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 void FuncNode::add_inst(ModelAction *act)
  51 {
  52         ASSERT(act);
  53         const char * position = act->get_position();
  54
  55         /* THREAD* actions, ATOMIC_LOCK, ATOMIC_TRYLOCK, and ATOMIC_UNLOCK
  56          * actions are not tagged with their source line numbers
  57          */
  58         if (position == NULL)
  59                 return;
  60
  61         FuncInst * func_inst = func_inst_map.get(position);
  62
  63         /* This position has not been inserted into hashtable before */
  64         if (func_inst == NULL) {
  65                 func_inst = create_new_inst(act);
  66                 func_inst_map.put(position, func_inst);
  67                 return;
  68         }
  69
  70         /* Volatile variables that use ++ or -- syntax may result in read and write actions with the same position */
  71         if (func_inst->get_type() != act->get_type()) {
  72                 FuncInst * collision_inst = func_inst->search_in_collision(act);
  73
  74                 if (collision_inst == NULL) {
  75                         collision_inst = create_new_inst(act);
  76                         func_inst->add_to_collision(collision_inst);
  77                         return;
  78                 } else {
  79                         func_inst = collision_inst;
  80                 }
  81         }
  82
  83         ASSERT(func_inst->get_type() == act->get_type());
  84         int curr_execution_number = model->get_execution_number();
  85
  86         /* Reset locations when new executions start */
  87         if (func_inst->get_execution_number() != curr_execution_number) {
  88                 func_inst->set_location(act->get_location());
  89                 func_inst->set_execution_number(curr_execution_number);
  90         }
  91
  92         /* Mark the memory location of such inst as not unique */
  93         if (func_inst->get_location() != act->get_location())
  94                 func_inst->not_single_location();
  95 }
  96
  97 FuncInst * FuncNode::create_new_inst(ModelAction * act)
  98 {
  99         FuncInst * func_inst = new FuncInst(act, this);
 100         int exec_num = model->get_execution_number();
 101         func_inst->set_execution_number(exec_num);
 102
 103         inst_list.push_back(func_inst);
 104
 105         return func_inst;
 106 }
 107
 108
 109 /* Get the FuncInst with the same type, position, and location
 110  * as act
 111  *
 112  * @return FuncInst with the same type, position, and location as act */
 113 FuncInst * FuncNode::get_inst(ModelAction *act)
 114 {
 115         ASSERT(act);
 116         const char * position = act->get_position();
 117
 118         /* THREAD* actions, ATOMIC_LOCK, ATOMIC_TRYLOCK, and ATOMIC_UNLOCK
 119          * actions are not tagged with their source line numbers
 120          */
 121         if (position == NULL)
 122                 return NULL;
 123
 124         FuncInst * inst = func_inst_map.get(position);
 125         if (inst == NULL)
 126                 return NULL;
 127
 128         action_type inst_type = inst->get_type();
 129         action_type act_type = act->get_type();
 130
 131         if (inst_type == act_type) {
 132                 return inst;
 133         }
 134         /* RMWRCAS actions are converted to RMW or READ actions */
 135         else if (inst_type == ATOMIC_RMWRCAS &&
 136                         (act_type == ATOMIC_RMW || act_type == ATOMIC_READ)) {
 137                 return inst;
 138         }
 139         /* Return the FuncInst in the collision list */
 140         else {
 141                 return inst->search_in_collision(act);
 142         }
 143 }
 144
 145
 146 void FuncNode::add_entry_inst(FuncInst * inst)
 147 {
 148         if (inst == NULL)
 149                 return;
 150
 151         mllnode<FuncInst *> * it;
 152         for (it = entry_insts.begin(); it != NULL; it = it->getNext()) {
 153                 if (inst == it->getVal())
 154                         return;
 155         }
 156
 157         entry_insts.push_back(inst);
 158 }
 159
 160 /**
 161  * @brief Convert ModelAdtion list to FuncInst list
 162  * @param act_list A list of ModelActions
 163  */
 164 void FuncNode::update_tree(action_list_t * act_list)
 165 {
 166         if (act_list == NULL || act_list->size() == 0)
 167                 return;
 168
 169         HashTable<void *, value_set_t *, uintptr_t, 0> * write_history = history->getWriteHistory();
 170
 171         /* build inst_list from act_list for later processing */
 172         func_inst_list_t inst_list;
 173         action_list_t rw_act_list;
 174
 175         for (sllnode<ModelAction *> * it = act_list->begin(); it != NULL; it = it->getNext()) {
 176                 ModelAction * act = it->getVal();
 177                 FuncInst * func_inst = get_inst(act);
 178                 void * loc = act->get_location();
 179
 180                 if (func_inst == NULL)
 181                         continue;
 182
 183                 inst_list.push_back(func_inst);
 184                 bool act_added = false;
 185
 186                 if (act->is_write()) {
 187                         rw_act_list.push_back(act);
 188                         act_added = true;
 189                         if (!write_locations->contains(loc)) {
 190                                 write_locations->add(loc);
 191                                 history->update_loc_wr_func_nodes_map(loc, this);
 192                         }
 193                 }
 194
 195                 if (act->is_read()) {
 196                         if (!act_added)
 197                                 rw_act_list.push_back(act);
 198
 199                         /* If func_inst may only read_from a single location, then:
 200                          *
 201                          * The first time an action reads from some location,
 202                          * import all the values that have been written to this
 203                          * location from ModelHistory and notify ModelHistory
 204                          * that this FuncNode may read from this location.
