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