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
 188                 if (act->get_original_type() != ATOMIC_NOP && act->get_swap_flag() == false)
 189                         act->use_original_type();
 190
 191                 // Remove func_act_ref so that actions can be deleted by Execution::collectActions
 192                 if (act->is_read()) {
 193                         // For every read or rmw actions in this list, the reads_from was marked, and not deleted.
 194                         // So it is safe to call get_reads_from
 195                         ModelAction * rf = act->get_reads_from();
 196                         if (rf->get_original_type() != ATOMIC_NOP && rf->get_swap_flag() == false)
 197                                 rf->use_original_type();
 198
 199                         rf->setFuncActRef(NULL);
 200                 }
 201                 act->setFuncActRef(NULL);
 202
 203                 FuncInst * func_inst = get_inst(act);
 204                 void * loc = act->get_location();
 205
 206                 if (func_inst == NULL)
 207                         continue;
 208
 209                 inst_list.push_back(func_inst);
 210                 bool act_added = false;
 211
 212                 if (act->is_write()) {
 213                         rw_act_list.push_back(act);
 214                         act_added = true;
 215                         if (!write_locations->contains(loc)) {
 216                                 write_locations->add(loc);
 217                                 history->update_loc_wr_func_nodes_map(loc, this);
 218                         }
 219                 }
 220
 221                 if (act->is_read()) {
 222                         if (!act_added)
 223                                 rw_act_list.push_back(act);
 224
 225                         /* If func_inst may only read_from a single location, then:
 226                          *
 227                          * The first time an action reads from some location,
 228                          * import all the values that have been written to this
 229                          * location from ModelHistory and notify ModelHistory
 230                          * that this FuncNode may read from this location.
 231                          */
 232                         if (!read_locations->contains(loc) && func_inst->is_single_location()) {
 233                                 read_locations->add(loc);
 234                                 value_set_t * write_values = write_history->get(loc);
 235                                 add_to_val_loc_map(write_values, loc);
 236                                 history->update_loc_rd_func_nodes_map(loc, this);
 237                         }
 238                 }
 239         }
 240
 241         update_inst_tree(&inst_list);
 242         update_predicate_tree(&rw_act_list);
 243
 244         // Revert back action types and free
 245         for (sllnode<ModelAction *> * it = act_list->begin(); it != NULL;) {
 246                 ModelAction * act = it->getVal();
 247                 // Do iteration early in case we delete act
 248                 it = it->getNext();
 249
 250                 // Revert back action types for actions whose types have been changed.
 251                 if (act->is_read()) {
 252                         ModelAction * rf = act->get_reads_from();
 253                         if (rf->get_swap_flag() == true)
 254                                 rf->use_original_type();
 255                 }
 256
 257                 if (act->get_swap_flag() == true)
 258                         act->use_original_type();
 259
 260                 if (act->is_free()) {
 261                         // TODO
 262                 } else if (act->is_read()) {
 263                         if (act->is_rmw()) {
 264                                 // reads_from can not be READY_FREE
 265                         } else {
 266                                 ModelAction *rf = act->get_reads_from();
 267                                 if (rf->is_free()) {
 268                                         model_print("delete read %d; %p\n", act->get_seq_number(), act);
 269                                         delete act;
 270                                 }
 271                         }
 272                 }
 273         }
 274
 275 //      print_predicate_tree();
 276 }
 277
 278 /**
 279  * @brief Link FuncInsts in inst_list  - add one FuncInst to another's predecessors and successors
 280  * @param inst_list A list of FuncInsts
 281  */
 282 void FuncNode::update_inst_tree(func_inst_list_t * inst_list)
 283 {
 284         if (inst_list == NULL)
 285                 return;
 286         else if (inst_list->size() == 0)
 287                 return;
 288
 289         /* start linking */
