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 <cmath>
  10
  11 FuncNode::FuncNode(ModelHistory * history) :
  12         history(history),
  13         exit_count(0),
  14         marker(1),
  15         func_inst_map(),
  16         inst_list(),
  17         entry_insts(),
  18         inst_pred_map(128),
  19         inst_id_map(128),
  20         loc_act_map(128),
  21         predicate_tree_position(),
  22         predicate_leaves(),
  23         leaves_tmp_storage(),
  24         weight_debug_vec(),
  25         failed_predicates(),
  26         edge_table(32),
  27         out_edges()
  28 {
  29         predicate_tree_entry = new Predicate(NULL, true);
  30         predicate_tree_entry->add_predicate_expr(NOPREDICATE, NULL, true);
  31
  32         predicate_tree_exit = new Predicate(NULL, false, true);
  33         predicate_tree_exit->set_depth(MAX_DEPTH);
  34
  35         /* Snapshot data structures below */
  36         action_list_buffer = new SnapList<action_list_t *>();
  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         action_list_buffer = new SnapList<action_list_t *>();
  49         read_locations = new loc_set_t();
  50         write_locations = new loc_set_t();
  51         val_loc_map = new HashTable<uint64_t, loc_set_t *, uint64_t, 0, snapshot_malloc, snapshot_calloc, snapshot_free, int64_hash>();
  52         loc_may_equal_map = new HashTable<void *, loc_set_t *, uintptr_t, 0>();
  53
  54         //values_may_read_from = new value_set_t();
  55 }
  56
  57 /* Check whether FuncInst with the same type, position, and location
  58  * as act has been added to func_inst_map or not. If not, add it.
  59  */
  60 void FuncNode::add_inst(ModelAction *act)
  61 {
  62         ASSERT(act);
  63         const char * position = act->get_position();
  64
  65         /* THREAD* actions, ATOMIC_LOCK, ATOMIC_TRYLOCK, and ATOMIC_UNLOCK
  66          * actions are not tagged with their source line numbers
  67          */
  68         if (position == NULL)
  69                 return;
  70
  71         FuncInst * func_inst = func_inst_map.get(position);
  72
  73         /* This position has not been inserted into hashtable before */
  74         if (func_inst == NULL) {
  75                 func_inst = create_new_inst(act);
  76                 func_inst_map.put(position, func_inst);
  77                 return;
  78         }
  79
  80         /* Volatile variables that use ++ or -- syntax may result in read and write actions with the same position */
  81         if (func_inst->get_type() != act->get_type()) {
  82                 FuncInst * collision_inst = func_inst->search_in_collision(act);
  83
  84                 if (collision_inst == NULL) {
  85                         collision_inst = create_new_inst(act);
  86                         func_inst->add_to_collision(collision_inst);
  87                         return;
  88                 } else {
  89                         func_inst = collision_inst;
  90                 }
  91         }
  92
  93         ASSERT(func_inst->get_type() == act->get_type());
  94         int curr_execution_number = model->get_execution_number();
  95
  96         /* Reset locations when new executions start */
  97         if (func_inst->get_execution_number() != curr_execution_number) {
  98                 func_inst->set_location(act->get_location());
  99                 func_inst->set_execution_number(curr_execution_number);
 100         }
 101
 102         /* Mark the memory location of such inst as not unique */
 103         if (func_inst->get_location() != act->get_location())
 104                 func_inst->not_single_location();
 105 }
 106
 107 FuncInst * FuncNode::create_new_inst(ModelAction * act)
 108 {
 109         FuncInst * func_inst = new FuncInst(act, this);
 110         int exec_num = model->get_execution_number();
 111         func_inst->set_execution_number(exec_num);
 112
 113         inst_list.push_back(func_inst);
 114
 115         return func_inst;
 116 }
 117
 118
 119 /* Get the FuncInst with the same type, position, and location
 120  * as act
 121  *
 122  * @return FuncInst with the same type, position, and location as act */
 123 FuncInst * FuncNode::get_inst(ModelAction *act)
 124 {
 125         ASSERT(act);
 126         const char * position = act->get_position();
 127
 128         /* THREAD* actions, ATOMIC_LOCK, ATOMIC_TRYLOCK, and ATOMIC_UNLOCK
 129          * actions are not tagged with their source line numbers
 130          */
 131         if (position == NULL)
 132                 return NULL;
 133
 134         FuncInst * inst = func_inst_map.get(position);
