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         edge_table(32),
  24         out_edges()
  25 {
  26         predicate_tree_entry = new Predicate(NULL, true);
  27         predicate_tree_entry->add_predicate_expr(NOPREDICATE, NULL, true);
  28
  29         predicate_tree_exit = new Predicate(NULL, false, true);
  30         predicate_tree_exit->set_depth(MAX_DEPTH);
  31
  32         /* Snapshot data structures below */
  33         action_list_buffer = new SnapList<action_list_t *>();
  34         read_locations = new loc_set_t();
  35         write_locations = new loc_set_t();
  36         val_loc_map = new HashTable<uint64_t, loc_set_t *, uint64_t, 0, snapshot_malloc, snapshot_calloc, snapshot_free, int64_hash>();
  37         loc_may_equal_map = new HashTable<void *, loc_set_t *, uintptr_t, 0>();
  38
  39         //values_may_read_from = new value_set_t();
  40 }
  41
  42 /* Reallocate snapshotted memories when new executions start */
  43 void FuncNode::set_new_exec_flag()
  44 {
  45         action_list_buffer = new SnapList<action_list_t *>();
  46         read_locations = new loc_set_t();
  47         write_locations = new loc_set_t();
  48         val_loc_map = new HashTable<uint64_t, loc_set_t *, uint64_t, 0, snapshot_malloc, snapshot_calloc, snapshot_free, int64_hash>();
  49         loc_may_equal_map = new HashTable<void *, loc_set_t *, uintptr_t, 0>();
  50
  51         //values_may_read_from = new value_set_t();
  52 }
  53
  54 /* Check whether FuncInst with the same type, position, and location
  55  * as act has been added to func_inst_map or not. If not, add it.
  56  */
  57 void FuncNode::add_inst(ModelAction *act)
  58 {
  59         ASSERT(act);
  60         const char * position = act->get_position();
  61
  62         /* THREAD* actions, ATOMIC_LOCK, ATOMIC_TRYLOCK, and ATOMIC_UNLOCK
  63          * actions are not tagged with their source line numbers
  64          */
  65         if (position == NULL)
  66                 return;
  67
  68         FuncInst * func_inst = func_inst_map.get(position);
  69
  70         /* This position has not been inserted into hashtable before */
  71         if (func_inst == NULL) {
  72                 func_inst = create_new_inst(act);
  73                 func_inst_map.put(position, func_inst);
  74                 return;
  75         }
  76
  77         /* Volatile variables that use ++ or -- syntax may result in read and write actions with the same position */
  78         if (func_inst->get_type() != act->get_type()) {
  79                 FuncInst * collision_inst = func_inst->search_in_collision(act);
  80
  81                 if (collision_inst == NULL) {
  82                         collision_inst = create_new_inst(act);
  83                         func_inst->add_to_collision(collision_inst);
  84                         return;
  85                 } else {
  86                         func_inst = collision_inst;
  87                 }
  88         }
  89
  90         ASSERT(func_inst->get_type() == act->get_type());
  91         int curr_execution_number = model->get_execution_number();
  92
  93         /* Reset locations when new executions start */
  94         if (func_inst->get_execution_number() != curr_execution_number) {
  95                 func_inst->set_location(act->get_location());
  96                 func_inst->set_execution_number(curr_execution_number);
  97         }
  98
  99         /* Mark the memory location of such inst as not unique */
 100         if (func_inst->get_location() != act->get_location())
 101                 func_inst->not_single_location();
 102 }
 103
 104 FuncInst * FuncNode::create_new_inst(ModelAction * act)
 105 {
 106         FuncInst * func_inst = new FuncInst(act, this);
 107         int exec_num = model->get_execution_number();
 108         func_inst->set_execution_number(exec_num);
