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                 model_print("trying to exit with a wrong function id\n");
  91                 model_print("--- last_func: %d, func_id: %d\n", last_func_id, func_id);
  92         }
  93         //model_print("thread %d exiting func %d\n", tid, func_id);
  94 }
  95
  96 void ModelHistory::resize_func_nodes(uint32_t new_size)
  97 {
  98         uint32_t old_size = func_nodes.size();
  99
 100         if ( old_size < new_size )
 101                 func_nodes.resize(new_size);
 102
 103         for (uint32_t id = old_size;id < new_size;id++) {
 104                 const char * func_name = func_map_rev[id];
 105                 FuncNode * func_node = new FuncNode(this);
 106                 func_node->set_func_id(id);
 107                 func_node->set_func_name(func_name);
 108                 func_nodes[id] = func_node;
 109         }
 110 }
 111
 112 void ModelHistory::process_action(ModelAction *act, thread_id_t tid)
 113 {
 114         uint32_t thread_id = id_to_int(tid);
 115         /* Return if thread tid has not entered any function that contains atomics */
 116         if ( thrd_func_list->size() <= thread_id )
 117                 return;
 118
 119         /* Monitor the statuses of threads waiting for tid */
 120         // monitor_waiting_thread_counter(tid);
 121
 122         /* Every write action should be processed, including
 123          * nonatomic writes (which have no position) */
 124         if (act->is_write()) {
 125                 void * location = act->get_location();
 126                 uint64_t value = act->get_write_value();
 127                 update_write_history(location, value);
 128
 129                 /* Notify FuncNodes that may read from this location */
 130                 SnapVector<FuncNode *> * func_node_list = getRdFuncNodes(location);
 131                 for (uint i = 0;i < func_node_list->size();i++) {
 132                         FuncNode * func_node = (*func_node_list)[i];
 133                         func_node->add_to_val_loc_map(value, location);
 134                 }
 135
 136                 // check_waiting_write(act);
 137         }
 138
 139         uint32_t func_id = (*thrd_func_list)[thread_id].back();
 140
 141         /* The following does not care about actions that are not inside
 142          * any function that contains atomics or actions without a position */
 143         if (func_id == 0 || act->get_position() == NULL)
 144                 return;
 145
 146         if (skip_action(act))
 147                 return;
 148
 149         FuncNode * func_node = func_nodes[func_id];
 150         func_node->add_inst(act);
 151
 152         if (act->is_read()) {
 153                 func_node->update_inst_act_map(tid, act);
 154
 155 //              Fuzzer * fuzzer = model->get_execution()->getFuzzer();
 156 //              Predicate * selected_branch = ((NewFuzzer *)fuzzer)->get_selected_child_branch(tid);
 157 //              func_node->set_predicate_tree_position(tid, selected_branch);
 158         }
 159 /*
 160         if (act->is_write()) {
 161                 Predicate * curr_pred = func_node->get_predicate_tree_position(tid);
 162                 FuncInst * curr_inst = func_node->get_inst(act);
 163
 164                 if (curr_pred) {
 165                         // Follow child
 166                         curr_pred = curr_pred->follow_write_child(curr_inst);
 167                 }
 168                 func_node->set_predicate_tree_position(tid, curr_pred);
 169         }
 170 */
 171
 172         func_node->update_tree(act);
 173         last_action = act;
 174 }
 175
 176 /* Return the FuncNode given its func_id  */
 177 FuncNode * ModelHistory::get_func_node(uint32_t func_id)
 178 {
 179         if (func_id == 0)
 180                 return NULL;
 181
 182         // This node has not been added to func_nodes
 183         if (func_nodes.size() <= func_id)
 184                 return NULL;
 185
 186         return func_nodes[func_id];
 187 }
 188
 189 /* Return the current FuncNode when given a thread id */
 190 FuncNode * ModelHistory::get_curr_func_node(thread_id_t tid)
