funcnode.cc

   1 #include "funcnode.h"
   2
   3 FuncNode::FuncNode(ModelHistory * history) :
   4         history(history),
   5         predicate_tree_initialized(false),
   6         predicate_tree_entry(new Predicate(NULL, true)),
   7         exit_count(0),
   8         func_inst_map(),
   9         inst_list(),
  10         entry_insts(),
  11         thrd_read_map(),
  12         action_list_buffer()
  13 {
  14         predicate_tree_entry->add_predicate_expr(NOPREDICATE, NULL, true);
  15 }
  16
  17 void FuncNode::set_new_exec_flag()
  18 {
  19         for (uint i = 0; i < thrd_read_map.size(); i++)
  20                 thrd_read_map[i] = new read_map_t();
  21
  22         for (mllnode<FuncInst *> * it = inst_list.begin(); it != NULL; it = it->getNext()) {
  23                 FuncInst * inst = it->getVal();
  24                 inst->reset_location();
  25         }
  26 }
  27
  28 /* Check whether FuncInst with the same type, position, and location
  29  * as act has been added to func_inst_map or not. If not, add it.
  30  *
  31  * Note: currently, actions with the same position are filtered out by process_action,
  32  * so the collision list of FuncInst is not used. May remove it later.
  33  */
  34 void FuncNode::add_inst(ModelAction *act)
  35 {
  36         ASSERT(act);
  37         const char * position = act->get_position();
  38
  39         /* THREAD* actions, ATOMIC_LOCK, ATOMIC_TRYLOCK, and ATOMIC_UNLOCK
  40          * actions are not tagged with their source line numbers
  41          */
  42         if (position == NULL)
  43                 return;
  44
  45         if ( func_inst_map.contains(position) ) {
  46                 FuncInst * inst = func_inst_map.get(position);
  47
  48                 ASSERT(inst->get_type() == act->get_type());
  49
  50                 // locations are set to NULL when new executions start
  51                 if (inst->get_location() == NULL)
  52                         inst->set_location(act->get_location());
  53
  54                 if (inst->get_location() != act->get_location())
  55                         inst->not_single_location();
  56
  57                 return;
  58         }
  59
  60         FuncInst * func_inst = new FuncInst(act, this);
  61
  62         func_inst_map.put(position, func_inst);
  63         inst_list.push_back(func_inst);
  64 }
  65
  66 /* Get the FuncInst with the same type, position, and location
  67  * as act
  68  *
  69  * @return FuncInst with the same type, position, and location as act */
  70 FuncInst * FuncNode::get_inst(ModelAction *act)
  71 {
  72         ASSERT(act);
  73         const char * position = act->get_position();
  74
  75         /* THREAD* actions, ATOMIC_LOCK, ATOMIC_TRYLOCK, and ATOMIC_UNLOCK
  76          * actions are not tagged with their source line numbers
  77          */
  78         if (position == NULL)
  79                 return NULL;
  80
  81         FuncInst * inst = func_inst_map.get(position);
  82         if (inst == NULL)
  83                 return NULL;
  84
  85         action_type inst_type = inst->get_type();
  86         action_type act_type = act->get_type();
  87
  88         // else if branch: an RMWRCAS action is converted to a RMW or READ action
  89         if (inst_type == act_type)
  90                 return inst;
  91         else if (inst_type == ATOMIC_RMWRCAS &&
  92                         (act_type == ATOMIC_RMW || act_type == ATOMIC_READ))
  93                 return inst;
  94
  95         return NULL;
  96 }
  97
  98
  99 void FuncNode::add_entry_inst(FuncInst * inst)
 100 {
 101         if (inst == NULL)
 102                 return;
 103
 104         mllnode<FuncInst *> * it;
 105         for (it = entry_insts.begin(); it != NULL; it = it->getNext()) {
 106                 if (inst == it->getVal())
 107                         return;
 108         }
 109
 110         entry_insts.push_back(inst);
 111 }
 112
 113 /**
 114  * @brief Convert ModelAdtion list to FuncInst list
 115  * @param act_list A list of ModelActions
 116  */
 117 void FuncNode::update_tree(action_list_t * act_list)
 118 {
 119         if (act_list == NULL || act_list->size() == 0)
 120                 return;
 121
 122         /* build inst_list from act_list for later processing */
 123         func_inst_list_t inst_list;
 124         action_list_t read_act_list;
 125
 126         for (sllnode<ModelAction *> * it = act_list->begin(); it != NULL; it = it->getNext()) {
 127                 ModelAction * act = it->getVal();
 128                 FuncInst * func_inst = get_inst(act);
 129
 130                 if (func_inst == NULL)
 131                         continue;
 132
 133                 inst_list.push_back(func_inst);
 134
 135                 if (func_inst->is_read())
 136                         read_act_list.push_back(act);
 137         }
 138
 139 //      model_print("function %s\n", func_name);
 140         update_inst_tree(&inst_list);
 141         update_predicate_tree(&read_act_list);
 142 //      deep_update(predicate_tree_entry);
 143
 144 //      print_predicate_tree();
 145 }
 146
 147 /**
 148  * @brief Link FuncInsts in inst_list  - add one FuncInst to another's predecessors and successors
 149  * @param inst_list A list of FuncInsts