 109
 110         inst_list.push_back(func_inst);
 111
 112         return func_inst;
 113 }
 114
 115
 116 /* Get the FuncInst with the same type, position, and location
 117  * as act
 118  *
 119  * @return FuncInst with the same type, position, and location as act */
 120 FuncInst * FuncNode::get_inst(ModelAction *act)
 121 {
 122         ASSERT(act);
 123         const char * position = act->get_position();
 124
 125         /* THREAD* actions, ATOMIC_LOCK, ATOMIC_TRYLOCK, and ATOMIC_UNLOCK
 126          * actions are not tagged with their source line numbers
 127          */
 128         if (position == NULL)
 129                 return NULL;
 130
 131         FuncInst * inst = func_inst_map.get(position);
 132         if (inst == NULL)
 133                 return NULL;
 134
 135         action_type inst_type = inst->get_type();
 136         action_type act_type = act->get_type();
 137
 138         if (inst_type == act_type) {
 139                 return inst;
 140         }
 141         /* RMWRCAS actions are converted to RMW or READ actions */
 142         else if (inst_type == ATOMIC_RMWRCAS &&
 143                                          (act_type == ATOMIC_RMW || act_type == ATOMIC_READ)) {
 144                 return inst;
 145         }
 146         /* Return the FuncInst in the collision list */
 147         else {
 148                 return inst->search_in_collision(act);
 149         }
 150 }
 151
 152
 153 void FuncNode::add_entry_inst(FuncInst * inst)
 154 {
 155         if (inst == NULL)
 156                 return;
 157
 158         mllnode<FuncInst *> * it;
 159         for (it = entry_insts.begin();it != NULL;it = it->getNext()) {
 160                 if (inst == it->getVal())
 161                         return;
 162         }
 163
 164         entry_insts.push_back(inst);
 165 }
 166
 167 /**
 168  * @brief Convert ModelAdtion list to FuncInst list
 169  * @param act_list A list of ModelActions
 170  */
 171 void FuncNode::update_tree(action_list_t * act_list)
 172 {
 173         if (act_list == NULL || act_list->size() == 0)
 174                 return;
 175
 176         HashTable<void *, value_set_t *, uintptr_t, 0> * write_history = history->getWriteHistory();
 177
 178         /* build inst_list from act_list for later processing */
 179         func_inst_list_t inst_list;
 180         action_list_t rw_act_list;
 181
 182         for (sllnode<ModelAction *> * it = act_list->begin();it != NULL;it = it->getNext()) {
 183                 ModelAction * act = it->getVal();
 184                 FuncInst * func_inst = get_inst(act);
 185                 void * loc = act->get_location();
 186
 187                 if (func_inst == NULL)
 188                         continue;
 189
 190                 inst_list.push_back(func_inst);
 191                 bool act_added = false;
 192
 193                 if (act->is_write()) {
 194                         rw_act_list.push_back(act);
 195                         act_added = true;
 196                         if (!write_locations->contains(loc)) {
 197                                 write_locations->add(loc);
 198                                 history->update_loc_wr_func_nodes_map(loc, this);
 199                         }
 200                 }
 201
 202                 if (act->is_read()) {
 203                         if (!act_added)
 204                                 rw_act_list.push_back(act);
 205
 206                         /* If func_inst may only read_from a single location, then:
 207                          *
 208                          * The first time an action reads from some location,
 209                          * import all the values that have been written to this
 210                          * location from ModelHistory and notify ModelHistory
 211                          * that this FuncNode may read from this location.