 290         sllnode<FuncInst *>* it = inst_list->begin();
 291         sllnode<FuncInst *>* prev;
 292
 293         /* add the first instruction to the list of entry insts */
 294         FuncInst * entry_inst = it->getVal();
 295         add_entry_inst(entry_inst);
 296
 297         it = it->getNext();
 298         while (it != NULL) {
 299                 prev = it->getPrev();
 300
 301                 FuncInst * prev_inst = prev->getVal();
 302                 FuncInst * curr_inst = it->getVal();
 303
 304                 prev_inst->add_succ(curr_inst);
 305                 curr_inst->add_pred(prev_inst);
 306
 307                 it = it->getNext();
 308         }
 309 }
 310
 311 void FuncNode::update_predicate_tree(action_list_t * act_list)
 312 {
 313         if (act_list == NULL || act_list->size() == 0)
 314                 return;
 315
 316         incr_marker();
 317         uint32_t inst_counter = 0;
 318
 319         // Clear hashtables
 320         loc_act_map.reset();
 321         inst_pred_map.reset();
 322         inst_id_map.reset();
 323
 324         // Clear the set of leaves encountered in this path
 325         leaves_tmp_storage.clear();
 326
 327         sllnode<ModelAction *> *it = act_list->begin();
 328         Predicate * curr_pred = predicate_tree_entry;
 329         while (it != NULL) {
 330                 ModelAction * next_act = it->getVal();
 331                 FuncInst * next_inst = get_inst(next_act);
 332                 next_inst->set_associated_act(next_act, marker);
 333
 334                 Predicate * unset_predicate = NULL;
 335                 bool branch_found = follow_branch(&curr_pred, next_inst, next_act, &unset_predicate);
 336
 337                 // A branch with unset predicate expression is detected
 338                 if (!branch_found && unset_predicate != NULL) {
 339                         bool amended = amend_predicate_expr(curr_pred, next_inst, next_act);
 340                         if (amended)
 341                                 continue;
 342                         else {
 343                                 curr_pred = unset_predicate;
 344                                 branch_found = true;
 345                         }
 346                 }
 347
 348                 // Detect loops
 349                 if (!branch_found && inst_id_map.contains(next_inst)) {
 350                         FuncInst * curr_inst = curr_pred->get_func_inst();
 351                         uint32_t curr_id = inst_id_map.get(curr_inst);
 352                         uint32_t next_id = inst_id_map.get(next_inst);
 353
 354                         if (curr_id >= next_id) {
 355                                 Predicate * old_pred = inst_pred_map.get(next_inst);
 356                                 Predicate * back_pred = old_pred->get_parent();
 357
 358                                 // For updating weights
 359                                 leaves_tmp_storage.push_back(curr_pred);
 360
 361                                 // Add to the set of backedges
 362                                 curr_pred->add_backedge(back_pred);
 363                                 curr_pred = back_pred;
 364                                 continue;
 365                         }
 366                 }
 367
 368                 // Generate new branches
 369                 if (!branch_found) {
 370                         SnapVector<struct half_pred_expr *> half_pred_expressions;
 371                         infer_predicates(next_inst, next_act, &half_pred_expressions);
 372                         generate_predicates(curr_pred, next_inst, &half_pred_expressions);
 373                         continue;
 374                 }
 375
 376                 if (next_act->is_write())
 377                         curr_pred->set_write(true);
 378
 379                 if (next_act->is_read()) {
 380                         /* Only need to store the locations of read actions */
 381                         loc_act_map.put(next_act->get_location(), next_act);
 382                 }
 383
 384                 inst_pred_map.put(next_inst, curr_pred);
 385                 if (!inst_id_map.contains(next_inst))
 386                         inst_id_map.put(next_inst, inst_counter++);
 387
 388                 it = it->getNext();
 389                 curr_pred->incr_expl_count();
 390         }
 391
 392         if (curr_pred->get_exit() == NULL) {
 393                 // Exit predicate is unset yet
 394                 curr_pred->set_exit(predicate_tree_exit);
 395         }
 396
 397         leaves_tmp_storage.push_back(curr_pred);
 398         update_predicate_tree_weight();
 399 }
 400
 401 /* Given curr_pred and next_inst, find the branch following curr_pred that
 402  * contains next_inst and the correct predicate.
