history.cc

   1 #include <inttypes.h>
   2 #include "history.h"
   3 #include "action.h"
   4 #include "funcnode.h"
   5 #include "funcinst.h"
   6 #include "common.h"
   7 #include "concretepredicate.h"
   8 #include "waitobj.h"
   9
  10 #include "model.h"
  11 #include "execution.h"
  12 #include "newfuzzer.h"
  13
  14 /** @brief Constructor */
  15 ModelHistory::ModelHistory() :
  16         func_counter(1),        /* function id starts with 1 */
  17         func_map(),
  18         func_map_rev(),
  19         func_nodes(),
  20         last_action(NULL)
  21 {
  22         /* The following are snapshot data structures */
  23         write_history = new HashTable<void *, value_set_t *, uintptr_t, 0>();
  24         loc_rd_func_nodes_map = new HashTable<void *, SnapVector<FuncNode *> *, uintptr_t, 0>();
  25         loc_wr_func_nodes_map = new HashTable<void *, SnapVector<FuncNode *> *, uintptr_t, 0>();
  26         loc_waiting_writes_map = new HashTable<void *, SnapVector<ConcretePredicate *> *, uintptr_t, 0>();
  27         thrd_func_list = new SnapVector<func_id_list_t>();
  28         thrd_last_entered_func = new SnapVector<uint32_t>();
  29         thrd_waiting_write = new SnapVector<ConcretePredicate *>();
  30         thrd_wait_obj = new SnapVector<WaitObj *>();
  31         func_inst_act_maps = new HashTable<uint32_t, SnapVector<inst_act_map_t *> *, int, 0>(128);
  32 }
  33
  34 ModelHistory::~ModelHistory()
  35 {
  36         // TODO: complete deconstructor; maybe not needed
  37         for (uint i = 0;i < thrd_wait_obj->size();i++)
  38                 delete (*thrd_wait_obj)[i];
  39 }
  40
  41 void ModelHistory::enter_function(const uint32_t func_id, thread_id_t tid)
  42 {
  43         //model_print("thread %d entering func %d\n", tid, func_id);
  44         uint id = id_to_int(tid);
  45
  46         if ( thrd_func_list->size() <= id ) {
  47                 uint oldsize = thrd_func_list->size();
  48                 thrd_func_list->resize( id + 1 );
  49
  50                 for (uint i = oldsize;i < id + 1;i++) {
  51                         // push 0 as a dummy function id to a void seg fault
  52                         new (&(*thrd_func_list)[i]) func_id_list_t();
  53                         (*thrd_func_list)[i].push_back(0);
  54                         thrd_last_entered_func->push_back(0);
  55                 }
  56         }
  57
  58         uint32_t last_entered_func_id = (*thrd_last_entered_func)[id];
  59         (*thrd_last_entered_func)[id] = func_id;
  60         (*thrd_func_list)[id].push_back(func_id);
  61
  62         if ( func_nodes.size() <= func_id )
  63                 resize_func_nodes( func_id + 1 );
  64
  65         FuncNode * func_node = func_nodes[func_id];
  66         func_node->function_entry_handler(tid);
  67
  68         /* Add edges between FuncNodes */
  69         if (last_entered_func_id != 0) {
  70                 FuncNode * last_func_node = func_nodes[last_entered_func_id];
  71                 last_func_node->add_out_edge(func_node);
  72         }
  73
  74         /* Monitor the statuses of threads waiting for tid */
  75         // monitor_waiting_thread(func_id, tid);
  76 }
  77
  78 /* @param func_id a non-zero value */
  79 void ModelHistory::exit_function(const uint32_t func_id, thread_id_t tid)
  80 {
  81         uint32_t id = id_to_int(tid);
  82         uint32_t last_func_id = (*thrd_func_list)[id].back();
  83
  84         if (last_func_id == func_id) {
  85                 FuncNode * func_node = func_nodes[func_id];
  86                 func_node->function_exit_handler(tid);
  87
  88                 (*thrd_func_list)[id].pop_back();
  89         } else {
  90                 ASSERT(false);
  91         }
  92         //model_print("thread %d exiting func %d\n", tid, func_id);
  93 }
  94
  95 void ModelHistory::resize_func_nodes(uint32_t new_size)
  96 {
  97         uint32_t old_size = func_nodes.size();
  98
  99         if ( old_size < new_size )
 100                 func_nodes.resize(new_size);
 101
