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 {
  21         /* The following are snapshot data structures */
  22         write_history = new HashTable<void *, value_set_t *, uintptr_t, 0>();
  23         loc_rd_func_nodes_map = new HashTable<void *, SnapVector<FuncNode *> *, uintptr_t, 0>();
  24         loc_wr_func_nodes_map = new HashTable<void *, SnapVector<FuncNode *> *, uintptr_t, 0>();
  25         loc_waiting_writes_map = new HashTable<void *, SnapVector<ConcretePredicate *> *, uintptr_t, 0>();
  26         thrd_func_act_lists = new SnapVector< SnapList<action_list_t *> *>();
  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                 thrd_func_act_lists->resize( id + 1 );
  50
  51                 for (uint i = oldsize;i < id + 1;i++) {
  52                         // push 0 as a dummy function id to a void seg fault
  53                         new (&(*thrd_func_list)[i]) func_id_list_t();
  54                         (*thrd_func_list)[i].push_back(0);
  55
  56                         (*thrd_func_act_lists)[i] = new SnapList<action_list_t *>();
  57                         thrd_last_entered_func->push_back(0);
  58                 }
  59         }
  60
  61         SnapList<action_list_t *> * func_act_lists = (*thrd_func_act_lists)[id];
  62         func_act_lists->push_back( new action_list_t() );
  63
  64         uint32_t last_entered_func_id = (*thrd_last_entered_func)[id];
  65         (*thrd_last_entered_func)[id] = func_id;
  66         (*thrd_func_list)[id].push_back(func_id);
  67
  68         if ( func_nodes.size() <= func_id )
  69                 resize_func_nodes( func_id + 1 );
  70
  71         FuncNode * func_node = func_nodes[func_id];
  72         func_node->function_entry_handler(tid);
  73
  74         /* Add edges between FuncNodes */
  75         if (last_entered_func_id != 0) {
  76                 FuncNode * last_func_node = func_nodes[last_entered_func_id];
  77                 last_func_node->add_out_edge(func_node);
  78         }
  79
  80         /* Monitor the statuses of threads waiting for tid */
  81         // monitor_waiting_thread(func_id, tid);
  82 }
  83
  84 /* @param func_id a non-zero value */
  85 void ModelHistory::exit_function(const uint32_t func_id, thread_id_t tid)
  86 {
  87         uint32_t id = id_to_int(tid);
  88
  89         SnapList<action_list_t *> * func_act_lists = (*thrd_func_act_lists)[id];
  90         uint32_t last_func_id = (*thrd_func_list)[id].back();
  91
  92         if (last_func_id == func_id) {
  93                 FuncNode * func_node = func_nodes[func_id];
  94                 func_node->function_exit_handler(tid);
  95
  96                 (*thrd_func_list)[id].pop_back();
  97                 func_act_lists->pop_back();
  98         } else {
  99                 model_print("trying to exit with a wrong function id\n");
 100                 model_print("--- last_func: %d, func_id: %d\n", last_func_id, func_id);
 101         }
 102         //model_print("thread %d exiting func %d\n", tid, func_id);
 103 }
 104
 105 void ModelHistory::resize_func_nodes(uint32_t new_size)
 106 {
 107         uint32_t old_size = func_nodes.size();
 108
 109         if ( old_size < new_size )
 110                 func_nodes.resize(new_size);
 111
 112         for (uint32_t id = old_size;id < new_size;id++) {
 113                 const char * func_name = func_map_rev[id];
 114                 FuncNode * func_node = new FuncNode(this);
 115                 func_node->set_func_id(id);
 116                 func_node->set_func_name(func_name);
 117                 func_nodes[id] = func_node;
 118         }
 119 }
 120
 121 void ModelHistory::process_action(ModelAction *act, thread_id_t tid)
 122 {
 123         uint32_t thread_id = id_to_int(tid);
 124         /* Return if thread tid has not entered any function that contains atomics */
 125         if ( thrd_func_list->size() <= thread_id )
 126                 return;
 127
 128         /* Monitor the statuses of threads waiting for tid */
