funcnode.cc

   1 #include "funcnode.h"
   2
   3 FuncNode::FuncNode(ModelHistory * history) :
   4         history(history),
   5         predicate_tree_initialized(false),
   6         exit_count(0),
   7         func_inst_map(),
   8         inst_list(),
   9         entry_insts(),
  10         action_list_buffer(),
  11         predicate_tree_position()
  12 {
  13         predicate_tree_entry = new Predicate(NULL, true);
  14         predicate_tree_entry->add_predicate_expr(NOPREDICATE, NULL, true);
  15
  16         // memories that are reclaimed after each execution
  17         read_locations = new loc_set_t();
  18         val_loc_map = new HashTable<uint64_t, loc_set_t *, uint64_t, 0>();
  19         loc_may_equal_map = new HashTable<void *, loc_set_t *, uintptr_t, 0>();
  20         thrd_inst_act_map = new SnapVector<inst_act_map_t *>();
  21
  22         //values_may_read_from = new value_set_t();
  23 }
  24
  25 /* Reallocate snapshotted memories when new executions start */
  26 void FuncNode::set_new_exec_flag()
  27 {
  28         for (mllnode<FuncInst *> * it = inst_list.begin(); it != NULL; it = it->getNext()) {
  29                 FuncInst * inst = it->getVal();
  30                 inst->unset_location();
  31         }
  32
  33         read_locations = new loc_set_t();
  34         val_loc_map = new HashTable<uint64_t, loc_set_t *, uint64_t, 0>();
  35         loc_may_equal_map = new HashTable<void *, loc_set_t *, uintptr_t, 0>();
  36         thrd_inst_act_map = new SnapVector<inst_act_map_t *>();
  37
  38         //values_may_read_from = new value_set_t();
  39 }
  40
  41 /* Check whether FuncInst with the same type, position, and location
  42  * as act has been added to func_inst_map or not. If not, add it.
  43  *
  44  * Note: currently, actions with the same position are filtered out by process_action,
  45  * so the collision list of FuncInst is not used. May remove it later.
  46  */
  47 void FuncNode::add_inst(ModelAction *act)
  48 {
  49         ASSERT(act);
  50         const char * position = act->get_position();
  51
  52         /* THREAD* actions, ATOMIC_LOCK, ATOMIC_TRYLOCK, and ATOMIC_UNLOCK
  53          * actions are not tagged with their source line numbers
  54          */
  55         if (position == NULL)
  56                 return;
  57
  58         if ( func_inst_map.contains(position) ) {
  59                 FuncInst * inst = func_inst_map.get(position);
  60
  61                 ASSERT(inst->get_type() == act->get_type());
  62
  63                 // locations are set to NULL when new executions start
  64                 if (inst->get_location() == NULL)
  65                         inst->set_location(act->get_location());
  66
  67                 if (inst->get_location() != act->get_location())
  68                         inst->not_single_location();
  69
  70                 return;
  71         }
  72
  73         FuncInst * func_inst = new FuncInst(act, this);
  74
  75         func_inst_map.put(position, func_inst);
  76         inst_list.push_back(func_inst);
  77 }
  78
  79 /* Get the FuncInst with the same type, position, and location
  80  * as act
  81  *
  82  * @return FuncInst with the same type, position, and location as act */
  83 FuncInst * FuncNode::get_inst(ModelAction *act)
  84 {
  85         ASSERT(act);
  86         const char * position = act->get_position();
  87
  88         /* THREAD* actions, ATOMIC_LOCK, ATOMIC_TRYLOCK, and ATOMIC_UNLOCK
  89          * actions are not tagged with their source line numbers
  90          */
  91         if (position == NULL)
  92                 return NULL;
  93
  94         FuncInst * inst = func_inst_map.get(position);
  95         if (inst == NULL)
  96                 return NULL;
  97
  98         action_type inst_type = inst->get_type();
  99         action_type act_type = act->get_type();
 100
 101         // else if branch: an RMWRCAS action is converted to a RMW or READ action
 102         if (inst_type == act_type)
 103                 return inst;
 104         else if (inst_type == ATOMIC_RMWRCAS &&
 105                         (act_type == ATOMIC_RMW || act_type == ATOMIC_READ))
 106                 return inst;
 107
 108         return NULL;
 109 }
 110
 111
 112 void FuncNode::add_entry_inst(FuncInst * inst)
 113 {
 114         if (inst == NULL)
 115                 return;
 116
 117         mllnode<FuncInst *> * it;