 102         for (uint32_t id = old_size;id < new_size;id++) {
 103                 const char * func_name = func_map_rev[id];
 104                 FuncNode * func_node = new FuncNode(this);
 105                 func_node->set_func_id(id);
 106                 func_node->set_func_name(func_name);
 107                 func_nodes[id] = func_node;
 108         }
 109 }
 110
 111 void ModelHistory::process_action(ModelAction *act, thread_id_t tid)
 112 {
 113         uint32_t thread_id = id_to_int(tid);
 114         /* Return if thread tid has not entered any function that contains atomics */
 115         if ( thrd_func_list->size() <= thread_id )
 116                 return;
 117
 118         /* Monitor the statuses of threads waiting for tid */
 119         // monitor_waiting_thread_counter(tid);
 120
 121         /* Every write action should be processed, including
 122          * nonatomic writes (which have no position) */
 123         if (act->is_write()) {
 124                 void * location = act->get_location();
 125                 uint64_t value = act->get_write_value();
 126                 update_write_history(location, value);
 127
 128                 /* Notify FuncNodes that may read from this location */
 129                 SnapVector<FuncNode *> * func_node_list = getRdFuncNodes(location);
 130                 for (uint i = 0;i < func_node_list->size();i++) {
 131                         FuncNode * func_node = (*func_node_list)[i];
 132                         func_node->add_to_val_loc_map(value, location);
 133                 }
 134
 135                 // check_waiting_write(act);
 136         }
 137
 138         uint32_t func_id = (*thrd_func_list)[thread_id].back();
 139
 140         /* The following does not care about actions that are not inside
 141          * any function that contains atomics or actions without a position */
 142         if (func_id == 0 || act->get_position() == NULL)
 143                 return;
 144
 145         if (skip_action(act))
 146                 return;
 147
 148         FuncNode * func_node = func_nodes[func_id];
 149         func_node->add_inst(act);
 150
 151         if (act->is_read()) {
 152                 func_node->update_inst_act_map(tid, act);
 153
 154 //              Fuzzer * fuzzer = model->get_execution()->getFuzzer();
 155 //              Predicate * selected_branch = ((NewFuzzer *)fuzzer)->get_selected_child_branch(tid);
 156 //              func_node->set_predicate_tree_position(tid, selected_branch);
 157         }
 158 /*
 159         if (act->is_write()) {
 160                 Predicate * curr_pred = func_node->get_predicate_tree_position(tid);
 161                 FuncInst * curr_inst = func_node->get_inst(act);
 162
 163                 if (curr_pred) {
 164                         // Follow child
 165                         curr_pred = curr_pred->follow_write_child(curr_inst);
 166                 }
 167                 func_node->set_predicate_tree_position(tid, curr_pred);
 168         }
 169 */
 170
 171         func_node->update_tree(act);
 172         last_action = act;
 173 }
 174
 175 /* Return the FuncNode given its func_id  */
 176 FuncNode * ModelHistory::get_func_node(uint32_t func_id)
 177 {
 178         if (func_id == 0)
 179                 return NULL;
 180
 181         // This node has not been added to func_nodes
 182         if (func_nodes.size() <= func_id)
 183                 return NULL;
 184
 185         return func_nodes[func_id];
 186 }
 187
 188 /* Return the current FuncNode when given a thread id */
 189 FuncNode * ModelHistory::get_curr_func_node(thread_id_t tid)
 190 {
 191         int thread_id = id_to_int(tid);
 192         uint32_t func_id = (*thrd_func_list)[thread_id].back();
 193
 194         if (func_id != 0) {
 195                 return func_nodes[func_id];
 196         }
 197
 198         return NULL;
 199 }
 200
 201 void ModelHistory::update_write_history(void * location, uint64_t write_val)
 202 {
 203         value_set_t * write_set = write_history->get(location);
 204
