 368 }
 369
 370 /* Given curr_pred and next_inst, find the branch following curr_pred that
 371  * contains next_inst and the correct predicate.
 372  * @return true if branch found, false otherwise.
 373  */
 374 bool FuncNode::follow_branch(Predicate ** curr_pred, FuncInst * next_inst,
 375                                                                                                                  ModelAction * next_act, Predicate ** unset_predicate)
 376 {
 377         /* Check if a branch with func_inst and corresponding predicate exists */
 378         bool branch_found = false;
 379         thread_id_t tid = next_act->get_tid();
 380         int thread_id = id_to_int(tid);
 381         uint32_t this_marker = thrd_markers[thread_id]->back();
 382         int recursion_depth = thrd_recursion_depth[thread_id];
 383
 384         ModelVector<Predicate *> * branches = (*curr_pred)->get_children();
 385         for (uint i = 0;i < branches->size();i++) {
 386                 Predicate * branch = (*branches)[i];
 387                 if (branch->get_func_inst() != next_inst)
 388                         continue;
 389
 390                 /* Check against predicate expressions */
 391                 bool predicate_correct = true;
 392                 PredExprSet * pred_expressions = branch->get_pred_expressions();
 393
 394                 /* Only read and rmw actions my have unset predicate expressions */
 395                 if (pred_expressions->getSize() == 0) {
 396                         predicate_correct = false;
 397
 398                         if (*unset_predicate == NULL)
 399                                 *unset_predicate = branch;
 400                         else
 401                                 ASSERT(false);
 402
 403                         continue;
 404                 }
 405
 406                 PredExprSetIter * pred_expr_it = pred_expressions->iterator();
 407                 while (pred_expr_it->hasNext()) {
 408                         pred_expr * pred_expression = pred_expr_it->next();
 409                         uint64_t last_read, next_read;
 410                         bool equality;
 411
 412                         switch(pred_expression->token) {
 413                         case NOPREDICATE:
 414                                 predicate_correct = true;
 415                                 break;
 416                         case EQUALITY:
 417                                 FuncInst * to_be_compared;
 418                                 to_be_compared = pred_expression->func_inst;
 419
 420                                 last_read = to_be_compared->get_associated_read(tid, recursion_depth, this_marker);
 421                                 ASSERT(last_read != VALUE_NONE);
 422
 423                                 next_read = next_act->get_reads_from_value();
 424                                 equality = (last_read == next_read);
 425                                 if (equality != pred_expression->value)
 426                                         predicate_correct = false;
 427
 428                                 break;
 429                         case NULLITY:
 430                                 next_read = next_act->get_reads_from_value();
 431                                 // TODO: implement likely to be null
 432                                 equality = ( (void*) (next_read & 0xffffffff) == NULL);
 433                                 if (equality != pred_expression->value)
 434                                         predicate_correct = false;
 435                                 break;
 436                         default:
 437                                 predicate_correct = false;
 438                                 model_print("unkown predicate token\n");
 439                                 break;
 440                         }
 441                 }
 442
 443                 delete pred_expr_it;
 444
 445                 if (predicate_correct) {
 446                         *curr_pred = branch;
 447                         branch_found = true;
 448                         break;
 449                 }
 450         }
 451
 452         return branch_found;
 453 }
 454
 455 /* Infer predicate expressions, which are generated in FuncNode::generate_predicates */
 456 void FuncNode::infer_predicates(FuncInst * next_inst, ModelAction * next_act,
 457                                                                                                                                 SnapVector<struct half_pred_expr *> * half_pred_expressions)
 458 {
 459         void * loc = next_act->get_location();
 460         int thread_id = id_to_int(next_act->get_tid());
 461         loc_inst_map_t * loc_inst_map = thrd_loc_inst_maps[thread_id]->back();
 462
 463         if (next_inst->is_read()) {
 464                 /* read + rmw */
 465                 if ( loc_inst_map->contains(loc) ) {
 466                         FuncInst * last_inst = loc_inst_map->get(loc);
 467                         struct half_pred_expr * expression = new half_pred_expr(EQUALITY, last_inst);
 468                         half_pred_expressions->push_back(expression);
 469                 } else if ( next_inst->is_single_location() ) {
 470                         loc_set_t * loc_may_equal = loc_may_equal_map->get(loc);
 471
 472                         if (loc_may_equal != NULL) {
 473                                 loc_set_iter * loc_it = loc_may_equal->iterator();
 474                                 while (loc_it->hasNext()) {
 475                                         void * neighbor = loc_it->next();
 476                                         if (loc_inst_map->contains(neighbor)) {
 477                                                 FuncInst * last_inst = loc_inst_map->get(neighbor);
 478
 479                                                 struct half_pred_expr * expression = new half_pred_expr(EQUALITY, last_inst);
 480                                                 half_pred_expressions->push_back(expression);
 481                                         }
 482                                 }
 483
 484                                 delete loc_it;
 485                         }
 486                 } else {
 487                         // next_inst is not single location
 488                         uint64_t read_val = next_act->get_reads_from_value();
 489
 490                         // only infer NULLITY predicate when it is actually NULL.