 150  */
 151 void FuncNode::update_inst_tree(func_inst_list_t * inst_list)
 152 {
 153         if (inst_list == NULL)
 154                 return;
 155         else if (inst_list->size() == 0)
 156                 return;
 157
 158         /* start linking */
 159         sllnode<FuncInst *>* it = inst_list->begin();
 160         sllnode<FuncInst *>* prev;
 161
 162         /* add the first instruction to the list of entry insts */
 163         FuncInst * entry_inst = it->getVal();
 164         add_entry_inst(entry_inst);
 165
 166         it = it->getNext();
 167         while (it != NULL) {
 168                 prev = it->getPrev();
 169
 170                 FuncInst * prev_inst = prev->getVal();
 171                 FuncInst * curr_inst = it->getVal();
 172
 173                 prev_inst->add_succ(curr_inst);
 174                 curr_inst->add_pred(prev_inst);
 175
 176                 it = it->getNext();
 177         }
 178 }
 179
 180 /* @param tid thread id
 181  * Store the values read by atomic read actions into thrd_read_map */
 182 void FuncNode::store_read(ModelAction * act, uint32_t tid)
 183 {
 184         ASSERT(act);
 185
 186         void * location = act->get_location();
 187         uint64_t read_from_val = act->get_reads_from_value();
 188
 189         /* resize and initialize */
 190
 191         uint32_t old_size = thrd_read_map.size();
 192         if (old_size <= tid) {
 193                 thrd_read_map.resize(tid + 1);
 194                 for (uint32_t i = old_size; i < tid + 1;i++)
 195                         thrd_read_map[i] = new read_map_t();
 196         }
 197
 198         read_map_t * read_map = thrd_read_map[tid];
 199         read_map->put(location, read_from_val);
 200
 201         /* Store the memory locations where atomic reads happen */
 202         // read_locations.add(location);
 203 }
 204
 205 uint64_t FuncNode::query_last_read(void * location, uint32_t tid)
 206 {
 207         if (thrd_read_map.size() <= tid)
 208                 return VALUE_NONE;
 209
 210         read_map_t * read_map = thrd_read_map[tid];
 211
 212         /* last read value not found */
 213         if ( !read_map->contains(location) )
 214                 return VALUE_NONE;
 215
 216         uint64_t read_val = read_map->get(location);
 217         return read_val;
 218 }
 219
 220 /* @param tid thread id
 221  * Reset read map for a thread. This function shall only be called
 222  * when a thread exits a function
 223  */
 224 void FuncNode::clear_read_map(uint32_t tid)
 225 {
 226         if (thrd_read_map.size() <= tid)
 227                 return;
 228
 229         thrd_read_map[tid]->reset();
 230 }
 231
 232 void FuncNode::update_predicate_tree(action_list_t * act_list)
 233 {
 234         if (act_list == NULL || act_list->size() == 0)
 235                 return;
 236 /*
 237         if (predicate_tree_initialized) {
 238                 return;
 239         }
 240         predicate_tree_initialized = true;
 241 */
 242         /* map a FuncInst to the its predicate */
 243         HashTable<FuncInst *, Predicate *, uintptr_t, 0> inst_pred_map(128);
 244
 245         // number FuncInsts to detect loops
 246         HashTable<FuncInst *, uint32_t, uintptr_t, 0> inst_id_map(128);
 247         uint32_t inst_counter = 0;
 248
 249         HashTable<void *, ModelAction *, uintptr_t, 0> loc_act_map(128);
 250         HashTable<FuncInst *, ModelAction *, uintptr_t, 0> inst_act_map(128);
 251
 252         sllnode<ModelAction *> *it = act_list->begin();
 253         Predicate * curr_pred = predicate_tree_entry;
 254         while (it != NULL) {
 255                 ModelAction * next_act = it->getVal();
 256                 FuncInst * next_inst = get_inst(next_act);
 257                 SnapVector<Predicate *> * unset_predicates = new SnapVector<Predicate *>();
 258
 259                 bool branch_found = follow_branch(&curr_pred, next_inst, next_act, &inst_act_map, unset_predicates);
 260
 261                 // no predicate expressions, follow the only branch
 262                 if (!branch_found && unset_predicates->size() != 0) {
 263                         ASSERT(unset_predicates->size() == 1);
 264                         Predicate * one_branch = (*unset_predicates)[0];
 265                         curr_pred = one_branch;
 266                         branch_found = true;
 267                 }
 268
 269                 delete unset_predicates;
 270
 271                 // detect loops
 272                 if (!branch_found && inst_id_map.contains(next_inst)) {
 273                         FuncInst * curr_inst = curr_pred->get_func_inst();
 274                         uint32_t curr_id = inst_id_map.get(curr_inst);
 275                         uint32_t next_id = inst_id_map.get(next_inst);
 276
 277                         if (curr_id >= next_id) {
 278                                 Predicate * old_pred = inst_pred_map.get(next_inst);
 279                                 Predicate * back_pred = old_pred->get_parent();
 280
 281                                 curr_pred->add_backedge(back_pred);
 282                                 curr_pred = back_pred;
 283
 284                                 continue;
 285                         }
 286                 }
 287