 205                          */
 206                         if (!read_locations->contains(loc) && func_inst->is_single_location()) {
 207                                 read_locations->add(loc);
 208                                 value_set_t * write_values = write_history->get(loc);
 209                                 add_to_val_loc_map(write_values, loc);
 210                                 history->update_loc_rd_func_nodes_map(loc, this);
 211                         }
 212                 }
 213         }
 214
 215 //      model_print("function %s\n", func_name);
 216 //      print_val_loc_map();
 217
 218         update_inst_tree(&inst_list);
 219         update_predicate_tree(&rw_act_list);
 220
 221 //      print_predicate_tree();
 222 }
 223
 224 /**
 225  * @brief Link FuncInsts in inst_list  - add one FuncInst to another's predecessors and successors
 226  * @param inst_list A list of FuncInsts
 227  */
 228 void FuncNode::update_inst_tree(func_inst_list_t * inst_list)
 229 {
 230         if (inst_list == NULL)
 231                 return;
 232         else if (inst_list->size() == 0)
 233                 return;
 234
 235         /* start linking */
 236         sllnode<FuncInst *>* it = inst_list->begin();
 237         sllnode<FuncInst *>* prev;
 238
 239         /* add the first instruction to the list of entry insts */
 240         FuncInst * entry_inst = it->getVal();
 241         add_entry_inst(entry_inst);
 242
 243         it = it->getNext();
 244         while (it != NULL) {
 245                 prev = it->getPrev();
 246
 247                 FuncInst * prev_inst = prev->getVal();
 248                 FuncInst * curr_inst = it->getVal();
 249
 250                 prev_inst->add_succ(curr_inst);
 251                 curr_inst->add_pred(prev_inst);
 252
 253                 it = it->getNext();
 254         }
 255 }
 256
 257 void FuncNode::update_predicate_tree(action_list_t * act_list)
 258 {
 259         if (act_list == NULL || act_list->size() == 0)
 260                 return;
 261
 262         incr_marker();
 263
 264         /* Map a FuncInst to the its predicate */
 265         HashTable<FuncInst *, Predicate *, uintptr_t, 0> inst_pred_map(128);
 266
 267         // Number FuncInsts to detect loops
 268         HashTable<FuncInst *, uint32_t, uintptr_t, 0> inst_id_map(128);
 269         uint32_t inst_counter = 0;
 270
 271         /* Only need to store the locations of read actions */
 272         HashTable<void *, ModelAction *, uintptr_t, 0> loc_act_map(128);
 273
 274         sllnode<ModelAction *> *it = act_list->begin();
 275         Predicate * curr_pred = predicate_tree_entry;
 276         while (it != NULL) {
 277                 ModelAction * next_act = it->getVal();
 278                 FuncInst * next_inst = get_inst(next_act);
 279                 next_inst->set_associated_act(next_act, marker);
 280
 281                 SnapVector<Predicate *> unset_predicates = SnapVector<Predicate *>();
 282                 bool branch_found = follow_branch(&curr_pred, next_inst, next_act, &unset_predicates);
 283
 284                 // A branch with unset predicate expression is detected
 285                 if (!branch_found && unset_predicates.size() != 0) {
 286                         ASSERT(unset_predicates.size() == 1);
 287                         Predicate * one_branch = unset_predicates[0];
 288
 289                         bool amended = amend_predicate_expr(&curr_pred, next_inst, next_act);
 290                         if (amended)
 291                                 continue;
 292                         else {
 293                                 curr_pred = one_branch;
 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, &loc_act_map, &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                         loc_act_map.put(next_act->get_location(), next_act);
 327                 }
 328
 329                 inst_pred_map.put(next_inst, curr_pred);
 330                 if (!inst_id_map.contains(next_inst))
 331                         inst_id_map.put(next_inst, inst_counter++);
 332
 333                 it = it->getNext();
 334                 curr_pred->incr_expl_count();
 335         }
 336
 337         curr_pred->set_exit(predicate_tree_exit);
 338 }
 339
 340 /* Given curr_pred and next_inst, find the branch following curr_pred that
 341  * contains next_inst and the correct predicate.
