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 //      thrd_read_map(),
  11         action_list_buffer(),
  12         predicate_tree_position()
  13 {
  14         predicate_tree_entry = new Predicate(NULL, true);
  15         predicate_tree_entry->add_predicate_expr(NOPREDICATE, NULL, true);
  16
  17         // memories that are reclaimed after each execution
  18         read_locations = new loc_set_t();
  19         val_loc_map = new HashTable<uint64_t, loc_set_t *, uint64_t, 0>();
  20         loc_may_equal_map = new HashTable<void *, loc_set_t *, uintptr_t, 0>();
  21         thrd_inst_act_map = new SnapVector<inst_act_map_t *>();
  22
  23         //values_may_read_from = new value_set_t();
  24 }
  25
  26 /* Reallocate snapshotted memories when new executions start */
  27 void FuncNode::set_new_exec_flag()
  28 {
  29 //      for (uint i = 0; i < thrd_read_map.size(); i++)
  30 //              thrd_read_map[i] = new read_map_t();
  31
  32         for (mllnode<FuncInst *> * it = inst_list.begin(); it != NULL; it = it->getNext()) {
  33                 FuncInst * inst = it->getVal();
  34                 inst->unset_location();
  35         }
  36
  37         read_locations = new loc_set_t();
  38         val_loc_map = new HashTable<uint64_t, loc_set_t *, uint64_t, 0>();
  39         loc_may_equal_map = new HashTable<void *, loc_set_t *, uintptr_t, 0>();
  40         thrd_inst_act_map = new SnapVector<inst_act_map_t *>();
  41
  42         //values_may_read_from = new value_set_t();
  43 }
  44
  45 /* Check whether FuncInst with the same type, position, and location
  46  * as act has been added to func_inst_map or not. If not, add it.
  47  *
  48  * Note: currently, actions with the same position are filtered out by process_action,
  49  * so the collision list of FuncInst is not used. May remove it later.
  50  */
  51 void FuncNode::add_inst(ModelAction *act)
  52 {
  53         ASSERT(act);
  54         const char * position = act->get_position();
  55
  56         /* THREAD* actions, ATOMIC_LOCK, ATOMIC_TRYLOCK, and ATOMIC_UNLOCK
  57          * actions are not tagged with their source line numbers
  58          */
  59         if (position == NULL)
  60                 return;
  61
  62         if ( func_inst_map.contains(position) ) {
  63                 FuncInst * inst = func_inst_map.get(position);
  64
  65                 ASSERT(inst->get_type() == act->get_type());
  66
  67                 // locations are set to NULL when new executions start
  68                 if (inst->get_location() == NULL)
  69                         inst->set_location(act->get_location());
  70
  71                 if (inst->get_location() != act->get_location())
  72                         inst->not_single_location();
  73
  74                 return;
  75         }
  76
  77         FuncInst * func_inst = new FuncInst(act, this);
  78
  79         func_inst_map.put(position, func_inst);
  80         inst_list.push_back(func_inst);
  81 }
  82
  83 /* Get the FuncInst with the same type, position, and location
  84  * as act
  85  *
  86  * @return FuncInst with the same type, position, and location as act */
  87 FuncInst * FuncNode::get_inst(ModelAction *act)
  88 {
  89         ASSERT(act);
  90         const char * position = act->get_position();
  91
  92         /* THREAD* actions, ATOMIC_LOCK, ATOMIC_TRYLOCK, and ATOMIC_UNLOCK
  93          * actions are not tagged with their source line numbers
  94          */
  95         if (position == NULL)
  96                 return NULL;
  97
  98         FuncInst * inst = func_inst_map.get(position);
  99         if (inst == NULL)
 100                 return NULL;
 101
 102         action_type inst_type = inst->get_type();
 103         action_type act_type = act->get_type();
 104
 105         // else if branch: an RMWRCAS action is converted to a RMW or READ action
 106         if (inst_type == act_type)
 107                 return inst;
 108         else if (inst_type == ATOMIC_RMWRCAS &&
 109                         (act_type == ATOMIC_RMW || act_type == ATOMIC_READ))
 110                 return inst;
 111
 112         return NULL;
 113 }
 114
 115
 116 void FuncNode::add_entry_inst(FuncInst * inst)
 117 {
 118         if (inst == NULL)