 118         for (it = entry_insts.begin(); it != NULL; it = it->getNext()) {
 119                 if (inst == it->getVal())
 120                         return;
 121         }
 122
 123         entry_insts.push_back(inst);
 124 }
 125
 126 /**
 127  * @brief Convert ModelAdtion list to FuncInst list
 128  * @param act_list A list of ModelActions
 129  */
 130 void FuncNode::update_tree(action_list_t * act_list)
 131 {
 132         if (act_list == NULL || act_list->size() == 0)
 133                 return;
 134
 135         HashTable<void *, value_set_t *, uintptr_t, 4> * write_history = history->getWriteHistory();
 136
 137         /* build inst_list from act_list for later processing */
 138         func_inst_list_t inst_list;
 139         action_list_t rw_act_list;
 140
 141         for (sllnode<ModelAction *> * it = act_list->begin(); it != NULL; it = it->getNext()) {
 142                 ModelAction * act = it->getVal();
 143                 FuncInst * func_inst = get_inst(act);
 144
 145                 if (func_inst == NULL)
 146                         continue;
 147
 148                 inst_list.push_back(func_inst);
 149
 150                 if (func_inst->is_write())
 151                         rw_act_list.push_back(act);
 152
 153                 if (func_inst->is_read()) {
 154                         rw_act_list.push_back(act);
 155                         /* If func_inst may only read_from a single location, then:
 156                          *
 157                          * The first time an action reads from some location, import all the values that have
 158                          * been written to this location from ModelHistory and notify ModelHistory that this
 159                          * FuncNode may read from this location.
 160                          */
 161                         void * loc = act->get_location();
 162                         if (!read_locations->contains(loc) && func_inst->is_single_location()) {
 163                                 read_locations->add(loc);
 164                                 value_set_t * write_values = write_history->get(loc);
 165                                 add_to_val_loc_map(write_values, loc);
 166                                 history->add_to_loc_func_nodes_map(loc, this);
 167                         }
 168                 }
 169         }
 170
 171 //      model_print("function %s\n", func_name);
 172 //      print_val_loc_map();
 173
 174         update_inst_tree(&inst_list);
 175         update_predicate_tree(&rw_act_list);
 176
 177 //      print_predicate_tree();
 178 }
 179
 180 /**
 181  * @brief Link FuncInsts in inst_list  - add one FuncInst to another's predecessors and successors
 182  * @param inst_list A list of FuncInsts
 183  */
 184 void FuncNode::update_inst_tree(func_inst_list_t * inst_list)
 185 {
 186         if (inst_list == NULL)
 187                 return;
 188         else if (inst_list->size() == 0)
 189                 return;
 190
 191         /* start linking */
 192         sllnode<FuncInst *>* it = inst_list->begin();
 193         sllnode<FuncInst *>* prev;
 194
 195         /* add the first instruction to the list of entry insts */
 196         FuncInst * entry_inst = it->getVal();
 197         add_entry_inst(entry_inst);
 198
 199         it = it->getNext();
 200         while (it != NULL) {
 201                 prev = it->getPrev();
 202
 203                 FuncInst * prev_inst = prev->getVal();
 204                 FuncInst * curr_inst = it->getVal();
 205
 206                 prev_inst->add_succ(curr_inst);
 207                 curr_inst->add_pred(prev_inst);
 208
 209                 it = it->getNext();
 210         }
 211 }
 212
 213 void FuncNode::update_predicate_tree(action_list_t * act_list)
 214 {
 215         if (act_list == NULL || act_list->size() == 0)
 216                 return;
 217
 218         /* map a FuncInst to the its predicate */
 219         HashTable<FuncInst *, Predicate *, uintptr_t, 0> inst_pred_map(128);
 220
 221         // number FuncInsts to detect loops
 222         HashTable<FuncInst *, uint32_t, uintptr_t, 0> inst_id_map(128);
 223         uint32_t inst_counter = 0;
 224
 225         HashTable<void *, ModelAction *, uintptr_t, 0> loc_act_map(128);
 226         HashTable<FuncInst *, ModelAction *, uintptr_t, 0> inst_act_map(128);
 227