 135         if (inst == NULL)
 136                 return NULL;
 137
 138         action_type inst_type = inst->get_type();
 139         action_type act_type = act->get_type();
 140
 141         if (inst_type == act_type) {
 142                 return inst;
 143         }
 144         /* RMWRCAS actions are converted to RMW or READ actions */
 145         else if (inst_type == ATOMIC_RMWRCAS &&
 146                                          (act_type == ATOMIC_RMW || act_type == ATOMIC_READ)) {
 147                 return inst;
 148         }
 149         /* Return the FuncInst in the collision list */
 150         else {
 151                 return inst->search_in_collision(act);
 152         }
 153 }
 154
 155
 156 void FuncNode::add_entry_inst(FuncInst * inst)
 157 {
 158         if (inst == NULL)
 159                 return;
 160
 161         mllnode<FuncInst *> * it;
 162         for (it = entry_insts.begin();it != NULL;it = it->getNext()) {
 163                 if (inst == it->getVal())
 164                         return;
 165         }
 166
 167         entry_insts.push_back(inst);
 168 }
 169
 170 /**
 171  * @brief Convert ModelAdtion list to FuncInst list
 172  * @param act_list A list of ModelActions
 173  */
 174 void FuncNode::update_tree(action_list_t * act_list)
 175 {
 176         if (act_list == NULL || act_list->size() == 0)
 177                 return;
 178
 179         HashTable<void *, value_set_t *, uintptr_t, 0> * write_history = history->getWriteHistory();
 180
 181         /* build inst_list from act_list for later processing */
 182         func_inst_list_t inst_list;
 183         action_list_t rw_act_list;
 184
 185         for (sllnode<ModelAction *> * it = act_list->begin();it != NULL;it = it->getNext()) {
 186                 ModelAction * act = it->getVal();
 187                 FuncInst * func_inst = get_inst(act);
 188                 void * loc = act->get_location();
 189
 190                 if (func_inst == NULL)
 191                         continue;
 192
 193                 inst_list.push_back(func_inst);
 194                 bool act_added = false;
 195
 196                 if (act->is_write()) {
 197                         rw_act_list.push_back(act);
 198                         act_added = true;
 199                         if (!write_locations->contains(loc)) {
 200                                 write_locations->add(loc);
 201                                 history->update_loc_wr_func_nodes_map(loc, this);
 202                         }
 203                 }
 204
 205                 if (act->is_read()) {
 206                         if (!act_added)
 207                                 rw_act_list.push_back(act);
 208
 209                         /* If func_inst may only read_from a single location, then:
 210                          *
 211                          * The first time an action reads from some location,
 212                          * import all the values that have been written to this
 213                          * location from ModelHistory and notify ModelHistory
 214                          * that this FuncNode may read from this location.
 215                          */
 216                         if (!read_locations->contains(loc) && func_inst->is_single_location()) {
 217                                 read_locations->add(loc);
 218                                 value_set_t * write_values = write_history->get(loc);
 219                                 add_to_val_loc_map(write_values, loc);
 220                                 history->update_loc_rd_func_nodes_map(loc, this);
 221                         }
 222                 }
 223         }
 224
 225 //      model_print("function %s\n", func_name);
 226 //      print_val_loc_map();
 227
 228         update_inst_tree(&inst_list);
 229         update_predicate_tree(&rw_act_list);
 230
 231 //      print_predicate_tree();
 232 }
 233
 234 /**
 235  * @brief Link FuncInsts in inst_list  - add one FuncInst to another's predecessors and successors
 236  * @param inst_list A list of FuncInsts
 237  */
 238 void FuncNode::update_inst_tree(func_inst_list_t * inst_list)
 239 {
 240         if (inst_list == NULL)
 241                 return;
 242         else if (inst_list->size() == 0)
 243                 return;
 244
 245         /* start linking */
 246         sllnode<FuncInst *>* it = inst_list->begin();
 247         sllnode<FuncInst *>* prev;
 248
 249         /* add the first instruction to the list of entry insts */
 250         FuncInst * entry_inst = it->getVal();