 403  * @return true if branch found, false otherwise.
 404  */
 405 bool FuncNode::follow_branch(Predicate ** curr_pred, FuncInst * next_inst,
 406                                                                                                                  ModelAction * next_act, Predicate ** unset_predicate)
 407 {
 408         /* Check if a branch with func_inst and corresponding predicate exists */
 409         bool branch_found = false;
 410         ModelVector<Predicate *> * branches = (*curr_pred)->get_children();
 411         for (uint i = 0;i < branches->size();i++) {
 412                 Predicate * branch = (*branches)[i];
 413                 if (branch->get_func_inst() != next_inst)
 414                         continue;
 415
 416                 /* Check against predicate expressions */
 417                 bool predicate_correct = true;
 418                 PredExprSet * pred_expressions = branch->get_pred_expressions();
 419
 420                 /* Only read and rmw actions my have unset predicate expressions */
 421                 if (pred_expressions->getSize() == 0) {
 422                         predicate_correct = false;
 423                         if (*unset_predicate == NULL)
 424                                 *unset_predicate = branch;
 425                         else
 426                                 ASSERT(false);
 427
 428                         continue;
 429                 }
 430
 431                 PredExprSetIter * pred_expr_it = pred_expressions->iterator();
 432                 while (pred_expr_it->hasNext()) {
 433                         pred_expr * pred_expression = pred_expr_it->next();
 434                         uint64_t last_read, next_read;
 435                         bool equality;
 436
 437                         switch(pred_expression->token) {
 438                         case NOPREDICATE:
 439                                 predicate_correct = true;
 440                                 break;
 441                         case EQUALITY:
 442                                 FuncInst * to_be_compared;
 443                                 ModelAction * last_act;
 444
 445                                 to_be_compared = pred_expression->func_inst;
 446                                 last_act = to_be_compared->get_associated_act(marker);
 447
 448                                 last_read = last_act->get_reads_from_value();
 449                                 next_read = next_act->get_reads_from_value();
 450                                 equality = (last_read == next_read);
 451                                 if (equality != pred_expression->value)
 452                                         predicate_correct = false;
 453
 454                                 break;
 455                         case NULLITY:
 456                                 next_read = next_act->get_reads_from_value();
 457                                 // TODO: implement likely to be null
 458                                 equality = ( (void*) (next_read & 0xffffffff) == NULL);
 459                                 if (equality != pred_expression->value)
 460                                         predicate_correct = false;
 461                                 break;
 462                         default:
 463                                 predicate_correct = false;
 464                                 model_print("unkown predicate token\n");
 465                                 break;
 466                         }
 467                 }
 468
 469                 delete pred_expr_it;
 470
 471                 if (predicate_correct) {
 472                         *curr_pred = branch;
 473                         branch_found = true;
 474                         break;
 475                 }
 476         }
 477
 478         return branch_found;
 479 }
 480
 481 /* Infer predicate expressions, which are generated in FuncNode::generate_predicates */
 482 void FuncNode::infer_predicates(FuncInst * next_inst, ModelAction * next_act,
 483                                                                                                                                 SnapVector<struct half_pred_expr *> * half_pred_expressions)
 484 {
 485         void * loc = next_act->get_location();
 486
 487         if (next_inst->is_read()) {
 488                 /* read + rmw */
 489                 if ( loc_act_map.contains(loc) ) {
 490                         ModelAction * last_act = loc_act_map.get(loc);
 491                         FuncInst * last_inst = get_inst(last_act);
 492                         struct half_pred_expr * expression = new half_pred_expr(EQUALITY, last_inst);
 493                         half_pred_expressions->push_back(expression);
 494                 } else if ( next_inst->is_single_location() ) {
 495                         loc_set_t * loc_may_equal = loc_may_equal_map->get(loc);
 496
 497                         if (loc_may_equal != NULL) {
 498                                 loc_set_iter * loc_it = loc_may_equal->iterator();
 499                                 while (loc_it->hasNext()) {
 500                                         void * neighbor = loc_it->next();
 501                                         if (loc_act_map.contains(neighbor)) {
 502                                                 ModelAction * last_act = loc_act_map.get(neighbor);
 503                                                 FuncInst * last_inst = get_inst(last_act);
 504
 505                                                 struct half_pred_expr * expression = new half_pred_expr(EQUALITY, last_inst);
 506                                                 half_pred_expressions->push_back(expression);
 507                                         }
 508                                 }
 509
 510                                 delete loc_it;
 511                         }
 512                 } else {
 513                         // next_inst is not single location
 514                         uint64_t read_val = next_act->get_reads_from_value();
 515
 516                         // only infer NULLITY predicate when it is actually NULL.