 205         if (write_set == NULL) {
 206                 write_set = new value_set_t();
 207                 write_history->put(location, write_set);
 208         }
 209
 210         write_set->add(write_val);
 211 }
 212
 213 void ModelHistory::update_loc_rd_func_nodes_map(void * location, FuncNode * node)
 214 {
 215         SnapVector<FuncNode *> * func_node_list = getRdFuncNodes(location);
 216         func_node_list->push_back(node);
 217 }
 218
 219 void ModelHistory::update_loc_wr_func_nodes_map(void * location, FuncNode * node)
 220 {
 221         SnapVector<FuncNode *> * func_node_list = getWrFuncNodes(location);
 222         func_node_list->push_back(node);
 223 }
 224
 225 SnapVector<FuncNode *> * ModelHistory::getRdFuncNodes(void * location)
 226 {
 227         SnapVector<FuncNode *> * func_node_list = loc_rd_func_nodes_map->get(location);
 228         if (func_node_list == NULL) {
 229                 func_node_list = new SnapVector<FuncNode *>();
 230                 loc_rd_func_nodes_map->put(location, func_node_list);
 231         }
 232
 233         return func_node_list;
 234 }
 235
 236 SnapVector<FuncNode *> * ModelHistory::getWrFuncNodes(void * location)
 237 {
 238         SnapVector<FuncNode *> * func_node_list = loc_wr_func_nodes_map->get(location);
 239         if (func_node_list == NULL) {
 240                 func_node_list = new SnapVector<FuncNode *>();
 241                 loc_wr_func_nodes_map->put(location, func_node_list);
 242         }
 243
 244         return func_node_list;
 245 }
 246
 247 /* When a thread is paused by Fuzzer, keep track of the condition it is waiting for */
 248 void ModelHistory::add_waiting_write(ConcretePredicate * concrete)
 249 {
 250         void * location = concrete->get_location();
 251         SnapVector<ConcretePredicate *> * waiting_conditions = loc_waiting_writes_map->get(location);
 252         if (waiting_conditions == NULL) {
 253                 waiting_conditions = new SnapVector<ConcretePredicate *>();
 254                 loc_waiting_writes_map->put(location, waiting_conditions);
 255         }
 256
 257         /* waiting_conditions should not have duplications */
 258         waiting_conditions->push_back(concrete);
 259
 260         int thread_id = id_to_int(concrete->get_tid());
 261         if (thrd_waiting_write->size() <= (uint) thread_id) {
 262                 thrd_waiting_write->resize(thread_id + 1);
 263         }
 264
 265         (*thrd_waiting_write)[thread_id] = concrete;
 266 }
 267
 268 void ModelHistory::remove_waiting_write(thread_id_t tid)
 269 {
 270         ConcretePredicate * concrete = (*thrd_waiting_write)[ id_to_int(tid) ];
 271         void * location = concrete->get_location();
 272         SnapVector<ConcretePredicate *> * concrete_preds = loc_waiting_writes_map->get(location);
 273
 274         /* Linear search should be fine because presumably not many ConcretePredicates
 275          * are at the same memory location */
 276         for (uint i = 0;i < concrete_preds->size();i++) {
 277                 ConcretePredicate * current = (*concrete_preds)[i];
 278                 if (concrete == current) {
 279                         (*concrete_preds)[i] = concrete_preds->back();
 280                         concrete_preds->pop_back();
 281                         break;
 282                 }
 283         }
 284
 285         int thread_id = id_to_int( concrete->get_tid() );
 286         (*thrd_waiting_write)[thread_id] = NULL;
 287         delete concrete;
 288 }
 289
 290 /* Check if any other thread is waiting for this write action. If so, "notify" them */
 291 void ModelHistory::check_waiting_write(ModelAction * write_act)
 292 {
 293         void * location = write_act->get_location();
 294         uint64_t value = write_act->get_write_value();
 295         SnapVector<ConcretePredicate *> * concrete_preds = loc_waiting_writes_map->get(location);
 296         if (concrete_preds == NULL)
 297                 return;
 298
 299         uint index = 0;
 300         while (index < concrete_preds->size()) {