 228         sllnode<ModelAction *> *it = act_list->begin();
 229         Predicate * curr_pred = predicate_tree_entry;
 230         while (it != NULL) {
 231                 ModelAction * next_act = it->getVal();
 232                 FuncInst * next_inst = get_inst(next_act);
 233
 234                 SnapVector<Predicate *> unset_predicates = SnapVector<Predicate *>();
 235                 bool branch_found = follow_branch(&curr_pred, next_inst, next_act, &inst_act_map, &unset_predicates);
 236
 237                 // A branch with unset predicate expression is detected
 238                 if (!branch_found && unset_predicates.size() != 0) {
 239                         ASSERT(unset_predicates.size() == 1);
 240                         Predicate * one_branch = unset_predicates[0];
 241
 242                         bool amended = amend_predicate_expr(&curr_pred, next_inst, next_act);
 243                         if (amended)
 244                                 continue;
 245                         else {
 246                                 curr_pred = one_branch;
 247                                 branch_found = true;
 248                         }
 249                 }
 250
 251                 // Detect loops
 252                 if (!branch_found && inst_id_map.contains(next_inst)) {
 253                         FuncInst * curr_inst = curr_pred->get_func_inst();
 254                         uint32_t curr_id = inst_id_map.get(curr_inst);
 255                         uint32_t next_id = inst_id_map.get(next_inst);
 256
 257                         if (curr_id >= next_id) {
 258                                 Predicate * old_pred = inst_pred_map.get(next_inst);
 259                                 Predicate * back_pred = old_pred->get_parent();
 260
 261                                 curr_pred->add_backedge(back_pred);
 262                                 curr_pred = back_pred;
 263
 264                                 continue;
 265                         }
 266                 }
 267
 268                 // Generate new branches
 269                 if (!branch_found) {
 270                         SnapVector<struct half_pred_expr *> half_pred_expressions;
 271                         void * loc = next_act->get_location();
 272
 273                         if (next_act->is_read()) {
 274                                 if ( loc_act_map.contains(loc) ) {
 275                                         ModelAction * last_act = loc_act_map.get(loc);
 276                                         FuncInst * last_inst = get_inst(last_act);
 277                                         struct half_pred_expr * expression = new half_pred_expr(EQUALITY, last_inst);
 278                                         half_pred_expressions.push_back(expression);
 279                                 } else if ( next_inst->is_single_location() ){
 280                                         loc_set_t * loc_may_equal = loc_may_equal_map->get(loc);
 281
 282                                         if (loc_may_equal != NULL) {
 283                                                 loc_set_iter * loc_it = loc_may_equal->iterator();
 284                                                 while (loc_it->hasNext()) {
 285                                                         void * neighbor = loc_it->next();
 286                                                         if (loc_act_map.contains(neighbor)) {
 287                                                                 ModelAction * last_act = loc_act_map.get(neighbor);
 288                                                                 FuncInst * last_inst = get_inst(last_act);
 289
 290                                                                 struct half_pred_expr * expression = new half_pred_expr(EQUALITY, last_inst);
 291                                                                 half_pred_expressions.push_back(expression);
 292                                                         }
 293                                                 }
 294                                         }
 295                                 } else {
 296                                         // next_inst is not single location
 297                                         uint64_t read_val = next_act->get_reads_from_value();
 298
 299                                         // only generate NULLITY predicate when it is actually NULL.