 191 {
 192         int thread_id = id_to_int(tid);
 193         uint32_t func_id = (*thrd_func_list)[thread_id].back();
 194
 195         if (func_id != 0) {
 196                 return func_nodes[func_id];
 197         }
 198
 199         return NULL;
 200 }
 201
 202 void ModelHistory::update_write_history(void * location, uint64_t write_val)
 203 {
 204         value_set_t * write_set = write_history->get(location);
 205
 206         if (write_set == NULL) {
 207                 write_set = new value_set_t();
 208                 write_history->put(location, write_set);
 209         }
 210
 211         write_set->add(write_val);
 212 }
 213
 214 void ModelHistory::update_loc_rd_func_nodes_map(void * location, FuncNode * node)
 215 {
 216         SnapVector<FuncNode *> * func_node_list = getRdFuncNodes(location);
 217         func_node_list->push_back(node);
 218 }
 219
 220 void ModelHistory::update_loc_wr_func_nodes_map(void * location, FuncNode * node)
 221 {
 222         SnapVector<FuncNode *> * func_node_list = getWrFuncNodes(location);
 223         func_node_list->push_back(node);
 224 }
 225
 226 SnapVector<FuncNode *> * ModelHistory::getRdFuncNodes(void * location)
 227 {
 228         SnapVector<FuncNode *> * func_node_list = loc_rd_func_nodes_map->get(location);
 229         if (func_node_list == NULL) {
 230                 func_node_list = new SnapVector<FuncNode *>();
 231                 loc_rd_func_nodes_map->put(location, func_node_list);
 232         }
 233
 234         return func_node_list;
 235 }
 236
 237 SnapVector<FuncNode *> * ModelHistory::getWrFuncNodes(void * location)
 238 {
 239         SnapVector<FuncNode *> * func_node_list = loc_wr_func_nodes_map->get(location);
 240         if (func_node_list == NULL) {
 241                 func_node_list = new SnapVector<FuncNode *>();
 242                 loc_wr_func_nodes_map->put(location, func_node_list);
 243         }
 244
 245         return func_node_list;
 246 }
 247
 248 /* When a thread is paused by Fuzzer, keep track of the condition it is waiting for */
 249 void ModelHistory::add_waiting_write(ConcretePredicate * concrete)
 250 {
 251         void * location = concrete->get_location();
 252         SnapVector<ConcretePredicate *> * waiting_conditions = loc_waiting_writes_map->get(location);
 253         if (waiting_conditions == NULL) {
 254                 waiting_conditions = new SnapVector<ConcretePredicate *>();
 255                 loc_waiting_writes_map->put(location, waiting_conditions);
 256         }
 257
 258         /* waiting_conditions should not have duplications */
 259         waiting_conditions->push_back(concrete);
 260
 261         int thread_id = id_to_int(concrete->get_tid());
 262         if (thrd_waiting_write->size() <= (uint) thread_id) {
 263                 thrd_waiting_write->resize(thread_id + 1);
 264         }
 265
 266         (*thrd_waiting_write)[thread_id] = concrete;
 267 }
 268
 269 void ModelHistory::remove_waiting_write(thread_id_t tid)
 270 {
 271         ConcretePredicate * concrete = (*thrd_waiting_write)[ id_to_int(tid) ];
 272         void * location = concrete->get_location();
 273         SnapVector<ConcretePredicate *> * concrete_preds = loc_waiting_writes_map->get(location);
 274
 275         /* Linear search should be fine because presumably not many ConcretePredicates
 276          * are at the same memory location */
 277         for (uint i = 0;i < concrete_preds->size();i++) {
 278                 ConcretePredicate * current = (*concrete_preds)[i];
 279                 if (concrete == current) {
 280                         (*concrete_preds)[i] = concrete_preds->back();
 281                         concrete_preds->pop_back();
 282                         break;
 283                 }
 284         }
 285
 286         int thread_id = id_to_int( concrete->get_tid() );
 287         (*thrd_waiting_write)[thread_id] = NULL;
 288         delete concrete;
 289 }
 290
 291 /* Check if any other thread is waiting for this write action. If so, "notify" them */
 292 void ModelHistory::check_waiting_write(ModelAction * write_act)
 293 {
 294         void * location = write_act->get_location();
