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         func_id(0),
  15         func_name(NULL),
  16         history(history),
  17         inst_counter(1),
  18         marker(1),
  19         exit_count(0),
  20         thrd_markers(),
  21         thrd_recursion_depth(),
  22         func_inst_map(),
  23         inst_list(),
  24         entry_insts(),
  25         thrd_inst_pred_maps(),
  26         thrd_inst_id_maps(),
  27         thrd_loc_inst_maps(),
  28         likely_null_set(),
  29         thrd_predicate_tree_position(),
  30         thrd_predicate_trace(),
  31         edge_table(32),
  32         out_edges()
  33 {
  34         predicate_tree_entry = new Predicate(NULL, true);
  35         predicate_tree_entry->add_predicate_expr(NOPREDICATE, NULL, true);
  36
  37         predicate_tree_exit = new Predicate(NULL, false, true);
  38         predicate_tree_exit->set_depth(MAX_DEPTH);
  39
  40         /* Snapshot data structures below */
  41         read_locations = new loc_set_t();
  42         write_locations = new loc_set_t();
  43         val_loc_map = new HashTable<uint64_t, loc_set_t *, uint64_t, 0, snapshot_malloc, snapshot_calloc, snapshot_free, int64_hash>();
  44         loc_may_equal_map = new HashTable<void *, loc_set_t *, uintptr_t, 0>();
  45
  46         //values_may_read_from = new value_set_t();
  47 }
  48
  49 /* Reallocate snapshotted memories when new executions start */
  50 void FuncNode::set_new_exec_flag()
  51 {
  52         read_locations = new loc_set_t();
  53         write_locations = new loc_set_t();
  54         val_loc_map = new HashTable<uint64_t, loc_set_t *, uint64_t, 0, snapshot_malloc, snapshot_calloc, snapshot_free, int64_hash>();
  55         loc_may_equal_map = new HashTable<void *, loc_set_t *, uintptr_t, 0>();
  56
  57         //values_may_read_from = new value_set_t();
  58 }
  59
  60 /* Check whether FuncInst with the same type, position, and location
  61  * as act has been added to func_inst_map or not. If not, add it.
  62  */
  63 void FuncNode::add_inst(ModelAction *act)
  64 {
  65         ASSERT(act);
  66         const char * position = act->get_position();
  67
  68         /* THREAD* actions, ATOMIC_LOCK, ATOMIC_TRYLOCK, and ATOMIC_UNLOCK
  69          * actions are not tagged with their source line numbers
  70          */
  71         if (position == NULL)
  72                 return;
  73
  74         FuncInst * func_inst = func_inst_map.get(position);
  75
  76         /* This position has not been inserted into hashtable before */
  77         if (func_inst == NULL) {
  78                 func_inst = create_new_inst(act);
  79                 func_inst_map.put(position, func_inst);
  80                 return;
  81         }
  82
  83         /* Volatile variables that use ++ or -- syntax may result in read and write actions with the same position */
  84         if (func_inst->get_type() != act->get_type()) {
  85                 FuncInst * collision_inst = func_inst->search_in_collision(act);
  86
  87                 if (collision_inst == NULL) {
  88                         collision_inst = create_new_inst(act);
  89                         func_inst->add_to_collision(collision_inst);
  90                         return;
  91                 } else {
  92                         func_inst = collision_inst;
  93                 }
  94         }
  95
  96         ASSERT(func_inst->get_type() == act->get_type());
  97         int curr_execution_number = model->get_execution_number();
  98
  99         /* Reset locations when new executions start */
 100         if (func_inst->get_execution_number() != curr_execution_number) {
 101                 func_inst->set_location(act->get_location());
 102                 func_inst->set_execution_number(curr_execution_number);
 103         }
 104
 105         /* Mark the memory location of such inst as not unique */
 106         if (func_inst->get_location() != act->get_location())
 107                 func_inst->not_single_location();
 108 }
 109
 110 FuncInst * FuncNode::create_new_inst(ModelAction * act)
 111 {
 112         FuncInst * func_inst = new FuncInst(act, this);
 113         int exec_num = model->get_execution_number();
 114         func_inst->set_execution_number(exec_num);