 119                 return;
 120
 121         mllnode<FuncInst *> * it;
 122         for (it = entry_insts.begin(); it != NULL; it = it->getNext()) {
 123                 if (inst == it->getVal())
 124                         return;
 125         }
 126
 127         entry_insts.push_back(inst);
 128 }
 129
 130 /**
 131  * @brief Convert ModelAdtion list to FuncInst list
 132  * @param act_list A list of ModelActions
 133  */
 134 void FuncNode::update_tree(action_list_t * act_list)
 135 {
 136         if (act_list == NULL || act_list->size() == 0)
 137                 return;
 138
 139         HashTable<void *, value_set_t *, uintptr_t, 4> * write_history = history->getWriteHistory();
 140
 141         /* build inst_list from act_list for later processing */
 142         func_inst_list_t inst_list;
 143         action_list_t read_act_list;
 144
 145         for (sllnode<ModelAction *> * it = act_list->begin(); it != NULL; it = it->getNext()) {
 146                 ModelAction * act = it->getVal();
 147                 FuncInst * func_inst = get_inst(act);
 148
 149                 if (func_inst == NULL)
 150                         continue;
 151
 152                 inst_list.push_back(func_inst);
 153
 154                 if (func_inst->is_read()) {
 155                         read_act_list.push_back(act);
 156
 157                         /* If func_inst may only read_from a single location, then:
 158                          *
 159                          * The first time an action reads from some location, import all the values that have
 160                          * been written to this location from ModelHistory and notify ModelHistory that this
 161                          * FuncNode may read from this location.
 162                          */
 163                         void * loc = act->get_location();
 164                         if (!read_locations->contains(loc) && func_inst->is_single_location()) {
 165                                 read_locations->add(loc);
 166                                 value_set_t * write_values = write_history->get(loc);
 167                                 add_to_val_loc_map(write_values, loc);
 168                                 history->add_to_loc_func_nodes_map(loc, this);
 169                         }
 170                 }
 171         }
 172
 173 //      model_print("function %s\n", func_name);
 174 //      print_val_loc_map();
 175
 176         update_inst_tree(&inst_list);
 177         update_predicate_tree(&read_act_list);
 178
 179 //      print_predicate_tree();
 180 }
 181
 182 /**
 183  * @brief Link FuncInsts in inst_list  - add one FuncInst to another's predecessors and successors
 184  * @param inst_list A list of FuncInsts
 185  */
 186 void FuncNode::update_inst_tree(func_inst_list_t * inst_list)
 187 {
 188         if (inst_list == NULL)
 189                 return;
 190         else if (inst_list->size() == 0)
 191                 return;
 192
 193         /* start linking */
 194         sllnode<FuncInst *>* it = inst_list->begin();
 195         sllnode<FuncInst *>* prev;
 196
 197         /* add the first instruction to the list of entry insts */
 198         FuncInst * entry_inst = it->getVal();
 199         add_entry_inst(entry_inst);
 200
 201         it = it->getNext();
 202         while (it != NULL) {
 203                 prev = it->getPrev();
 204
 205                 FuncInst * prev_inst = prev->getVal();
 206                 FuncInst * curr_inst = it->getVal();
 207
 208                 prev_inst->add_succ(curr_inst);
 209                 curr_inst->add_pred(prev_inst);
 210
 211                 it = it->getNext();
 212         }
 213 }
 214
 215 void FuncNode::update_predicate_tree(action_list_t * act_list)
 216 {
 217         if (act_list == NULL || act_list->size() == 0)
 218                 return;
 219
 220         /* map a FuncInst to the its predicate */
 221         HashTable<FuncInst *, Predicate *, uintptr_t, 0> inst_pred_map(128);
 222
 223         // number FuncInsts to detect loops
 224         HashTable<FuncInst *, uint32_t, uintptr_t, 0> inst_id_map(128);
 225         uint32_t inst_counter = 0;
 226
 227         HashTable<void *, ModelAction *, uintptr_t, 0> loc_act_map(128);