 212                          */
 213                         if (!read_locations->contains(loc) && func_inst->is_single_location()) {
 214                                 read_locations->add(loc);
 215                                 value_set_t * write_values = write_history->get(loc);
 216                                 add_to_val_loc_map(write_values, loc);
 217                                 history->update_loc_rd_func_nodes_map(loc, this);
 218                         }
 219                 }
 220         }
 221
 222 //      model_print("function %s\n", func_name);
 223 //      print_val_loc_map();
 224
 225         update_inst_tree(&inst_list);
 226         update_predicate_tree(&rw_act_list);
 227
 228 //      print_predicate_tree();
 229 }
 230
 231 /**
 232  * @brief Link FuncInsts in inst_list  - add one FuncInst to another's predecessors and successors
 233  * @param inst_list A list of FuncInsts
 234  */
 235 void FuncNode::update_inst_tree(func_inst_list_t * inst_list)
 236 {
 237         if (inst_list == NULL)
 238                 return;
 239         else if (inst_list->size() == 0)
 240                 return;
 241
 242         /* start linking */
 243         sllnode<FuncInst *>* it = inst_list->begin();
 244         sllnode<FuncInst *>* prev;
 245
 246         /* add the first instruction to the list of entry insts */
 247         FuncInst * entry_inst = it->getVal();
 248         add_entry_inst(entry_inst);
 249
 250         it = it->getNext();
 251         while (it != NULL) {
 252                 prev = it->getPrev();
 253
 254                 FuncInst * prev_inst = prev->getVal();
 255                 FuncInst * curr_inst = it->getVal();
 256
 257                 prev_inst->add_succ(curr_inst);
 258                 curr_inst->add_pred(prev_inst);
 259
 260                 it = it->getNext();
 261         }
 262 }
 263
 264 void FuncNode::update_predicate_tree(action_list_t * act_list)
 265 {
 266         if (act_list == NULL || act_list->size() == 0)
 267                 return;
 268
 269         incr_marker();
 270         uint32_t inst_counter = 0;
 271
 272         // Clear hashtables
 273         loc_act_map.reset();
 274         inst_pred_map.reset();
 275         inst_id_map.reset();
 276
 277         sllnode<ModelAction *> *it = act_list->begin();
 278         Predicate * curr_pred = predicate_tree_entry;
 279         while (it != NULL) {
 280                 ModelAction * next_act = it->getVal();
 281                 FuncInst * next_inst = get_inst(next_act);
 282                 next_inst->set_associated_act(next_act, marker);
 283
 284                 Predicate * unset_predicate = NULL;
 285                 bool branch_found = follow_branch(&curr_pred, next_inst, next_act, &unset_predicate);
 286
 287                 // A branch with unset predicate expression is detected
 288                 if (!branch_found && unset_predicate != NULL) {
 289                         bool amended = amend_predicate_expr(curr_pred, next_inst, next_act);
 290                         if (amended)
 291                                 continue;
 292                         else {
 293                                 curr_pred = unset_predicate;
 294                                 branch_found = true;
 295                         }
 296                 }
 297
 298                 // Detect loops
 299                 if (!branch_found && inst_id_map.contains(next_inst)) {
 300                         FuncInst * curr_inst = curr_pred->get_func_inst();
 301                         uint32_t curr_id = inst_id_map.get(curr_inst);
 302                         uint32_t next_id = inst_id_map.get(next_inst);
 303
 304                         if (curr_id >= next_id) {
 305                                 Predicate * old_pred = inst_pred_map.get(next_inst);
 306                                 Predicate * back_pred = old_pred->get_parent();
 307
 308                                 curr_pred->add_backedge(back_pred);
 309                                 curr_pred = back_pred;
 310                                 continue;
 311                         }
 312                 }
 313
 314                 // Generate new branches
 315                 if (!branch_found) {
 316                         SnapVector<struct half_pred_expr *> half_pred_expressions;
 317                         infer_predicates(next_inst, next_act, &half_pred_expressions);
 318                         generate_predicates(curr_pred, next_inst, &half_pred_expressions);
 319                         continue;
 320                 }
 321
 322                 if (next_act->is_write())
 323                         curr_pred->set_write(true);
 324
 325                 if (next_act->is_read()) {
 326                         /* Only need to store the locations of read actions */
 327                         loc_act_map.put(next_act->get_location(), next_act);
 328                 }
 329
 330                 inst_pred_map.put(next_inst, curr_pred);
 331                 if (!inst_id_map.contains(next_inst))
 332                         inst_id_map.put(next_inst, inst_counter++);
 333
 334                 it = it->getNext();
 335                 curr_pred->incr_expl_count();
 336         }
 337
 338         if (curr_pred->get_exit() == NULL) {
 339                 // Exit predicate is unset yet
 340                 curr_pred->set_exit(predicate_tree_exit);
 341         }
 342
 343         update_predicate_tree_weight();
 344 }
 345
 346 /* Given curr_pred and next_inst, find the branch following curr_pred that
 347  * contains next_inst and the correct predicate.
