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         edge_table(32),
  26         out_edges()
  27 {
  28         predicate_tree_entry = new Predicate(NULL, true);
  29         predicate_tree_entry->add_predicate_expr(NOPREDICATE, NULL, true);
  30
  31         predicate_tree_exit = new Predicate(NULL, false, true);
  32         predicate_tree_exit->set_depth(MAX_DEPTH);
  33
  34         /* Snapshot data structures below */
  35         action_list_buffer = new SnapList<action_list_t *>();
  36         read_locations = new loc_set_t();
  37         write_locations = new loc_set_t();
  38         val_loc_map = new HashTable<uint64_t, loc_set_t *, uint64_t, 0, snapshot_malloc, snapshot_calloc, snapshot_free, int64_hash>();
  39         loc_may_equal_map = new HashTable<void *, loc_set_t *, uintptr_t, 0>();
  40
  41         //values_may_read_from = new value_set_t();
  42 }
  43
  44 /* Reallocate snapshotted memories when new executions start */
  45 void FuncNode::set_new_exec_flag()
  46 {
  47         action_list_buffer = new SnapList<action_list_t *>();
  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
 155 void FuncNode::add_entry_inst(FuncInst * inst)
 156 {
 157         if (inst == NULL)
 158                 return;
 159
 160         mllnode<FuncInst *> * it;
 161         for (it = entry_insts.begin();it != NULL;it = it->getNext()) {
 162                 if (inst == it->getVal())
 163                         return;
 164         }
 165
 166         entry_insts.push_back(inst);
 167 }
 168
 169 /**
 170  * @brief Convert ModelAdtion list to FuncInst list
 171  * @param act_list A list of ModelActions
 172  */
 173 void FuncNode::update_tree(action_list_t * act_list)
 174 {
 175         if (act_list == NULL || act_list->size() == 0)
 176                 return;
 177
 178         HashTable<void *, value_set_t *, uintptr_t, 0> * write_history = history->getWriteHistory();
 179
 180         /* build inst_list from act_list for later processing */
 181         func_inst_list_t inst_list;
 182         action_list_t rw_act_list;
 183
 184         for (sllnode<ModelAction *> * it = act_list->begin();it != NULL;it = it->getNext()) {
 185                 ModelAction * act = it->getVal();
 186                 FuncInst * func_inst = get_inst(act);
 187                 void * loc = act->get_location();
 188
 189                 if (func_inst == NULL)
 190                         continue;
 191
 192                 inst_list.push_back(func_inst);
 193                 bool act_added = false;
 194
 195                 if (act->is_write()) {
 196                         rw_act_list.push_back(act);
 197                         act_added = true;
 198                         if (!write_locations->contains(loc)) {
 199                                 write_locations->add(loc);
 200                                 history->update_loc_wr_func_nodes_map(loc, this);
 201                         }
 202                 }
 203
 204                 if (act->is_read()) {
 205                         if (!act_added)
 206                                 rw_act_list.push_back(act);
 207
 208                         /* If func_inst may only read_from a single location, then:
 209                          *
 210                          * The first time an action reads from some location,
 211                          * import all the values that have been written to this
 212                          * location from ModelHistory and notify ModelHistory
 213                          * that this FuncNode may read from this location.