 115
 116         inst_list.push_back(func_inst);
 117
 118         return func_inst;
 119 }
 120
 121
 122 /* Get the FuncInst with the same type, position, and location
 123  * as act
 124  *
 125  * @return FuncInst with the same type, position, and location as act */
 126 FuncInst * FuncNode::get_inst(ModelAction *act)
 127 {
 128         ASSERT(act);
 129         const char * position = act->get_position();
 130
 131         /* THREAD* actions, ATOMIC_LOCK, ATOMIC_TRYLOCK, and ATOMIC_UNLOCK
 132          * actions are not tagged with their source line numbers
 133          */
 134         if (position == NULL)
 135                 return NULL;
 136
 137         FuncInst * inst = func_inst_map.get(position);
 138         if (inst == NULL)
 139                 return NULL;
 140
 141         action_type inst_type = inst->get_type();
 142         action_type act_type = act->get_type();
 143
 144         if (inst_type == act_type) {
 145                 return inst;
 146         }
 147         /* RMWRCAS actions are converted to RMW or READ actions */
 148         else if (inst_type == ATOMIC_RMWRCAS &&
 149                                          (act_type == ATOMIC_RMW || act_type == ATOMIC_READ)) {
 150                 return inst;
 151         }
 152         /* Return the FuncInst in the collision list */
 153         else {
 154                 return inst->search_in_collision(act);
 155         }
 156 }
 157
 158 void FuncNode::add_entry_inst(FuncInst * inst)
 159 {
 160         if (inst == NULL)
 161                 return;
 162
 163         mllnode<FuncInst *> * it;
 164         for (it = entry_insts.begin();it != NULL;it = it->getNext()) {
 165                 if (inst == it->getVal())
 166                         return;
 167         }
 168
 169         entry_insts.push_back(inst);
 170 }
 171
 172 void FuncNode::function_entry_handler(thread_id_t tid)
 173 {
 174         init_marker(tid);
 175         init_local_maps(tid);
 176         init_predicate_tree_data_structure(tid);
 177 }
 178
 179 void FuncNode::function_exit_handler(thread_id_t tid)
 180 {
 181         int thread_id = id_to_int(tid);
 182
 183         reset_local_maps(tid);
 184
 185         thrd_recursion_depth[thread_id]--;
 186         thrd_markers[thread_id]->pop_back();
 187
 188         Predicate * exit_pred = get_predicate_tree_position(tid);
 189         if (exit_pred->get_exit() == NULL) {
 190                 // Exit predicate is unset yet
 191                 exit_pred->set_exit(predicate_tree_exit);
 192         }
 193
 194         update_predicate_tree_weight(tid);
 195         reset_predicate_tree_data_structure(tid);
 196
 197         exit_count++;
 198         //model_print("exit count: %d\n", exit_count);
 199
 200 //      print_predicate_tree();
 201 }
 202
 203 /**
 204  * @brief Convert ModelAdtion list to FuncInst list
 205  * @param act_list A list of ModelActions
 206  */
 207 void FuncNode::update_tree(ModelAction * act)
 208 {
 209         bool should_process = act->is_read() || act->is_write();
 210         if (!should_process)
 211                 return;
 212
 213         HashTable<void *, value_set_t *, uintptr_t, 0> * write_history = history->getWriteHistory();
 214
 215         /* build inst_list from act_list for later processing */
 216 //      func_inst_list_t inst_list;
 217
 218         FuncInst * func_inst = get_inst(act);
 219         void * loc = act->get_location();
 220
 221         if (func_inst == NULL)
 222                 return;
 223
 224 //      inst_list.push_back(func_inst);
 225
 226         if (act->is_write()) {
 227                 if (!write_locations->contains(loc)) {
 228                         write_locations->add(loc);
 229                         history->update_loc_wr_func_nodes_map(loc, this);
 230                 }
 231         }
 232
 233         if (act->is_read()) {
 234                 /* If func_inst may only read_from a single location, then:
 235                  *
 236                  * The first time an action reads from some location,
 237                  * import all the values that have been written to this
 238                  * location from ModelHistory and notify ModelHistory
 239                  * that this FuncNode may read from this location.