 228         HashTable<FuncInst *, ModelAction *, uintptr_t, 0> inst_act_map(128);
 229
 230         sllnode<ModelAction *> *it = act_list->begin();
 231         Predicate * curr_pred = predicate_tree_entry;
 232         while (it != NULL) {
 233                 ModelAction * next_act = it->getVal();
 234                 FuncInst * next_inst = get_inst(next_act);
 235
 236                 SnapVector<Predicate *> unset_predicates = SnapVector<Predicate *>();
 237                 bool branch_found = follow_branch(&curr_pred, next_inst, next_act, &inst_act_map, &unset_predicates);
 238
 239                 // no predicate expressions
 240                 if (!branch_found && unset_predicates.size() != 0) {
 241                         ASSERT(unset_predicates.size() == 1);
 242                         Predicate * one_branch = unset_predicates[0];
 243
 244                         bool amended = amend_predicate_expr(&curr_pred, next_inst, next_act);
 245                         if (amended)
 246                                 continue;
 247                         else {
 248                                 curr_pred = one_branch;
 249                                 branch_found = true;
 250                         }
 251                 }
 252
 253                 // detect loops
 254                 if (!branch_found && inst_id_map.contains(next_inst)) {
 255                         FuncInst * curr_inst = curr_pred->get_func_inst();
 256                         uint32_t curr_id = inst_id_map.get(curr_inst);
 257                         uint32_t next_id = inst_id_map.get(next_inst);
 258
 259                         if (curr_id >= next_id) {
 260                                 Predicate * old_pred = inst_pred_map.get(next_inst);
 261                                 Predicate * back_pred = old_pred->get_parent();
 262
 263                                 curr_pred->add_backedge(back_pred);
 264                                 curr_pred = back_pred;
 265
 266                                 continue;
 267                         }
 268                 }
 269
 270                 // generate new branches
 271                 if (!branch_found) {
 272                         SnapVector<struct half_pred_expr *> half_pred_expressions;
 273                         void * loc = next_act->get_location();
 274
 275                         if ( loc_act_map.contains(loc) ) {
 276                                 ModelAction * last_act = loc_act_map.get(loc);
 277                                 FuncInst * last_inst = get_inst(last_act);
 278                                 struct half_pred_expr * expression = new half_pred_expr(EQUALITY, last_inst);
 279                                 half_pred_expressions.push_back(expression);
 280                         } else if ( next_inst->is_single_location() ){
 281                                 loc_set_t * loc_may_equal = loc_may_equal_map->get(loc);
 282
 283                                 if (loc_may_equal != NULL) {
 284                                         loc_set_iter * loc_it = loc_may_equal->iterator();
 285                                         while (loc_it->hasNext()) {
 286                                                 void * neighbor = loc_it->next();
 287                                                 if (loc_act_map.contains(neighbor)) {
 288                                                         ModelAction * last_act = loc_act_map.get(neighbor);
 289                                                         FuncInst * last_inst = get_inst(last_act);
 290
 291                                                         struct half_pred_expr * expression = new half_pred_expr(EQUALITY, last_inst);
 292                                                         half_pred_expressions.push_back(expression);
 293                                                 }
 294                                         }
 295                                 }
 296                         } else {
 297                                 // next_inst is not single location
 298                                 uint64_t read_val = next_act->get_reads_from_value();
 299
 300                                 // only generate NULLITY predicate when it is actually NULL.