 517                         if ( (void*)read_val == NULL) {
 518                                 struct half_pred_expr * expression = new half_pred_expr(NULLITY, NULL);
 519                                 half_pred_expressions->push_back(expression);
 520                         }
 521                 }
 522         } else {
 523                 /* Pure writes */
 524                 // TODO: do anything here?
 525         }
 526 }
 527
 528 /* Able to generate complex predicates when there are multiple predciate expressions */
 529 void FuncNode::generate_predicates(Predicate * curr_pred, FuncInst * next_inst,
 530                                                                                                                                          SnapVector<struct half_pred_expr *> * half_pred_expressions)
 531 {
 532         if (half_pred_expressions->size() == 0) {
 533                 Predicate * new_pred = new Predicate(next_inst);
 534                 curr_pred->add_child(new_pred);
 535                 new_pred->set_parent(curr_pred);
 536
 537                 /* Maintain predicate leaves */
 538                 predicate_leaves.add(new_pred);
 539                 predicate_leaves.remove(curr_pred);
 540
 541                 /* entry predicates and predicates containing pure write actions
 542                  * have no predicate expressions */
 543                 if ( curr_pred->is_entry_predicate() )
 544                         new_pred->add_predicate_expr(NOPREDICATE, NULL, true);
 545                 else if (next_inst->is_write()) {
 546                         /* next_inst->is_write() <==> pure writes */
 547                         new_pred->add_predicate_expr(NOPREDICATE, NULL, true);
 548                 }
 549
 550                 return;
 551         }
 552
 553         SnapVector<Predicate *> predicates;
 554
 555         struct half_pred_expr * half_expr = (*half_pred_expressions)[0];
 556         predicates.push_back(new Predicate(next_inst));
 557         predicates.push_back(new Predicate(next_inst));
 558
 559         predicates[0]->add_predicate_expr(half_expr->token, half_expr->func_inst, true);
 560         predicates[1]->add_predicate_expr(half_expr->token, half_expr->func_inst, false);
 561
 562         for (uint i = 1;i < half_pred_expressions->size();i++) {
 563                 half_expr = (*half_pred_expressions)[i];
 564
 565                 uint old_size = predicates.size();
 566                 for (uint j = 0;j < old_size;j++) {
 567                         Predicate * pred = predicates[j];
 568                         Predicate * new_pred = new Predicate(next_inst);
 569                         new_pred->copy_predicate_expr(pred);
 570
 571                         pred->add_predicate_expr(half_expr->token, half_expr->func_inst, true);
 572                         new_pred->add_predicate_expr(half_expr->token, half_expr->func_inst, false);
 573
 574                         predicates.push_back(new_pred);
 575                 }
 576         }
 577
 578         for (uint i = 0;i < predicates.size();i++) {
 579                 Predicate * pred= predicates[i];
 580                 curr_pred->add_child(pred);
 581                 pred->set_parent(curr_pred);
 582
 583                 /* Add new predicate leaves */
 584                 predicate_leaves.add(pred);
 585         }
 586
 587         /* Remove predicate node that has children */
 588         predicate_leaves.remove(curr_pred);
 589