 240                  */
 241                 if (!read_locations->contains(loc) && func_inst->is_single_location()) {
 242                         read_locations->add(loc);
 243                         value_set_t * write_values = write_history->get(loc);
 244                         add_to_val_loc_map(write_values, loc);
 245                         history->update_loc_rd_func_nodes_map(loc, this);
 246                 }
 247
 248                 // Keep a has-been-zero-set record
 249                 if ( likely_reads_from_null(act) )
 250                         likely_null_set.put(func_inst, true);
 251         }
 252
 253 //      update_inst_tree(&inst_list); TODO
 254
 255         update_predicate_tree(act);
 256 }
 257
 258 /**
 259  * @brief Link FuncInsts in inst_list  - add one FuncInst to another's predecessors and successors
 260  * @param inst_list A list of FuncInsts
 261  */
 262 void FuncNode::update_inst_tree(func_inst_list_t * inst_list)
 263 {
 264         if (inst_list == NULL)
 265                 return;
 266         else if (inst_list->size() == 0)
 267                 return;
 268
 269         /* start linking */
 270         sllnode<FuncInst *>* it = inst_list->begin();
 271         sllnode<FuncInst *>* prev;
 272
 273         /* add the first instruction to the list of entry insts */
 274         FuncInst * entry_inst = it->getVal();
 275         add_entry_inst(entry_inst);
 276
 277         it = it->getNext();
 278         while (it != NULL) {
 279                 prev = it->getPrev();
 280
 281                 FuncInst * prev_inst = prev->getVal();
 282                 FuncInst * curr_inst = it->getVal();
 283
 284                 prev_inst->add_succ(curr_inst);
 285                 curr_inst->add_pred(prev_inst);
 286
 287                 it = it->getNext();
 288         }
 289 }
 290
 291 void FuncNode::update_predicate_tree(ModelAction * next_act)
 292 {
 293         thread_id_t tid = next_act->get_tid();
 294         int thread_id = id_to_int(tid);
 295         uint32_t this_marker = thrd_markers[thread_id]->back();
 296         int recursion_depth = thrd_recursion_depth[thread_id];
 297
 298         loc_inst_map_t * loc_inst_map = thrd_loc_inst_maps[thread_id]->back();
 299         inst_pred_map_t * inst_pred_map = thrd_inst_pred_maps[thread_id]->back();
 300         inst_id_map_t * inst_id_map = thrd_inst_id_maps[thread_id]->back();
 301
 302         Predicate * curr_pred = get_predicate_tree_position(tid);
 303         NewFuzzer * fuzzer = (NewFuzzer *)model->get_execution()->getFuzzer();
 304         Predicate * selected_branch = fuzzer->get_selected_child_branch(tid);
 305
 306         bool amended;
 307         while (true) {
 308                 FuncInst * next_inst = get_inst(next_act);
 309
 310                 Predicate * unset_predicate = NULL;
 311                 bool branch_found = follow_branch(&curr_pred, next_inst, next_act, &unset_predicate);
 312
 313                 // A branch with unset predicate expression is detected
 314                 if (!branch_found && unset_predicate != NULL) {
 315                         amended = amend_predicate_expr(curr_pred, next_inst, next_act);
 316                         if (amended)
 317                                 continue;
 318                         else {
 319                                 curr_pred = unset_predicate;
 320                                 branch_found = true;
 321                         }
 322                 }
 323
 324                 // Detect loops
 325                 if (!branch_found && inst_id_map->contains(next_inst)) {
 326                         FuncInst * curr_inst = curr_pred->get_func_inst();
 327                         uint32_t curr_id = inst_id_map->get(curr_inst);
 328                         uint32_t next_id = inst_id_map->get(next_inst);
 329
 330                         if (curr_id >= next_id) {
 331                                 Predicate * old_pred = inst_pred_map->get(next_inst);
 332                                 Predicate * back_pred = old_pred->get_parent();
 333
 334                                 // Add to the set of backedges
 335                                 curr_pred->add_backedge(back_pred);
 336                                 curr_pred = back_pred;
 337
 338                                 continue;
 339                         }
 340                 }
 341
 342                 // Generate new branches
 343                 if (!branch_found) {
 344                         SnapVector<struct half_pred_expr *> half_pred_expressions;
 345                         infer_predicates(next_inst, next_act, &half_pred_expressions);
 346                         generate_predicates(curr_pred, next_inst, &half_pred_expressions);
 347                         continue;
 348                 }
 349
 350                 if (next_act->is_write()) {
 351                         curr_pred->set_write(true);
 352                 }
 353
 354                 if (next_act->is_read()) {
 355                         /* Only need to store the locations of read actions */
 356                         loc_inst_map->put(next_act->get_location(), next_inst);
 357                 }
 358
 359                 inst_pred_map->put(next_inst, curr_pred);
 360                 set_predicate_tree_position(tid, curr_pred);
 361
 362                 if (!inst_id_map->contains(next_inst))
 363                         inst_id_map->put(next_inst, inst_counter++);
 364
 365                 curr_pred->incr_expl_count();
 366                 add_predicate_to_trace(tid, curr_pred);
 367                 if (next_act->is_read())
 368                         next_inst->set_associated_read(tid, recursion_depth, this_marker, next_act->get_reads_from_value());
 369
 370                 break;
 371         }
 372
 373         // A check
 374         if (next_act->is_read()) {
 375 //              if (selected_branch != NULL && !amended)
 376 //                      ASSERT(selected_branch == curr_pred);
 377         }
 378 }
 379
 380 /* Given curr_pred and next_inst, find the branch following curr_pred that
 381  * contains next_inst and the correct predicate.