 295         uint64_t value = write_act->get_write_value();
 296         SnapVector<ConcretePredicate *> * concrete_preds = loc_waiting_writes_map->get(location);
 297         if (concrete_preds == NULL)
 298                 return;
 299
 300         uint index = 0;
 301         while (index < concrete_preds->size()) {
 302                 ConcretePredicate * concrete_pred = (*concrete_preds)[index];
 303                 SnapVector<struct concrete_pred_expr> * concrete_exprs = concrete_pred->getExpressions();
 304                 bool satisfy_predicate = true;
 305                 /* Check if the written value satisfies every predicate expression */
 306                 for (uint i = 0;i < concrete_exprs->size();i++) {
 307                         struct concrete_pred_expr concrete = (*concrete_exprs)[i];
 308                         bool equality = false;
 309                         switch (concrete.token) {
 310                         case EQUALITY:
 311                                 equality = (value == concrete.value);
 312                                 break;
 313                         case NULLITY:
 314                                 equality = ((void*)value == NULL);
 315                                 break;
 316                         default:
 317                                 model_print("unknown predicate token");
 318                                 break;
 319                         }
 320
 321                         if (equality != concrete.equality) {
 322                                 satisfy_predicate = false;
 323                                 break;
 324                         }
 325                 }
 326
 327                 if (satisfy_predicate) {
 328                         /* Wake up threads */
 329                         thread_id_t tid = concrete_pred->get_tid();
 330                         Thread * thread = model->get_thread(tid);
 331
 332                         //model_print("** thread %d is woken up\n", thread->get_id());
 333                         ((NewFuzzer *)model->get_execution()->getFuzzer())->notify_paused_thread(thread);
 334                 }
 335
 336                 index++;
 337         }
 338 }
 339
 340 WaitObj * ModelHistory::getWaitObj(thread_id_t tid)
 341 {
 342         int thread_id = id_to_int(tid);
 343         int old_size = thrd_wait_obj->size();
 344         if (old_size <= thread_id) {
 345                 thrd_wait_obj->resize(thread_id + 1);
 346                 for (int i = old_size;i < thread_id + 1;i++) {
 347                         (*thrd_wait_obj)[i] = new WaitObj( int_to_id(i) );
 348                 }
 349         }
 350
 351         return (*thrd_wait_obj)[thread_id];
 352 }
 353
 354 void ModelHistory::add_waiting_thread(thread_id_t self_id,
 355                                                                                                                                                         thread_id_t waiting_for_id, FuncNode * target_node, int dist)
 356 {
 357         WaitObj * self_wait_obj = getWaitObj(self_id);
 358         self_wait_obj->add_waiting_for(waiting_for_id, target_node, dist);
 359
 360         /* Update waited-by relation */
 361         WaitObj * other_wait_obj = getWaitObj(waiting_for_id);
 362         other_wait_obj->add_waited_by(self_id);
 363 }
 364
 365 /* Thread tid is woken up (or notified), so it is not waiting for others anymore */
 366 void ModelHistory::remove_waiting_thread(thread_id_t tid)
 367 {
 368         WaitObj * self_wait_obj = getWaitObj(tid);
 369         thrd_id_set_t * waiting_for = self_wait_obj->getWaitingFor();
 370
 371         /* Remove tid from waited_by's */
 372         thrd_id_set_iter * iter = waiting_for->iterator();
 373         while (iter->hasNext()) {
 374                 thread_id_t other_id = iter->next();
 375                 WaitObj * other_wait_obj = getWaitObj(other_id);
 376                 other_wait_obj->remove_waited_by(tid);
 377         }
 378
 379         self_wait_obj->clear_waiting_for();
 380         delete iter;
 381 }
 382
 383 void ModelHistory::stop_waiting_for_node(thread_id_t self_id,