 288                 if (!branch_found) {
 289                         if ( loc_act_map.contains(next_act->get_location()) ) {
 290                                 ModelAction * last_act = loc_act_map.get(next_act->get_location());
 291                                 FuncInst * last_inst = get_inst(last_act);
 292
 293                                 Predicate * new_pred1 = new Predicate(next_inst);
 294                                 new_pred1->add_predicate_expr(EQUALITY, last_inst, true);
 295
 296                                 Predicate * new_pred2 = new Predicate(next_inst);
 297                                 new_pred2->add_predicate_expr(EQUALITY, last_inst, false);
 298
 299                                 curr_pred->add_child(new_pred1);
 300                                 curr_pred->add_child(new_pred2);
 301                                 new_pred1->set_parent(curr_pred);
 302                                 new_pred2->set_parent(curr_pred);
 303
 304                                 uint64_t last_read = last_act->get_reads_from_value();
 305                                 uint64_t next_read = next_act->get_reads_from_value();
 306
 307                                 if ( last_read == next_read )
 308                                         curr_pred = new_pred1;
 309                                 else
 310                                         curr_pred = new_pred2;
 311                         } else if (!next_inst->is_single_location()) {
 312                                 Predicate * new_pred1 = new Predicate(next_inst);
 313                                 new_pred1->add_predicate_expr(NULLITY, NULL, true);
 314
 315                                 Predicate * new_pred2 = new Predicate(next_inst);
 316                                 new_pred2->add_predicate_expr(NULLITY, NULL, false);
 317
 318                                 curr_pred->add_child(new_pred1);
 319                                 curr_pred->add_child(new_pred2);
 320                                 new_pred1->set_parent(curr_pred);
 321                                 new_pred2->set_parent(curr_pred);
 322
 323                                 uint64_t next_read = next_act->get_reads_from_value();
 324                                 bool isnull = ((void*)next_read == NULL);
 325                                 if (isnull)
 326                                         curr_pred = new_pred1;
 327                                 else
 328                                         curr_pred = new_pred2;
 329                         } else {
 330                                 Predicate * new_pred = new Predicate(next_inst);
 331                                 curr_pred->add_child(new_pred);
 332                                 new_pred->set_parent(curr_pred);
 333
 334                                 if (curr_pred->is_entry_predicate())
 335                                         new_pred->add_predicate_expr(NOPREDICATE, NULL, true);
 336
 337                                 curr_pred = new_pred;
 338                         }
 339                 }
 340
 341                 inst_pred_map.put(next_inst, curr_pred);
 342                 if (!inst_id_map.contains(next_inst))
 343                         inst_id_map.put(next_inst, inst_counter++);
 344
 345                 loc_act_map.put(next_act->get_location(), next_act);
 346                 inst_act_map.put(next_inst, next_act);
 347                 it = it->getNext();
 348         }
 349 }
 350
 351 void FuncNode::deep_update(Predicate * curr_pred)
 352 {
 353         FuncInst * func_inst = curr_pred->get_func_inst();
 354         if (func_inst != NULL && !func_inst->is_single_location()) {
 355                 bool has_null_pred = false;
 356                 PredExprSet * pred_expressions = curr_pred->get_pred_expressions();
 357                 PredExprSetIter * pred_expr_it = pred_expressions->iterator();
 358                 while (pred_expr_it->hasNext()) {
 359                         pred_expr * pred_expression = pred_expr_it->next();
 360                         if (pred_expression->token == NULLITY) {
 361                                 has_null_pred = true;
 362                                 break;
 363                         }
 364                 }
 365
 366                 if (!has_null_pred) {
 367 //                      func_inst->print();
 368                         Predicate * another_branch = new Predicate(func_inst);
 369                         another_branch->copy_predicate_expr(curr_pred);
 370                         another_branch->add_predicate_expr(NULLITY, NULL, 1);
 371                         curr_pred->add_predicate_expr(NULLITY, NULL, 0);
 372
 373                         Predicate * parent = curr_pred->get_parent();
 374                         parent->add_child(another_branch);
 375                 }
 376         }
 377
 378         ModelVector<Predicate *> * branches = curr_pred->get_children();
 379         for (uint i = 0; i < branches->size(); i++) {
 380                 Predicate * branch = (*branches)[i];
 381                 deep_update(branch);
 382         }
 383 }
 384
 385 /* Given curr_pred and next_inst, find the branch following curr_pred that
 386  * contains next_inst and the correct predicate.