 129         // monitor_waiting_thread_counter(tid);
 130
 131         /* Every write action should be processed, including
 132          * nonatomic writes (which have no position) */
 133         if (act->is_write()) {
 134                 void * location = act->get_location();
 135                 uint64_t value = act->get_write_value();
 136                 update_write_history(location, value);
 137
 138                 /* Notify FuncNodes that may read from this location */
 139                 SnapVector<FuncNode *> * func_node_list = getRdFuncNodes(location);
 140                 for (uint i = 0;i < func_node_list->size();i++) {
 141                         FuncNode * func_node = (*func_node_list)[i];
 142                         func_node->add_to_val_loc_map(value, location);
 143                 }
 144
 145                 // check_waiting_write(act);
 146         }
 147
 148         uint32_t func_id = (*thrd_func_list)[thread_id].back();
 149
 150         /* The following does not care about actions that are not inside
 151          * any function that contains atomics or actions without a position */
 152         if (func_id == 0 || act->get_position() == NULL)
 153                 return;
 154
 155         SnapList<action_list_t *> * func_act_lists = (*thrd_func_act_lists)[thread_id];
 156
 157         /* The list of actions that thread tid has taken in its current function */
 158         action_list_t * curr_act_list = func_act_lists->back();
 159
 160         if (skip_action(act, curr_act_list))
 161                 return;
 162
 163         /* Add to curr_inst_list */
 164         curr_act_list->push_back(act);
 165
 166         FuncNode * func_node = func_nodes[func_id];
 167         func_node->add_inst(act);
 168
 169         if (act->is_read()) {
 170                 func_node->update_inst_act_map(tid, act);
 171
 172 //              Fuzzer * fuzzer = model->get_execution()->getFuzzer();
 173 //              Predicate * selected_branch = ((NewFuzzer *)fuzzer)->get_selected_child_branch(tid);
 174 //              func_node->set_predicate_tree_position(tid, selected_branch);
 175         }
 176 /*
 177         if (act->is_write()) {
 178                 Predicate * curr_pred = func_node->get_predicate_tree_position(tid);
 179                 FuncInst * curr_inst = func_node->get_inst(act);
 180
 181                 if (curr_pred) {
 182                         // Follow child
 183                         curr_pred = curr_pred->follow_write_child(curr_inst);
 184                 }
 185                 func_node->set_predicate_tree_position(tid, curr_pred);
 186         }
 187 */
 188
 189         func_node->update_tree(act);
 190 }
 191
 192 /* Return the FuncNode given its func_id  */
 193 FuncNode * ModelHistory::get_func_node(uint32_t func_id)
 194 {
 195         if (func_id == 0)
 196                 return NULL;
 197
 198         // This node has not been added to func_nodes
 199         if (func_nodes.size() <= func_id)
 200                 return NULL;
 201
 202         return func_nodes[func_id];
 203 }
 204
 205 /* Return the current FuncNode when given a thread id */
 206 FuncNode * ModelHistory::get_curr_func_node(thread_id_t tid)
 207 {
 208         int thread_id = id_to_int(tid);
 209         uint32_t func_id = (*thrd_func_list)[thread_id].back();
 210
 211         if (func_id != 0) {
 212                 return func_nodes[func_id];
 213         }
 214
 215         return NULL;
 216 }
 217
 218 void ModelHistory::update_write_history(void * location, uint64_t write_val)
 219 {
 220         value_set_t * write_set = write_history->get(location);
 221
 222         if (write_set == NULL) {
 223                 write_set = new value_set_t();
 224                 write_history->put(location, write_set);
 225         }
 226
 227         write_set->add(write_val);
 228 }
 229
 230 void ModelHistory::update_loc_rd_func_nodes_map(void * location, FuncNode * node)
 231 {