 382  * @return true if branch found, false otherwise.
 383  */
 384 bool FuncNode::follow_branch(Predicate ** curr_pred, FuncInst * next_inst,
 385                                                                                                                  ModelAction * next_act, Predicate ** unset_predicate)
 386 {
 387         /* Check if a branch with func_inst and corresponding predicate exists */
 388         bool branch_found = false;
 389         thread_id_t tid = next_act->get_tid();
 390
 391         ModelVector<Predicate *> * branches = (*curr_pred)->get_children();
 392         for (uint i = 0;i < branches->size();i++) {
 393                 Predicate * branch = (*branches)[i];
 394                 if (branch->get_func_inst() != next_inst)
 395                         continue;
 396
 397                 /* Check against predicate expressions */
 398                 bool predicate_correct = true;
 399                 PredExprSet * pred_expressions = branch->get_pred_expressions();
 400
 401                 /* Only read and rmw actions my have unset predicate expressions */
 402                 if (pred_expressions->getSize() == 0) {
 403                         predicate_correct = false;
 404
 405                         if (*unset_predicate == NULL)
 406                                 *unset_predicate = branch;
 407                         else
 408                                 ASSERT(false);
 409
 410                         continue;
 411                 }
 412
 413                 PredExprSetIter * pred_expr_it = pred_expressions->iterator();
 414                 while (pred_expr_it->hasNext()) {
 415                         pred_expr * pred_expression = pred_expr_it->next();
 416                         uint64_t last_read, next_read;
 417                         bool equality;
 418
 419                         switch(pred_expression->token) {
 420                         case NOPREDICATE:
 421                                 predicate_correct = true;
 422                                 break;
 423                         case EQUALITY:
 424                                 FuncInst * to_be_compared;
 425                                 to_be_compared = pred_expression->func_inst;
 426
 427                                 last_read = get_associated_read(tid, to_be_compared);
 428                                 if (last_read == VALUE_NONE)
 429                                         predicate_correct = false;
 430                                 // ASSERT(last_read != VALUE_NONE);
 431
 432                                 next_read = next_act->get_reads_from_value();
 433                                 equality = (last_read == next_read);
 434                                 if (equality != pred_expression->value)
 435                                         predicate_correct = false;
 436
 437                                 break;
 438                         case NULLITY:
 439                                 // TODO: implement likely to be null
 440                                 equality = likely_reads_from_null(next_act);
 441                                 if (equality != pred_expression->value)
 442                                         predicate_correct = false;
 443                                 break;
 444                         default:
 445                                 predicate_correct = false;
 446                                 model_print("unkown predicate token\n");
 447                                 break;
 448                         }
 449                 }
 450
 451                 delete pred_expr_it;
 452
 453                 if (predicate_correct) {
 454                         *curr_pred = branch;
 455                         branch_found = true;
 456                         break;
 457                 }
 458         }
 459
 460         return branch_found;
 461 }
 462
 463 /* Infer predicate expressions, which are generated in FuncNode::generate_predicates */
 464 void FuncNode::infer_predicates(FuncInst * next_inst, ModelAction * next_act,
 465                                                                                                                                 SnapVector<struct half_pred_expr *> * half_pred_expressions)
 466 {
 467         void * loc = next_act->get_location();
 468         int thread_id = id_to_int(next_act->get_tid());
 469         loc_inst_map_t * loc_inst_map = thrd_loc_inst_maps[thread_id]->back();
 470
 471         if (next_inst->is_read()) {
 472                 /* read + rmw */
 473                 if ( loc_inst_map->contains(loc) ) {
 474                         FuncInst * last_inst = loc_inst_map->get(loc);
 475                         struct half_pred_expr * expression = new half_pred_expr(EQUALITY, last_inst);
 476                         half_pred_expressions->push_back(expression);
 477                 } else if ( next_inst->is_single_location() ) {
 478                         loc_set_t * loc_may_equal = loc_may_equal_map->get(loc);
 479
 480                         if (loc_may_equal != NULL) {