 214                          */
 215                         if (!read_locations->contains(loc) && func_inst->is_single_location()) {
 216                                 read_locations->add(loc);
 217                                 value_set_t * write_values = write_history->get(loc);
 218                                 add_to_val_loc_map(write_values, loc);
 219                                 history->update_loc_rd_func_nodes_map(loc, this);
 220                         }
 221                 }
 222         }
 223
 224 //      model_print("function %s\n", func_name);
 225 //      print_val_loc_map();
 226
 227         update_inst_tree(&inst_list);
 228         update_predicate_tree(&rw_act_list);
 229
 230 //      print_predicate_tree();
 231 }
 232
 233 /**
 234  * @brief Link FuncInsts in inst_list  - add one FuncInst to another's predecessors and successors
 235  * @param inst_list A list of FuncInsts
 236  */
 237 void FuncNode::update_inst_tree(func_inst_list_t * inst_list)
 238 {
 239         if (inst_list == NULL)
 240                 return;
 241         else if (inst_list->size() == 0)
 242                 return;
 243
 244         /* start linking */
 245         sllnode<FuncInst *>* it = inst_list->begin();
 246         sllnode<FuncInst *>* prev;
 247
 248         /* add the first instruction to the list of entry insts */
 249         FuncInst * entry_inst = it->getVal();
 250         add_entry_inst(entry_inst);
 251
 252         it = it->getNext();
 253         while (it != NULL) {
 254                 prev = it->getPrev();
 255
 256                 FuncInst * prev_inst = prev->getVal();
 257                 FuncInst * curr_inst = it->getVal();
 258
 259                 prev_inst->add_succ(curr_inst);
 260                 curr_inst->add_pred(prev_inst);
 261
 262                 it = it->getNext();
 263         }
 264 }
 265
 266 void FuncNode::update_predicate_tree(action_list_t * act_list)
 267 {
 268         if (act_list == NULL || act_list->size() == 0)
 269                 return;
 270
 271         incr_marker();
 272         uint32_t inst_counter = 0;
 273
 274         // Clear hashtables
 275         loc_act_map.reset();
 276         inst_pred_map.reset();
 277         inst_id_map.reset();
 278
 279         // Clear the set of leaves encountered in this path
 280         leaves_tmp_storage.clear();
 281
 282         sllnode<ModelAction *> *it = act_list->begin();
 283         Predicate * curr_pred = predicate_tree_entry;
 284         while (it != NULL) {
 285                 ModelAction * next_act = it->getVal();
 286                 FuncInst * next_inst = get_inst(next_act);
 287                 next_inst->set_associated_act(next_act, marker);
 288
 289                 Predicate * unset_predicate = NULL;
 290                 bool branch_found = follow_branch(&curr_pred, next_inst, next_act, &unset_predicate);
 291
 292                 // A branch with unset predicate expression is detected
 293                 if (!branch_found && unset_predicate != NULL) {
 294                         bool amended = amend_predicate_expr(curr_pred, next_inst, next_act);
 295                         if (amended)
 296                                 continue;
 297                         else {
 298                                 curr_pred = unset_predicate;
 299                                 branch_found = true;
 300                         }
 301                 }
 302
 303                 // Detect loops
 304                 if (!branch_found && inst_id_map.contains(next_inst)) {
 305                         FuncInst * curr_inst = curr_pred->get_func_inst();
 306                         uint32_t curr_id = inst_id_map.get(curr_inst);
 307                         uint32_t next_id = inst_id_map.get(next_inst);
 308
 309                         if (curr_id >= next_id) {
 310                                 Predicate * old_pred = inst_pred_map.get(next_inst);
 311                                 Predicate * back_pred = old_pred->get_parent();
 312
 313                                 // For updating weights
 314                                 leaves_tmp_storage.push_back(curr_pred);
 315
 316                                 // Add to the set of backedges
 317                                 curr_pred->add_backedge(back_pred);
 318                                 curr_pred = back_pred;
 319                                 continue;
 320                         }
 321                 }
 322
 323                 // Generate new branches
 324                 if (!branch_found) {
 325                         SnapVector<struct half_pred_expr *> half_pred_expressions;
 326                         infer_predicates(next_inst, next_act, &half_pred_expressions);
 327                         generate_predicates(curr_pred, next_inst, &half_pred_expressions);
 328                         continue;
 329                 }
 330
 331                 if (next_act->is_write())
 332                         curr_pred->set_write(true);
 333
 334                 if (next_act->is_read()) {
 335                         /* Only need to store the locations of read actions */
 336                         loc_act_map.put(next_act->get_location(), next_act);
 337                 }
 338
 339                 inst_pred_map.put(next_inst, curr_pred);
 340                 if (!inst_id_map.contains(next_inst))
 341                         inst_id_map.put(next_inst, inst_counter++);
 342
 343                 it = it->getNext();
 344                 curr_pred->incr_expl_count();
 345         }
 346
 347         if (curr_pred->get_exit() == NULL) {
 348                 // Exit predicate is unset yet
 349                 curr_pred->set_exit(predicate_tree_exit);
 350         }
 351
 352         leaves_tmp_storage.push_back(curr_pred);
 353         update_predicate_tree_weight();
 354 }
 355
 356 /* Given curr_pred and next_inst, find the branch following curr_pred that
 357  * contains next_inst and the correct predicate.
 358  * @return true if branch found, false otherwise.