 590         /* Free memories allocated by infer_predicate */
 591         for (uint i = 0;i < half_pred_expressions->size();i++) {
 592                 struct half_pred_expr * tmp = (*half_pred_expressions)[i];
 593                 snapshot_free(tmp);
 594         }
 595 }
 596
 597 /* Amend predicates that contain no predicate expressions. Currenlty only amend with NULLITY predicates */
 598 bool FuncNode::amend_predicate_expr(Predicate * curr_pred, FuncInst * next_inst, ModelAction * next_act)
 599 {
 600         ModelVector<Predicate *> * children = curr_pred->get_children();
 601
 602         Predicate * unset_pred = NULL;
 603         for (uint i = 0;i < children->size();i++) {
 604                 Predicate * child = (*children)[i];
 605                 if (child->get_func_inst() == next_inst) {
 606                         unset_pred = child;
 607                         break;
 608                 }
 609         }
 610
 611         uint64_t read_val = next_act->get_reads_from_value();
 612
 613         // only generate NULLITY predicate when it is actually NULL.
 614         if ( !next_inst->is_single_location() && (void*)read_val == NULL ) {
 615                 Predicate * new_pred = new Predicate(next_inst);
 616
 617                 curr_pred->add_child(new_pred);
 618                 new_pred->set_parent(curr_pred);
 619
 620                 unset_pred->add_predicate_expr(NULLITY, NULL, false);
 621                 new_pred->add_predicate_expr(NULLITY, NULL, true);
 622
 623                 return true;
 624         }
 625
 626         return false;
 627 }
 628
 629 void FuncNode::add_to_val_loc_map(uint64_t val, void * loc)
 630 {
 631         loc_set_t * locations = val_loc_map->get(val);
 632
 633         if (locations == NULL) {
 634                 locations = new loc_set_t();
 635                 val_loc_map->put(val, locations);
 636         }
 637
 638         update_loc_may_equal_map(loc, locations);
 639         locations->add(loc);
 640         // values_may_read_from->add(val);
 641 }
 642
 643 void FuncNode::add_to_val_loc_map(value_set_t * values, void * loc)
 644 {
 645         if (values == NULL)
 646                 return;
 647
 648         value_set_iter * it = values->iterator();
 649         while (it->hasNext()) {
 650                 uint64_t val = it->next();
 651                 add_to_val_loc_map(val, loc);
 652         }
 653
 654         delete it;
 655 }
 656
 657 void FuncNode::update_loc_may_equal_map(void * new_loc, loc_set_t * old_locations)
 658 {
 659         if ( old_locations->contains(new_loc) )
 660                 return;
 661
 662         loc_set_t * neighbors = loc_may_equal_map->get(new_loc);
 663
 664         if (neighbors == NULL) {
 665                 neighbors = new loc_set_t();
 666                 loc_may_equal_map->put(new_loc, neighbors);
 667         }
 668
 669         loc_set_iter * loc_it = old_locations->iterator();
 670         while (loc_it->hasNext()) {
 671                 // new_loc: { old_locations, ... }
 672                 void * member = loc_it->next();
 673                 neighbors->add(member);
 674
 675                 // for each i in old_locations, i : { new_loc, ... }
 676                 loc_set_t * _neighbors = loc_may_equal_map->get(member);
 677                 if (_neighbors == NULL) {
 678                         _neighbors = new loc_set_t();
 679                         loc_may_equal_map->put(member, _neighbors);
 680                 }
 681                 _neighbors->add(new_loc);