 251         add_entry_inst(entry_inst);
 252
 253         it = it->getNext();
 254         while (it != NULL) {
 255                 prev = it->getPrev();
 256
 257                 FuncInst * prev_inst = prev->getVal();
 258                 FuncInst * curr_inst = it->getVal();
 259
 260                 prev_inst->add_succ(curr_inst);
 261                 curr_inst->add_pred(prev_inst);
 262
 263                 it = it->getNext();
 264         }
 265 }
 266
 267 void FuncNode::update_predicate_tree(action_list_t * act_list)
 268 {
 269         if (act_list == NULL || act_list->size() == 0)
 270                 return;
 271
 272         incr_marker();
 273         uint32_t inst_counter = 0;
 274
 275         // Clear hashtables
 276         loc_act_map.reset();
 277         inst_pred_map.reset();
 278         inst_id_map.reset();
 279
 280         // Clear the set of leaves encountered in this path
 281         leaves_tmp_storage.clear();
 282
 283         sllnode<ModelAction *> *it = act_list->begin();
 284         Predicate * curr_pred = predicate_tree_entry;
 285         while (it != NULL) {
 286                 ModelAction * next_act = it->getVal();
 287                 FuncInst * next_inst = get_inst(next_act);
 288                 next_inst->set_associated_act(next_act, marker);
 289
 290                 Predicate * unset_predicate = NULL;
 291                 bool branch_found = follow_branch(&curr_pred, next_inst, next_act, &unset_predicate);
 292
 293                 // A branch with unset predicate expression is detected
 294                 if (!branch_found && unset_predicate != NULL) {
 295                         bool amended = amend_predicate_expr(curr_pred, next_inst, next_act);
 296                         if (amended)
 297                                 continue;
 298                         else {
 299                                 curr_pred = unset_predicate;
 300                                 branch_found = true;
 301                         }
 302                 }
 303
 304                 // Detect loops
 305                 if (!branch_found && inst_id_map.contains(next_inst)) {
 306                         FuncInst * curr_inst = curr_pred->get_func_inst();
 307                         uint32_t curr_id = inst_id_map.get(curr_inst);
 308                         uint32_t next_id = inst_id_map.get(next_inst);
 309
 310                         if (curr_id >= next_id) {
 311                                 Predicate * old_pred = inst_pred_map.get(next_inst);
 312                                 Predicate * back_pred = old_pred->get_parent();
 313
 314                                 // For updating weights
 315                                 leaves_tmp_storage.push_back(curr_pred);
 316
 317                                 // Add to the set of backedges
 318                                 curr_pred->add_backedge(back_pred);
 319                                 curr_pred = back_pred;
 320                                 continue;
 321                         }
 322                 }
 323
 324                 // Generate new branches
 325                 if (!branch_found) {
 326                         SnapVector<struct half_pred_expr *> half_pred_expressions;
 327                         infer_predicates(next_inst, next_act, &half_pred_expressions);
 328                         generate_predicates(curr_pred, next_inst, &half_pred_expressions);
 329                         continue;
 330                 }
 331
 332                 if (next_act->is_write())
 333                         curr_pred->set_write(true);
 334
 335                 if (next_act->is_read()) {
 336                         /* Only need to store the locations of read actions */
 337                         loc_act_map.put(next_act->get_location(), next_act);
 338                 }
 339
 340                 inst_pred_map.put(next_inst, curr_pred);
 341                 if (!inst_id_map.contains(next_inst))
 342                         inst_id_map.put(next_inst, inst_counter++);
 343
 344                 it = it->getNext();
 345                 curr_pred->incr_expl_count();
 346         }
 347
 348         if (curr_pred->get_exit() == NULL) {
 349                 // Exit predicate is unset yet
 350                 curr_pred->set_exit(predicate_tree_exit);
 351         }
 352
 353         leaves_tmp_storage.push_back(curr_pred);
 354         update_predicate_tree_weight();
 355 }
 356
 357 /* Given curr_pred and next_inst, find the branch following curr_pred that
 358  * contains next_inst and the correct predicate.
 359  * @return true if branch found, false otherwise.