 359  */
 360 bool FuncNode::follow_branch(Predicate ** curr_pred, FuncInst * next_inst,
 361 ModelAction * next_act, Predicate ** unset_predicate)
 362 {
 363         /* Check if a branch with func_inst and corresponding predicate exists */
 364         bool branch_found = false;
 365         ModelVector<Predicate *> * branches = (*curr_pred)->get_children();
 366         for (uint i = 0;i < branches->size();i++) {
 367                 Predicate * branch = (*branches)[i];
 368                 if (branch->get_func_inst() != next_inst)
 369                         continue;
 370
 371                 /* Check against predicate expressions */
 372                 bool predicate_correct = true;
 373                 PredExprSet * pred_expressions = branch->get_pred_expressions();
 374
 375                 /* Only read and rmw actions my have unset predicate expressions */
 376                 if (pred_expressions->getSize() == 0) {
 377                         predicate_correct = false;
 378                         if (*unset_predicate == NULL)
 379                                 *unset_predicate = branch;
 380                         else
 381                                 ASSERT(false);
 382
 383                         continue;
 384                 }
 385
 386                 PredExprSetIter * pred_expr_it = pred_expressions->iterator();
 387                 while (pred_expr_it->hasNext()) {
 388                         pred_expr * pred_expression = pred_expr_it->next();
 389                         uint64_t last_read, next_read;
 390                         bool equality;
 391
 392                         switch(pred_expression->token) {
 393                                 case NOPREDICATE:
 394                                         predicate_correct = true;
 395                                         break;
 396                                 case EQUALITY:
 397                                         FuncInst * to_be_compared;
 398                                         ModelAction * last_act;
 399
 400                                         to_be_compared = pred_expression->func_inst;
 401                                         last_act = to_be_compared->get_associated_act(marker);
 402
 403                                         last_read = last_act->get_reads_from_value();
 404                                         next_read = next_act->get_reads_from_value();
 405                                         equality = (last_read == next_read);
 406                                         if (equality != pred_expression->value)
 407                                                 predicate_correct = false;
 408
 409                                         break;
 410                                 case NULLITY:
 411                                         next_read = next_act->get_reads_from_value();
 412                                         // TODO: implement likely to be null
 413                                         equality = ( (void*) (next_read & 0xffffffff) == NULL);
 414                                         if (equality != pred_expression->value)
 415                                                 predicate_correct = false;
 416                                         break;
 417                                 default:
 418                                         predicate_correct = false;
 419                                         model_print("unkown predicate token\n");
 420                                         break;
 421                         }
 422                 }
 423
 424                 delete pred_expr_it;
 425
 426                 if (predicate_correct) {
 427                         *curr_pred = branch;
 428                         branch_found = true;
 429                         break;
 430                 }
 431         }
 432
 433         return branch_found;
 434 }
 435
 436 /* Infer predicate expressions, which are generated in FuncNode::generate_predicates */
 437 void FuncNode::infer_predicates(FuncInst * next_inst, ModelAction * next_act,
 438 SnapVector<struct half_pred_expr *> * half_pred_expressions)
 439 {
 440         void * loc = next_act->get_location();
 441
 442         if (next_inst->is_read()) {
 443                 /* read + rmw */
 444                 if ( loc_act_map.contains(loc) ) {
 445                         ModelAction * last_act = loc_act_map.get(loc);
 446                         FuncInst * last_inst = get_inst(last_act);
 447                         struct half_pred_expr * expression = new half_pred_expr(EQUALITY, last_inst);
 448                         half_pred_expressions->push_back(expression);
 449                 } else if ( next_inst->is_single_location() ) {
 450                         loc_set_t * loc_may_equal = loc_may_equal_map->get(loc);
 451
 452                         if (loc_may_equal != NULL) {
 453                                 loc_set_iter * loc_it = loc_may_equal->iterator();
 454                                 while (loc_it->hasNext()) {
 455                                         void * neighbor = loc_it->next();
 456                                         if (loc_act_map.contains(neighbor)) {
 457                                                 ModelAction * last_act = loc_act_map.get(neighbor);
 458                                                 FuncInst * last_inst = get_inst(last_act);
 459
 460                                                 struct half_pred_expr * expression = new half_pred_expr(EQUALITY, last_inst);
 461                                                 half_pred_expressions->push_back(expression);
 462                                         }
 463                                 }
 464
 465                                 delete loc_it;
 466                         }
 467                 } else {
 468                         // next_inst is not single location
 469                         uint64_t read_val = next_act->get_reads_from_value();
 470
 471                         // only infer NULLITY predicate when it is actually NULL.
