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