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