 348  * @return true if branch found, false otherwise.
 349  */
 350 bool FuncNode::follow_branch(Predicate ** curr_pred, FuncInst * next_inst,
 351 ModelAction * next_act, Predicate ** unset_predicate)
 352 {
 353         /* Check if a branch with func_inst and corresponding predicate exists */
 354         bool branch_found = false;
 355         ModelVector<Predicate *> * branches = (*curr_pred)->get_children();
 356         for (uint i = 0;i < branches->size();i++) {
 357                 Predicate * branch = (*branches)[i];
 358                 if (branch->get_func_inst() != next_inst)
 359                         continue;
 360
 361                 /* Check against predicate expressions */
 362                 bool predicate_correct = true;
 363                 PredExprSet * pred_expressions = branch->get_pred_expressions();
 364
 365                 /* Only read and rmw actions my have unset predicate expressions */
 366                 if (pred_expressions->getSize() == 0) {
 367                         predicate_correct = false;
 368                         if (*unset_predicate == NULL)
 369                                 *unset_predicate = branch;
 370                         else
 371                                 ASSERT(false);
 372
 373                         continue;
 374                 }
 375
 376                 PredExprSetIter * pred_expr_it = pred_expressions->iterator();
 377                 while (pred_expr_it->hasNext()) {
 378                         pred_expr * pred_expression = pred_expr_it->next();
 379                         uint64_t last_read, next_read;
 380                         bool equality;
 381
 382                         switch(pred_expression->token) {
 383                                 case NOPREDICATE:
 384                                         predicate_correct = true;
 385                                         break;
 386                                 case EQUALITY:
 387                                         FuncInst * to_be_compared;
 388                                         ModelAction * last_act;
 389
 390                                         to_be_compared = pred_expression->func_inst;
 391                                         last_act = to_be_compared->get_associated_act(marker);
 392
 393                                         last_read = last_act->get_reads_from_value();
 394                                         next_read = next_act->get_reads_from_value();
 395                                         equality = (last_read == next_read);
 396                                         if (equality != pred_expression->value)
 397                                                 predicate_correct = false;
 398
 399                                         break;
 400                                 case NULLITY:
 401                                         next_read = next_act->get_reads_from_value();
 402                                         // TODO: implement likely to be null
 403                                         equality = ( (void*) (next_read & 0xffffffff) == NULL);
 404                                         if (equality != pred_expression->value)
 405                                                 predicate_correct = false;
 406                                         break;
 407                                 default:
 408                                         predicate_correct = false;
 409                                         model_print("unkown predicate token\n");
 410                                         break;
 411                         }
 412                 }
 413
 414                 if (predicate_correct) {
 415                         *curr_pred = branch;
 416                         branch_found = true;
 417                         break;
 418                 }
 419         }
 420
 421         return branch_found;
 422 }
 423
 424 /* Infer predicate expressions, which are generated in FuncNode::generate_predicates */
 425 void FuncNode::infer_predicates(FuncInst * next_inst, ModelAction * next_act,
 426 SnapVector<struct half_pred_expr *> * half_pred_expressions)
 427 {
 428         void * loc = next_act->get_location();
 429
 430         if (next_inst->is_read()) {
 431                 /* read + rmw */
 432                 if ( loc_act_map.contains(loc) ) {
 433                         ModelAction * last_act = loc_act_map.get(loc);
 434                         FuncInst * last_inst = get_inst(last_act);
 435                         struct half_pred_expr * expression = new half_pred_expr(EQUALITY, last_inst);
 436                         half_pred_expressions->push_back(expression);
 437                 } else if ( next_inst->is_single_location() ) {
 438                         loc_set_t * loc_may_equal = loc_may_equal_map->get(loc);
 439
 440                         if (loc_may_equal != NULL) {
 441                                 loc_set_iter * loc_it = loc_may_equal->iterator();
 442                                 while (loc_it->hasNext()) {
 443                                         void * neighbor = loc_it->next();
 444                                         if (loc_act_map.contains(neighbor)) {
 445                                                 ModelAction * last_act = loc_act_map.get(neighbor);
 446                                                 FuncInst * last_inst = get_inst(last_act);
 447
 448                                                 struct half_pred_expr * expression = new half_pred_expr(EQUALITY, last_inst);
 449                                                 half_pred_expressions->push_back(expression);
 450                                         }
 451                                 }
 452                         }
 453                 } else {
 454                         // next_inst is not single location
 455                         uint64_t read_val = next_act->get_reads_from_value();
 456
 457                         // only infer NULLITY predicate when it is actually NULL.