 481                                 loc_set_iter * loc_it = loc_may_equal->iterator();
 482                                 while (loc_it->hasNext()) {
 483                                         void * neighbor = loc_it->next();
 484                                         if (loc_inst_map->contains(neighbor)) {
 485                                                 FuncInst * last_inst = loc_inst_map->get(neighbor);
 486
 487                                                 struct half_pred_expr * expression = new half_pred_expr(EQUALITY, last_inst);
 488                                                 half_pred_expressions->push_back(expression);
 489                                         }
 490                                 }
 491
 492                                 delete loc_it;
 493                         }
 494                 }
 495
 496                 // next_inst is not single location and has been null
 497                 bool likely_null = likely_null_set.contains(next_inst);
 498                 if ( !next_inst->is_single_location() && likely_null ) {
 499                         struct half_pred_expr * expression = new half_pred_expr(NULLITY, NULL);
 500                         half_pred_expressions->push_back(expression);
 501                 }
 502         } else {
 503                 /* Pure writes */
 504                 // TODO: do anything here?
 505         }
 506 }
 507
 508 /* Able to generate complex predicates when there are multiple predciate expressions */
 509 void FuncNode::generate_predicates(Predicate * curr_pred, FuncInst * next_inst,
 510                                                                                                                                          SnapVector<struct half_pred_expr *> * half_pred_expressions)
 511 {
 512         if (half_pred_expressions->size() == 0) {
 513                 Predicate * new_pred = new Predicate(next_inst);
 514                 curr_pred->add_child(new_pred);
 515                 new_pred->set_parent(curr_pred);
 516
 517                 /* entry predicates and predicates containing pure write actions
 518                  * have no predicate expressions */
 519                 if ( curr_pred->is_entry_predicate() )
 520                         new_pred->add_predicate_expr(NOPREDICATE, NULL, true);
 521                 else if (next_inst->is_write()) {
 522                         /* next_inst->is_write() <==> pure writes */
 523                         new_pred->add_predicate_expr(NOPREDICATE, NULL, true);
 524                 }
 525
 526                 return;
 527         }
 528
 529         SnapVector<Predicate *> predicates;
 530
 531         struct half_pred_expr * half_expr = (*half_pred_expressions)[0];
 532         predicates.push_back(new Predicate(next_inst));
 533         predicates.push_back(new Predicate(next_inst));
 534
 535         predicates[0]->add_predicate_expr(half_expr->token, half_expr->func_inst, true);
 536         predicates[1]->add_predicate_expr(half_expr->token, half_expr->func_inst, false);
 537
 538         for (uint i = 1;i < half_pred_expressions->size();i++) {
 539                 half_expr = (*half_pred_expressions)[i];
 540
 541                 uint old_size = predicates.size();
 542                 for (uint j = 0;j < old_size;j++) {
 543                         Predicate * pred = predicates[j];
 544                         Predicate * new_pred = new Predicate(next_inst);
 545                         new_pred->copy_predicate_expr(pred);
 546
 547                         pred->add_predicate_expr(half_expr->token, half_expr->func_inst, true);
 548                         new_pred->add_predicate_expr(half_expr->token, half_expr->func_inst, false);
 549
 550                         predicates.push_back(new_pred);
 551                 }
 552         }
 553
 554         for (uint i = 0;i < predicates.size();i++) {
 555                 Predicate * pred= predicates[i];
 556                 curr_pred->add_child(pred);
 557                 pred->set_parent(curr_pred);
 558         }
 559
 560         /* Free memories allocated by infer_predicate */
 561         for (uint i = 0;i < half_pred_expressions->size();i++) {
 562                 struct half_pred_expr * tmp = (*half_pred_expressions)[i];
 563                 snapshot_free(tmp);
 564         }
 565 }
 566
 567 /* Amend predicates that contain no predicate expressions. Currenlty only amend with NULLITY predicates */
 568 bool FuncNode::amend_predicate_expr(Predicate * curr_pred, FuncInst * next_inst, ModelAction * next_act)
 569 {
 570         ModelVector<Predicate *> * children = curr_pred->get_children();
 571
 572         Predicate * unset_pred = NULL;
 573         for (uint i = 0;i < children->size();i++) {
 574                 Predicate * child = (*children)[i];
 575                 if (child->get_func_inst() == next_inst) {
 576                         unset_pred = child;
 577                         break;
 578                 }
 579         }
 580
 581         bool likely_null = likely_null_set.contains(next_inst);
 582
 583         // only generate NULLITY predicate when it is actually NULL.