 301                                 if ( (void*)read_val == NULL) {
 302                                         struct half_pred_expr * expression = new half_pred_expr(NULLITY, NULL);
 303                                         half_pred_expressions.push_back(expression);
 304                                 }
 305                         }
 306
 307                         if (half_pred_expressions.size() == 0) {
 308                                 // no predicate needs to be generated
 309                                 Predicate * new_pred = new Predicate(next_inst);
 310                                 curr_pred->add_child(new_pred);
 311                                 new_pred->set_parent(curr_pred);
 312
 313                                 if (curr_pred->is_entry_predicate())
 314                                         new_pred->add_predicate_expr(NOPREDICATE, NULL, true);
 315
 316                                 curr_pred = new_pred;
 317                         } else {
 318                                 generate_predicate(&curr_pred, next_inst, &half_pred_expressions);
 319                                 bool branch_found = follow_branch(&curr_pred, next_inst, next_act, &inst_act_map, NULL);
 320                                 ASSERT(branch_found);
 321                         }
 322                 }
 323
 324                 inst_pred_map.put(next_inst, curr_pred);
 325                 if (!inst_id_map.contains(next_inst))
 326                         inst_id_map.put(next_inst, inst_counter++);
 327
 328                 loc_act_map.put(next_act->get_location(), next_act);
 329                 inst_act_map.put(next_inst, next_act);
 330                 it = it->getNext();
 331         }
 332 }
 333
 334 /* Given curr_pred and next_inst, find the branch following curr_pred that
 335  * contains next_inst and the correct predicate.
 336  * @return true if branch found, false otherwise.
 337  */
 338 bool FuncNode::follow_branch(Predicate ** curr_pred, FuncInst * next_inst, ModelAction * next_act,
 339         HashTable<FuncInst *, ModelAction *, uintptr_t, 0> * inst_act_map,
 340         SnapVector<Predicate *> * unset_predicates)
 341 {
 342         /* check if a branch with func_inst and corresponding predicate exists */
 343         bool branch_found = false;
 344         ModelVector<Predicate *> * branches = (*curr_pred)->get_children();
 345         for (uint i = 0; i < branches->size(); i++) {
 346                 Predicate * branch = (*branches)[i];
 347                 if (branch->get_func_inst() != next_inst)
 348                         continue;
 349
 350                 /* check against predicate expressions */
 351                 bool predicate_correct = true;
 352                 PredExprSet * pred_expressions = branch->get_pred_expressions();
 353                 PredExprSetIter * pred_expr_it = pred_expressions->iterator();
 354
 355                 if (pred_expressions->getSize() == 0) {
 356                         predicate_correct = false;
 357                         unset_predicates->push_back(branch);
 358                 }
 359
 360                 while (pred_expr_it->hasNext()) {
 361                         pred_expr * pred_expression = pred_expr_it->next();
 362                         uint64_t last_read, next_read;
 363                         bool equality;
 364
 365                         switch(pred_expression->token) {
 366                                 case NOPREDICATE:
 367                                         predicate_correct = true;
 368                                         break;
 369                                 case EQUALITY:
 370                                         FuncInst * to_be_compared;
 371                                         ModelAction * last_act;
 372
 373                                         to_be_compared = pred_expression->func_inst;
 374                                         last_act = inst_act_map->get(to_be_compared);
 375
 376                                         last_read = last_act->get_reads_from_value();
 377                                         next_read = next_act->get_reads_from_value();
 378                                         equality = (last_read == next_read);
 379                                         if (equality != pred_expression->value)
 380                                                 predicate_correct = false;
 381
 382                                         break;
 383                                 case NULLITY:
 384                                         next_read = next_act->get_reads_from_value();