 472                         if ( (void*)read_val == NULL) {
 473                                 struct half_pred_expr * expression = new half_pred_expr(NULLITY, NULL);
 474                                 half_pred_expressions->push_back(expression);
 475                         }
 476                 }
 477         } else {
 478                 /* Pure writes */
 479                 // TODO: do anything here?
 480         }
 481 }
 482
 483 /* Able to generate complex predicates when there are multiple predciate expressions */
 484 void FuncNode::generate_predicates(Predicate * curr_pred, FuncInst * next_inst,
 485 SnapVector<struct half_pred_expr *> * half_pred_expressions)
 486 {
 487         if (half_pred_expressions->size() == 0) {
 488                 Predicate * new_pred = new Predicate(next_inst);
 489                 curr_pred->add_child(new_pred);
 490                 new_pred->set_parent(curr_pred);
 491
 492                 /* Maintain predicate leaves */
 493                 predicate_leaves.add(new_pred);
 494                 predicate_leaves.remove(curr_pred);
 495
 496                 /* entry predicates and predicates containing pure write actions
 497                  * have no predicate expressions */
 498                 if ( curr_pred->is_entry_predicate() )
 499                         new_pred->add_predicate_expr(NOPREDICATE, NULL, true);
 500                 else if (next_inst->is_write()) {
 501                         /* next_inst->is_write() <==> pure writes */
 502                         new_pred->add_predicate_expr(NOPREDICATE, NULL, true);
 503                 }
 504
 505                 return;
 506         }
 507
 508         SnapVector<Predicate *> predicates;
 509
 510         struct half_pred_expr * half_expr = (*half_pred_expressions)[0];
 511         predicates.push_back(new Predicate(next_inst));
 512         predicates.push_back(new Predicate(next_inst));
 513
 514         predicates[0]->add_predicate_expr(half_expr->token, half_expr->func_inst, true);
 515         predicates[1]->add_predicate_expr(half_expr->token, half_expr->func_inst, false);
 516
 517         for (uint i = 1;i < half_pred_expressions->size();i++) {
 518                 half_expr = (*half_pred_expressions)[i];
 519
 520                 uint old_size = predicates.size();
 521                 for (uint j = 0;j < old_size;j++) {
 522                         Predicate * pred = predicates[j];
 523                         Predicate * new_pred = new Predicate(next_inst);
 524                         new_pred->copy_predicate_expr(pred);
 525
 526                         pred->add_predicate_expr(half_expr->token, half_expr->func_inst, true);
 527                         new_pred->add_predicate_expr(half_expr->token, half_expr->func_inst, false);
 528
 529                         predicates.push_back(new_pred);
 530                 }
 531         }
 532
 533         for (uint i = 0;i < predicates.size();i++) {
 534                 Predicate * pred= predicates[i];
 535                 curr_pred->add_child(pred);
 536                 pred->set_parent(curr_pred);
 537
 538                 /* Add new predicate leaves */
 539                 predicate_leaves.add(pred);
 540         }
 541
 542         /* Remove predicate node that has children */
 543         predicate_leaves.remove(curr_pred);
 544
 545         /* Free memories allocated by infer_predicate */
 546         for (uint i = 0;i < half_pred_expressions->size();i++) {
 547                 struct half_pred_expr * tmp = (*half_pred_expressions)[i];
 548                 snapshot_free(tmp);
 549         }
 550 }
 551
 552 /* Amend predicates that contain no predicate expressions. Currenlty only amend with NULLITY predicates */
 553 bool FuncNode::amend_predicate_expr(Predicate * curr_pred, FuncInst * next_inst, ModelAction * next_act)
 554 {
 555         ModelVector<Predicate *> * children = curr_pred->get_children();
 556         ASSERT(children->size() == 1);
 557
 558         // there should only be only child
 559         Predicate * unset_pred = (*children)[0];
 560         uint64_t read_val = next_act->get_reads_from_value();
 561
 562         // only generate NULLITY predicate when it is actually NULL.