 458                         if ( (void*)read_val == NULL) {
 459                                 struct half_pred_expr * expression = new half_pred_expr(NULLITY, NULL);
 460                                 half_pred_expressions->push_back(expression);
 461                         }
 462                 }
 463         } else {
 464                 /* Pure writes */
 465                 // TODO: do anything here?
 466         }
 467 }
 468
 469 /* Able to generate complex predicates when there are multiple predciate expressions */
 470 void FuncNode::generate_predicates(Predicate * curr_pred, FuncInst * next_inst,
 471 SnapVector<struct half_pred_expr *> * half_pred_expressions)
 472 {
 473         if (half_pred_expressions->size() == 0) {
 474                 Predicate * new_pred = new Predicate(next_inst);
 475                 curr_pred->add_child(new_pred);
 476                 new_pred->set_parent(curr_pred);
 477
 478                 /* Maintain predicate leaves */
 479                 predicate_leaves.add(new_pred);
 480                 predicate_leaves.remove(curr_pred);
 481
 482                 /* entry predicates and predicates containing pure write actions
 483                  * have no predicate expressions */
 484                 if ( curr_pred->is_entry_predicate() )
 485                         new_pred->add_predicate_expr(NOPREDICATE, NULL, true);
 486                 else if (next_inst->is_write()) {
 487                         /* next_inst->is_write() <==> pure writes */
 488                         new_pred->add_predicate_expr(NOPREDICATE, NULL, true);
 489                 }
 490
 491                 return;
 492         }
 493
 494         SnapVector<Predicate *> predicates;
 495
 496         struct half_pred_expr * half_expr = (*half_pred_expressions)[0];
 497         predicates.push_back(new Predicate(next_inst));
 498         predicates.push_back(new Predicate(next_inst));
 499
 500         predicates[0]->add_predicate_expr(half_expr->token, half_expr->func_inst, true);
 501         predicates[1]->add_predicate_expr(half_expr->token, half_expr->func_inst, false);
 502
 503         for (uint i = 1;i < half_pred_expressions->size();i++) {
 504                 half_expr = (*half_pred_expressions)[i];
 505
 506                 uint old_size = predicates.size();
 507                 for (uint j = 0;j < old_size;j++) {
 508                         Predicate * pred = predicates[j];
 509                         Predicate * new_pred = new Predicate(next_inst);
 510                         new_pred->copy_predicate_expr(pred);
 511
 512                         pred->add_predicate_expr(half_expr->token, half_expr->func_inst, true);
 513                         new_pred->add_predicate_expr(half_expr->token, half_expr->func_inst, false);
 514
 515                         predicates.push_back(new_pred);
 516                 }
 517         }
 518
 519         for (uint i = 0;i < predicates.size();i++) {
 520                 Predicate * pred= predicates[i];
 521                 curr_pred->add_child(pred);
 522                 pred->set_parent(curr_pred);
 523
 524                 /* Add new predicate leaves */
 525                 predicate_leaves.add(pred);
 526         }
 527
 528         /* Remove predicate node that has children */
 529         predicate_leaves.remove(curr_pred);
 530
 531         /* Free memories allocated by infer_predicate */
 532         for (uint i = 0;i < half_pred_expressions->size();i++) {
 533                 struct half_pred_expr * tmp = (*half_pred_expressions)[i];
 534                 snapshot_free(tmp);
 535         }
 536 }
 537
 538 /* Amend predicates that contain no predicate expressions. Currenlty only amend with NULLITY predicates */
 539 bool FuncNode::amend_predicate_expr(Predicate * curr_pred, FuncInst * next_inst, ModelAction * next_act)
 540 {
 541         ModelVector<Predicate *> * children = curr_pred->get_children();
 542         ASSERT(children->size() == 1);
 543
 544         // there should only be only child
 545         Predicate * unset_pred = (*children)[0];
 546         uint64_t read_val = next_act->get_reads_from_value();
 547
 548         // only generate NULLITY predicate when it is actually NULL.