 491                         if ( (void*)read_val == NULL) {
 492                                 struct half_pred_expr * expression = new half_pred_expr(NULLITY, NULL);
 493                                 half_pred_expressions->push_back(expression);
 494                         }
 495                 }
 496         } else {
 497                 /* Pure writes */
 498                 // TODO: do anything here?
 499         }
 500 }
 501
 502 /* Able to generate complex predicates when there are multiple predciate expressions */
 503 void FuncNode::generate_predicates(Predicate * curr_pred, FuncInst * next_inst,
 504                                                                                                                                          SnapVector<struct half_pred_expr *> * half_pred_expressions)
 505 {
 506         if (half_pred_expressions->size() == 0) {
 507                 Predicate * new_pred = new Predicate(next_inst);
 508                 curr_pred->add_child(new_pred);
 509                 new_pred->set_parent(curr_pred);
 510
 511                 /* entry predicates and predicates containing pure write actions
 512                  * have no predicate expressions */
 513                 if ( curr_pred->is_entry_predicate() )
 514                         new_pred->add_predicate_expr(NOPREDICATE, NULL, true);
 515                 else if (next_inst->is_write()) {
 516                         /* next_inst->is_write() <==> pure writes */
 517                         new_pred->add_predicate_expr(NOPREDICATE, NULL, true);
 518                 }
 519
 520                 return;
 521         }
 522
 523         SnapVector<Predicate *> predicates;
 524
 525         struct half_pred_expr * half_expr = (*half_pred_expressions)[0];
 526         predicates.push_back(new Predicate(next_inst));
 527         predicates.push_back(new Predicate(next_inst));
 528
 529         predicates[0]->add_predicate_expr(half_expr->token, half_expr->func_inst, true);
 530         predicates[1]->add_predicate_expr(half_expr->token, half_expr->func_inst, false);
 531
 532         for (uint i = 1;i < half_pred_expressions->size();i++) {
 533                 half_expr = (*half_pred_expressions)[i];
 534
 535                 uint old_size = predicates.size();
 536                 for (uint j = 0;j < old_size;j++) {
 537                         Predicate * pred = predicates[j];
 538                         Predicate * new_pred = new Predicate(next_inst);
 539                         new_pred->copy_predicate_expr(pred);
 540
 541                         pred->add_predicate_expr(half_expr->token, half_expr->func_inst, true);
 542                         new_pred->add_predicate_expr(half_expr->token, half_expr->func_inst, false);
 543
 544                         predicates.push_back(new_pred);
 545                 }
 546         }
 547
 548         for (uint i = 0;i < predicates.size();i++) {
 549                 Predicate * pred= predicates[i];
 550                 curr_pred->add_child(pred);
 551                 pred->set_parent(curr_pred);
 552         }
 553
 554         /* Free memories allocated by infer_predicate */
 555         for (uint i = 0;i < half_pred_expressions->size();i++) {
 556                 struct half_pred_expr * tmp = (*half_pred_expressions)[i];
 557                 snapshot_free(tmp);
 558         }
 559 }
 560
 561 /* Amend predicates that contain no predicate expressions. Currenlty only amend with NULLITY predicates */
 562 bool FuncNode::amend_predicate_expr(Predicate * curr_pred, FuncInst * next_inst, ModelAction * next_act)
 563 {
 564         ModelVector<Predicate *> * children = curr_pred->get_children();
 565
 566         Predicate * unset_pred = NULL;
 567         for (uint i = 0;i < children->size();i++) {
 568                 Predicate * child = (*children)[i];
 569                 if (child->get_func_inst() == next_inst) {
 570                         unset_pred = child;
 571                         break;
 572                 }
 573         }
 574
 575         uint64_t read_val = next_act->get_reads_from_value();
 576
 577         // only generate NULLITY predicate when it is actually NULL.