 563         if ( !next_inst->is_single_location() && (void*)read_val == NULL ) {
 564                 Predicate * new_pred = new Predicate(next_inst);
 565
 566                 curr_pred->add_child(new_pred);
 567                 new_pred->set_parent(curr_pred);
 568
 569                 unset_pred->add_predicate_expr(NULLITY, NULL, false);
 570                 new_pred->add_predicate_expr(NULLITY, NULL, true);
 571
 572                 return true;
 573         }
 574
 575         return false;
 576 }
 577
 578 void FuncNode::add_to_val_loc_map(uint64_t val, void * loc)
 579 {
 580         loc_set_t * locations = val_loc_map->get(val);
 581
 582         if (locations == NULL) {
 583                 locations = new loc_set_t();
 584                 val_loc_map->put(val, locations);
 585         }
 586
 587         update_loc_may_equal_map(loc, locations);
 588         locations->add(loc);
 589         // values_may_read_from->add(val);
 590 }
 591
 592 void FuncNode::add_to_val_loc_map(value_set_t * values, void * loc)
 593 {
 594         if (values == NULL)
 595                 return;
 596
 597         value_set_iter * it = values->iterator();
 598         while (it->hasNext()) {
 599                 uint64_t val = it->next();
 600                 add_to_val_loc_map(val, loc);
 601         }
 602
 603         delete it;
 604 }
 605
 606 void FuncNode::update_loc_may_equal_map(void * new_loc, loc_set_t * old_locations)
 607 {
 608         if ( old_locations->contains(new_loc) )
 609                 return;
 610
 611         loc_set_t * neighbors = loc_may_equal_map->get(new_loc);
 612
 613         if (neighbors == NULL) {
 614                 neighbors = new loc_set_t();
 615                 loc_may_equal_map->put(new_loc, neighbors);
 616         }
 617
 618         loc_set_iter * loc_it = old_locations->iterator();
 619         while (loc_it->hasNext()) {
 620                 // new_loc: { old_locations, ... }
 621                 void * member = loc_it->next();
 622                 neighbors->add(member);
 623
 624                 // for each i in old_locations, i : { new_loc, ... }
 625                 loc_set_t * _neighbors = loc_may_equal_map->get(member);
 626                 if (_neighbors == NULL) {
 627                         _neighbors = new loc_set_t();
 628                         loc_may_equal_map->put(member, _neighbors);
 629                 }
 630                 _neighbors->add(new_loc);
 631         }
 632
 633         delete loc_it;
 634 }
 635
 636 /* Every time a thread enters a function, set its position to the predicate tree entry */
 637 void FuncNode::init_predicate_tree_position(thread_id_t tid)
 638 {
 639         int thread_id = id_to_int(tid);
 640         if (predicate_tree_position.size() <= (uint) thread_id)
 641                 predicate_tree_position.resize(thread_id + 1);
 642
 643         predicate_tree_position[thread_id] = predicate_tree_entry;
 644 }
 645
 646 void FuncNode::set_predicate_tree_position(thread_id_t tid, Predicate * pred)
 647 {
 648         int thread_id = id_to_int(tid);
 649         predicate_tree_position[thread_id] = pred;
 650 }
 651
 652 /* @return The position of a thread in a predicate tree */
 653 Predicate * FuncNode::get_predicate_tree_position(thread_id_t tid)
 654 {
 655         int thread_id = id_to_int(tid);
 656         return predicate_tree_position[thread_id];
 657 }
 658
 659 /* Make sure elements of thrd_inst_act_map are initialized properly when threads enter functions */
 660 void FuncNode::init_inst_act_map(thread_id_t tid)
 661 {
 662         int thread_id = id_to_int(tid);
 663         SnapVector<inst_act_map_t *> * thrd_inst_act_map = history->getThrdInstActMap(func_id);
 664         uint old_size = thrd_inst_act_map->size();
 665
 666         if (thrd_inst_act_map->size() <= (uint) thread_id) {
 667                 uint new_size = thread_id + 1;
 668                 thrd_inst_act_map->resize(new_size);
 669
 670                 for (uint i = old_size;i < new_size;i++)
 671                         (*thrd_inst_act_map)[i] = new inst_act_map_t(128);
 672         }
 673 }
 674
 675 /* Reset elements of thrd_inst_act_map when threads exit functions */
 676 void FuncNode::reset_inst_act_map(thread_id_t tid)
 677 {
 678         int thread_id = id_to_int(tid);
 679         SnapVector<inst_act_map_t *> * thrd_inst_act_map = history->getThrdInstActMap(func_id);
 680
 681         inst_act_map_t * map = (*thrd_inst_act_map)[thread_id];
 682         map->reset();
 683 }
 684
 685 void FuncNode::update_inst_act_map(thread_id_t tid, ModelAction * read_act)
 686 {
 687         int thread_id = id_to_int(tid);
 688         SnapVector<inst_act_map_t *> * thrd_inst_act_map = history->getThrdInstActMap(func_id);
 689