 232         SnapVector<FuncNode *> * func_node_list = getRdFuncNodes(location);
 233         func_node_list->push_back(node);
 234 }
 235
 236 void ModelHistory::update_loc_wr_func_nodes_map(void * location, FuncNode * node)
 237 {
 238         SnapVector<FuncNode *> * func_node_list = getWrFuncNodes(location);
 239         func_node_list->push_back(node);
 240 }
 241
 242 SnapVector<FuncNode *> * ModelHistory::getRdFuncNodes(void * location)
 243 {
 244         SnapVector<FuncNode *> * func_node_list = loc_rd_func_nodes_map->get(location);
 245         if (func_node_list == NULL) {
 246                 func_node_list = new SnapVector<FuncNode *>();
 247                 loc_rd_func_nodes_map->put(location, func_node_list);
 248         }
 249
 250         return func_node_list;
 251 }
 252
 253 SnapVector<FuncNode *> * ModelHistory::getWrFuncNodes(void * location)
 254 {
 255         SnapVector<FuncNode *> * func_node_list = loc_wr_func_nodes_map->get(location);
 256         if (func_node_list == NULL) {
 257                 func_node_list = new SnapVector<FuncNode *>();
 258                 loc_wr_func_nodes_map->put(location, func_node_list);
 259         }
 260
 261         return func_node_list;
 262 }
 263
 264 /* When a thread is paused by Fuzzer, keep track of the condition it is waiting for */
 265 void ModelHistory::add_waiting_write(ConcretePredicate * concrete)
 266 {
 267         void * location = concrete->get_location();
 268         SnapVector<ConcretePredicate *> * waiting_conditions = loc_waiting_writes_map->get(location);
 269         if (waiting_conditions == NULL) {
 270                 waiting_conditions = new SnapVector<ConcretePredicate *>();
 271                 loc_waiting_writes_map->put(location, waiting_conditions);
 272         }
 273
 274         /* waiting_conditions should not have duplications */
 275         waiting_conditions->push_back(concrete);
 276
 277         int thread_id = id_to_int(concrete->get_tid());
 278         if (thrd_waiting_write->size() <= (uint) thread_id) {
 279                 thrd_waiting_write->resize(thread_id + 1);
 280         }
 281
 282         (*thrd_waiting_write)[thread_id] = concrete;
 283 }
 284
 285 void ModelHistory::remove_waiting_write(thread_id_t tid)
 286 {
 287         ConcretePredicate * concrete = (*thrd_waiting_write)[ id_to_int(tid) ];
 288         void * location = concrete->get_location();
 289         SnapVector<ConcretePredicate *> * concrete_preds = loc_waiting_writes_map->get(location);
 290
 291         /* Linear search should be fine because presumably not many ConcretePredicates
 292          * are at the same memory location */
 293         for (uint i = 0;i < concrete_preds->size();i++) {
 294                 ConcretePredicate * current = (*concrete_preds)[i];
 295                 if (concrete == current) {
 296                         (*concrete_preds)[i] = concrete_preds->back();
 297                         concrete_preds->pop_back();
 298                         break;
 299                 }
 300         }
 301
 302         int thread_id = id_to_int( concrete->get_tid() );
 303         (*thrd_waiting_write)[thread_id] = NULL;
 304         delete concrete;
 305 }
 306
 307 /* Check if any other thread is waiting for this write action. If so, "notify" them */
 308 void ModelHistory::check_waiting_write(ModelAction * write_act)
 309 {
 310         void * location = write_act->get_location();
 311         uint64_t value = write_act->get_write_value();
 312         SnapVector<ConcretePredicate *> * concrete_preds = loc_waiting_writes_map->get(location);
 313         if (concrete_preds == NULL)
 314                 return;
 315
 316         uint index = 0;
 317         while (index < concrete_preds->size()) {
 318                 ConcretePredicate * concrete_pred = (*concrete_preds)[index];
 319                 SnapVector<struct concrete_pred_expr> * concrete_exprs = concrete_pred->getExpressions();
 320                 bool satisfy_predicate = true;
 321                 /* Check if the written value satisfies every predicate expression */