 360  */
 361 bool FuncNode::follow_branch(Predicate ** curr_pred, FuncInst * next_inst,
 362 ModelAction * next_act, Predicate ** unset_predicate)
 363 {
 364         /* Check if a branch with func_inst and corresponding predicate exists */
 365         bool branch_found = false;
 366         ModelVector<Predicate *> * branches = (*curr_pred)->get_children();
 367         for (uint i = 0;i < branches->size();i++) {
 368                 Predicate * branch = (*branches)[i];
 369                 if (branch->get_func_inst() != next_inst)
 370                         continue;
 371
 372                 /* Check against predicate expressions */
 373                 bool predicate_correct = true;
 374                 PredExprSet * pred_expressions = branch->get_pred_expressions();
 375
 376                 /* Only read and rmw actions my have unset predicate expressions */
 377                 if (pred_expressions->getSize() == 0) {
 378                         predicate_correct = false;
 379                         if (*unset_predicate == NULL)
 380                                 *unset_predicate = branch;
 381                         else
 382                                 ASSERT(false);
 383
 384                         continue;
 385                 }
 386
 387                 PredExprSetIter * pred_expr_it = pred_expressions->iterator();
 388                 while (pred_expr_it->hasNext()) {
 389                         pred_expr * pred_expression = pred_expr_it->next();
 390                         uint64_t last_read, next_read;
 391                         bool equality;
 392
 393                         switch(pred_expression->token) {
 394                                 case NOPREDICATE:
 395                                         predicate_correct = true;
 396                                         break;
 397                                 case EQUALITY:
 398                                         FuncInst * to_be_compared;
 399                                         ModelAction * last_act;
 400
 401                                         to_be_compared = pred_expression->func_inst;
 402                                         last_act = to_be_compared->get_associated_act(marker);
 403
 404                                         last_read = last_act->get_reads_from_value();
 405                                         next_read = next_act->get_reads_from_value();
 406                                         equality = (last_read == next_read);
 407                                         if (equality != pred_expression->value)
 408                                                 predicate_correct = false;
 409
 410                                         break;
 411                                 case NULLITY:
 412                                         next_read = next_act->get_reads_from_value();
 413                                         // TODO: implement likely to be null
 414                                         equality = ( (void*) (next_read & 0xffffffff) == NULL);
 415                                         if (equality != pred_expression->value)
 416                                                 predicate_correct = false;
 417                                         break;
 418                                 default:
 419                                         predicate_correct = false;
 420                                         model_print("unkown predicate token\n");
 421                                         break;
 422                         }
 423                 }
 424
 425                 delete pred_expr_it;
 426
 427                 if (predicate_correct) {
 428                         *curr_pred = branch;
 429                         branch_found = true;
 430                         break;
 431                 }
 432         }
 433
 434         return branch_found;
 435 }
 436
 437 /* Infer predicate expressions, which are generated in FuncNode::generate_predicates */
 438 void FuncNode::infer_predicates(FuncInst * next_inst, ModelAction * next_act,
 439 SnapVector<struct half_pred_expr *> * half_pred_expressions)
 440 {
 441         void * loc = next_act->get_location();
 442
 443         if (next_inst->is_read()) {
 444                 /* read + rmw */
 445                 if ( loc_act_map.contains(loc) ) {
 446                         ModelAction * last_act = loc_act_map.get(loc);
 447                         FuncInst * last_inst = get_inst(last_act);
 448                         struct half_pred_expr * expression = new half_pred_expr(EQUALITY, last_inst);
 449                         half_pred_expressions->push_back(expression);
 450                 } else if ( next_inst->is_single_location() ) {
 451                         loc_set_t * loc_may_equal = loc_may_equal_map->get(loc);
 452
 453                         if (loc_may_equal != NULL) {
 454                                 loc_set_iter * loc_it = loc_may_equal->iterator();
 455                                 while (loc_it->hasNext()) {
 456                                         void * neighbor = loc_it->next();
 457                                         if (loc_act_map.contains(neighbor)) {
 458                                                 ModelAction * last_act = loc_act_map.get(neighbor);
 459                                                 FuncInst * last_inst = get_inst(last_act);
 460
 461                                                 struct half_pred_expr * expression = new half_pred_expr(EQUALITY, last_inst);
 462                                                 half_pred_expressions->push_back(expression);
 463                                         }
 464                                 }
 465
 466                                 delete loc_it;
 467                         }
 468                 } else {
 469                         // next_inst is not single location
 470                         uint64_t read_val = next_act->get_reads_from_value();
 471
 472                         // only infer NULLITY predicate when it is actually NULL.
 473                         if ( (void*)read_val == NULL) {
 474                                 struct half_pred_expr * expression = new half_pred_expr(NULLITY, NULL);
 475                                 half_pred_expressions->push_back(expression);
 476                         }
 477                 }
 478         } else {
 479                 /* Pure writes */
 480                 // TODO: do anything here?