 690         inst_act_map_t * map = (*thrd_inst_act_map)[thread_id];
 691         FuncInst * read_inst = get_inst(read_act);
 692         map->put(read_inst, read_act);
 693 }
 694
 695 inst_act_map_t * FuncNode::get_inst_act_map(thread_id_t tid)
 696 {
 697         int thread_id = id_to_int(tid);
 698         SnapVector<inst_act_map_t *> * thrd_inst_act_map = history->getThrdInstActMap(func_id);
 699
 700         return (*thrd_inst_act_map)[thread_id];
 701 }
 702
 703 /* Add FuncNodes that this node may follow */
 704 void FuncNode::add_out_edge(FuncNode * other)
 705 {
 706         if ( !edge_table.contains(other) ) {
 707                 edge_table.put(other, OUT_EDGE);
 708                 out_edges.push_back(other);
 709                 return;
 710         }
 711
 712         edge_type_t edge = edge_table.get(other);
 713         if (edge == IN_EDGE) {
 714                 edge_table.put(other, BI_EDGE);
 715                 out_edges.push_back(other);
 716         }
 717 }
 718
 719 /* Compute the distance between this FuncNode and the target node.
 720  * Return -1 if the target node is unreachable or the actual distance
 721  * is greater than max_step.
 722  */
 723 int FuncNode::compute_distance(FuncNode * target, int max_step)
 724 {
 725         if (target == NULL)
 726                 return -1;
 727         else if (target == this)
 728                 return 0;
 729
 730         SnapList<FuncNode *> queue;
 731         HashTable<FuncNode *, int, uintptr_t, 0> distances(128);
 732
 733         queue.push_back(this);
 734         distances.put(this, 0);
 735
 736         while (!queue.empty()) {
 737                 FuncNode * curr = queue.front();
 738                 queue.pop_front();
 739                 int dist = distances.get(curr);
 740
 741                 if (max_step <= dist)
 742                         return -1;
 743
 744                 ModelList<FuncNode *> * outEdges = curr->get_out_edges();
 745                 mllnode<FuncNode *> * it;
 746                 for (it = outEdges->begin();it != NULL;it = it->getNext()) {
 747                         FuncNode * out_node = it->getVal();
 748
 749                         /* This node has not been visited before */
 750                         if ( !distances.contains(out_node) ) {
 751                                 if (out_node == target)
 752                                         return dist + 1;
 753
 754                                 queue.push_back(out_node);
 755                                 distances.put(out_node, dist + 1);
 756                         }
 757                 }
 758         }
 759
 760         /* Target node is unreachable */
 761         return -1;
 762 }
 763
 764 /* Implement quick sort to sort leaves before assigning base scores */
 765 template<typename _Tp>
 766 static int partition(ModelVector<_Tp *> * arr, int low, int high)
 767 {
 768         unsigned int pivot = (*arr)[high]->get_depth();
 769         int i = low - 1;
 770
 771         for (int j = low; j <= high - 1; j++) {
 772                 if ( (*arr)[j]->get_depth() < pivot ) {
 773                         i++;
 774                         _Tp * tmp = (*arr)[i];
 775                         (*arr)[i] = (*arr)[j];
 776                         (*arr)[j] = tmp;
 777                 }
 778         }
 779
 780         _Tp * tmp = (*arr)[i + 1];
 781         (*arr)[i + 1] = (*arr)[high];
 782         (*arr)[high] = tmp;
 783
 784         return i + 1;
 785 }
 786
 787 /* Implement quick sort to sort leaves before assigning base scores */
 788 template<typename _Tp>
 789 static void quickSort(ModelVector<_Tp *> * arr, int low, int high)
 790 {
 791         if (low < high) {
 792                 int pi = partition(arr, low, high);
 793
 794                 quickSort(arr, low, pi - 1);
 795                 quickSort(arr, pi + 1, high);
 796         }
 797 }
 798
 799 void FuncNode::assign_initial_weight()
 800 {
 801         PredSetIter * it = predicate_leaves.iterator();
 802         leaves_tmp_storage.clear();
 803
 804         while (it->hasNext()) {
 805                 Predicate * pred = it->next();
 806                 double weight = 100.0 / sqrt(pred->get_expl_count() + 1);
 807                 pred->set_weight(weight);
 808                 leaves_tmp_storage.push_back(pred);
 809         }
 810         delete it;
 811
 812         quickSort(&leaves_tmp_storage, 0, leaves_tmp_storage.size() - 1);
 813
 814         // assign scores for internal nodes;
 815         while ( !leaves_tmp_storage.empty() ) {
 816                 Predicate * leaf = leaves_tmp_storage.back();
 817                 leaves_tmp_storage.pop_back();
 818
 819                 Predicate * curr = leaf->get_parent();
 820                 while (curr != NULL) {
 821                         if (curr->get_weight() != 0) {