 584         if ( !next_inst->is_single_location() && likely_null ) {
 585                 Predicate * new_pred = new Predicate(next_inst);
 586
 587                 curr_pred->add_child(new_pred);
 588                 new_pred->set_parent(curr_pred);
 589
 590                 unset_pred->add_predicate_expr(NULLITY, NULL, false);
 591                 new_pred->add_predicate_expr(NULLITY, NULL, true);
 592
 593                 return true;
 594         }
 595
 596         return false;
 597 }
 598
 599 void FuncNode::add_to_val_loc_map(uint64_t val, void * loc)
 600 {
 601         loc_set_t * locations = val_loc_map->get(val);
 602
 603         if (locations == NULL) {
 604                 locations = new loc_set_t();
 605                 val_loc_map->put(val, locations);
 606         }
 607
 608         update_loc_may_equal_map(loc, locations);
 609         locations->add(loc);
 610         // values_may_read_from->add(val);
 611 }
 612
 613 void FuncNode::add_to_val_loc_map(value_set_t * values, void * loc)
 614 {
 615         if (values == NULL)
 616                 return;
 617
 618         value_set_iter * it = values->iterator();
 619         while (it->hasNext()) {
 620                 uint64_t val = it->next();
 621                 add_to_val_loc_map(val, loc);
 622         }
 623
 624         delete it;
 625 }
 626
 627 void FuncNode::update_loc_may_equal_map(void * new_loc, loc_set_t * old_locations)
 628 {
 629         if ( old_locations->contains(new_loc) )
 630                 return;
 631
 632         loc_set_t * neighbors = loc_may_equal_map->get(new_loc);
 633
 634         if (neighbors == NULL) {
 635                 neighbors = new loc_set_t();
 636                 loc_may_equal_map->put(new_loc, neighbors);
 637         }
 638
 639         loc_set_iter * loc_it = old_locations->iterator();
 640         while (loc_it->hasNext()) {
 641                 // new_loc: { old_locations, ... }
 642                 void * member = loc_it->next();
 643                 neighbors->add(member);
 644
 645                 // for each i in old_locations, i : { new_loc, ... }
 646                 loc_set_t * _neighbors = loc_may_equal_map->get(member);
 647                 if (_neighbors == NULL) {
 648                         _neighbors = new loc_set_t();
 649                         loc_may_equal_map->put(member, _neighbors);
 650                 }
 651                 _neighbors->add(new_loc);
 652         }
 653
 654         delete loc_it;
 655 }
 656
 657 bool FuncNode::likely_reads_from_null(ModelAction * read)
 658 {
 659         uint64_t read_val = read->get_reads_from_value();
 660         if ( (void *)(read_val && 0xffffffff) == NULL )
 661                 return true;
 662
 663         return false;
 664 }
 665
 666 void FuncNode::set_predicate_tree_position(thread_id_t tid, Predicate * pred)
 667 {
 668         int thread_id = id_to_int(tid);
 669         ModelVector<Predicate *> * stack = thrd_predicate_tree_position[thread_id];
 670         (*stack)[stack->size() - 1] = pred;
 671 }
 672
 673 /* @return The position of a thread in a predicate tree */
 674 Predicate * FuncNode::get_predicate_tree_position(thread_id_t tid)
 675 {
 676         int thread_id = id_to_int(tid);
 677         return thrd_predicate_tree_position[thread_id]->back();
 678 }
 679
 680 void FuncNode::add_predicate_to_trace(thread_id_t tid, Predicate * pred)
 681 {
 682         int thread_id = id_to_int(tid);
 683         thrd_predicate_trace[thread_id]->back()->push_back(pred);
 684 }
 685
 686 void FuncNode::init_marker(thread_id_t tid)
 687 {
 688         marker++;
 689
 690         int thread_id = id_to_int(tid);
 691         int old_size = thrd_markers.size();
 692
 693         if (old_size < thread_id + 1) {
 694                 thrd_markers.resize(thread_id + 1);
 695
 696                 for (int i = old_size; i < thread_id + 1; i++) {
 697                         thrd_markers[i] = new ModelVector<uint32_t>();
 698                         thrd_recursion_depth.push_back(-1);
 699                 }
 700         }
 701