 578         if ( !next_inst->is_single_location() && (void*)read_val == NULL ) {
 579                 Predicate * new_pred = new Predicate(next_inst);
 580
 581                 curr_pred->add_child(new_pred);
 582                 new_pred->set_parent(curr_pred);
 583
 584                 unset_pred->add_predicate_expr(NULLITY, NULL, false);
 585                 new_pred->add_predicate_expr(NULLITY, NULL, true);
 586
 587                 return true;
 588         }
 589
 590         return false;
 591 }
 592
 593 void FuncNode::add_to_val_loc_map(uint64_t val, void * loc)
 594 {
 595         loc_set_t * locations = val_loc_map->get(val);
 596
 597         if (locations == NULL) {
 598                 locations = new loc_set_t();
 599                 val_loc_map->put(val, locations);
 600         }
 601
 602         update_loc_may_equal_map(loc, locations);
 603         locations->add(loc);
 604         // values_may_read_from->add(val);
 605 }
 606
 607 void FuncNode::add_to_val_loc_map(value_set_t * values, void * loc)
 608 {
 609         if (values == NULL)
 610                 return;
 611
 612         value_set_iter * it = values->iterator();
 613         while (it->hasNext()) {
 614                 uint64_t val = it->next();
 615                 add_to_val_loc_map(val, loc);
 616         }
 617
 618         delete it;
 619 }
 620
 621 void FuncNode::update_loc_may_equal_map(void * new_loc, loc_set_t * old_locations)
 622 {
 623         if ( old_locations->contains(new_loc) )
 624                 return;
 625
 626         loc_set_t * neighbors = loc_may_equal_map->get(new_loc);
 627
 628         if (neighbors == NULL) {
 629                 neighbors = new loc_set_t();
 630                 loc_may_equal_map->put(new_loc, neighbors);
 631         }
 632
 633         loc_set_iter * loc_it = old_locations->iterator();
 634         while (loc_it->hasNext()) {
 635                 // new_loc: { old_locations, ... }
 636                 void * member = loc_it->next();
 637                 neighbors->add(member);
 638
 639                 // for each i in old_locations, i : { new_loc, ... }
 640                 loc_set_t * _neighbors = loc_may_equal_map->get(member);
 641                 if (_neighbors == NULL) {
 642                         _neighbors = new loc_set_t();
 643                         loc_may_equal_map->put(member, _neighbors);
 644                 }
 645                 _neighbors->add(new_loc);
 646         }
 647
 648         delete loc_it;
 649 }
 650
 651 void FuncNode::set_predicate_tree_position(thread_id_t tid, Predicate * pred)
 652 {
 653         int thread_id = id_to_int(tid);
 654         ModelVector<Predicate *> * stack = thrd_predicate_tree_position[thread_id];
 655         (*stack)[stack->size() - 1] = pred;
 656 }
 657
 658 /* @return The position of a thread in a predicate tree */
 659 Predicate * FuncNode::get_predicate_tree_position(thread_id_t tid)
 660 {
 661         int thread_id = id_to_int(tid);
 662         return thrd_predicate_tree_position[thread_id]->back();
 663 }
 664
 665 void FuncNode::add_predicate_to_trace(thread_id_t tid, Predicate * pred)
 666 {
 667         int thread_id = id_to_int(tid);
 668         thrd_predicate_trace[thread_id]->back()->push_back(pred);
 669 }
 670
 671 void FuncNode::init_marker(thread_id_t tid)
 672 {
 673         marker++;
 674
 675         int thread_id = id_to_int(tid);
 676         int old_size = thrd_markers.size();
 677
 678         if (old_size < thread_id + 1) {
 679                 thrd_markers.resize(thread_id + 1);
 680
 681                 for (int i = old_size; i < thread_id + 1; i++) {
 682                         thrd_markers[i] = new ModelVector<uint32_t>();
 683                         thrd_recursion_depth.push_back(-1);
 684                 }
 685         }
 686
 687         thrd_markers[thread_id]->push_back(marker);
 688         thrd_recursion_depth[thread_id]++;
 689 }
 690
 691 uint32_t FuncNode::get_marker(thread_id_t tid)
 692 {