 322                 for (uint i = 0;i < concrete_exprs->size();i++) {
 323                         struct concrete_pred_expr concrete = (*concrete_exprs)[i];
 324                         bool equality = false;
 325                         switch (concrete.token) {
 326                         case EQUALITY:
 327                                 equality = (value == concrete.value);
 328                                 break;
 329                         case NULLITY:
 330                                 equality = ((void*)value == NULL);
 331                                 break;
 332                         default:
 333                                 model_print("unknown predicate token");
 334                                 break;
 335                         }
 336
 337                         if (equality != concrete.equality) {
 338                                 satisfy_predicate = false;
 339                                 break;
 340                         }
 341                 }
 342
 343                 if (satisfy_predicate) {
 344                         /* Wake up threads */
 345                         thread_id_t tid = concrete_pred->get_tid();
 346                         Thread * thread = model->get_thread(tid);
 347
 348                         //model_print("** thread %d is woken up\n", thread->get_id());
 349                         ((NewFuzzer *)model->get_execution()->getFuzzer())->notify_paused_thread(thread);
 350                 }
 351
 352                 index++;
 353         }
 354 }
 355
 356 WaitObj * ModelHistory::getWaitObj(thread_id_t tid)
 357 {
 358         int thread_id = id_to_int(tid);
 359         int old_size = thrd_wait_obj->size();
 360         if (old_size <= thread_id) {
 361                 thrd_wait_obj->resize(thread_id + 1);
 362                 for (int i = old_size;i < thread_id + 1;i++) {
 363                         (*thrd_wait_obj)[i] = new WaitObj( int_to_id(i) );
 364                 }
 365         }
 366
 367         return (*thrd_wait_obj)[thread_id];
 368 }
 369
 370 void ModelHistory::add_waiting_thread(thread_id_t self_id,
 371                                                                                                                                                         thread_id_t waiting_for_id, FuncNode * target_node, int dist)
 372 {
 373         WaitObj * self_wait_obj = getWaitObj(self_id);
 374         self_wait_obj->add_waiting_for(waiting_for_id, target_node, dist);
 375
 376         /* Update waited-by relation */
 377         WaitObj * other_wait_obj = getWaitObj(waiting_for_id);
 378         other_wait_obj->add_waited_by(self_id);
 379 }
 380
 381 /* Thread tid is woken up (or notified), so it is not waiting for others anymore */
 382 void ModelHistory::remove_waiting_thread(thread_id_t tid)
 383 {
 384         WaitObj * self_wait_obj = getWaitObj(tid);
 385         thrd_id_set_t * waiting_for = self_wait_obj->getWaitingFor();
 386
 387         /* Remove tid from waited_by's */
 388         thrd_id_set_iter * iter = waiting_for->iterator();
 389         while (iter->hasNext()) {
 390                 thread_id_t other_id = iter->next();
 391                 WaitObj * other_wait_obj = getWaitObj(other_id);
 392                 other_wait_obj->remove_waited_by(tid);
 393         }
 394
 395         self_wait_obj->clear_waiting_for();
 396         delete iter;
 397 }
 398
 399 void ModelHistory::stop_waiting_for_node(thread_id_t self_id,
 400                                                                                                                                                                  thread_id_t waiting_for_id, FuncNode * target_node)
 401 {
 402         WaitObj * self_wait_obj = getWaitObj(self_id);
 403         bool thread_removed = self_wait_obj->remove_waiting_for_node(waiting_for_id, target_node);
 404
 405         // model_print("\t%d gives up %d on node %d\n", self_id, waiting_for_id, target_node->get_func_id());
