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
  10 FuncNode::FuncNode(ModelHistory * history) :
  11         history(history),
  12         exit_count(0),
  13         marker(1),
  14         func_inst_map(),
  15         inst_list(),
  16         entry_insts(),
  17         predicate_tree_position(),
  18         edge_table(32),
  19         out_edges()
  20 {
  21         predicate_tree_entry = new Predicate(NULL, true);
  22         predicate_tree_entry->add_predicate_expr(NOPREDICATE, NULL, true);
  23         predicate_tree_exit = new Predicate(NULL, false, true);
  24
  25         /* Snapshot data structures below */
  26         action_list_buffer = new SnapList<action_list_t *>();
  27         read_locations = new loc_set_t();
  28         write_locations = new loc_set_t();
  29         val_loc_map = new HashTable<uint64_t, loc_set_t *, uint64_t, 0, snapshot_malloc, snapshot_calloc, snapshot_free, int64_hash>();
  30         loc_may_equal_map = new HashTable<void *, loc_set_t *, uintptr_t, 0>();
  31
  32         //values_may_read_from = new value_set_t();
  33 }
  34
  35 /* Reallocate snapshotted memories when new executions start */
  36 void FuncNode::set_new_exec_flag()
  37 {
  38         action_list_buffer = new SnapList<action_list_t *>();
  39         read_locations = new loc_set_t();
  40         write_locations = new loc_set_t();
  41         val_loc_map = new HashTable<uint64_t, loc_set_t *, uint64_t, 0, snapshot_malloc, snapshot_calloc, snapshot_free, int64_hash>();
  42         loc_may_equal_map = new HashTable<void *, loc_set_t *, uintptr_t, 0>();
  43
  44         //values_may_read_from = new value_set_t();
  45 }
  46
  47 /* Check whether FuncInst with the same type, position, and location
  48  * as act has been added to func_inst_map or not. If not, add it.
  49  *
  50  * Note: currently, actions with the same position are filtered out by process_action,
  51  * so the collision list of FuncInst is not used. May remove it later.
  52  */
  53 void FuncNode::add_inst(ModelAction *act)
  54 {
  55         ASSERT(act);
  56         const char * position = act->get_position();
  57
  58         /* THREAD* actions, ATOMIC_LOCK, ATOMIC_TRYLOCK, and ATOMIC_UNLOCK
  59          * actions are not tagged with their source line numbers
  60          */
  61         if (position == NULL)
  62                 return;
  63
  64         if ( func_inst_map.contains(position) ) {
  65                 FuncInst * inst = func_inst_map.get(position);
  66
  67                 /* TODO: The assertion fails when encountering volatile variables that use ++ or -- syntax, i.e. read and write have the same position */
  68                 ASSERT(inst->get_type() == act->get_type());
  69                 int curr_execution_number = model->get_execution_number();
  70
  71                 /* Reset locations when new executions start */
  72                 if (inst->get_execution_number() != curr_execution_number) {
  73                         inst->set_location(act->get_location());
  74                         inst->set_execution_number(curr_execution_number);
  75                 }
  76
  77                 if (inst->get_location() != act->get_location())
  78                         inst->not_single_location();
  79
  80                 return;
  81         }
  82
  83         FuncInst * func_inst = new FuncInst(act, this);
  84
  85         func_inst_map.put(position, func_inst);
  86         inst_list.push_back(func_inst);
  87 }
  88
  89 /* Get the FuncInst with the same type, position, and location
  90  * as act
  91  *
  92  * @return FuncInst with the same type, position, and location as act */
  93 FuncInst * FuncNode::get_inst(ModelAction *act)
  94 {
  95         ASSERT(act);
  96         const char * position = act->get_position();
  97
  98         /* THREAD* actions, ATOMIC_LOCK, ATOMIC_TRYLOCK, and ATOMIC_UNLOCK
  99          * actions are not tagged with their source line numbers
 100          */
 101         if (position == NULL)
 102                 return NULL;
 103
 104         FuncInst * inst = func_inst_map.get(position);
 105         if (inst == NULL)
 106                 return NULL;
 107
 108         action_type inst_type = inst->get_type();
 109         action_type act_type = act->get_type();
 110
