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