 301                 ConcretePredicate * concrete_pred = (*concrete_preds)[index];
 302                 SnapVector<struct concrete_pred_expr> * concrete_exprs = concrete_pred->getExpressions();
 303                 bool satisfy_predicate = true;
 304                 /* Check if the written value satisfies every predicate expression */
 305                 for (uint i = 0;i < concrete_exprs->size();i++) {
 306                         struct concrete_pred_expr concrete = (*concrete_exprs)[i];
 307                         bool equality = false;
 308                         switch (concrete.token) {
 309                         case EQUALITY:
 310                                 equality = (value == concrete.value);
 311                                 break;
 312                         case NULLITY:
 313                                 equality = ((void*)value == NULL);
 314                                 break;
 315                         default:
 316                                 model_print("unknown predicate token");
 317                                 break;
 318                         }
 319
 320                         if (equality != concrete.equality) {
 321                                 satisfy_predicate = false;
 322                                 break;
 323                         }
 324                 }
 325
 326                 if (satisfy_predicate) {
 327                         /* Wake up threads */
 328                         thread_id_t tid = concrete_pred->get_tid();
 329                         Thread * thread = model->get_thread(tid);
 330
 331                         //model_print("** thread %d is woken up\n", thread->get_id());
 332                         ((NewFuzzer *)model->get_execution()->getFuzzer())->notify_paused_thread(thread);
 333                 }
 334
 335                 index++;
 336         }
 337 }
 338
 339 WaitObj * ModelHistory::getWaitObj(thread_id_t tid)
 340 {
 341         int thread_id = id_to_int(tid);
 342         int old_size = thrd_wait_obj->size();
 343         if (old_size <= thread_id) {
 344                 thrd_wait_obj->resize(thread_id + 1);
 345                 for (int i = old_size;i < thread_id + 1;i++) {
 346                         (*thrd_wait_obj)[i] = new WaitObj( int_to_id(i) );
 347                 }
 348         }
 349
 350         return (*thrd_wait_obj)[thread_id];
 351 }
 352
 353 void ModelHistory::add_waiting_thread(thread_id_t self_id,
 354                                                                                                                                                         thread_id_t waiting_for_id, FuncNode * target_node, int dist)
 355 {
 356         WaitObj * self_wait_obj = getWaitObj(self_id);
 357         self_wait_obj->add_waiting_for(waiting_for_id, target_node, dist);
 358
 359         /* Update waited-by relation */
 360         WaitObj * other_wait_obj = getWaitObj(waiting_for_id);
 361         other_wait_obj->add_waited_by(self_id);
 362 }
 363
 364 /* Thread tid is woken up (or notified), so it is not waiting for others anymore */
 365 void ModelHistory::remove_waiting_thread(thread_id_t tid)
 366 {
 367         WaitObj * self_wait_obj = getWaitObj(tid);
 368         thrd_id_set_t * waiting_for = self_wait_obj->getWaitingFor();
 369
 370         /* Remove tid from waited_by's */
 371         thrd_id_set_iter * iter = waiting_for->iterator();
 372         while (iter->hasNext()) {
 373                 thread_id_t other_id = iter->next();
 374                 WaitObj * other_wait_obj = getWaitObj(other_id);
 375                 other_wait_obj->remove_waited_by(tid);
 376         }
 377
 378         self_wait_obj->clear_waiting_for();
 379         delete iter;
 380 }
 381
 382 void ModelHistory::stop_waiting_for_node(thread_id_t self_id,
 383                                                                                                                                                                  thread_id_t waiting_for_id, FuncNode * target_node)
 384 {