 406
 407         /* If thread self_id is not waiting for waiting_for_id anymore */
 408         if (thread_removed) {
 409                 WaitObj * other_wait_obj = getWaitObj(waiting_for_id);
 410                 other_wait_obj->remove_waited_by(self_id);
 411
 412                 thrd_id_set_t * self_waiting_for = self_wait_obj->getWaitingFor();
 413                 if ( self_waiting_for->isEmpty() ) {
 414                         // model_print("\tthread %d waits for nobody, wake up\n", self_id);
 415                         ModelExecution * execution = model->get_execution();
 416                         Thread * thread = execution->get_thread(self_id);
 417                         ((NewFuzzer *)execution->getFuzzer())->notify_paused_thread(thread);
 418                 }
 419         }
 420 }
 421
 422 SnapVector<inst_act_map_t *> * ModelHistory::getThrdInstActMap(uint32_t func_id)
 423 {
 424         ASSERT(func_id != 0);
 425
 426         SnapVector<inst_act_map_t *> * maps = func_inst_act_maps->get(func_id);
 427         if (maps == NULL) {
 428                 maps = new SnapVector<inst_act_map_t *>();
 429                 func_inst_act_maps->put(func_id, maps);
 430         }
 431
 432         return maps;
 433 }
 434
 435 bool ModelHistory::skip_action(ModelAction * act, SnapList<ModelAction *> * curr_act_list)
 436 {
 437         ASSERT(curr_act_list != NULL);
 438
 439         bool second_part_of_rmw = act->is_rmwc() || act->is_rmw();
 440         modelclock_t curr_seq_number = act->get_seq_number();
 441
 442         /* Skip actions that are second part of a read modify write */
 443         if (second_part_of_rmw)
 444                 return true;
 445
 446         /* Skip actions with the same sequence number */
 447         if (curr_act_list->size() != 0) {
 448                 ModelAction * last_act = curr_act_list->back();
 449                 if (last_act->get_seq_number() == curr_seq_number)
 450                         return true;
 451         }
 452
 453         /* Skip actions that are paused by fuzzer (sequence number is 0) */
 454         if (curr_seq_number == 0)
 455                 return true;
 456
 457         return false;
 458 }
 459
 460 /* Monitor thread tid and decide whether other threads (that are waiting for tid)
 461  * should keep waiting for this thread or not. Shall only be called when a thread
 462  * enters a function.
 463  *
 464  * Heuristics: If the distance from the current FuncNode to some target node
 465  * ever increases, stop waiting for this thread on this target node.
 466  */
 467 void ModelHistory::monitor_waiting_thread(uint32_t func_id, thread_id_t tid)
 468 {
 469         WaitObj * wait_obj = getWaitObj(tid);
 470         thrd_id_set_t * waited_by = wait_obj->getWaitedBy();
 471         FuncNode * curr_node = func_nodes[func_id];
 472
 473         /* For each thread waiting for tid */
 474         thrd_id_set_iter * tid_iter = waited_by->iterator();
 475         while (tid_iter->hasNext()) {
 476                 thread_id_t waited_by_id = tid_iter->next();
 477                 WaitObj * other_wait_obj = getWaitObj(waited_by_id);
 478
 479                 node_set_t * target_nodes = other_wait_obj->getTargetNodes(tid);
 480                 node_set_iter * node_iter = target_nodes->iterator();
 481                 while (node_iter->hasNext()) {
 482                         FuncNode * target = node_iter->next();
 483                         int old_dist = other_wait_obj->lookup_dist(tid, target);
 484                         int new_dist = curr_node->compute_distance(target, old_dist);
 485
 486                         if (new_dist == -1) {
 487                                 stop_waiting_for_node(waited_by_id, tid, target);
 488                         }
 489                 }
 490
 491                 delete node_iter;
 492         }
 493
 494         delete tid_iter;
 495 }
 496
 497 void ModelHistory::monitor_waiting_thread_counter(thread_id_t tid)
 498 {
