funcnode.cc

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