 342  * @return true if branch found, false otherwise.
 343  */
 344 bool FuncNode::follow_branch(Predicate ** curr_pred, FuncInst * next_inst,
 345         ModelAction * next_act, SnapVector<Predicate *> * unset_predicates)
 346 {
 347         /* Check if a branch with func_inst and corresponding predicate exists */
 348         bool branch_found = false;
 349         ModelVector<Predicate *> * branches = (*curr_pred)->get_children();
 350         for (uint i = 0; i < branches->size(); i++) {
 351                 Predicate * branch = (*branches)[i];
 352                 if (branch->get_func_inst() != next_inst)
 353                         continue;
 354
 355                 /* Check against predicate expressions */
 356                 bool predicate_correct = true;
 357                 PredExprSet * pred_expressions = branch->get_pred_expressions();
 358                 PredExprSetIter * pred_expr_it = pred_expressions->iterator();
 359
 360                 /* Only read and rmw actions my have unset predicate expressions */
 361                 if (pred_expressions->getSize() == 0) {
 362                         predicate_correct = false;
 363                         unset_predicates->push_back(branch);
 364                 }
 365
 366                 while (pred_expr_it->hasNext()) {
 367                         pred_expr * pred_expression = pred_expr_it->next();
 368                         uint64_t last_read, next_read;
 369                         bool equality;
 370
 371                         switch(pred_expression->token) {
 372                                 case NOPREDICATE:
 373                                         predicate_correct = true;
 374                                         break;
 375                                 case EQUALITY:
 376                                         FuncInst * to_be_compared;
 377                                         ModelAction * last_act;
 378
 379                                         to_be_compared = pred_expression->func_inst;
 380                                         last_act = to_be_compared->get_associated_act(marker);
 381
 382                                         last_read = last_act->get_reads_from_value();
 383                                         next_read = next_act->get_reads_from_value();
 384                                         equality = (last_read == next_read);
 385                                         if (equality != pred_expression->value)
 386                                                 predicate_correct = false;
 387
 388                                         break;
 389                                 case NULLITY:
 390                                         next_read = next_act->get_reads_from_value();
 391                                         equality = ((void*)next_read == NULL);
 392                                         if (equality != pred_expression->value)
 393                                                 predicate_correct = false;
 394                                         break;
 395                                 default:
 396                                         predicate_correct = false;
 397                                         model_print("unkown predicate token\n");
 398                                         break;
 399                         }
 400                 }
 401
 402                 if (predicate_correct) {
 403                         *curr_pred = branch;
 404                         branch_found = true;
 405                         break;
 406                 }
 407         }
 408
 409         return branch_found;
 410 }
 411
 412 /* Infer predicate expressions, which are generated in FuncNode::generate_predicates */
 413 void FuncNode::infer_predicates(FuncInst * next_inst, ModelAction * next_act,
 414         HashTable<void *, ModelAction *, uintptr_t, 0> * loc_act_map,
 415         SnapVector<struct half_pred_expr *> * half_pred_expressions)
 416 {
 417         void * loc = next_act->get_location();
 418
 419         if (next_inst->is_read()) {
 420                 /* read + rmw */
 421                 if ( loc_act_map->contains(loc) ) {
 422                         ModelAction * last_act = loc_act_map->get(loc);
 423                         FuncInst * last_inst = get_inst(last_act);
 424                         struct half_pred_expr * expression = new half_pred_expr(EQUALITY, last_inst);
 425                         half_pred_expressions->push_back(expression);
 426                 } else if ( next_inst->is_single_location() ){
 427                         loc_set_t * loc_may_equal = loc_may_equal_map->get(loc);
 428
 429                         if (loc_may_equal != NULL) {
 430                                 loc_set_iter * loc_it = loc_may_equal->iterator();
 431                                 while (loc_it->hasNext()) {
 432                                         void * neighbor = loc_it->next();
 433                                         if (loc_act_map->contains(neighbor)) {
 434                                                 ModelAction * last_act = loc_act_map->get(neighbor);
 435                                                 FuncInst * last_inst = get_inst(last_act);
 436
 437                                                 struct half_pred_expr * expression = new half_pred_expr(EQUALITY, last_inst);
 438                                                 half_pred_expressions->push_back(expression);
 439                                         }
 440                                 }
 441                         }
 442                 } else {
 443                         // next_inst is not single location
 444                         uint64_t read_val = next_act->get_reads_from_value();
 445
 446                         // only infer NULLITY predicate when it is actually NULL.