 385         WaitObj * self_wait_obj = getWaitObj(self_id);
 386         bool thread_removed = self_wait_obj->remove_waiting_for_node(waiting_for_id, target_node);
 387
 388         // model_print("\t%d gives up %d on node %d\n", self_id, waiting_for_id, target_node->get_func_id());
 389
 390         /* If thread self_id is not waiting for waiting_for_id anymore */
 391         if (thread_removed) {
 392                 WaitObj * other_wait_obj = getWaitObj(waiting_for_id);
 393                 other_wait_obj->remove_waited_by(self_id);
 394
 395                 thrd_id_set_t * self_waiting_for = self_wait_obj->getWaitingFor();
 396                 if ( self_waiting_for->isEmpty() ) {
 397                         // model_print("\tthread %d waits for nobody, wake up\n", self_id);
 398                         ModelExecution * execution = model->get_execution();
 399                         Thread * thread = execution->get_thread(self_id);
 400                         ((NewFuzzer *)execution->getFuzzer())->notify_paused_thread(thread);
 401                 }
 402         }
 403 }
 404
 405 SnapVector<inst_act_map_t *> * ModelHistory::getThrdInstActMap(uint32_t func_id)
 406 {
 407         ASSERT(func_id != 0);
 408
 409         SnapVector<inst_act_map_t *> * maps = func_inst_act_maps->get(func_id);
 410         if (maps == NULL) {
 411                 maps = new SnapVector<inst_act_map_t *>();
 412                 func_inst_act_maps->put(func_id, maps);
 413         }
 414
 415         return maps;
 416 }
 417
 418 bool ModelHistory::skip_action(ModelAction * act)
 419 {
 420         bool second_part_of_rmw = act->is_rmwc() || act->is_rmw();
 421         modelclock_t curr_seq_number = act->get_seq_number();
 422
 423         /* Skip actions that are second part of a read modify write */
 424         if (second_part_of_rmw)
 425                 return true;
 426
 427         /* Skip actions with the same sequence number */
 428         if (last_action != NULL) {
 429                 if (last_action->get_seq_number() == curr_seq_number)
 430                         return true;
 431         }
 432
 433         /* Skip actions that are paused by fuzzer (sequence number is 0) */
 434         if (curr_seq_number == 0)
 435                 return true;
 436
 437         return false;
 438 }
 439
 440 /* Monitor thread tid and decide whether other threads (that are waiting for tid)
 441  * should keep waiting for this thread or not. Shall only be called when a thread
 442  * enters a function.
 443  *
 444  * Heuristics: If the distance from the current FuncNode to some target node
 445  * ever increases, stop waiting for this thread on this target node.
 446  */
 447 void ModelHistory::monitor_waiting_thread(uint32_t func_id, thread_id_t tid)
 448 {
 449         WaitObj * wait_obj = getWaitObj(tid);
 450         thrd_id_set_t * waited_by = wait_obj->getWaitedBy();
 451         FuncNode * curr_node = func_nodes[func_id];
 452
 453         /* For each thread waiting for tid */
 454         thrd_id_set_iter * tid_iter = waited_by->iterator();
 455         while (tid_iter->hasNext()) {
 456                 thread_id_t waited_by_id = tid_iter->next();
 457                 WaitObj * other_wait_obj = getWaitObj(waited_by_id);
 458
 459                 node_set_t * target_nodes = other_wait_obj->getTargetNodes(tid);
 460                 node_set_iter * node_iter = target_nodes->iterator();
 461                 while (node_iter->hasNext()) {
 462                         FuncNode * target = node_iter->next();
 463                         int old_dist = other_wait_obj->lookup_dist(tid, target);
 464                         int new_dist = curr_node->compute_distance(target, old_dist);
 465
 466                         if (new_dist == -1) {
 467                                 stop_waiting_for_node(waited_by_id, tid, target);
 468                         }
 469                 }
 470
 471                 delete node_iter;
 472         }
 473
 474         delete tid_iter;
 475 }
 476
 477 void ModelHistory::monitor_waiting_thread_counter(thread_id_t tid)