 387  * @return true if branch found, false otherwise.
 388  */
 389 bool FuncNode::follow_branch(Predicate ** curr_pred, FuncInst * next_inst, ModelAction * next_act,
 390         HashTable<FuncInst *, ModelAction *, uintptr_t, 0> * inst_act_map,
 391         SnapVector<Predicate *> * unset_predicates)
 392 {
 393         /* check if a branch with func_inst and corresponding predicate exists */
 394         bool branch_found = false;
 395         ModelVector<Predicate *> * branches = (*curr_pred)->get_children();
 396         for (uint i = 0; i < branches->size(); i++) {
 397                 Predicate * branch = (*branches)[i];
 398                 if (branch->get_func_inst() != next_inst)
 399                         continue;
 400
 401                 /* check against predicate expressions */
 402                 bool predicate_correct = true;
 403                 PredExprSet * pred_expressions = branch->get_pred_expressions();
 404                 PredExprSetIter * pred_expr_it = pred_expressions->iterator();
 405
 406                 if (pred_expressions->getSize() == 0) {
 407                         predicate_correct = false;
 408                         unset_predicates->push_back(branch);
 409                 }
 410
 411                 while (pred_expr_it->hasNext()) {
 412                         pred_expr * pred_expression = pred_expr_it->next();
 413                         uint64_t last_read, next_read;
 414                         bool equality;
 415
 416                         switch(pred_expression->token) {
 417                                 case NOPREDICATE:
 418                                         predicate_correct = true;
 419                                         break;
 420                                 case EQUALITY:
 421                                         FuncInst * to_be_compared;
 422                                         ModelAction * last_act;
 423
 424                                         to_be_compared = pred_expression->func_inst;
 425                                         last_act = inst_act_map->get(to_be_compared);
 426
 427                                         last_read = last_act->get_reads_from_value();
 428                                         next_read = next_act->get_reads_from_value();
 429                                         equality = (last_read == next_read);
 430                                         if (equality != pred_expression->value)
 431                                                 predicate_correct = false;
 432
 433                                         break;
 434                                 case NULLITY:
 435                                         next_read = next_act->get_reads_from_value();
 436                                         equality = ((void*)next_read == NULL);
 437                                         if (equality != pred_expression->value)
 438                                                 predicate_correct = false;
 439                                         break;
 440                                 default:
 441                                         predicate_correct = false;
 442                                         model_print("unkown predicate token\n");
 443                                         break;
 444                         }
 445                 }
 446
 447                 if (predicate_correct) {
 448                         *curr_pred = branch;
 449                         branch_found = true;
 450                         break;
 451                 }
 452         }
 453
 454         return branch_found;
 455 }
 456
 457 void FuncNode::print_predicate_tree()
 458 {
 459         model_print("digraph function_%s {\n", func_name);
 460         predicate_tree_entry->print_pred_subtree();
 461         model_print("}\n");     // end of graph
 462 }
 463
 464 /* @param tid thread id
 465  * Print the values read by the last read actions for each memory location
 466  */
 467 /*
 468 void FuncNode::print_last_read(uint32_t tid)
 469 {
 470         ASSERT(thrd_read_map.size() > tid);
 471         read_map_t * read_map = thrd_read_map[tid];
 472
 473         mllnode<void *> * it;
 474         for (it = read_locations.begin();it != NULL;it=it->getNext()) {
 475                 if ( !read_map->contains(it->getVal()) )
 476                         break;
 477
 478                 uint64_t read_val = read_map->get(it->getVal());
 479                 model_print("last read of thread %d at %p: 0x%x\n", tid, it->getVal(), read_val);
 480         }
 481 }
 482 */