 499         WaitObj * wait_obj = getWaitObj(tid);
 500         thrd_id_set_t * waited_by = wait_obj->getWaitedBy();
 501
 502         // Thread tid has taken an action, update the counter for threads waiting for tid
 503         thrd_id_set_iter * tid_iter = waited_by->iterator();
 504         while (tid_iter->hasNext()) {
 505                 thread_id_t waited_by_id = tid_iter->next();
 506                 WaitObj * other_wait_obj = getWaitObj(waited_by_id);
 507
 508                 bool expire = other_wait_obj->incr_counter(tid);
 509                 if (expire) {
 510 //                      model_print("thread %d stops waiting for thread %d\n", waited_by_id, tid);
 511                         wait_obj->remove_waited_by(waited_by_id);
 512                         other_wait_obj->remove_waiting_for(tid);
 513
 514                         thrd_id_set_t * other_waiting_for = other_wait_obj->getWaitingFor();
 515                         if ( other_waiting_for->isEmpty() ) {
 516                                 // model_print("\tthread %d waits for nobody, wake up\n", self_id);
 517                                 ModelExecution * execution = model->get_execution();
 518                                 Thread * thread = execution->get_thread(waited_by_id);
 519                                 ((NewFuzzer *)execution->getFuzzer())->notify_paused_thread(thread);
 520                         }
 521                 }
 522         }
 523
 524         delete tid_iter;
 525 }
 526
 527 /* Reallocate some snapshotted memories when new executions start */
 528 void ModelHistory::set_new_exec_flag()
 529 {
 530         for (uint i = 1;i < func_nodes.size();i++) {
 531                 FuncNode * func_node = func_nodes[i];
 532                 func_node->set_new_exec_flag();
 533         }
 534 }
 535
 536 void ModelHistory::dump_func_node_graph()
 537 {
 538         model_print("digraph func_node_graph {\n");
 539         for (uint i = 1;i < func_nodes.size();i++) {
 540                 FuncNode * node = func_nodes[i];
 541                 ModelList<FuncNode *> * out_edges = node->get_out_edges();
 542
 543                 model_print("\"%p\" [label=\"%s\"]\n", node, node->get_func_name());
 544                 mllnode<FuncNode *> * it;
 545                 for (it = out_edges->begin();it != NULL;it = it->getNext()) {
 546                         FuncNode * other = it->getVal();
 547                         model_print("\"%p\" -> \"%p\"\n", node, other);
 548                 }
 549         }
 550         model_print("}\n");
 551 }
 552
 553 void ModelHistory::print_func_node()
 554 {
 555         /* function id starts with 1 */
 556         for (uint32_t i = 1;i < func_nodes.size();i++) {
 557                 FuncNode * func_node = func_nodes[i];
 558                 func_node->print_predicate_tree();
 559
 560 /*
 561                 func_inst_list_mt * entry_insts = func_node->get_entry_insts();
 562                 model_print("function %s has entry actions\n", func_node->get_func_name());
 563
 564                 mllnode<FuncInst*>* it;
 565                 for (it = entry_insts->begin();it != NULL;it=it->getNext()) {
 566                         FuncInst *inst = it->getVal();
 567                         model_print("type: %d, at: %s\n", inst->get_type(), inst->get_position());
 568                 }
 569 */
 570         }
 571 }
 572
 573 void ModelHistory::print_waiting_threads()
 574 {
 575         ModelExecution * execution = model->get_execution();
 576         for (unsigned int i = 0;i < execution->get_num_threads();i++) {
 577                 thread_id_t tid = int_to_id(i);
 578                 WaitObj * wait_obj = getWaitObj(tid);
 579                 wait_obj->print_waiting_for();
 580         }
 581
 582         for (unsigned int i = 0;i < execution->get_num_threads();i++) {
 583                 thread_id_t tid = int_to_id(i);
 584                 WaitObj * wait_obj = getWaitObj(tid);
 585                 wait_obj->print_waited_by();
 586         }
 587 }