 693         int thread_id = id_to_int(tid);
 694         return thrd_markers[thread_id]->back();
 695 }
 696
 697 int FuncNode::get_recursion_depth(thread_id_t tid)
 698 {
 699         return thrd_recursion_depth[id_to_int(tid)];
 700 }
 701
 702 /* Make sure elements of maps are initialized properly when threads enter functions */
 703 void FuncNode::init_local_maps(thread_id_t tid)
 704 {
 705         int thread_id = id_to_int(tid);
 706         int old_size = thrd_loc_inst_maps.size();
 707
 708         if (old_size < thread_id + 1) {
 709                 int new_size = thread_id + 1;
 710
 711                 thrd_loc_inst_maps.resize(new_size);
 712                 thrd_inst_id_maps.resize(new_size);
 713                 thrd_inst_pred_maps.resize(new_size);
 714
 715                 for (int i = old_size; i < new_size; i++) {
 716                         thrd_loc_inst_maps[i] = new ModelVector<loc_inst_map_t *>;
 717                         thrd_inst_id_maps[i] = new ModelVector<inst_id_map_t *>;
 718                         thrd_inst_pred_maps[i] = new ModelVector<inst_pred_map_t *>;
 719                 }
 720         }
 721
 722         ModelVector<loc_inst_map_t *> * map = thrd_loc_inst_maps[thread_id];
 723         int index = thrd_recursion_depth[thread_id];
 724
 725         // If there are recursive calls, push more hashtables into the vector.
 726         if (map->size() < (uint) index + 1) {
 727                 thrd_loc_inst_maps[thread_id]->push_back(new loc_inst_map_t(64));
 728                 thrd_inst_id_maps[thread_id]->push_back(new inst_id_map_t(64));
 729                 thrd_inst_pred_maps[thread_id]->push_back(new inst_pred_map_t(64));
 730         }
 731
 732         ASSERT(map->size() == (uint) index + 1);
 733 }
 734
 735 /* Reset elements of maps when threads exit functions */
 736 void FuncNode::reset_local_maps(thread_id_t tid)
 737 {
 738         int thread_id = id_to_int(tid);
 739         int index = thrd_recursion_depth[thread_id];
 740
 741         // When recursive call ends, keep only one hashtable in the vector
 742         if (index > 0) {
 743                 delete thrd_loc_inst_maps[thread_id]->back();
 744                 delete thrd_inst_id_maps[thread_id]->back();
 745                 delete thrd_inst_pred_maps[thread_id]->back();
 746
 747                 thrd_loc_inst_maps[thread_id]->pop_back();
 748                 thrd_inst_id_maps[thread_id]->pop_back();
 749                 thrd_inst_pred_maps[thread_id]->pop_back();
 750         } else {
 751                 thrd_loc_inst_maps[thread_id]->back()->reset();
 752                 thrd_inst_id_maps[thread_id]->back()->reset();
 753                 thrd_inst_pred_maps[thread_id]->back()->reset();
 754         }
 755 }
 756
 757 void FuncNode::init_predicate_tree_data_structure(thread_id_t tid)
 758 {
 759         int thread_id = id_to_int(tid);
 760         int old_size = thrd_predicate_tree_position.size();
 761
 762         if (old_size < thread_id + 1) {
 763                 thrd_predicate_tree_position.resize(thread_id + 1);
 764                 thrd_predicate_trace.resize(thread_id + 1);
 765
 766                 for (int i = old_size; i < thread_id + 1; i++) {
 767                         thrd_predicate_tree_position[i] = new ModelVector<Predicate *>();
 768                         thrd_predicate_trace[i] = new ModelVector<predicate_trace_t *>();
 769                 }
 770         }
 771
 772         thrd_predicate_tree_position[thread_id]->push_back(predicate_tree_entry);
 773         thrd_predicate_trace[thread_id]->push_back(new predicate_trace_t());
 774 }
 775
 776 void FuncNode::reset_predicate_tree_data_structure(thread_id_t tid)
 777 {
 778         int thread_id = id_to_int(tid);
 779         thrd_predicate_tree_position[thread_id]->pop_back();
 780
 781         // Free memories allocated in init_predicate_tree_data_structure
 782         predicate_trace_t * trace = thrd_predicate_trace[thread_id]->back();