 111         // else if branch: an RMWRCAS action is converted to a RMW or READ action
 112         if (inst_type == act_type)
 113                 return inst;
 114         else if (inst_type == ATOMIC_RMWRCAS &&
 115                         (act_type == ATOMIC_RMW || act_type == ATOMIC_READ))
 116                 return inst;
 117
 118         return NULL;
 119 }
 120
 121
 122 void FuncNode::add_entry_inst(FuncInst * inst)
 123 {
 124         if (inst == NULL)
 125                 return;
 126
 127         mllnode<FuncInst *> * it;
 128         for (it = entry_insts.begin(); it != NULL; it = it->getNext()) {
 129                 if (inst == it->getVal())
 130                         return;
 131         }
 132
 133         entry_insts.push_back(inst);
 134 }
 135
 136 /**
 137  * @brief Convert ModelAdtion list to FuncInst list
 138  * @param act_list A list of ModelActions
 139  */
 140 void FuncNode::update_tree(action_list_t * act_list)
 141 {
 142         if (act_list == NULL || act_list->size() == 0)
 143                 return;
 144
 145         HashTable<void *, value_set_t *, uintptr_t, 0> * write_history = history->getWriteHistory();
 146
 147         /* build inst_list from act_list for later processing */
 148         func_inst_list_t inst_list;
 149         action_list_t rw_act_list;
 150
 151         for (sllnode<ModelAction *> * it = act_list->begin(); it != NULL; it = it->getNext()) {
 152                 ModelAction * act = it->getVal();
 153                 FuncInst * func_inst = get_inst(act);
 154                 void * loc = act->get_location();
 155
 156                 if (func_inst == NULL)
 157                         continue;
 158
 159                 inst_list.push_back(func_inst);
 160                 bool act_added = false;
 161
 162                 if (act->is_write()) {
 163                         rw_act_list.push_back(act);
 164                         act_added = true;
 165                         if (!write_locations->contains(loc)) {
 166                                 write_locations->add(loc);
 167                                 history->update_loc_wr_func_nodes_map(loc, this);
 168                         }
 169                 }
 170
 171                 if (act->is_read()) {
 172                         if (!act_added)
 173                                 rw_act_list.push_back(act);
 174
 175                         /* If func_inst may only read_from a single location, then:
 176                          *
 177                          * The first time an action reads from some location,
 178                          * import all the values that have been written to this
 179                          * location from ModelHistory and notify ModelHistory
 180                          * that this FuncNode may read from this location.
 181                          */
 182                         if (!read_locations->contains(loc) && func_inst->is_single_location()) {
 183                                 read_locations->add(loc);
 184                                 value_set_t * write_values = write_history->get(loc);
 185                                 add_to_val_loc_map(write_values, loc);
 186                                 history->update_loc_rd_func_nodes_map(loc, this);
 187                         }
 188                 }
 189         }
 190
 191 //      model_print("function %s\n", func_name);
 192 //      print_val_loc_map();
 193
 194         update_inst_tree(&inst_list);
 195         update_predicate_tree(&rw_act_list);
 196
 197 //      print_predicate_tree();
 198 }
 199
 200 /**
 201  * @brief Link FuncInsts in inst_list  - add one FuncInst to another's predecessors and successors
 202  * @param inst_list A list of FuncInsts
 203  */
 204 void FuncNode::update_inst_tree(func_inst_list_t * inst_list)
 205 {
 206         if (inst_list == NULL)
 207                 return;
 208         else if (inst_list->size() == 0)
 209                 return;
 210
 211         /* start linking */
 212         sllnode<FuncInst *>* it = inst_list->begin();
 213         sllnode<FuncInst *>* prev;
 214
 215         /* add the first instruction to the list of entry insts */
 216         FuncInst * entry_inst = it->getVal();
 217         add_entry_inst(entry_inst);
 218
 219         it = it->getNext();
 220         while (it != NULL) {
 221                 prev = it->getPrev();