 702         thrd_markers[thread_id]->push_back(marker);
 703         thrd_recursion_depth[thread_id]++;
 704 }
 705
 706 uint64_t FuncNode::get_associated_read(thread_id_t tid, FuncInst * inst)
 707 {
 708         int thread_id = id_to_int(tid);
 709         int recursion_depth = thrd_recursion_depth[thread_id];
 710         uint marker = thrd_markers[thread_id]->back();
 711
 712         return inst->get_associated_read(tid, recursion_depth, marker);
 713 }
 714
 715 /* Make sure elements of maps are initialized properly when threads enter functions */
 716 void FuncNode::init_local_maps(thread_id_t tid)
 717 {
 718         int thread_id = id_to_int(tid);
 719         int old_size = thrd_loc_inst_maps.size();
 720
 721         if (old_size < thread_id + 1) {
 722                 int new_size = thread_id + 1;
 723
 724                 thrd_loc_inst_maps.resize(new_size);
 725                 thrd_inst_id_maps.resize(new_size);
 726                 thrd_inst_pred_maps.resize(new_size);
 727
 728                 for (int i = old_size; i < new_size; i++) {
 729                         thrd_loc_inst_maps[i] = new ModelVector<loc_inst_map_t *>;
 730                         thrd_inst_id_maps[i] = new ModelVector<inst_id_map_t *>;
 731                         thrd_inst_pred_maps[i] = new ModelVector<inst_pred_map_t *>;
 732                 }
 733         }
 734
 735         ModelVector<loc_inst_map_t *> * map = thrd_loc_inst_maps[thread_id];
 736         int index = thrd_recursion_depth[thread_id];
 737
 738         // If there are recursive calls, push more hashtables into the vector.
 739         if (map->size() < (uint) index + 1) {
 740                 thrd_loc_inst_maps[thread_id]->push_back(new loc_inst_map_t(64));
 741                 thrd_inst_id_maps[thread_id]->push_back(new inst_id_map_t(64));
 742                 thrd_inst_pred_maps[thread_id]->push_back(new inst_pred_map_t(64));
 743         }
 744
 745         ASSERT(map->size() == (uint) index + 1);
 746 }
 747
 748 /* Reset elements of maps when threads exit functions */
 749 void FuncNode::reset_local_maps(thread_id_t tid)
 750 {
 751         int thread_id = id_to_int(tid);
 752         int index = thrd_recursion_depth[thread_id];
 753
 754         // When recursive call ends, keep only one hashtable in the vector
 755         if (index > 0) {
 756                 delete thrd_loc_inst_maps[thread_id]->back();
 757                 delete thrd_inst_id_maps[thread_id]->back();
 758                 delete thrd_inst_pred_maps[thread_id]->back();
 759
 760                 thrd_loc_inst_maps[thread_id]->pop_back();
 761                 thrd_inst_id_maps[thread_id]->pop_back();
 762                 thrd_inst_pred_maps[thread_id]->pop_back();
 763         } else {
 764                 thrd_loc_inst_maps[thread_id]->back()->reset();
 765                 thrd_inst_id_maps[thread_id]->back()->reset();
 766                 thrd_inst_pred_maps[thread_id]->back()->reset();
 767         }
 768 }
 769
 770 void FuncNode::init_predicate_tree_data_structure(thread_id_t tid)
 771 {
 772         int thread_id = id_to_int(tid);
 773         int old_size = thrd_predicate_tree_position.size();
 774
 775         if (old_size < thread_id + 1) {
 776                 thrd_predicate_tree_position.resize(thread_id + 1);
 777                 thrd_predicate_trace.resize(thread_id + 1);
 778
 779                 for (int i = old_size; i < thread_id + 1; i++) {
 780                         thrd_predicate_tree_position[i] = new ModelVector<Predicate *>();
 781                         thrd_predicate_trace[i] = new ModelVector<predicate_trace_t *>();
 782                 }
 783         }
 784
 785         thrd_predicate_tree_position[thread_id]->push_back(predicate_tree_entry);
 786         thrd_predicate_trace[thread_id]->push_back(new predicate_trace_t());
 787 }
 788
 789 void FuncNode::reset_predicate_tree_data_structure(thread_id_t tid)
 790 {
 791         int thread_id = id_to_int(tid);
 792         thrd_predicate_tree_position[thread_id]->pop_back();
 793