 682         }
 683
 684         delete loc_it;
 685 }
 686
 687 /* Every time a thread enters a function, set its position to the predicate tree entry */
 688 void FuncNode::init_predicate_tree_position(thread_id_t tid)
 689 {
 690         int thread_id = id_to_int(tid);
 691         if (predicate_tree_position.size() <= (uint) thread_id)
 692                 predicate_tree_position.resize(thread_id + 1);
 693
 694         predicate_tree_position[thread_id] = predicate_tree_entry;
 695 }
 696
 697 void FuncNode::set_predicate_tree_position(thread_id_t tid, Predicate * pred)
 698 {
 699         int thread_id = id_to_int(tid);
 700         predicate_tree_position[thread_id] = pred;
 701 }
 702
 703 /* @return The position of a thread in a predicate tree */
 704 Predicate * FuncNode::get_predicate_tree_position(thread_id_t tid)
 705 {
 706         int thread_id = id_to_int(tid);
 707         return predicate_tree_position[thread_id];
 708 }
 709
 710 /* Make sure elements of thrd_inst_act_map are initialized properly when threads enter functions */
 711 void FuncNode::init_inst_act_map(thread_id_t tid)
 712 {
 713         int thread_id = id_to_int(tid);
 714         SnapVector<inst_act_map_t *> * thrd_inst_act_map = history->getThrdInstActMap(func_id);
 715         uint old_size = thrd_inst_act_map->size();
 716
 717         if (thrd_inst_act_map->size() <= (uint) thread_id) {
 718                 uint new_size = thread_id + 1;
 719                 thrd_inst_act_map->resize(new_size);
 720
 721                 for (uint i = old_size;i < new_size;i++)
 722                         (*thrd_inst_act_map)[i] = new inst_act_map_t(128);
 723         }
 724 }
 725
 726 /* Reset elements of thrd_inst_act_map when threads exit functions */
 727 void FuncNode::reset_inst_act_map(thread_id_t tid)
 728 {
 729         int thread_id = id_to_int(tid);
 730         SnapVector<inst_act_map_t *> * thrd_inst_act_map = history->getThrdInstActMap(func_id);
 731
 732         inst_act_map_t * map = (*thrd_inst_act_map)[thread_id];
 733         map->reset();
 734 }
 735
 736 void FuncNode::update_inst_act_map(thread_id_t tid, ModelAction * read_act)
 737 {
 738         int thread_id = id_to_int(tid);
 739         SnapVector<inst_act_map_t *> * thrd_inst_act_map = history->getThrdInstActMap(func_id);
 740
 741         inst_act_map_t * map = (*thrd_inst_act_map)[thread_id];
 742         FuncInst * read_inst = get_inst(read_act);
 743         map->put(read_inst, read_act);
 744 }
 745
 746 inst_act_map_t * FuncNode::get_inst_act_map(thread_id_t tid)
 747 {
 748         int thread_id = id_to_int(tid);
 749         SnapVector<inst_act_map_t *> * thrd_inst_act_map = history->getThrdInstActMap(func_id);
 750
 751         return (*thrd_inst_act_map)[thread_id];
 752 }
 753
 754 /* Add FuncNodes that this node may follow */
 755 void FuncNode::add_out_edge(FuncNode * other)
 756 {
 757         if ( !edge_table.contains(other) ) {
 758                 edge_table.put(other, OUT_EDGE);
 759                 out_edges.push_back(other);
 760                 return;
 761         }
 762
 763         edge_type_t edge = edge_table.get(other);
 764         if (edge == IN_EDGE) {
 765                 edge_table.put(other, BI_EDGE);
 766                 out_edges.push_back(other);
 767         }
 768 }
 769
 770 /* Compute the distance between this FuncNode and the target node.
 771  * Return -1 if the target node is unreachable or the actual distance
 772  * is greater than max_step.