 222
 223                 FuncInst * prev_inst = prev->getVal();
 224                 FuncInst * curr_inst = it->getVal();
 225
 226                 prev_inst->add_succ(curr_inst);
 227                 curr_inst->add_pred(prev_inst);
 228
 229                 it = it->getNext();
 230         }
 231 }
 232
 233 void FuncNode::update_predicate_tree(action_list_t * act_list)
 234 {
 235         if (act_list == NULL || act_list->size() == 0)
 236                 return;
 237
 238         incr_marker();
 239
 240         /* Map a FuncInst to the its predicate */
 241         HashTable<FuncInst *, Predicate *, uintptr_t, 0> inst_pred_map(128);
 242
 243         // Number FuncInsts to detect loops
 244         HashTable<FuncInst *, uint32_t, uintptr_t, 0> inst_id_map(128);
 245         uint32_t inst_counter = 0;
 246
 247         /* Only need to store the locations of read actions */
 248         HashTable<void *, ModelAction *, uintptr_t, 0> loc_act_map(128);
 249
 250         sllnode<ModelAction *> *it = act_list->begin();
 251         Predicate * curr_pred = predicate_tree_entry;
 252         while (it != NULL) {
 253                 ModelAction * next_act = it->getVal();
 254                 FuncInst * next_inst = get_inst(next_act);
 255                 next_inst->set_associated_act(next_act, marker);
 256
 257                 SnapVector<Predicate *> unset_predicates = SnapVector<Predicate *>();
 258                 bool branch_found = follow_branch(&curr_pred, next_inst, next_act, &unset_predicates);
 259
 260                 // A branch with unset predicate expression is detected
 261                 if (!branch_found && unset_predicates.size() != 0) {
 262                         ASSERT(unset_predicates.size() == 1);
 263                         Predicate * one_branch = unset_predicates[0];
 264
 265                         bool amended = amend_predicate_expr(&curr_pred, next_inst, next_act);
 266                         if (amended)
 267                                 continue;
 268                         else {
 269                                 curr_pred = one_branch;
 270                                 branch_found = true;
 271                         }
 272                 }
 273
 274                 // Detect loops
 275                 if (!branch_found && inst_id_map.contains(next_inst)) {
 276                         FuncInst * curr_inst = curr_pred->get_func_inst();
 277                         uint32_t curr_id = inst_id_map.get(curr_inst);
 278                         uint32_t next_id = inst_id_map.get(next_inst);
 279
 280                         if (curr_id >= next_id) {
 281                                 Predicate * old_pred = inst_pred_map.get(next_inst);
 282                                 Predicate * back_pred = old_pred->get_parent();
 283
 284                                 curr_pred->add_backedge(back_pred);
 285                                 curr_pred = back_pred;
 286                                 continue;
 287                         }
 288                 }
 289
 290                 // Generate new branches
 291                 if (!branch_found) {
 292                         SnapVector<struct half_pred_expr *> half_pred_expressions;
 293                         infer_predicates(next_inst, next_act, &loc_act_map, &half_pred_expressions);
 294                         generate_predicates(&curr_pred, next_inst, &half_pred_expressions);
 295                         continue;
 296                 }
 297
 298                 if (next_act->is_write())
 299                         curr_pred->set_write(true);
 300
 301                 if (next_act->is_read()) {
 302                         loc_act_map.put(next_act->get_location(), next_act);
 303                 }
 304
 305                 inst_pred_map.put(next_inst, curr_pred);
 306                 if (!inst_id_map.contains(next_inst))
 307                         inst_id_map.put(next_inst, inst_counter++);
 308
 309                 it = it->getNext();
 310                 curr_pred->incr_expl_count();
 311         }
 312
 313         curr_pred->set_exit(predicate_tree_exit);
 314 }
 315
 316 /* Given curr_pred and next_inst, find the branch following curr_pred that
 317  * contains next_inst and the correct predicate.
 318  * @return true if branch found, false otherwise.