 447                         if ( (void*)read_val == NULL) {
 448                                 struct half_pred_expr * expression = new half_pred_expr(NULLITY, NULL);
 449                                 half_pred_expressions->push_back(expression);
 450                         }
 451                 }
 452         } else {
 453                 /* Pure writes */
 454                 // TODO: do anything here?
 455         }
 456 }
 457
 458 /* Able to generate complex predicates when there are multiple predciate expressions */
 459 void FuncNode::generate_predicates(Predicate ** curr_pred, FuncInst * next_inst,
 460         SnapVector<struct half_pred_expr *> * half_pred_expressions)
 461 {
 462         if (half_pred_expressions->size() == 0) {
 463                 Predicate * new_pred = new Predicate(next_inst);
 464                 (*curr_pred)->add_child(new_pred);
 465                 new_pred->set_parent(*curr_pred);
 466
 467                 /* entry predicates and predicates containing pure write actions
 468                  * have no predicate expressions */
 469                 if ( (*curr_pred)->is_entry_predicate() )
 470                         new_pred->add_predicate_expr(NOPREDICATE, NULL, true);
 471                 else if (next_inst->is_write()) {
 472                         /* next_inst->is_write() <==> pure writes */
 473                         new_pred->add_predicate_expr(NOPREDICATE, NULL, true);
 474                 }
 475
 476                 return;
 477         }
 478
 479         SnapVector<Predicate *> predicates;
 480
 481         struct half_pred_expr * half_expr = (*half_pred_expressions)[0];
 482         predicates.push_back(new Predicate(next_inst));
 483         predicates.push_back(new Predicate(next_inst));
 484
 485         predicates[0]->add_predicate_expr(half_expr->token, half_expr->func_inst, true);
 486         predicates[1]->add_predicate_expr(half_expr->token, half_expr->func_inst, false);
 487
 488         for (uint i = 1; i < half_pred_expressions->size(); i++) {
 489                 half_expr = (*half_pred_expressions)[i];
 490
 491                 uint old_size = predicates.size();
 492                 for (uint j = 0; j < old_size; j++) {
 493                         Predicate * pred = predicates[j];
 494                         Predicate * new_pred = new Predicate(next_inst);
 495                         new_pred->copy_predicate_expr(pred);
 496
 497                         pred->add_predicate_expr(half_expr->token, half_expr->func_inst, true);
 498                         new_pred->add_predicate_expr(half_expr->token, half_expr->func_inst, false);
 499
 500                         predicates.push_back(new_pred);
 501                 }
 502         }
 503
 504         for (uint i = 0; i < predicates.size(); i++) {
 505                 Predicate * pred= predicates[i];
 506                 (*curr_pred)->add_child(pred);
 507                 pred->set_parent(*curr_pred);
 508         }
 509
 510         /* Free memories allocated by infer_predicate */
 511         for (uint i = 0; i < half_pred_expressions->size(); i++) {
 512                 struct half_pred_expr * tmp = (*half_pred_expressions)[i];
 513                 snapshot_free(tmp);
 514         }
 515 }
 516
 517 /* Amend predicates that contain no predicate expressions. Currenlty only amend with NULLITY predicates */
 518 bool FuncNode::amend_predicate_expr(Predicate ** curr_pred, FuncInst * next_inst, ModelAction * next_act)
 519 {
 520         // there should only be only child
 521         Predicate * unset_pred = (*curr_pred)->get_children()->back();
 522         uint64_t read_val = next_act->get_reads_from_value();
 523
 524         // only generate NULLITY predicate when it is actually NULL.