 549         if ( !next_inst->is_single_location() && (void*)read_val == NULL ) {
 550                 Predicate * new_pred = new Predicate(next_inst);
 551
 552                 curr_pred->add_child(new_pred);
 553                 new_pred->set_parent(curr_pred);
 554
 555                 unset_pred->add_predicate_expr(NULLITY, NULL, false);
 556                 new_pred->add_predicate_expr(NULLITY, NULL, true);
 557
 558                 return true;
 559         }
 560
 561         return false;
 562 }
 563
 564 void FuncNode::add_to_val_loc_map(uint64_t val, void * loc)
 565 {
 566         loc_set_t * locations = val_loc_map->get(val);
 567
 568         if (locations == NULL) {
 569                 locations = new loc_set_t();
 570                 val_loc_map->put(val, locations);
 571         }
 572
 573         update_loc_may_equal_map(loc, locations);
 574         locations->add(loc);
 575         // values_may_read_from->add(val);
 576 }
 577
 578 void FuncNode::add_to_val_loc_map(value_set_t * values, void * loc)
 579 {
 580         if (values == NULL)
 581                 return;
 582
 583         value_set_iter * it = values->iterator();
 584         while (it->hasNext()) {
 585                 uint64_t val = it->next();
 586                 add_to_val_loc_map(val, loc);
 587         }
 588 }
 589
 590 void FuncNode::update_loc_may_equal_map(void * new_loc, loc_set_t * old_locations)
 591 {
 592         if ( old_locations->contains(new_loc) )
 593                 return;
 594
 595         loc_set_t * neighbors = loc_may_equal_map->get(new_loc);
 596
 597         if (neighbors == NULL) {
 598                 neighbors = new loc_set_t();
 599                 loc_may_equal_map->put(new_loc, neighbors);
 600         }
 601
 602         loc_set_iter * loc_it = old_locations->iterator();
 603         while (loc_it->hasNext()) {
 604                 // new_loc: { old_locations, ... }
 605                 void * member = loc_it->next();
 606                 neighbors->add(member);
 607
 608                 // for each i in old_locations, i : { new_loc, ... }
 609                 loc_set_t * _neighbors = loc_may_equal_map->get(member);
 610                 if (_neighbors == NULL) {
 611                         _neighbors = new loc_set_t();
 612                         loc_may_equal_map->put(member, _neighbors);
 613                 }
 614                 _neighbors->add(new_loc);
 615         }
 616 }
 617
 618 /* Every time a thread enters a function, set its position to the predicate tree entry */
 619 void FuncNode::init_predicate_tree_position(thread_id_t tid)
 620 {
 621         int thread_id = id_to_int(tid);
 622         if (predicate_tree_position.size() <= (uint) thread_id)
 623                 predicate_tree_position.resize(thread_id + 1);
 624
 625         predicate_tree_position[thread_id] = predicate_tree_entry;