 319  */
 320 bool FuncNode::follow_branch(Predicate ** curr_pred, FuncInst * next_inst,
 321         ModelAction * next_act, SnapVector<Predicate *> * unset_predicates)
 322 {
 323         /* Check if a branch with func_inst and corresponding predicate exists */
 324         bool branch_found = false;
 325         ModelVector<Predicate *> * branches = (*curr_pred)->get_children();
 326         for (uint i = 0; i < branches->size(); i++) {
 327                 Predicate * branch = (*branches)[i];
 328                 if (branch->get_func_inst() != next_inst)
 329                         continue;
 330
 331                 /* Check against predicate expressions */
 332                 bool predicate_correct = true;
 333                 PredExprSet * pred_expressions = branch->get_pred_expressions();
 334                 PredExprSetIter * pred_expr_it = pred_expressions->iterator();
 335
 336                 /* Only read and rmw actions my have unset predicate expressions */
 337                 if (pred_expressions->getSize() == 0) {
 338                         predicate_correct = false;
 339                         unset_predicates->push_back(branch);
 340                 }
 341
 342                 while (pred_expr_it->hasNext()) {
 343                         pred_expr * pred_expression = pred_expr_it->next();
 344                         uint64_t last_read, next_read;
 345                         bool equality;
 346
 347                         switch(pred_expression->token) {
 348                                 case NOPREDICATE:
 349                                         predicate_correct = true;
 350                                         break;
 351                                 case EQUALITY:
 352                                         FuncInst * to_be_compared;
 353                                         ModelAction * last_act;
 354
 355                                         to_be_compared = pred_expression->func_inst;
 356                                         last_act = to_be_compared->get_associated_act(marker);
 357
 358                                         last_read = last_act->get_reads_from_value();
 359                                         next_read = next_act->get_reads_from_value();
 360                                         equality = (last_read == next_read);
 361                                         if (equality != pred_expression->value)
 362                                                 predicate_correct = false;
 363
 364                                         break;
 365                                 case NULLITY:
 366                                         next_read = next_act->get_reads_from_value();
 367                                         equality = ((void*)next_read == NULL);
 368                                         if (equality != pred_expression->value)
 369                                                 predicate_correct = false;
 370                                         break;
 371                                 default:
 372                                         predicate_correct = false;
 373                                         model_print("unkown predicate token\n");
 374                                         break;
 375                         }
 376                 }
 377
 378                 if (predicate_correct) {
 379                         *curr_pred = branch;
 380                         branch_found = true;
 381                         break;
 382                 }
 383         }
 384
 385         return branch_found;
 386 }
 387
 388 /* Infer predicate expressions, which are generated in FuncNode::generate_predicates */
 389 void FuncNode::infer_predicates(FuncInst * next_inst, ModelAction * next_act,
 390         HashTable<void *, ModelAction *, uintptr_t, 0> * loc_act_map,
 391         SnapVector<struct half_pred_expr *> * half_pred_expressions)
 392 {
 393         void * loc = next_act->get_location();
 394
 395         if (next_inst->is_read()) {
 396                 /* read + rmw */
 397                 if ( loc_act_map->contains(loc) ) {
 398                         ModelAction * last_act = loc_act_map->get(loc);
 399                         FuncInst * last_inst = get_inst(last_act);
 400                         struct half_pred_expr * expression = new half_pred_expr(EQUALITY, last_inst);
 401                         half_pred_expressions->push_back(expression);
 402                 } else if ( next_inst->is_single_location() ){
 403                         loc_set_t * loc_may_equal = loc_may_equal_map->get(loc);
 404
 405                         if (loc_may_equal != NULL) {
 406                                 loc_set_iter * loc_it = loc_may_equal->iterator();
 407                                 while (loc_it->hasNext()) {
 408                                         void * neighbor = loc_it->next();
 409                                         if (loc_act_map->contains(neighbor)) {
 410                                                 ModelAction * last_act = loc_act_map->get(neighbor);
 411                                                 FuncInst * last_inst = get_inst(last_act);
 412
 413                                                 struct half_pred_expr * expression = new half_pred_expr(EQUALITY, last_inst);
 414                                                 half_pred_expressions->push_back(expression);
 415                                         }
 416                                 }
 417                         }
 418                 } else {
 419                         // next_inst is not single location
 420                         uint64_t read_val = next_act->get_reads_from_value();
 421
 422                         // only infer NULLITY predicate when it is actually NULL.