 478 {
 479         WaitObj * wait_obj = getWaitObj(tid);
 480         thrd_id_set_t * waited_by = wait_obj->getWaitedBy();
 481
 482         // Thread tid has taken an action, update the counter for threads waiting for tid
 483         thrd_id_set_iter * tid_iter = waited_by->iterator();
 484         while (tid_iter->hasNext()) {
 485                 thread_id_t waited_by_id = tid_iter->next();
 486                 WaitObj * other_wait_obj = getWaitObj(waited_by_id);
 487
 488                 bool expire = other_wait_obj->incr_counter(tid);
 489                 if (expire) {
 490 //                      model_print("thread %d stops waiting for thread %d\n", waited_by_id, tid);
 491                         wait_obj->remove_waited_by(waited_by_id);
 492                         other_wait_obj->remove_waiting_for(tid);
 493
 494                         thrd_id_set_t * other_waiting_for = other_wait_obj->getWaitingFor();
 495                         if ( other_waiting_for->isEmpty() ) {
 496                                 // model_print("\tthread %d waits for nobody, wake up\n", self_id);
 497                                 ModelExecution * execution = model->get_execution();
 498                                 Thread * thread = execution->get_thread(waited_by_id);
 499                                 ((NewFuzzer *)execution->getFuzzer())->notify_paused_thread(thread);
 500                         }
 501                 }
 502         }
 503
 504         delete tid_iter;
 505 }
 506
 507 /* Reallocate some snapshotted memories when new executions start */
 508 void ModelHistory::set_new_exec_flag()
 509 {
 510         for (uint i = 1;i < func_nodes.size();i++) {
 511                 FuncNode * func_node = func_nodes[i];
 512                 func_node->set_new_exec_flag();
 513         }
 514 }
 515
 516 void ModelHistory::dump_func_node_graph()
 517 {
 518         model_print("digraph func_node_graph {\n");
 519         for (uint i = 1;i < func_nodes.size();i++) {
 520                 FuncNode * node = func_nodes[i];
 521                 ModelList<FuncNode *> * out_edges = node->get_out_edges();
 522
 523                 model_print("\"%p\" [label=\"%s\"]\n", node, node->get_func_name());
 524                 mllnode<FuncNode *> * it;
 525                 for (it = out_edges->begin();it != NULL;it = it->getNext()) {
 526                         FuncNode * other = it->getVal();
 527                         model_print("\"%p\" -> \"%p\"\n", node, other);
 528                 }
 529         }
 530         model_print("}\n");
 531 }
 532
 533 void ModelHistory::print_func_node()
 534 {
 535         /* function id starts with 1 */
 536         for (uint32_t i = 1;i < func_nodes.size();i++) {
 537                 FuncNode * func_node = func_nodes[i];
 538                 func_node->print_predicate_tree();
 539
 540 /*
 541                 func_inst_list_mt * entry_insts = func_node->get_entry_insts();
 542                 model_print("function %s has entry actions\n", func_node->get_func_name());
 543
 544                 mllnode<FuncInst*>* it;
 545                 for (it = entry_insts->begin();it != NULL;it=it->getNext()) {
 546                         FuncInst *inst = it->getVal();
 547                         model_print("type: %d, at: %s\n", inst->get_type(), inst->get_position());
 548                 }
 549 */
 550         }
 551 }
 552
 553 void ModelHistory::print_waiting_threads()
 554 {
 555         ModelExecution * execution = model->get_execution();
 556         for (unsigned int i = 0;i < execution->get_num_threads();i++) {
 557                 thread_id_t tid = int_to_id(i);
 558                 WaitObj * wait_obj = getWaitObj(tid);
 559                 wait_obj->print_waiting_for();
 560         }
 561
 562         for (unsigned int i = 0;i < execution->get_num_threads();i++) {
 563                 thread_id_t tid = int_to_id(i);
 564                 WaitObj * wait_obj = getWaitObj(tid);
 565                 wait_obj->print_waited_by();
 566         }
 567 }