 626 }
 627
 628 void FuncNode::set_predicate_tree_position(thread_id_t tid, Predicate * pred)
 629 {
 630         int thread_id = id_to_int(tid);
 631         predicate_tree_position[thread_id] = pred;
 632 }
 633
 634 /* @return The position of a thread in a predicate tree */
 635 Predicate * FuncNode::get_predicate_tree_position(thread_id_t tid)
 636 {
 637         int thread_id = id_to_int(tid);
 638         return predicate_tree_position[thread_id];
 639 }
 640
 641 /* Make sure elements of thrd_inst_act_map are initialized properly when threads enter functions */
 642 void FuncNode::init_inst_act_map(thread_id_t tid)
 643 {
 644         int thread_id = id_to_int(tid);
 645         SnapVector<inst_act_map_t *> * thrd_inst_act_map = history->getThrdInstActMap(func_id);
 646         uint old_size = thrd_inst_act_map->size();
 647
 648         if (thrd_inst_act_map->size() <= (uint) thread_id) {
 649                 uint new_size = thread_id + 1;
 650                 thrd_inst_act_map->resize(new_size);
 651
 652                 for (uint i = old_size;i < new_size;i++)
 653                         (*thrd_inst_act_map)[i] = new inst_act_map_t(128);
 654         }
 655 }
 656
 657 /* Reset elements of thrd_inst_act_map when threads exit functions */
 658 void FuncNode::reset_inst_act_map(thread_id_t tid)
 659 {
 660         int thread_id = id_to_int(tid);
 661         SnapVector<inst_act_map_t *> * thrd_inst_act_map = history->getThrdInstActMap(func_id);
 662
 663         inst_act_map_t * map = (*thrd_inst_act_map)[thread_id];
 664         map->reset();
 665 }
 666
 667 void FuncNode::update_inst_act_map(thread_id_t tid, ModelAction * read_act)
 668 {
 669         int thread_id = id_to_int(tid);
 670         SnapVector<inst_act_map_t *> * thrd_inst_act_map = history->getThrdInstActMap(func_id);
 671
 672         inst_act_map_t * map = (*thrd_inst_act_map)[thread_id];
 673         FuncInst * read_inst = get_inst(read_act);
 674         map->put(read_inst, read_act);
 675 }
 676
 677 inst_act_map_t * FuncNode::get_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         return (*thrd_inst_act_map)[thread_id];
 683 }
 684
 685 /* Add FuncNodes that this node may follow */
 686 void FuncNode::add_out_edge(FuncNode * other)
 687 {
 688         if ( !edge_table.contains(other) ) {
 689                 edge_table.put(other, OUT_EDGE);
 690                 out_edges.push_back(other);
 691                 return;
 692         }
 693
 694         edge_type_t edge = edge_table.get(other);
 695         if (edge == IN_EDGE) {
 696                 edge_table.put(other, BI_EDGE);
 697                 out_edges.push_back(other);
 698         }
 699 }
 700
 701 /* Compute the distance between this FuncNode and the target node.
 702  * Return -1 if the target node is unreachable or the actual distance
 703  * is greater than max_step.