 423                         if ( (void*)read_val == NULL) {
 424                                 struct half_pred_expr * expression = new half_pred_expr(NULLITY, NULL);
 425                                 half_pred_expressions->push_back(expression);
 426                         }
 427                 }
 428         } else {
 429                 /* Pure writes */
 430                 // TODO: do anything here?
 431         }
 432 }
 433
 434 /* Able to generate complex predicates when there are multiple predciate expressions */
 435 void FuncNode::generate_predicates(Predicate ** curr_pred, FuncInst * next_inst,
 436         SnapVector<struct half_pred_expr *> * half_pred_expressions)
 437 {
 438         if (half_pred_expressions->size() == 0) {
 439                 Predicate * new_pred = new Predicate(next_inst);
 440                 (*curr_pred)->add_child(new_pred);
 441                 new_pred->set_parent(*curr_pred);
 442
 443                 /* entry predicates and predicates containing pure write actions
 444                  * have no predicate expressions */
 445                 if ( (*curr_pred)->is_entry_predicate() )
 446                         new_pred->add_predicate_expr(NOPREDICATE, NULL, true);
 447                 else if (next_inst->is_write()) {
 448                         /* next_inst->is_write() <==> pure writes */
 449                         new_pred->add_predicate_expr(NOPREDICATE, NULL, true);
 450                 }
 451
 452                 return;
 453         }
 454
 455         SnapVector<Predicate *> predicates;
 456
 457         struct half_pred_expr * half_expr = (*half_pred_expressions)[0];
 458         predicates.push_back(new Predicate(next_inst));
 459         predicates.push_back(new Predicate(next_inst));
 460
 461         predicates[0]->add_predicate_expr(half_expr->token, half_expr->func_inst, true);
 462         predicates[1]->add_predicate_expr(half_expr->token, half_expr->func_inst, false);
 463
 464         for (uint i = 1; i < half_pred_expressions->size(); i++) {
 465                 half_expr = (*half_pred_expressions)[i];
 466
 467                 uint old_size = predicates.size();
 468                 for (uint j = 0; j < old_size; j++) {
 469                         Predicate * pred = predicates[j];
 470                         Predicate * new_pred = new Predicate(next_inst);
 471                         new_pred->copy_predicate_expr(pred);
 472
 473                         pred->add_predicate_expr(half_expr->token, half_expr->func_inst, true);
 474                         new_pred->add_predicate_expr(half_expr->token, half_expr->func_inst, false);
 475
 476                         predicates.push_back(new_pred);
 477                 }
 478         }
 479
 480         for (uint i = 0; i < predicates.size(); i++) {
 481                 Predicate * pred= predicates[i];
 482                 (*curr_pred)->add_child(pred);
 483                 pred->set_parent(*curr_pred);
 484         }
 485
 486         /* Free memories allocated by infer_predicate */
 487         for (uint i = 0; i < half_pred_expressions->size(); i++) {
 488                 struct half_pred_expr * tmp = (*half_pred_expressions)[i];
 489                 snapshot_free(tmp);
 490         }
 491 }
 492
 493 /* Amend predicates that contain no predicate expressions. Currenlty only amend with NULLITY predicates */
 494 bool FuncNode::amend_predicate_expr(Predicate ** curr_pred, FuncInst * next_inst, ModelAction * next_act)
 495 {
 496         // there should only be only child
 497         Predicate * unset_pred = (*curr_pred)->get_children()->back();
 498         uint64_t read_val = next_act->get_reads_from_value();
 499
 500         // only generate NULLITY predicate when it is actually NULL.