 385                                         equality = ((void*)next_read == NULL);
 386                                         if (equality != pred_expression->value)
 387                                                 predicate_correct = false;
 388                                         break;
 389                                 default:
 390                                         predicate_correct = false;
 391                                         model_print("unkown predicate token\n");
 392                                         break;
 393                         }
 394                 }
 395
 396                 if (predicate_correct) {
 397                         *curr_pred = branch;
 398                         branch_found = true;
 399                         break;
 400                 }
 401         }
 402
 403         return branch_found;
 404 }
 405
 406 /* Able to generate complex predicates when there are multiple predciate expressions */
 407 void FuncNode::generate_predicate(Predicate ** curr_pred, FuncInst * next_inst,
 408         SnapVector<struct half_pred_expr *> * half_pred_expressions)
 409 {
 410         ASSERT(half_pred_expressions->size() != 0);
 411         SnapVector<Predicate *> predicates;
 412
 413         struct half_pred_expr * half_expr = (*half_pred_expressions)[0];
 414         predicates.push_back(new Predicate(next_inst));
 415         predicates.push_back(new Predicate(next_inst));
 416
 417         predicates[0]->add_predicate_expr(half_expr->token, half_expr->func_inst, true);
 418         predicates[1]->add_predicate_expr(half_expr->token, half_expr->func_inst, false);
 419
 420         for (uint i = 1; i < half_pred_expressions->size(); i++) {
 421                 half_expr = (*half_pred_expressions)[i];
 422
 423                 uint old_size = predicates.size();
 424                 for (uint j = 0; j < old_size; j++) {
 425                         Predicate * pred = predicates[j];
 426                         Predicate * new_pred = new Predicate(next_inst);
 427                         new_pred->copy_predicate_expr(pred);
 428
 429                         pred->add_predicate_expr(half_expr->token, half_expr->func_inst, true);
 430                         new_pred->add_predicate_expr(half_expr->token, half_expr->func_inst, false);
 431
 432                         predicates.push_back(new_pred);
 433                 }
 434         }
 435
 436         for (uint i = 0; i < predicates.size(); i++) {
 437                 Predicate * pred= predicates[i];
 438                 (*curr_pred)->add_child(pred);
 439                 pred->set_parent(*curr_pred);
 440         }
 441 }
 442
 443 /* Amend predicates that contain no predicate expressions. Currenlty only amend with NULLITY predicates */
 444 bool FuncNode::amend_predicate_expr(Predicate ** curr_pred, FuncInst * next_inst, ModelAction * next_act)
 445 {
 446         // there should only be only child
 447         Predicate * unset_pred = (*curr_pred)->get_children()->back();
 448         uint64_t read_val = next_act->get_reads_from_value();
 449
 450         // only generate NULLITY predicate when it is actually NULL.
 451         if ( !next_inst->is_single_location() && (void*)read_val == NULL ) {
 452                 Predicate * new_pred = new Predicate(next_inst);
 453
 454                 (*curr_pred)->add_child(new_pred);
 455                 new_pred->set_parent(*curr_pred);
 456
 457                 unset_pred->add_predicate_expr(NULLITY, NULL, false);
 458                 new_pred->add_predicate_expr(NULLITY, NULL, true);
 459
 460                 return true;
 461         }
 462
 463         return false;
 464 }
 465
 466 void FuncNode::add_to_val_loc_map(uint64_t val, void * loc)
 467 {
 468         loc_set_t * locations = val_loc_map->get(val);
 469
 470         if (locations == NULL) {
 471                 locations = new loc_set_t();
 472                 val_loc_map->put(val, locations);
 473         }
 474
 475         update_loc_may_equal_map(loc, locations);
 476         locations->add(loc);
 477         // values_may_read_from->add(val);
 478 }
 479
 480 void FuncNode::add_to_val_loc_map(value_set_t * values, void * loc)
 481 {
 482         if (values == NULL)
 483                 return;
 484
 485         value_set_iter * it = values->iterator();
 486         while (it->hasNext()) {
 487                 uint64_t val = it->next();
 488                 add_to_val_loc_map(val, loc);
 489         }
 490 }
 491
 492 void FuncNode::update_loc_may_equal_map(void * new_loc, loc_set_t * old_locations)
 493 {