 300                                         if ( (void*)read_val == NULL) {
 301                                                 struct half_pred_expr * expression = new half_pred_expr(NULLITY, NULL);
 302                                                 half_pred_expressions.push_back(expression);
 303                                         }
 304                                 }
 305                         } else {
 306                                 // TODO: when next_act is a write action, do anything?
 307                         }
 308
 309                         generate_predicate(&curr_pred, next_inst, &half_pred_expressions);
 310                         continue;
 311                 }
 312
 313                 inst_pred_map.put(next_inst, curr_pred);
 314                 if (!inst_id_map.contains(next_inst))
 315                         inst_id_map.put(next_inst, inst_counter++);
 316
 317                 loc_act_map.put(next_act->get_location(), next_act);
 318                 inst_act_map.put(next_inst, next_act);
 319                 it = it->getNext();
 320         }
 321 }
 322
 323 /* Given curr_pred and next_inst, find the branch following curr_pred that
 324  * contains next_inst and the correct predicate.
 325  * @return true if branch found, false otherwise.
 326  */
 327 bool FuncNode::follow_branch(Predicate ** curr_pred, FuncInst * next_inst, ModelAction * next_act,
 328         HashTable<FuncInst *, ModelAction *, uintptr_t, 0> * inst_act_map,
 329         SnapVector<Predicate *> * unset_predicates)
 330 {
 331         /* check if a branch with func_inst and corresponding predicate exists */
 332         bool branch_found = false;
 333         ModelVector<Predicate *> * branches = (*curr_pred)->get_children();
 334         for (uint i = 0; i < branches->size(); i++) {
 335                 Predicate * branch = (*branches)[i];
 336                 if (branch->get_func_inst() != next_inst)
 337                         continue;
 338
 339                 /* check against predicate expressions */
 340                 bool predicate_correct = true;
 341                 PredExprSet * pred_expressions = branch->get_pred_expressions();
 342                 PredExprSetIter * pred_expr_it = pred_expressions->iterator();
 343
 344                 if (pred_expressions->getSize() == 0) {
 345                         predicate_correct = false;
 346                         unset_predicates->push_back(branch);
 347                 }
 348
 349                 while (pred_expr_it->hasNext()) {
 350                         pred_expr * pred_expression = pred_expr_it->next();
 351                         uint64_t last_read, next_read;
 352                         bool equality;
 353
 354                         switch(pred_expression->token) {
 355                                 case NOPREDICATE:
 356                                         predicate_correct = true;
 357                                         break;
 358                                 case EQUALITY:
 359                                         FuncInst * to_be_compared;
 360                                         ModelAction * last_act;
 361
 362                                         to_be_compared = pred_expression->func_inst;
 363                                         last_act = inst_act_map->get(to_be_compared);
 364
 365                                         last_read = last_act->get_reads_from_value();
 366                                         next_read = next_act->get_reads_from_value();
 367                                         equality = (last_read == next_read);
 368                                         if (equality != pred_expression->value)
 369                                                 predicate_correct = false;
 370
 371                                         break;
 372                                 case NULLITY:
 373                                         next_read = next_act->get_reads_from_value();
 374                                         equality = ((void*)next_read == NULL);
 375                                         if (equality != pred_expression->value)
 376                                                 predicate_correct = false;
 377                                         break;
 378                                 default:
 379                                         predicate_correct = false;