 501         if ( !next_inst->is_single_location() && (void*)read_val == NULL ) {
 502                 Predicate * new_pred = new Predicate(next_inst);
 503
 504                 (*curr_pred)->add_child(new_pred);
 505                 new_pred->set_parent(*curr_pred);
 506
 507                 unset_pred->add_predicate_expr(NULLITY, NULL, false);
 508                 new_pred->add_predicate_expr(NULLITY, NULL, true);
 509
 510                 return true;
 511         }
 512
 513         return false;
 514 }
 515
 516 void FuncNode::add_to_val_loc_map(uint64_t val, void * loc)
 517 {
 518         loc_set_t * locations = val_loc_map->get(val);
 519
 520         if (locations == NULL) {
 521                 locations = new loc_set_t();
 522                 val_loc_map->put(val, locations);
 523         }
 524
 525         update_loc_may_equal_map(loc, locations);
 526         locations->add(loc);
 527         // values_may_read_from->add(val);
 528 }
 529
 530 void FuncNode::add_to_val_loc_map(value_set_t * values, void * loc)
 531 {
 532         if (values == NULL)
 533                 return;
 534
 535         value_set_iter * it = values->iterator();
 536         while (it->hasNext()) {
 537                 uint64_t val = it->next();
 538                 add_to_val_loc_map(val, loc);
 539         }
 540 }
 541
 542 void FuncNode::update_loc_may_equal_map(void * new_loc, loc_set_t * old_locations)
 543 {
 544         if ( old_locations->contains(new_loc) )
 545                 return;
 546
 547         loc_set_t * neighbors = loc_may_equal_map->get(new_loc);
 548
 549         if (neighbors == NULL) {
 550                 neighbors = new loc_set_t();
 551                 loc_may_equal_map->put(new_loc, neighbors);
 552         }
 553
 554         loc_set_iter * loc_it = old_locations->iterator();
 555         while (loc_it->hasNext()) {
 556                 // new_loc: { old_locations, ... }
 557                 void * member = loc_it->next();
 558                 neighbors->add(member);
 559
 560                 // for each i in old_locations, i : { new_loc, ... }
 561                 loc_set_t * _neighbors = loc_may_equal_map->get(member);
 562                 if (_neighbors == NULL) {
 563                         _neighbors = new loc_set_t();
 564                         loc_may_equal_map->put(member, _neighbors);
 565                 }
 566                 _neighbors->add(new_loc);
 567         }
 568 }
 569
 570 /* Every time a thread enters a function, set its position to the predicate tree entry */
 571 void FuncNode::init_predicate_tree_position(thread_id_t tid)
 572 {
 573         int thread_id = id_to_int(tid);
 574         if (predicate_tree_position.size() <= (uint) thread_id)
 575                 predicate_tree_position.resize(thread_id + 1);
 576
 577         predicate_tree_position[thread_id] = predicate_tree_entry;
 578 }
 579
 580 void FuncNode::set_predicate_tree_position(thread_id_t tid, Predicate * pred)
 581 {
 582         int thread_id = id_to_int(tid);
 583         predicate_tree_position[thread_id] = pred;
 584 }
 585
 586 /* @return The position of a thread in a predicate tree */
 587 Predicate * FuncNode::get_predicate_tree_position(thread_id_t tid)
 588 {
 589         int thread_id = id_to_int(tid);
 590         return predicate_tree_position[thread_id];
 591 }
 592
 593 /* Make sure elements of thrd_inst_act_map are initialized properly when threads enter functions */
 594 void FuncNode::init_inst_act_map(thread_id_t tid)
 595 {
 596         int thread_id = id_to_int(tid);
 597         SnapVector<inst_act_map_t *> * thrd_inst_act_map = history->getThrdInstActMap(func_id);
 598         uint old_size = thrd_inst_act_map->size();
 599
 600         if (thrd_inst_act_map->size() <= (uint) thread_id) {
 601                 uint new_size = thread_id + 1;
 602                 thrd_inst_act_map->resize(new_size);
 603
 604                 for (uint i = old_size; i < new_size; i++)
 605                         (*thrd_inst_act_map)[i] = new inst_act_map_t(128);
 606         }
 607 }
 608
 609 /* Reset elements of thrd_inst_act_map when threads exit functions */
 610 void FuncNode::reset_inst_act_map(thread_id_t tid)