 494         if ( old_locations->contains(new_loc) )
 495                 return;
 496
 497         loc_set_t * neighbors = loc_may_equal_map->get(new_loc);
 498
 499         if (neighbors == NULL) {
 500                 neighbors = new loc_set_t();
 501                 loc_may_equal_map->put(new_loc, neighbors);
 502         }
 503
 504         loc_set_iter * loc_it = old_locations->iterator();
 505         while (loc_it->hasNext()) {
 506                 // new_loc: { old_locations, ... }
 507                 void * member = loc_it->next();
 508                 neighbors->add(member);
 509
 510                 // for each i in old_locations, i : { new_loc, ... }
 511                 loc_set_t * _neighbors = loc_may_equal_map->get(member);
 512                 if (_neighbors == NULL) {
 513                         _neighbors = new loc_set_t();
 514                         loc_may_equal_map->put(member, _neighbors);
 515                 }
 516                 _neighbors->add(new_loc);
 517         }
 518 }
 519
 520 void FuncNode::init_predicate_tree_position(thread_id_t tid)
 521 {
 522         int thread_id = id_to_int(tid);
 523         if (predicate_tree_position.size() <= (uint) thread_id)
 524                 predicate_tree_position.resize(thread_id + 1);
 525
 526         predicate_tree_position[thread_id] = predicate_tree_entry;
 527 }
 528
 529 void FuncNode::set_predicate_tree_position(thread_id_t tid, Predicate * pred)
 530 {
 531         int thread_id = id_to_int(tid);
 532         predicate_tree_position[thread_id] = pred;
 533 }
 534
 535 Predicate * FuncNode::get_predicate_tree_position(thread_id_t tid)
 536 {
 537         int thread_id = id_to_int(tid);
 538         return predicate_tree_position[thread_id];
 539 }
 540
 541 void FuncNode::init_inst_act_map(thread_id_t tid)
 542 {
 543         int thread_id = id_to_int(tid);
 544         uint old_size = thrd_inst_act_map->size();
 545
 546         if (thrd_inst_act_map->size() <= (uint) thread_id) {
 547                 uint new_size = thread_id + 1;
 548                 thrd_inst_act_map->resize(new_size);
 549
 550                 for (uint i = old_size; i < new_size; i++)
 551                         (*thrd_inst_act_map)[i] = new inst_act_map_t(128);
 552         }
 553 }
 554
 555 void FuncNode::reset_inst_act_map(thread_id_t tid)
 556 {
 557         int thread_id = id_to_int(tid);
 558         inst_act_map_t * map = (*thrd_inst_act_map)[thread_id];
 559         map->reset();
 560 }
 561
 562 void FuncNode::update_inst_act_map(thread_id_t tid, ModelAction * read_act)
 563 {
 564         int thread_id = id_to_int(tid);
 565         inst_act_map_t * map = (*thrd_inst_act_map)[thread_id];
 566         FuncInst * read_inst = get_inst(read_act);
 567         map->put(read_inst, read_act);
 568 }
 569
 570 inst_act_map_t * FuncNode::get_inst_act_map(thread_id_t tid)
 571 {
 572         int thread_id = id_to_int(tid);
 573         return (*thrd_inst_act_map)[thread_id];
 574 }
 575
 576 void FuncNode::print_predicate_tree()
 577 {
 578         model_print("digraph function_%s {\n", func_name);
 579         predicate_tree_entry->print_pred_subtree();
 580         model_print("}\n");     // end of graph
 581 }
 582
 583 void FuncNode::print_val_loc_map()
 584 {
 585 /*
 586         value_set_iter * val_it = values_may_read_from->iterator();
 587         while (val_it->hasNext()) {
 588                 uint64_t value = val_it->next();
 589                 model_print("val %llx: ", value);
 590
 591                 loc_set_t * locations = val_loc_map->get(value);
 592                 loc_set_iter * loc_it = locations->iterator();
 593                 while (loc_it->hasNext()) {
 594                         void * location = loc_it->next();
 595                         model_print("%p ", location);
 596                 }
 597                 model_print("\n");
 598         }
 599 */
 600 }
 601
 602 /* @param tid thread id
 603  * Print the values read by the last read actions for each memory location
 604  */
 605 /*
 606 void FuncNode::print_last_read(thread_id_t tid)
 607 {
 608         ASSERT(thrd_read_map.size() > tid);
 609         read_map_t * read_map = thrd_read_map[tid];
 610
 611         mllnode<void *> * it;
 612         for (it = read_locations.begin();it != NULL;it=it->getNext()) {
 613                 if ( !read_map->contains(it->getVal()) )
 614                         break;
 615
 616                 uint64_t read_val = read_map->get(it->getVal());
 617                 model_print("last read of thread %d at %p: 0x%x\n", tid, it->getVal(), read_val);
 618         }
 619 }
 620 */