 525         if ( !next_inst->is_single_location() && (void*)read_val == NULL ) {
 526                 Predicate * new_pred = new Predicate(next_inst);
 527
 528                 (*curr_pred)->add_child(new_pred);
 529                 new_pred->set_parent(*curr_pred);
 530
 531                 unset_pred->add_predicate_expr(NULLITY, NULL, false);
 532                 new_pred->add_predicate_expr(NULLITY, NULL, true);
 533
 534                 return true;
 535         }
 536
 537         return false;
 538 }
 539
 540 void FuncNode::add_to_val_loc_map(uint64_t val, void * loc)
 541 {
 542         loc_set_t * locations = val_loc_map->get(val);
 543
 544         if (locations == NULL) {
 545                 locations = new loc_set_t();
 546                 val_loc_map->put(val, locations);
 547         }
 548
 549         update_loc_may_equal_map(loc, locations);
 550         locations->add(loc);
 551         // values_may_read_from->add(val);
 552 }
 553
 554 void FuncNode::add_to_val_loc_map(value_set_t * values, void * loc)
 555 {
 556         if (values == NULL)
 557                 return;
 558
 559         value_set_iter * it = values->iterator();
 560         while (it->hasNext()) {
 561                 uint64_t val = it->next();
 562                 add_to_val_loc_map(val, loc);
 563         }
 564 }
 565
 566 void FuncNode::update_loc_may_equal_map(void * new_loc, loc_set_t * old_locations)
 567 {
 568         if ( old_locations->contains(new_loc) )
 569                 return;
 570
 571         loc_set_t * neighbors = loc_may_equal_map->get(new_loc);
 572
 573         if (neighbors == NULL) {
 574                 neighbors = new loc_set_t();
 575                 loc_may_equal_map->put(new_loc, neighbors);
 576         }
 577
 578         loc_set_iter * loc_it = old_locations->iterator();
 579         while (loc_it->hasNext()) {
 580                 // new_loc: { old_locations, ... }
 581                 void * member = loc_it->next();
 582                 neighbors->add(member);
 583
 584                 // for each i in old_locations, i : { new_loc, ... }
 585                 loc_set_t * _neighbors = loc_may_equal_map->get(member);
 586                 if (_neighbors == NULL) {
 587                         _neighbors = new loc_set_t();
 588                         loc_may_equal_map->put(member, _neighbors);
 589                 }
 590                 _neighbors->add(new_loc);
 591         }
 592 }
 593
 594 /* Every time a thread enters a function, set its position to the predicate tree entry */
 595 void FuncNode::init_predicate_tree_position(thread_id_t tid)
 596 {
 597         int thread_id = id_to_int(tid);
 598         if (predicate_tree_position.size() <= (uint) thread_id)
 599                 predicate_tree_position.resize(thread_id + 1);
 600
 601         predicate_tree_position[thread_id] = predicate_tree_entry;
 602 }
 603
 604 void FuncNode::set_predicate_tree_position(thread_id_t tid, Predicate * pred)
 605 {
 606         int thread_id = id_to_int(tid);
 607         predicate_tree_position[thread_id] = pred;
 608 }
 609
 610 /* @return The position of a thread in a predicate tree */
 611 Predicate * FuncNode::get_predicate_tree_position(thread_id_t tid)
 612 {
 613         int thread_id = id_to_int(tid);
 614         return predicate_tree_position[thread_id];
 615 }
 616
 617 /* Make sure elements of thrd_inst_act_map are initialized properly when threads enter functions */
 618 void FuncNode::init_inst_act_map(thread_id_t tid)
 619 {
 620         int thread_id = id_to_int(tid);
 621         SnapVector<inst_act_map_t *> * thrd_inst_act_map = history->getThrdInstActMap(func_id);
 622         uint old_size = thrd_inst_act_map->size();
 623
 624         if (thrd_inst_act_map->size() <= (uint) thread_id) {
 625                 uint new_size = thread_id + 1;
 626                 thrd_inst_act_map->resize(new_size);
 627
 628                 for (uint i = old_size; i < new_size; i++)
 629                         (*thrd_inst_act_map)[i] = new inst_act_map_t(128);
 630         }
 631 }
 632
 633 /* Reset elements of thrd_inst_act_map when threads exit functions */
 634 void FuncNode::reset_inst_act_map(thread_id_t tid)