 611 {
 612         int thread_id = id_to_int(tid);
 613         SnapVector<inst_act_map_t *> * thrd_inst_act_map = history->getThrdInstActMap(func_id);
 614
 615         inst_act_map_t * map = (*thrd_inst_act_map)[thread_id];
 616         map->reset();
 617 }
 618
 619 void FuncNode::update_inst_act_map(thread_id_t tid, ModelAction * read_act)
 620 {
 621         int thread_id = id_to_int(tid);
 622         SnapVector<inst_act_map_t *> * thrd_inst_act_map = history->getThrdInstActMap(func_id);
 623
 624         inst_act_map_t * map = (*thrd_inst_act_map)[thread_id];
 625         FuncInst * read_inst = get_inst(read_act);
 626         map->put(read_inst, read_act);
 627 }
 628
 629 inst_act_map_t * FuncNode::get_inst_act_map(thread_id_t tid)
 630 {
 631         int thread_id = id_to_int(tid);
 632         SnapVector<inst_act_map_t *> * thrd_inst_act_map = history->getThrdInstActMap(func_id);
 633
 634         return (*thrd_inst_act_map)[thread_id];
 635 }
 636
 637 /* Add FuncNodes that this node may follow */
 638 void FuncNode::add_out_edge(FuncNode * other)
 639 {
 640         if ( !edge_table.contains(other) ) {
 641                 edge_table.put(other, OUT_EDGE);
 642                 out_edges.push_back(other);
 643                 return;
 644         }
 645
 646         edge_type_t edge = edge_table.get(other);
 647         if (edge == IN_EDGE) {
 648                 edge_table.put(other, BI_EDGE);
 649                 out_edges.push_back(other);
 650         }
 651 }
 652
 653 /* Compute the distance between this FuncNode and the target node.
 654  * Return -1 if the target node is unreachable or the actual distance
 655  * is greater than max_step.
 656  */
 657 int FuncNode::compute_distance(FuncNode * target, int max_step)
 658 {
 659         if (target == NULL)
 660                 return -1;
 661         else if (target == this)
 662                 return 0;
 663
 664         SnapList<FuncNode *> queue;
 665         HashTable<FuncNode *, int, uintptr_t, 0> distances(128);
 666
 667         queue.push_back(this);
 668         distances.put(this, 0);
 669
 670         while (!queue.empty()) {
 671                 FuncNode * curr = queue.front();
 672                 queue.pop_front();
 673                 int dist = distances.get(curr);
 674
 675                 if (max_step <= dist)
 676                         return -1;
 677
 678                 ModelList<FuncNode *> * outEdges = curr->get_out_edges();
 679                 mllnode<FuncNode *> * it;
 680                 for (it = outEdges->begin(); it != NULL; it = it->getNext()) {
 681                         FuncNode * out_node = it->getVal();
 682
 683                         /* This node has not been visited before */
 684                         if ( !distances.contains(out_node) ) {
 685                                 if (out_node == target)
 686                                         return dist + 1;
 687
 688                                 queue.push_back(out_node);
 689                                 distances.put(out_node, dist + 1);
 690                         }
 691                 }
 692         }
 693
 694         /* Target node is unreachable */
 695         return -1;
 696 }
 697
 698 void FuncNode::print_predicate_tree()
 699 {
 700         model_print("digraph function_%s {\n", func_name);
 701         predicate_tree_entry->print_pred_subtree();
 702         predicate_tree_exit->print_predicate();
 703         model_print("}\n");     // end of graph
 704 }
 705
 706 void FuncNode::print_val_loc_map()
 707 {
 708 /*
 709         value_set_iter * val_it = values_may_read_from->iterator();
 710         while (val_it->hasNext()) {
 711                 uint64_t value = val_it->next();
 712                 model_print("val %llx: ", value);
 713
 714                 loc_set_t * locations = val_loc_map->get(value);
 715                 loc_set_iter * loc_it = locations->iterator();
 716                 while (loc_it->hasNext()) {
 717                         void * location = loc_it->next();
 718                         model_print("%p ", location);
 719                 }
 720                 model_print("\n");
 721         }
 722 */
 723 }