 794         // Free memories allocated in init_predicate_tree_data_structure
 795         delete thrd_predicate_trace[thread_id]->back();
 796         thrd_predicate_trace[thread_id]->pop_back();
 797 }
 798
 799 /* Add FuncNodes that this node may follow */
 800 void FuncNode::add_out_edge(FuncNode * other)
 801 {
 802         if ( !edge_table.contains(other) ) {
 803                 edge_table.put(other, OUT_EDGE);
 804                 out_edges.push_back(other);
 805                 return;
 806         }
 807
 808         edge_type_t edge = edge_table.get(other);
 809         if (edge == IN_EDGE) {
 810                 edge_table.put(other, BI_EDGE);
 811                 out_edges.push_back(other);
 812         }
 813 }
 814
 815 /* Compute the distance between this FuncNode and the target node.
 816  * Return -1 if the target node is unreachable or the actual distance
 817  * is greater than max_step.
 818  */
 819 int FuncNode::compute_distance(FuncNode * target, int max_step)
 820 {
 821         if (target == NULL)
 822                 return -1;
 823         else if (target == this)
 824                 return 0;
 825
 826         // Be careful with memory
 827         SnapList<FuncNode *> queue;
 828         HashTable<FuncNode *, int, uintptr_t, 0> distances(128);
 829
 830         queue.push_back(this);
 831         distances.put(this, 0);
 832
 833         while (!queue.empty()) {
 834                 FuncNode * curr = queue.front();
 835                 queue.pop_front();
 836                 int dist = distances.get(curr);
 837
 838                 if (max_step <= dist)
 839                         return -1;
 840
 841                 ModelList<FuncNode *> * outEdges = curr->get_out_edges();
 842                 mllnode<FuncNode *> * it;
 843                 for (it = outEdges->begin();it != NULL;it = it->getNext()) {
 844                         FuncNode * out_node = it->getVal();
 845
 846                         /* This node has not been visited before */
 847                         if ( !distances.contains(out_node) ) {
 848                                 if (out_node == target)
 849                                         return dist + 1;
 850
 851                                 queue.push_back(out_node);
 852                                 distances.put(out_node, dist + 1);
 853                         }
 854                 }
 855         }
 856
 857         /* Target node is unreachable */
 858         return -1;
 859 }
 860
 861 void FuncNode::update_predicate_tree_weight(thread_id_t tid)
 862 {
 863         predicate_trace_t * trace = thrd_predicate_trace[id_to_int(tid)]->back();
 864
 865         // Update predicate weights based on prediate trace
 866         for (int i = trace->size() - 1; i >= 0; i--) {
 867                 Predicate * node = (*trace)[i];
 868                 ModelVector<Predicate *> * children = node->get_children();
 869
 870                 if (children->size() == 0) {
 871                         double weight = 100.0 / sqrt(node->get_expl_count() + node->get_fail_count() + 1);
 872                         node->set_weight(weight);
 873                 } else {
 874                         double weight_sum = 0.0;
 875                         for (uint i = 0;i < children->size();i++) {
 876                                 Predicate * child = (*children)[i];
 877                                 double weight = child->get_weight();
 878                                 weight_sum += weight;
 879                         }
 880
 881                         double average_weight = (double) weight_sum / (double) children->size();
 882                         double weight = average_weight * pow(0.9, node->get_depth());
 883                         node->set_weight(weight);
 884                 }
 885         }
 886 }
 887
 888 void FuncNode::print_predicate_tree()
 889 {
 890         model_print("digraph function_%s {\n", func_name);
 891         predicate_tree_entry->print_pred_subtree();
 892         predicate_tree_exit->print_predicate();
 893         model_print("}\n");     // end of graph
 894 }