 783         delete trace;
 784         thrd_predicate_trace[thread_id]->pop_back();
 785 }
 786
 787 /* Add FuncNodes that this node may follow */
 788 void FuncNode::add_out_edge(FuncNode * other)
 789 {
 790         if ( !edge_table.contains(other) ) {
 791                 edge_table.put(other, OUT_EDGE);
 792                 out_edges.push_back(other);
 793                 return;
 794         }
 795
 796         edge_type_t edge = edge_table.get(other);
 797         if (edge == IN_EDGE) {
 798                 edge_table.put(other, BI_EDGE);
 799                 out_edges.push_back(other);
 800         }
 801 }
 802
 803 /* Compute the distance between this FuncNode and the target node.
 804  * Return -1 if the target node is unreachable or the actual distance
 805  * is greater than max_step.
 806  */
 807 int FuncNode::compute_distance(FuncNode * target, int max_step)
 808 {
 809         if (target == NULL)
 810                 return -1;
 811         else if (target == this)
 812                 return 0;
 813
 814         SnapList<FuncNode *> queue;
 815         HashTable<FuncNode *, int, uintptr_t, 0> distances(128);
 816
 817         queue.push_back(this);
 818         distances.put(this, 0);
 819
 820         while (!queue.empty()) {
 821                 FuncNode * curr = queue.front();
 822                 queue.pop_front();
 823                 int dist = distances.get(curr);
 824
 825                 if (max_step <= dist)
 826                         return -1;
 827
 828                 ModelList<FuncNode *> * outEdges = curr->get_out_edges();
 829                 mllnode<FuncNode *> * it;
 830                 for (it = outEdges->begin();it != NULL;it = it->getNext()) {
 831                         FuncNode * out_node = it->getVal();
 832
 833                         /* This node has not been visited before */
 834                         if ( !distances.contains(out_node) ) {
 835                                 if (out_node == target)
 836                                         return dist + 1;
 837
 838                                 queue.push_back(out_node);
 839                                 distances.put(out_node, dist + 1);
 840                         }
 841                 }
 842         }
 843
 844         /* Target node is unreachable */
 845         return -1;
 846 }
 847
 848 void FuncNode::update_predicate_tree_weight(thread_id_t tid)
 849 {
 850         predicate_trace_t * trace = thrd_predicate_trace[id_to_int(tid)]->back();
 851
 852         // Update predicate weights based on prediate trace
 853         for (mllnode<Predicate *> * rit = trace->end(); rit != NULL; rit = rit->getPrev()) {
 854                 Predicate * node = rit->getVal();
 855                 ModelVector<Predicate *> * children = node->get_children();
 856
 857                 if (children->size() == 0) {
 858                         double weight = 100.0 / sqrt(node->get_expl_count() + node->get_fail_count() + 1);
 859                         node->set_weight(weight);
 860                 } else {
 861                         double weight_sum = 0.0;
 862                         for (uint i = 0;i < children->size();i++) {
 863                                 Predicate * child = (*children)[i];
 864                                 double weight = child->get_weight();
 865                                 weight_sum += weight;
 866                         }
 867
 868                         double average_weight = (double) weight_sum / (double) children->size();
 869                         double weight = average_weight * pow(0.9, node->get_depth());
 870                         node->set_weight(weight);
 871                 }
 872         }
 873 }
 874
 875 void FuncNode::print_predicate_tree()
 876 {
 877         model_print("digraph function_%s {\n", func_name);
 878         predicate_tree_entry->print_pred_subtree();
 879         predicate_tree_exit->print_predicate();
 880         model_print("}\n");     // end of graph
 881 }