 773  */
 774 int FuncNode::compute_distance(FuncNode * target, int max_step)
 775 {
 776         if (target == NULL)
 777                 return -1;
 778         else if (target == this)
 779                 return 0;
 780
 781         SnapList<FuncNode *> queue;
 782         HashTable<FuncNode *, int, uintptr_t, 0> distances(128);
 783
 784         queue.push_back(this);
 785         distances.put(this, 0);
 786
 787         while (!queue.empty()) {
 788                 FuncNode * curr = queue.front();
 789                 queue.pop_front();
 790                 int dist = distances.get(curr);
 791
 792                 if (max_step <= dist)
 793                         return -1;
 794
 795                 ModelList<FuncNode *> * outEdges = curr->get_out_edges();
 796                 mllnode<FuncNode *> * it;
 797                 for (it = outEdges->begin();it != NULL;it = it->getNext()) {
 798                         FuncNode * out_node = it->getVal();
 799
 800                         /* This node has not been visited before */
 801                         if ( !distances.contains(out_node) ) {
 802                                 if (out_node == target)
 803                                         return dist + 1;
 804
 805                                 queue.push_back(out_node);
 806                                 distances.put(out_node, dist + 1);
 807                         }
 808                 }
 809         }
 810
 811         /* Target node is unreachable */
 812         return -1;
 813 }
 814
 815 void FuncNode::add_failed_predicate(Predicate * pred)
 816 {
 817         failed_predicates.add(pred);
 818 }
 819
 820 /* Implement quick sort to sort leaves before assigning base scores */
 821 template<typename _Tp>
 822 static int partition(ModelVector<_Tp *> * arr, int low, int high)
 823 {
 824         unsigned int pivot = (*arr)[high] -> get_depth();
 825         int i = low - 1;
 826
 827         for (int j = low;j <= high - 1;j ++) {
 828                 if ( (*arr)[j] -> get_depth() < pivot ) {
 829                         i ++;
 830                         _Tp * tmp = (*arr)[i];
 831                         (*arr)[i] = (*arr)[j];
 832                         (*arr)[j] = tmp;
 833                 }
 834         }
 835
 836         _Tp * tmp = (*arr)[i + 1];
 837         (*arr)[i + 1] = (*arr)[high];
 838         (*arr)[high] = tmp;
 839
 840         return i + 1;
 841 }
 842
 843 /* Implement quick sort to sort leaves before assigning base scores */
 844 template<typename _Tp>
 845 static void quickSort(ModelVector<_Tp *> * arr, int low, int high)
 846 {
 847         if (low < high) {
 848                 int pi = partition(arr, low, high);
 849
 850                 quickSort(arr, low, pi - 1);
 851                 quickSort(arr, pi + 1, high);
 852         }
 853 }
 854
 855 void FuncNode::assign_initial_weight()
 856 {
 857         PredSetIter * it = predicate_leaves.iterator();
 858         leaves_tmp_storage.clear();
 859
 860         while (it->hasNext()) {
 861                 Predicate * pred = it->next();
 862                 double weight = 100.0 / sqrt(pred->get_expl_count() + pred->get_fail_count() + 1);
 863                 pred->set_weight(weight);
 864                 leaves_tmp_storage.push_back(pred);
 865         }
 866         delete it;
 867
 868         quickSort(&leaves_tmp_storage, 0, leaves_tmp_storage.size() - 1);
 869
 870         // assign scores for internal nodes;
 871         while ( !leaves_tmp_storage.empty() ) {
 872                 Predicate * leaf = leaves_tmp_storage.back();
 873                 leaves_tmp_storage.pop_back();
 874
 875                 Predicate * curr = leaf->get_parent();
 876                 while (curr != NULL) {
 877                         if (curr->get_weight() != 0) {
 878                                 // Has been exlpored
 879                                 break;
 880                         }
 881
 882                         ModelVector<Predicate *> * children = curr->get_children();
 883                         double weight_sum = 0;
 884                         bool has_unassigned_node = false;
 885
 886                         for (uint i = 0;i < children->size();i++) {
 887                                 Predicate * child = (*children)[i];
 888
 889                                 // If a child has unassigned weight
 890                                 double weight = child->get_weight();