 384                                                                                                                                                                  thread_id_t waiting_for_id, FuncNode * target_node)
 385 {
 386         WaitObj * self_wait_obj = getWaitObj(self_id);
 387         bool thread_removed = self_wait_obj->remove_waiting_for_node(waiting_for_id, target_node);
 388
 389         // model_print("\t%d gives up %d on node %d\n", self_id, waiting_for_id, target_node->get_func_id());
 390
 391         /* If thread self_id is not waiting for waiting_for_id anymore */
 392         if (thread_removed) {
 393                 WaitObj * other_wait_obj = getWaitObj(waiting_for_id);
 394                 other_wait_obj->remove_waited_by(self_id);
 395
 396                 thrd_id_set_t * self_waiting_for = self_wait_obj->getWaitingFor();
 397                 if ( self_waiting_for->isEmpty() ) {
 398                         // model_print("\tthread %d waits for nobody, wake up\n", self_id);
 399                         ModelExecution * execution = model->get_execution();
 400                         Thread * thread = execution->get_thread(self_id);
 401                         ((NewFuzzer *)execution->getFuzzer())->notify_paused_thread(thread);
 402                 }
 403         }
 404 }
 405
 406 SnapVector<inst_act_map_t *> * ModelHistory::getThrdInstActMap(uint32_t func_id)
 407 {
 408         ASSERT(func_id != 0);
 409
 410         SnapVector<inst_act_map_t *> * maps = func_inst_act_maps->get(func_id);
 411         if (maps == NULL) {
 412                 maps = new SnapVector<inst_act_map_t *>();
 413                 func_inst_act_maps->put(func_id, maps);
 414         }
 415
 416         return maps;
 417 }
 418
 419 bool ModelHistory::skip_action(ModelAction * act)
 420 {
 421         bool second_part_of_rmw = act->is_rmwc() || act->is_rmw();
 422         modelclock_t curr_seq_number = act->get_seq_number();
 423
 424         /* Skip actions that are second part of a read modify write */
 425         if (second_part_of_rmw)
 426                 return true;
 427
 428         /* Skip actions with the same sequence number */
 429         if (last_action != NULL) {
 430                 if (last_action->get_seq_number() == curr_seq_number)
 431                         return true;
 432         }
 433
 434         /* Skip actions that are paused by fuzzer (sequence number is 0) */
 435         if (curr_seq_number == 0)
 436                 return true;
 437
 438         return false;
 439 }
 440
 441 /* Monitor thread tid and decide whether other threads (that are waiting for tid)
 442  * should keep waiting for this thread or not. Shall only be called when a thread
 443  * enters a function.
 444  *
 445  * Heuristics: If the distance from the current FuncNode to some target node
 446  * ever increases, stop waiting for this thread on this target node.
 447  */
 448 void ModelHistory::monitor_waiting_thread(uint32_t func_id, thread_id_t tid)
 449 {
 450         WaitObj * wait_obj = getWaitObj(tid);
 451         thrd_id_set_t * waited_by = wait_obj->getWaitedBy();
 452         FuncNode * curr_node = func_nodes[func_id];
 453
 454         /* For each thread waiting for tid */
 455         thrd_id_set_iter * tid_iter = waited_by->iterator();
 456         while (tid_iter->hasNext()) {
 457                 thread_id_t waited_by_id = tid_iter->next();
 458                 WaitObj * other_wait_obj = getWaitObj(waited_by_id);
 459
 460                 node_set_t * target_nodes = other_wait_obj->getTargetNodes(tid);
 461                 node_set_iter * node_iter = target_nodes->iterator();
 462                 while (node_iter->hasNext()) {
 463                         FuncNode * target = node_iter->next();
 464                         int old_dist = other_wait_obj->lookup_dist(tid, target);
 465                         int new_dist = curr_node->compute_distance(target, old_dist);
 466
 467                         if (new_dist == -1) {
 468                                 stop_waiting_for_node(waited_by_id, tid, target);
 469                         }
 470                 }
 471
 472                 delete node_iter;