 380                                         model_print("unkown predicate token\n");
 381                                         break;
 382                         }
 383                 }
 384
 385                 if (predicate_correct) {
 386                         *curr_pred = branch;
 387                         branch_found = true;
 388                         break;
 389                 }
 390         }
 391
 392         return branch_found;
 393 }
 394
 395 /* Able to generate complex predicates when there are multiple predciate expressions */
 396 void FuncNode::generate_predicate(Predicate ** curr_pred, FuncInst * next_inst,
 397         SnapVector<struct half_pred_expr *> * half_pred_expressions)
 398 {
 399         if (half_pred_expressions->size() == 0) {
 400                 Predicate * new_pred = new Predicate(next_inst);
 401                 (*curr_pred)->add_child(new_pred);
 402                 new_pred->set_parent(*curr_pred);
 403
 404                 /* entry predicates and predicates containing write actions
 405                  * have no predicate expressions */
 406                 if ( (*curr_pred)->is_entry_predicate() )
 407                         new_pred->add_predicate_expr(NOPREDICATE, NULL, true);
 408                 else if (next_inst->is_write())
 409                         new_pred->add_predicate_expr(NOPREDICATE, NULL, true);
 410
 411                 return;
 412         }
 413
 414         SnapVector<Predicate *> predicates;
 415
 416         struct half_pred_expr * half_expr = (*half_pred_expressions)[0];
 417         predicates.push_back(new Predicate(next_inst));
 418         predicates.push_back(new Predicate(next_inst));
 419
 420         predicates[0]->add_predicate_expr(half_expr->token, half_expr->func_inst, true);
 421         predicates[1]->add_predicate_expr(half_expr->token, half_expr->func_inst, false);
 422
 423         for (uint i = 1; i < half_pred_expressions->size(); i++) {
 424                 half_expr = (*half_pred_expressions)[i];
 425
 426                 uint old_size = predicates.size();
 427                 for (uint j = 0; j < old_size; j++) {
 428                         Predicate * pred = predicates[j];
 429                         Predicate * new_pred = new Predicate(next_inst);
 430                         new_pred->copy_predicate_expr(pred);
 431
 432                         pred->add_predicate_expr(half_expr->token, half_expr->func_inst, true);
 433                         new_pred->add_predicate_expr(half_expr->token, half_expr->func_inst, false);
 434
 435                         predicates.push_back(new_pred);
 436                 }
 437         }
 438
 439         for (uint i = 0; i < predicates.size(); i++) {
 440                 Predicate * pred= predicates[i];
 441                 (*curr_pred)->add_child(pred);
 442                 pred->set_parent(*curr_pred);
 443         }
 444 }
 445
 446 /* Amend predicates that contain no predicate expressions. Currenlty only amend with NULLITY predicates */
 447 bool FuncNode::amend_predicate_expr(Predicate ** curr_pred, FuncInst * next_inst, ModelAction * next_act)
 448 {
 449         // there should only be only child
 450         Predicate * unset_pred = (*curr_pred)->get_children()->back();
 451         uint64_t read_val = next_act->get_reads_from_value();
 452
 453         // only generate NULLITY predicate when it is actually NULL.
 454         if ( !next_inst->is_single_location() && (void*)read_val == NULL ) {
 455                 Predicate * new_pred = new Predicate(next_inst);
 456
 457                 (*curr_pred)->add_child(new_pred);
 458                 new_pred->set_parent(*curr_pred);
 459
 460                 unset_pred->add_predicate_expr(NULLITY, NULL, false);
 461                 new_pred->add_predicate_expr(NULLITY, NULL, true);
 462
 463                 return true;
 464         }
 465
 466         return false;
 467 }
 468
 469 void FuncNode::add_to_val_loc_map(uint64_t val, void * loc)
 470 {
 471         loc_set_t * locations = val_loc_map->get(val);
 472
 473         if (locations == NULL) {
 474                 locations = new loc_set_t();
 475                 val_loc_map->put(val, locations);
 476         }
 477
 478         update_loc_may_equal_map(loc, locations);
 479         locations->add(loc);
 480         // values_may_read_from->add(val);