 704  */
 705 int FuncNode::compute_distance(FuncNode * target, int max_step)
 706 {
 707         if (target == NULL)
 708                 return -1;
 709         else if (target == this)
 710                 return 0;
 711
 712         SnapList<FuncNode *> queue;
 713         HashTable<FuncNode *, int, uintptr_t, 0> distances(128);
 714
 715         queue.push_back(this);
 716         distances.put(this, 0);
 717
 718         while (!queue.empty()) {
 719                 FuncNode * curr = queue.front();
 720                 queue.pop_front();
 721                 int dist = distances.get(curr);
 722
 723                 if (max_step <= dist)
 724                         return -1;
 725
 726                 ModelList<FuncNode *> * outEdges = curr->get_out_edges();
 727                 mllnode<FuncNode *> * it;
 728                 for (it = outEdges->begin();it != NULL;it = it->getNext()) {
 729                         FuncNode * out_node = it->getVal();
 730
 731                         /* This node has not been visited before */
 732                         if ( !distances.contains(out_node) ) {
 733                                 if (out_node == target)
 734                                         return dist + 1;
 735
 736                                 queue.push_back(out_node);
 737                                 distances.put(out_node, dist + 1);
 738                         }
 739                 }
 740         }
 741
 742         /* Target node is unreachable */
 743         return -1;
 744 }
 745
 746 /* Implement quick sort to sort leaves before assigning base scores */
 747 static int partition(SnapVector<Predicate *> * arr, int low, int high)
 748 {
 749         unsigned int pivot = (*arr)[high]->get_depth();
 750         int i = low - 1;
 751
 752         for (int j = low; j <= high - 1; j++) {
 753                 if ( (*arr)[j]->get_depth() < pivot ) {
 754                         i++;
 755                         Predicate *tmp = (*arr)[i];
 756                         (*arr)[i] = (*arr)[j];
 757                         (*arr)[j] = tmp;
 758                 }
 759         }
 760
 761         Predicate * tmp = (*arr)[i + 1];
 762         (*arr)[i + 1] = (*arr)[high];
 763         (*arr)[high] = tmp;
 764
 765         return i + 1;
 766 }
 767
 768 /* Implement quick sort to sort leaves before assigning base scores */
 769 static void quickSort(SnapVector<Predicate *> * arr, int low, int high)
 770 {
 771         if (low < high) {
 772                 int pi = partition(arr, low, high);
 773
 774                 quickSort(arr, low, pi - 1);
 775                 quickSort(arr, pi + 1, high);
 776         }
 777 }
 778
 779 void FuncNode::assign_initial_weight()
 780 {
 781         PredSetIter * it = predicate_leaves.iterator();
 782         SnapVector<Predicate *> leaves;
 783         while (it->hasNext()) {
 784                 Predicate * pred = it->next();
 785                 double weight = 100.0 / sqrt(pred->get_expl_count() + 1);
 786                 pred->set_weight(weight);
 787                 leaves.push_back(pred);
 788         }
 789
 790         quickSort(&leaves, 0, leaves.size() - 1);
 791
 792         // assign scores for internal nodes;
 793         while ( !leaves.empty() ) {
 794                 Predicate * leaf = leaves.back();
 795                 leaves.pop_back();
 796
 797                 Predicate * curr = leaf->get_parent();
 798                 while (curr != NULL) {
 799                         if (curr->get_weight() != 0) {
 800                                 // Has been exlpored
 801                                 break;
 802                         }
 803
 804                         ModelVector<Predicate *> * children = curr->get_children();
 805                         double weight_sum = 0;
 806                         bool has_unassigned_node = false;
 807
 808                         for (uint i = 0; i < children->size(); i++) {
 809                                 Predicate * child = (*children)[i];
 810
 811                                 // If a child has unassigned weight
 812                                 double weight = child->get_weight();
 813                                 if (weight == 0) {
 814                                         has_unassigned_node = true;
 815                                         break;
 816                                 } else
 817                                         weight_sum += weight;
 818                         }
 819
 820                         if (!has_unassigned_node) {
 821                                 double average_weight = (double) weight_sum / (double) children->size();
 822                                 double weight = average_weight * pow(0.9, curr->get_depth());
 823                                 curr->set_weight(weight);
 824                         } else
 825                                 break;
 826
 827                         curr = curr->get_parent();
 828                 }
 829         }
 830 }
 831
 832 void FuncNode::update_predicate_tree_weight()
 833 {
 834         if (marker == 2) {
 835                 // Predicate tree is initially built
 836                 assign_initial_weight();
 837         } else {
 838
 839         }
 840 }
 841
 842 void FuncNode::print_predicate_tree()
 843 {
 844         model_print("digraph function_%s {\n", func_name);
 845         predicate_tree_entry->print_pred_subtree();
 846         predicate_tree_exit->print_predicate();
 847         model_print("}\n");     // end of graph
 848 }