 635 {
 636         int thread_id = id_to_int(tid);
 637         SnapVector<inst_act_map_t *> * thrd_inst_act_map = history->getThrdInstActMap(func_id);
 638
 639         inst_act_map_t * map = (*thrd_inst_act_map)[thread_id];
 640         map->reset();
 641 }
 642
 643 void FuncNode::update_inst_act_map(thread_id_t tid, ModelAction * read_act)
 644 {
 645         int thread_id = id_to_int(tid);
 646         SnapVector<inst_act_map_t *> * thrd_inst_act_map = history->getThrdInstActMap(func_id);
 647
 648         inst_act_map_t * map = (*thrd_inst_act_map)[thread_id];
 649         FuncInst * read_inst = get_inst(read_act);
 650         map->put(read_inst, read_act);
 651 }
 652
 653 inst_act_map_t * FuncNode::get_inst_act_map(thread_id_t tid)
 654 {
 655         int thread_id = id_to_int(tid);
 656         SnapVector<inst_act_map_t *> * thrd_inst_act_map = history->getThrdInstActMap(func_id);
 657
 658         return (*thrd_inst_act_map)[thread_id];
 659 }
 660
 661 /* Add FuncNodes that this node may follow */
 662 void FuncNode::add_out_edge(FuncNode * other)
 663 {
 664         if ( !edge_table.contains(other) ) {
 665                 edge_table.put(other, OUT_EDGE);
 666                 out_edges.push_back(other);
 667                 return;
 668         }
 669
 670         edge_type_t edge = edge_table.get(other);
 671         if (edge == IN_EDGE) {
 672                 edge_table.put(other, BI_EDGE);
 673                 out_edges.push_back(other);
 674         }
 675 }
 676
 677 /* Compute the distance between this FuncNode and the target node.
 678  * Return -1 if the target node is unreachable or the actual distance
 679  * is greater than max_step.
 680  */
 681 int FuncNode::compute_distance(FuncNode * target, int max_step)
 682 {
 683         if (target == NULL)
 684                 return -1;
 685         else if (target == this)
 686                 return 0;
 687
 688         SnapList<FuncNode *> queue;
 689         HashTable<FuncNode *, int, uintptr_t, 0> distances(128);
 690
 691         queue.push_back(this);
 692         distances.put(this, 0);
 693
 694         while (!queue.empty()) {
 695                 FuncNode * curr = queue.front();
 696                 queue.pop_front();
 697                 int dist = distances.get(curr);
 698
 699                 if (max_step <= dist)
 700                         return -1;
 701
 702                 ModelList<FuncNode *> * outEdges = curr->get_out_edges();
 703                 mllnode<FuncNode *> * it;
 704                 for (it = outEdges->begin(); it != NULL; it = it->getNext()) {
 705                         FuncNode * out_node = it->getVal();
 706
 707                         /* This node has not been visited before */
 708                         if ( !distances.contains(out_node) ) {
 709                                 if (out_node == target)
 710                                         return dist + 1;
 711
 712                                 queue.push_back(out_node);
 713                                 distances.put(out_node, dist + 1);
 714                         }
 715                 }
 716         }
 717
 718         /* Target node is unreachable */
 719         return -1;
 720 }
 721
 722 void FuncNode::print_predicate_tree()
 723 {
 724         model_print("digraph function_%s {\n", func_name);
 725         predicate_tree_entry->print_pred_subtree();
 726         predicate_tree_exit->print_predicate();
 727         model_print("}\n");     // end of graph
 728 }
 729
 730 void FuncNode::print_val_loc_map()
 731 {
 732 /*
 733         value_set_iter * val_it = values_may_read_from->iterator();
 734         while (val_it->hasNext()) {
 735                 uint64_t value = val_it->next();
 736                 model_print("val %llx: ", value);
 737
 738                 loc_set_t * locations = val_loc_map->get(value);
 739                 loc_set_iter * loc_it = locations->iterator();
 740                 while (loc_it->hasNext()) {
 741                         void * location = loc_it->next();
 742                         model_print("%p ", location);
 743                 }
 744                 model_print("\n");
 745         }
 746 */
 747 }