 481         }
 482 }
 483
 484 /* Able to generate complex predicates when there are multiple predciate expressions */
 485 void FuncNode::generate_predicates(Predicate * curr_pred, FuncInst * next_inst,
 486 SnapVector<struct half_pred_expr *> * half_pred_expressions)
 487 {
 488         if (half_pred_expressions->size() == 0) {
 489                 Predicate * new_pred = new Predicate(next_inst);
 490                 curr_pred->add_child(new_pred);
 491                 new_pred->set_parent(curr_pred);
 492
 493                 /* Maintain predicate leaves */
 494                 predicate_leaves.add(new_pred);
 495                 predicate_leaves.remove(curr_pred);
 496
 497                 /* entry predicates and predicates containing pure write actions
 498                  * have no predicate expressions */
 499                 if ( curr_pred->is_entry_predicate() )
 500                         new_pred->add_predicate_expr(NOPREDICATE, NULL, true);
 501                 else if (next_inst->is_write()) {
 502                         /* next_inst->is_write() <==> pure writes */
 503                         new_pred->add_predicate_expr(NOPREDICATE, NULL, true);
 504                 }
 505
 506                 return;
 507         }
 508
 509         SnapVector<Predicate *> predicates;
 510
 511         struct half_pred_expr * half_expr = (*half_pred_expressions)[0];
 512         predicates.push_back(new Predicate(next_inst));
 513         predicates.push_back(new Predicate(next_inst));
 514
 515         predicates[0]->add_predicate_expr(half_expr->token, half_expr->func_inst, true);
 516         predicates[1]->add_predicate_expr(half_expr->token, half_expr->func_inst, false);
 517
 518         for (uint i = 1;i < half_pred_expressions->size();i++) {
 519                 half_expr = (*half_pred_expressions)[i];
 520
 521                 uint old_size = predicates.size();
 522                 for (uint j = 0;j < old_size;j++) {
 523                         Predicate * pred = predicates[j];
 524                         Predicate * new_pred = new Predicate(next_inst);
 525                         new_pred->copy_predicate_expr(pred);
 526
 527                         pred->add_predicate_expr(half_expr->token, half_expr->func_inst, true);
 528                         new_pred->add_predicate_expr(half_expr->token, half_expr->func_inst, false);
 529
 530                         predicates.push_back(new_pred);
 531                 }
 532         }
 533
 534         for (uint i = 0;i < predicates.size();i++) {
 535                 Predicate * pred= predicates[i];
 536                 curr_pred->add_child(pred);
 537                 pred->set_parent(curr_pred);
 538
 539                 /* Add new predicate leaves */
 540                 predicate_leaves.add(pred);
 541         }
 542
 543         /* Remove predicate node that has children */
 544         predicate_leaves.remove(curr_pred);
 545
 546         /* Free memories allocated by infer_predicate */
 547         for (uint i = 0;i < half_pred_expressions->size();i++) {
 548                 struct half_pred_expr * tmp = (*half_pred_expressions)[i];
 549                 snapshot_free(tmp);
 550         }
 551 }
 552
 553 /* Amend predicates that contain no predicate expressions. Currenlty only amend with NULLITY predicates */
 554 bool FuncNode::amend_predicate_expr(Predicate * curr_pred, FuncInst * next_inst, ModelAction * next_act)
 555 {
 556         ModelVector<Predicate *> * children = curr_pred->get_children();
 557         ASSERT(children->size() == 1);
 558
 559         // there should only be only child
 560         Predicate * unset_pred = (*children)[0];
 561         uint64_t read_val = next_act->get_reads_from_value();
 562
 563         // only generate NULLITY predicate when it is actually NULL.