 481 }
 482
 483 void FuncNode::add_to_val_loc_map(value_set_t * values, void * loc)
 484 {
 485         if (values == NULL)
 486                 return;
 487
 488         value_set_iter * it = values->iterator();
 489         while (it->hasNext()) {
 490                 uint64_t val = it->next();
 491                 add_to_val_loc_map(val, loc);
 492         }
 493 }
 494
 495 void FuncNode::update_loc_may_equal_map(void * new_loc, loc_set_t * old_locations)
 496 {
 497         if ( old_locations->contains(new_loc) )
 498                 return;
 499
 500         loc_set_t * neighbors = loc_may_equal_map->get(new_loc);
 501
 502         if (neighbors == NULL) {
 503                 neighbors = new loc_set_t();
 504                 loc_may_equal_map->put(new_loc, neighbors);
 505         }
 506
 507         loc_set_iter * loc_it = old_locations->iterator();
 508         while (loc_it->hasNext()) {
 509                 // new_loc: { old_locations, ... }
 510                 void * member = loc_it->next();
 511                 neighbors->add(member);
 512
 513                 // for each i in old_locations, i : { new_loc, ... }
 514                 loc_set_t * _neighbors = loc_may_equal_map->get(member);
 515                 if (_neighbors == NULL) {
 516                         _neighbors = new loc_set_t();
 517                         loc_may_equal_map->put(member, _neighbors);
 518                 }
 519                 _neighbors->add(new_loc);
 520         }
 521 }
 522
 523 void FuncNode::init_predicate_tree_position(thread_id_t tid)
 524 {
 525         int thread_id = id_to_int(tid);
 526         if (predicate_tree_position.size() <= (uint) thread_id)
 527                 predicate_tree_position.resize(thread_id + 1);
 528
 529         predicate_tree_position[thread_id] = predicate_tree_entry;
 530 }
 531
 532 void FuncNode::set_predicate_tree_position(thread_id_t tid, Predicate * pred)
 533 {
 534         int thread_id = id_to_int(tid);
 535         predicate_tree_position[thread_id] = pred;
 536 }
 537
 538 Predicate * FuncNode::get_predicate_tree_position(thread_id_t tid)
 539 {
 540         int thread_id = id_to_int(tid);
 541         return predicate_tree_position[thread_id];
 542 }
 543
 544 void FuncNode::init_inst_act_map(thread_id_t tid)
 545 {
 546         int thread_id = id_to_int(tid);
 547         uint old_size = thrd_inst_act_map->size();
 548
 549         if (thrd_inst_act_map->size() <= (uint) thread_id) {
 550                 uint new_size = thread_id + 1;
 551                 thrd_inst_act_map->resize(new_size);
 552
 553                 for (uint i = old_size; i < new_size; i++)
 554                         (*thrd_inst_act_map)[i] = new inst_act_map_t(128);
 555         }
 556 }
 557
 558 void FuncNode::reset_inst_act_map(thread_id_t tid)
 559 {
 560         int thread_id = id_to_int(tid);
 561         inst_act_map_t * map = (*thrd_inst_act_map)[thread_id];
 562         map->reset();
 563 }
 564
 565 void FuncNode::update_inst_act_map(thread_id_t tid, ModelAction * read_act)
 566 {
 567         int thread_id = id_to_int(tid);
 568         inst_act_map_t * map = (*thrd_inst_act_map)[thread_id];
 569         FuncInst * read_inst = get_inst(read_act);
 570         map->put(read_inst, read_act);
 571 }
 572
 573 inst_act_map_t * FuncNode::get_inst_act_map(thread_id_t tid)
 574 {
 575         int thread_id = id_to_int(tid);
 576         return (*thrd_inst_act_map)[thread_id];
 577 }
 578
 579 void FuncNode::print_predicate_tree()
 580 {
 581         model_print("digraph function_%s {\n", func_name);
 582         predicate_tree_entry->print_pred_subtree();
 583         model_print("}\n");     // end of graph
 584 }
 585
 586 void FuncNode::print_val_loc_map()
 587 {
 588 /*
 589         value_set_iter * val_it = values_may_read_from->iterator();
 590         while (val_it->hasNext()) {
 591                 uint64_t value = val_it->next();
 592                 model_print("val %llx: ", value);
 593
 594                 loc_set_t * locations = val_loc_map->get(value);
 595                 loc_set_iter * loc_it = locations->iterator();
 596                 while (loc_it->hasNext()) {
 597                         void * location = loc_it->next();
 598                         model_print("%p ", location);
 599                 }
 600                 model_print("\n");
 601         }
 602 */
 603 }