 473         }
 474
 475         delete tid_iter;
 476 }
 477
 478 void ModelHistory::monitor_waiting_thread_counter(thread_id_t tid)
 479 {
 480         WaitObj * wait_obj = getWaitObj(tid);
 481         thrd_id_set_t * waited_by = wait_obj->getWaitedBy();
 482
 483         // Thread tid has taken an action, update the counter for threads waiting for tid
 484         thrd_id_set_iter * tid_iter = waited_by->iterator();
 485         while (tid_iter->hasNext()) {
 486                 thread_id_t waited_by_id = tid_iter->next();
 487                 WaitObj * other_wait_obj = getWaitObj(waited_by_id);
 488
 489                 bool expire = other_wait_obj->incr_counter(tid);
 490                 if (expire) {
 491 //                      model_print("thread %d stops waiting for thread %d\n", waited_by_id, tid);
 492                         wait_obj->remove_waited_by(waited_by_id);
 493                         other_wait_obj->remove_waiting_for(tid);
 494
 495                         thrd_id_set_t * other_waiting_for = other_wait_obj->getWaitingFor();
 496                         if ( other_waiting_for->isEmpty() ) {
 497                                 // model_print("\tthread %d waits for nobody, wake up\n", self_id);
 498                                 ModelExecution * execution = model->get_execution();
 499                                 Thread * thread = execution->get_thread(waited_by_id);
 500                                 ((NewFuzzer *)execution->getFuzzer())->notify_paused_thread(thread);
 501                         }
 502                 }
 503         }
 504
 505         delete tid_iter;
 506 }
 507
 508 /* Reallocate some snapshotted memories when new executions start */
 509 void ModelHistory::set_new_exec_flag()
 510 {
 511         for (uint i = 1;i < func_nodes.size();i++) {
 512                 FuncNode * func_node = func_nodes[i];
 513                 func_node->set_new_exec_flag();
 514         }
 515 }
 516
 517 void ModelHistory::dump_func_node_graph()
 518 {
 519         model_print("digraph func_node_graph {\n");
 520         for (uint i = 1;i < func_nodes.size();i++) {
 521                 FuncNode * node = func_nodes[i];
 522                 ModelList<FuncNode *> * out_edges = node->get_out_edges();
 523
 524                 model_print("\"%p\" [label=\"%s\"]\n", node, node->get_func_name());
 525                 mllnode<FuncNode *> * it;
 526                 for (it = out_edges->begin();it != NULL;it = it->getNext()) {
 527                         FuncNode * other = it->getVal();
 528                         model_print("\"%p\" -> \"%p\"\n", node, other);
 529                 }
 530         }
 531         model_print("}\n");
 532 }
 533
 534 void ModelHistory::print_func_node()
 535 {
 536         /* function id starts with 1 */
 537         for (uint32_t i = 1;i < func_nodes.size();i++) {
 538                 FuncNode * func_node = func_nodes[i];
 539                 func_node->print_predicate_tree();
 540
 541 /*
 542                 func_inst_list_mt * entry_insts = func_node->get_entry_insts();
 543                 model_print("function %s has entry actions\n", func_node->get_func_name());
 544
 545                 mllnode<FuncInst*>* it;
 546                 for (it = entry_insts->begin();it != NULL;it=it->getNext()) {
 547                         FuncInst *inst = it->getVal();
 548                         model_print("type: %d, at: %s\n", inst->get_type(), inst->get_position());
 549                 }
 550 */
 551         }
 552 }
 553
 554 void ModelHistory::print_waiting_threads()
 555 {
 556         ModelExecution * execution = model->get_execution();
 557         for (unsigned int i = 0;i < execution->get_num_threads();i++) {
 558                 thread_id_t tid = int_to_id(i);
 559                 WaitObj * wait_obj = getWaitObj(tid);
 560                 wait_obj->print_waiting_for();
 561         }
 562
 563         for (unsigned int i = 0;i < execution->get_num_threads();i++) {
 564                 thread_id_t tid = int_to_id(i);
 565                 WaitObj * wait_obj = getWaitObj(tid);
 566                 wait_obj->print_waited_by();
 567         }
 568 }