 564         if ( !next_inst->is_single_location() && (void*)read_val == NULL ) {
 565                 Predicate * new_pred = new Predicate(next_inst);
 566
 567                 curr_pred->add_child(new_pred);
 568                 new_pred->set_parent(curr_pred);
 569
 570                 unset_pred->add_predicate_expr(NULLITY, NULL, false);
 571                 new_pred->add_predicate_expr(NULLITY, NULL, true);
 572
 573                 return true;
 574         }
 575
 576         return false;
 577 }
 578
 579 void FuncNode::add_to_val_loc_map(uint64_t val, void * loc)
 580 {
 581         loc_set_t * locations = val_loc_map->get(val);
 582
 583         if (locations == NULL) {
 584                 locations = new loc_set_t();
 585                 val_loc_map->put(val, locations);
 586         }
 587
 588         update_loc_may_equal_map(loc, locations);
 589         locations->add(loc);
 590         // values_may_read_from->add(val);
 591 }
 592
 593 void FuncNode::add_to_val_loc_map(value_set_t * values, void * loc)
 594 {
 595         if (values == NULL)
 596                 return;
 597
 598         value_set_iter * it = values->iterator();
 599         while (it->hasNext()) {
 600                 uint64_t val = it->next();
 601                 add_to_val_loc_map(val, loc);
 602         }
 603
 604         delete it;
 605 }
 606
 607 void FuncNode::update_loc_may_equal_map(void * new_loc, loc_set_t * old_locations)
 608 {
 609         if ( old_locations->contains(new_loc) )
 610                 return;
 611
 612         loc_set_t * neighbors = loc_may_equal_map->get(new_loc);
 613
 614         if (neighbors == NULL) {
 615                 neighbors = new loc_set_t();
 616                 loc_may_equal_map->put(new_loc, neighbors);
 617         }
 618
 619         loc_set_iter * loc_it = old_locations->iterator();
 620         while (loc_it->hasNext()) {
 621                 // new_loc: { old_locations, ... }
 622                 void * member = loc_it->next();
 623                 neighbors->add(member);
 624
 625                 // for each i in old_locations, i : { new_loc, ... }
 626                 loc_set_t * _neighbors = loc_may_equal_map->get(member);
 627                 if (_neighbors == NULL) {
 628                         _neighbors = new loc_set_t();
 629                         loc_may_equal_map->put(member, _neighbors);
 630                 }
 631                 _neighbors->add(new_loc);
 632         }
 633
 634         delete loc_it;
 635 }
 636
 637 /* Every time a thread enters a function, set its position to the predicate tree entry */
 638 void FuncNode::init_predicate_tree_position(thread_id_t tid)
 639 {
 640         int thread_id = id_to_int(tid);
 641         if (predicate_tree_position.size() <= (uint) thread_id)
 642                 predicate_tree_position.resize(thread_id + 1);
 643
 644         predicate_tree_position[thread_id] = predicate_tree_entry;
 645 }
 646
 647 void FuncNode::set_predicate_tree_position(thread_id_t tid, Predicate * pred)
 648 {
 649         int thread_id = id_to_int(tid);
 650         predicate_tree_position[thread_id] = pred;
 651 }
 652
 653 /* @return The position of a thread in a predicate tree */
 654 Predicate * FuncNode::get_predicate_tree_position(thread_id_t tid)
 655 {
 656         int thread_id = id_to_int(tid);
 657         return predicate_tree_position[thread_id];
 658 }
 659
 660 /* Make sure elements of thrd_inst_act_map are initialized properly when threads enter functions */
 661 void FuncNode::init_inst_act_map(thread_id_t tid)
 662 {
 663         int thread_id = id_to_int(tid);
 664         SnapVector<inst_act_map_t *> * thrd_inst_act_map = history->getThrdInstActMap(func_id);
 665         uint old_size = thrd_inst_act_map->size();
 666
 667         if (thrd_inst_act_map->size() <= (uint) thread_id) {
 668                 uint new_size = thread_id + 1;
 669                 thrd_inst_act_map->resize(new_size);
 670
 671                 for (uint i = old_size;i < new_size;i++)
 672                         (*thrd_inst_act_map)[i] = new inst_act_map_t(128);
 673         }
 674 }
 675
 676 /* Reset elements of thrd_inst_act_map when threads exit functions */
 677 void FuncNode::reset_inst_act_map(thread_id_t tid)
 678 {
 679         int thread_id = id_to_int(tid);
 680         SnapVector<inst_act_map_t *> * thrd_inst_act_map = history->getThrdInstActMap(func_id);
 681
 682         inst_act_map_t * map = (*thrd_inst_act_map)[thread_id];
 683         map->reset();
 684 }
 685
 686 void FuncNode::update_inst_act_map(thread_id_t tid, ModelAction * read_act)
 687 {
 688         int thread_id = id_to_int(tid);
 689         SnapVector<inst_act_map_t *> * thrd_inst_act_map = history->getThrdInstActMap(func_id);
 690
 691         inst_act_map_t * map = (*thrd_inst_act_map)[thread_id];
 692         FuncInst * read_inst = get_inst(read_act);
 693         map->put(read_inst, read_act);
 694 }
 695
 696 inst_act_map_t * FuncNode::get_inst_act_map(thread_id_t tid)
 697 {
 698         int thread_id = id_to_int(tid);
 699         SnapVector<inst_act_map_t *> * thrd_inst_act_map = history->getThrdInstActMap(func_id);
 700
 701         return (*thrd_inst_act_map)[thread_id];
 702 }
 703
 704 /* Add FuncNodes that this node may follow */
 705 void FuncNode::add_out_edge(FuncNode * other)
 706 {
 707         if ( !edge_table.contains(other) ) {
 708                 edge_table.put(other, OUT_EDGE);
 709                 out_edges.push_back(other);
 710                 return;
 711         }
 712
 713         edge_type_t edge = edge_table.get(other);
 714         if (edge == IN_EDGE) {
 715                 edge_table.put(other, BI_EDGE);
 716                 out_edges.push_back(other);
 717         }
 718 }
 719
 720 /* Compute the distance between this FuncNode and the target node.