 822                                 // Has been exlpored
 823                                 break;
 824                         }
 825
 826                         ModelVector<Predicate *> * children = curr->get_children();
 827                         double weight_sum = 0;
 828                         bool has_unassigned_node = false;
 829
 830                         for (uint i = 0; i < children->size(); i++) {
 831                                 Predicate * child = (*children)[i];
 832
 833                                 // If a child has unassigned weight
 834                                 double weight = child->get_weight();
 835                                 if (weight == 0) {
 836                                         has_unassigned_node = true;
 837                                         break;
 838                                 } else
 839                                         weight_sum += weight;
 840                         }
 841
 842                         if (!has_unassigned_node) {
 843                                 double average_weight = (double) weight_sum / (double) children->size();
 844                                 double weight = average_weight * pow(0.9, curr->get_depth());
 845                                 curr->set_weight(weight);
 846                         } else
 847                                 break;
 848
 849                         curr = curr->get_parent();
 850                 }
 851         }
 852 }
 853
 854 void FuncNode::update_predicate_tree_weight()
 855 {
 856         if (marker == 2) {
 857                 // Predicate tree is initially built
 858                 assign_initial_weight();
 859                 return;
 860         }
 861
 862         weight_debug_vec.clear();
 863
 864         quickSort(&leaves_tmp_storage, 0, leaves_tmp_storage.size() - 1);
 865         for (uint i = 0; i < leaves_tmp_storage.size(); i++) {
 866                 Predicate * pred = leaves_tmp_storage[i];
 867                 double weight = 100.0 / sqrt(pred->get_expl_count() + 1);
 868                 pred->set_weight(weight);
 869         }
 870
 871         // Update weights in internal nodes
 872         while ( !leaves_tmp_storage.empty() ) {
 873                 Predicate * leaf = leaves_tmp_storage.back();
 874                 leaves_tmp_storage.pop_back();
 875
 876                 Predicate * curr = leaf->get_parent();
 877                 while (curr != NULL) {
 878                         ModelVector<Predicate *> * children = curr->get_children();
 879                         double weight_sum = 0;
 880                         bool has_unassigned_node = false;
 881
 882                         for (uint i = 0; i < children->size(); i++) {
 883                                 Predicate * child = (*children)[i];
 884
 885                                 double weight = child->get_weight();
 886                                 if (weight != 0)
 887                                         weight_sum += weight;
 888                                 else if ( predicate_leaves.contains(child) ) {
 889                                         // If this child is a leaf
 890                                         double weight = 100.0 / sqrt(child->get_expl_count() + 1);
 891                                         child->set_weight(weight);
 892                                         weight_sum += weight;
 893                                 } else {
 894                                         has_unassigned_node = true;
 895                                         weight_debug_vec.push_back(child);      // For debugging purpose
 896                                         break;
 897                                 }
 898                         }
 899
 900                         if (!has_unassigned_node) {
 901                                 double average_weight = (double) weight_sum / (double) children->size();
 902                                 double weight = average_weight * pow(0.9, curr->get_depth());
 903                                 curr->set_weight(weight);
 904                         } else
 905                                 break;
 906
 907                         curr = curr->get_parent();
 908                 }
 909         }
 910
 911         for (uint i = 0; i < weight_debug_vec.size(); i++) {
 912                 Predicate * tmp = weight_debug_vec[i];
 913                 ASSERT( tmp->get_weight() != 0 );
 914         }
 915 }
 916
 917 void FuncNode::print_predicate_tree()
 918 {
 919         model_print("digraph function_%s {\n", func_name);
 920         predicate_tree_entry->print_pred_subtree();
 921         predicate_tree_exit->print_predicate();
 922         model_print("}\n");     // end of graph
 923 }