 891                                 if (weight == 0) {
 892                                         has_unassigned_node = true;
 893                                         break;
 894                                 } else
 895                                         weight_sum += weight;
 896                         }
 897
 898                         if (!has_unassigned_node) {
 899                                 double average_weight = (double) weight_sum / (double) children->size();
 900                                 double weight = average_weight * pow(0.9, curr->get_depth());
 901                                 curr->set_weight(weight);
 902                         } else
 903                                 break;
 904
 905                         curr = curr->get_parent();
 906                 }
 907         }
 908 }
 909
 910 void FuncNode::update_predicate_tree_weight()
 911 {
 912         if (marker == 2) {
 913                 // Predicate tree is initially built
 914                 assign_initial_weight();
 915                 return;
 916         }
 917
 918         weight_debug_vec.clear();
 919
 920         PredSetIter * it = failed_predicates.iterator();
 921         while (it->hasNext()) {
 922                 Predicate * pred = it->next();
 923                 leaves_tmp_storage.push_back(pred);
 924         }
 925         delete it;
 926         failed_predicates.reset();
 927
 928         quickSort(&leaves_tmp_storage, 0, leaves_tmp_storage.size() - 1);
 929         for (uint i = 0;i < leaves_tmp_storage.size();i++) {
 930                 Predicate * pred = leaves_tmp_storage[i];
 931                 double weight = 100.0 / sqrt(pred->get_expl_count() + pred->get_fail_count() + 1);
 932                 pred->set_weight(weight);
 933         }
 934
 935         // Update weights in internal nodes
 936         while ( !leaves_tmp_storage.empty() ) {
 937                 Predicate * leaf = leaves_tmp_storage.back();
 938                 leaves_tmp_storage.pop_back();
 939
 940                 Predicate * curr = leaf->get_parent();
 941                 while (curr != NULL) {
 942                         ModelVector<Predicate *> * children = curr->get_children();
 943                         double weight_sum = 0;
 944                         bool has_unassigned_node = false;
 945
 946                         for (uint i = 0;i < children->size();i++) {
 947                                 Predicate * child = (*children)[i];
 948
 949                                 double weight = child->get_weight();
 950                                 if (weight != 0)
 951                                         weight_sum += weight;
 952                                 else if ( predicate_leaves.contains(child) ) {
 953                                         // If this child is a leaf
 954                                         double weight = 100.0 / sqrt(child->get_expl_count() + 1);
 955                                         child->set_weight(weight);
 956                                         weight_sum += weight;
 957                                 } else {
 958                                         has_unassigned_node = true;
 959                                         weight_debug_vec.push_back(child);      // For debugging purpose
 960                                         break;
 961                                 }
 962                         }
 963
 964                         if (!has_unassigned_node) {
 965                                 double average_weight = (double) weight_sum / (double) children->size();
 966                                 double weight = average_weight * pow(0.9, curr->get_depth());
 967                                 curr->set_weight(weight);
 968                         } else
 969                                 break;
 970
 971                         curr = curr->get_parent();
 972                 }
 973         }
 974
 975         for (uint i = 0;i < weight_debug_vec.size();i++) {
 976                 Predicate * tmp = weight_debug_vec[i];
 977                 ASSERT( tmp->get_weight() != 0 );
 978         }
 979 }
 980
 981 void FuncNode::print_predicate_tree()
 982 {
 983         model_print("digraph function_%s {\n", func_name);
 984         predicate_tree_entry->print_pred_subtree();
 985         predicate_tree_exit->print_predicate();
 986         model_print("}\n");     // end of graph
 987 }