 721  * Return -1 if the target node is unreachable or the actual distance
 722  * is greater than max_step.
 723  */
 724 int FuncNode::compute_distance(FuncNode * target, int max_step)
 725 {
 726         if (target == NULL)
 727                 return -1;
 728         else if (target == this)
 729                 return 0;
 730
 731         SnapList<FuncNode *> queue;
 732         HashTable<FuncNode *, int, uintptr_t, 0> distances(128);
 733
 734         queue.push_back(this);
 735         distances.put(this, 0);
 736
 737         while (!queue.empty()) {
 738                 FuncNode * curr = queue.front();
 739                 queue.pop_front();
 740                 int dist = distances.get(curr);
 741
 742                 if (max_step <= dist)
 743                         return -1;
 744
 745                 ModelList<FuncNode *> * outEdges = curr->get_out_edges();
 746                 mllnode<FuncNode *> * it;
 747                 for (it = outEdges->begin();it != NULL;it = it->getNext()) {
 748                         FuncNode * out_node = it->getVal();
 749
 750                         /* This node has not been visited before */
 751                         if ( !distances.contains(out_node) ) {
 752                                 if (out_node == target)
 753                                         return dist + 1;
 754
 755                                 queue.push_back(out_node);
 756                                 distances.put(out_node, dist + 1);
 757                         }
 758                 }
 759         }
 760
 761         /* Target node is unreachable */
 762         return -1;
 763 }
 764
 765 void FuncNode::add_failed_predicate(Predicate * pred)
 766 {
 767         failed_predicates.add(pred);
 768 }
 769
 770 /* Implement quick sort to sort leaves before assigning base scores */
 771 template<typename _Tp>
 772 static int partition(ModelVector<_Tp *> * arr, int low, int high)
 773 {
 774         unsigned int pivot = (*arr)[high]->get_depth();
 775         int i = low - 1;
 776
 777         for (int j = low; j <= high - 1; j++) {
 778                 if ( (*arr)[j]->get_depth() < pivot ) {
 779                         i++;
 780                         _Tp * tmp = (*arr)[i];
 781                         (*arr)[i] = (*arr)[j];
 782                         (*arr)[j] = tmp;
 783                 }
 784         }
 785
 786         _Tp * tmp = (*arr)[i + 1];
 787         (*arr)[i + 1] = (*arr)[high];
 788         (*arr)[high] = tmp;
 789
 790         return i + 1;
 791 }
 792
 793 /* Implement quick sort to sort leaves before assigning base scores */
 794 template<typename _Tp>
 795 static void quickSort(ModelVector<_Tp *> * arr, int low, int high)
 796 {
 797         if (low < high) {
 798                 int pi = partition(arr, low, high);
 799
 800                 quickSort(arr, low, pi - 1);
 801                 quickSort(arr, pi + 1, high);
 802         }
 803 }
 804
 805 void FuncNode::assign_initial_weight()
 806 {
 807         PredSetIter * it = predicate_leaves.iterator();
 808         leaves_tmp_storage.clear();
 809
 810         while (it->hasNext()) {
 811                 Predicate * pred = it->next();
 812                 double weight = 100.0 / sqrt(pred->get_expl_count() + pred->get_fail_count() + 1);
 813                 pred->set_weight(weight);
 814                 leaves_tmp_storage.push_back(pred);
 815         }
 816         delete it;
 817
 818         quickSort(&leaves_tmp_storage, 0, leaves_tmp_storage.size() - 1);
 819
 820         // assign scores for internal nodes;
 821         while ( !leaves_tmp_storage.empty() ) {
 822                 Predicate * leaf = leaves_tmp_storage.back();
 823                 leaves_tmp_storage.pop_back();
 824
 825                 Predicate * curr = leaf->get_parent();
 826                 while (curr != NULL) {
 827                         if (curr->get_weight() != 0) {
 828                                 // Has been exlpored
 829                                 break;
 830                         }
 831
 832                         ModelVector<Predicate *> * children = curr->get_children();
 833                         double weight_sum = 0;
 834                         bool has_unassigned_node = false;
 835
 836                         for (uint i = 0; i < children->size(); i++) {
 837                                 Predicate * child = (*children)[i];
 838
 839                                 // If a child has unassigned weight
 840                                 double weight = child->get_weight();
 841                                 if (weight == 0) {
 842                                         has_unassigned_node = true;
 843                                         break;
 844                                 } else
 845                                         weight_sum += weight;
 846                         }
 847
 848                         if (!has_unassigned_node) {
 849                                 double average_weight = (double) weight_sum / (double) children->size();
 850                                 double weight = average_weight * pow(0.9, curr->get_depth());
 851                                 curr->set_weight(weight);
 852                         } else
 853                                 break;
 854
 855                         curr = curr->get_parent();
 856                 }
 857         }
 858 }
 859
 860 void FuncNode::update_predicate_tree_weight()
 861 {
 862         if (marker == 2) {
 863                 // Predicate tree is initially built
 864                 assign_initial_weight();
 865                 return;
 866         }
 867
 868         weight_debug_vec.clear();
 869
 870         PredSetIter * it = failed_predicates.iterator();
 871         while (it->hasNext()) {
 872                 Predicate * pred = it->next();
 873                 leaves_tmp_storage.push_back(pred);
 874         }
 875         delete it;
 876         failed_predicates.reset();
 877
 878         quickSort(&leaves_tmp_storage, 0, leaves_tmp_storage.size() - 1);
 879         for (uint i = 0; i < leaves_tmp_storage.size(); i++) {
 880                 Predicate * pred = leaves_tmp_storage[i];
 881                 double weight = 100.0 / sqrt(pred->get_expl_count() + pred->get_fail_count() + 1);
 882                 pred->set_weight(weight);
 883         }
 884
 885         // Update weights in internal nodes
 886         while ( !leaves_tmp_storage.empty() ) {
 887                 Predicate * leaf = leaves_tmp_storage.back();
 888                 leaves_tmp_storage.pop_back();
 889
 890                 Predicate * curr = leaf->get_parent();
 891                 while (curr != NULL) {
 892                         ModelVector<Predicate *> * children = curr->get_children();
 893                         double weight_sum = 0;
 894                         bool has_unassigned_node = false;
 895
 896                         for (uint i = 0; i < children->size(); i++) {
 897                                 Predicate * child = (*children)[i];
 898
 899                                 double weight = child->get_weight();
 900                                 if (weight != 0)
 901                                         weight_sum += weight;
 902                                 else if ( predicate_leaves.contains(child) ) {
 903                                         // If this child is a leaf
 904                                         double weight = 100.0 / sqrt(child->get_expl_count() + 1);
 905                                         child->set_weight(weight);
 906                                         weight_sum += weight;
 907                                 } else {
 908                                         has_unassigned_node = true;
 909                                         weight_debug_vec.push_back(child);      // For debugging purpose
 910                                         break;
 911                                 }
 912                         }
 913
 914                         if (!has_unassigned_node) {
 915                                 double average_weight = (double) weight_sum / (double) children->size();
 916                                 double weight = average_weight * pow(0.9, curr->get_depth());
 917                                 curr->set_weight(weight);
 918                         } else
 919                                 break;
 920
 921                         curr = curr->get_parent();
 922                 }
 923         }
 924
 925         for (uint i = 0; i < weight_debug_vec.size(); i++) {
 926                 Predicate * tmp = weight_debug_vec[i];
 927                 ASSERT( tmp->get_weight() != 0 );
 928         }
 929 }
 930
 931 void FuncNode::print_predicate_tree()
 932 {
 933         model_print("digraph function_%s {\n", func_name);
 934         predicate_tree_entry->print_pred_subtree();
 935         predicate_tree_exit->print_predicate();
 936         model_print("}\n");     // end of graph
 937 }