Fix memory issue; ModelList should be cleared before deletion; use ModelVector instead
[c11tester.git] / funcnode.cc
1 #include "action.h"
2 #include "history.h"
3 #include "funcnode.h"
4 #include "funcinst.h"
5 #include "predicate.h"
6 #include "concretepredicate.h"
7
8 #include "model.h"
9 #include "execution.h"
10 #include "newfuzzer.h"
11 #include <cmath>
12
13 FuncNode::FuncNode(ModelHistory * history) :
14         history(history),
15         inst_counter(1),
16         marker(1),
17         thrd_markers(),
18         thrd_recursion_depth(),
19         func_inst_map(),
20         inst_list(),
21         entry_insts(),
22         thrd_inst_pred_maps(),
23         thrd_inst_id_maps(),
24         thrd_loc_inst_maps(),
25         thrd_predicate_tree_position(),
26         thrd_predicate_trace(),
27         edge_table(32),
28         out_edges()
29 {
30         predicate_tree_entry = new Predicate(NULL, true);
31         predicate_tree_entry->add_predicate_expr(NOPREDICATE, NULL, true);
32
33         predicate_tree_exit = new Predicate(NULL, false, true);
34         predicate_tree_exit->set_depth(MAX_DEPTH);
35
36         /* Snapshot data structures below */
37         read_locations = new loc_set_t();
38         write_locations = new loc_set_t();
39         val_loc_map = new HashTable<uint64_t, loc_set_t *, uint64_t, 0, snapshot_malloc, snapshot_calloc, snapshot_free, int64_hash>();
40         loc_may_equal_map = new HashTable<void *, loc_set_t *, uintptr_t, 0>();
41
42         //values_may_read_from = new value_set_t();
43 }
44
45 /* Reallocate snapshotted memories when new executions start */
46 void FuncNode::set_new_exec_flag()
47 {
48         read_locations = new loc_set_t();
49         write_locations = new loc_set_t();
50         val_loc_map = new HashTable<uint64_t, loc_set_t *, uint64_t, 0, snapshot_malloc, snapshot_calloc, snapshot_free, int64_hash>();
51         loc_may_equal_map = new HashTable<void *, loc_set_t *, uintptr_t, 0>();
52
53         //values_may_read_from = new value_set_t();
54 }
55
56 /* Check whether FuncInst with the same type, position, and location
57  * as act has been added to func_inst_map or not. If not, add it.
58  */
59 void FuncNode::add_inst(ModelAction *act)
60 {
61         ASSERT(act);
62         const char * position = act->get_position();
63
64         /* THREAD* actions, ATOMIC_LOCK, ATOMIC_TRYLOCK, and ATOMIC_UNLOCK
65          * actions are not tagged with their source line numbers
66          */
67         if (position == NULL)
68                 return;
69
70         FuncInst * func_inst = func_inst_map.get(position);
71
72         /* This position has not been inserted into hashtable before */
73         if (func_inst == NULL) {
74                 func_inst = create_new_inst(act);
75                 func_inst_map.put(position, func_inst);
76                 return;
77         }
78
79         /* Volatile variables that use ++ or -- syntax may result in read and write actions with the same position */
80         if (func_inst->get_type() != act->get_type()) {
81                 FuncInst * collision_inst = func_inst->search_in_collision(act);
82
83                 if (collision_inst == NULL) {
84                         collision_inst = create_new_inst(act);
85                         func_inst->add_to_collision(collision_inst);
86                         return;
87                 } else {
88                         func_inst = collision_inst;
89                 }
90         }
91
92         ASSERT(func_inst->get_type() == act->get_type());
93         int curr_execution_number = model->get_execution_number();
94
95         /* Reset locations when new executions start */
96         if (func_inst->get_execution_number() != curr_execution_number) {
97                 func_inst->set_location(act->get_location());
98                 func_inst->set_execution_number(curr_execution_number);
99         }
100
101         /* Mark the memory location of such inst as not unique */
102         if (func_inst->get_location() != act->get_location())
103                 func_inst->not_single_location();
104 }
105
106 FuncInst * FuncNode::create_new_inst(ModelAction * act)
107 {
108         FuncInst * func_inst = new FuncInst(act, this);
109         int exec_num = model->get_execution_number();
110         func_inst->set_execution_number(exec_num);
111
112         inst_list.push_back(func_inst);
113
114         return func_inst;
115 }
116
117
118 /* Get the FuncInst with the same type, position, and location
119  * as act
120  *
121  * @return FuncInst with the same type, position, and location as act */
122 FuncInst * FuncNode::get_inst(ModelAction *act)
123 {
124         ASSERT(act);
125         const char * position = act->get_position();
126
127         /* THREAD* actions, ATOMIC_LOCK, ATOMIC_TRYLOCK, and ATOMIC_UNLOCK
128          * actions are not tagged with their source line numbers
129          */
130         if (position == NULL)
131                 return NULL;
132
133         FuncInst * inst = func_inst_map.get(position);
134         if (inst == NULL)
135                 return NULL;
136
137         action_type inst_type = inst->get_type();
138         action_type act_type = act->get_type();
139
140         if (inst_type == act_type) {
141                 return inst;
142         }
143         /* RMWRCAS actions are converted to RMW or READ actions */
144         else if (inst_type == ATOMIC_RMWRCAS &&
145                                          (act_type == ATOMIC_RMW || act_type == ATOMIC_READ)) {
146                 return inst;
147         }
148         /* Return the FuncInst in the collision list */
149         else {
150                 return inst->search_in_collision(act);
151         }
152 }
153
154 void FuncNode::add_entry_inst(FuncInst * inst)
155 {
156         if (inst == NULL)
157                 return;
158
159         mllnode<FuncInst *> * it;
160         for (it = entry_insts.begin();it != NULL;it = it->getNext()) {
161                 if (inst == it->getVal())
162                         return;
163         }
164
165         entry_insts.push_back(inst);
166 }
167
168 void FuncNode::function_entry_handler(thread_id_t tid)
169 {
170         init_marker(tid);
171         init_local_maps(tid);
172         init_predicate_tree_data_structure(tid);
173 }
174
175 void FuncNode::function_exit_handler(thread_id_t tid)
176 {
177         int thread_id = id_to_int(tid);
178
179         reset_local_maps(tid);
180
181         thrd_recursion_depth[thread_id]--;
182         thrd_markers[thread_id]->pop_back();
183
184         Predicate * exit_pred = get_predicate_tree_position(tid);
185         if (exit_pred->get_exit() == NULL) {
186                 // Exit predicate is unset yet
187                 exit_pred->set_exit(predicate_tree_exit);
188         }
189
190         update_predicate_tree_weight(tid);
191         reset_predicate_tree_data_structure(tid);
192 }
193
194 /**
195  * @brief Convert ModelAdtion list to FuncInst list
196  * @param act_list A list of ModelActions
197  */
198 void FuncNode::update_tree(ModelAction * act)
199 {
200         bool should_process = act->is_read() || act->is_write();
201         if (!should_process)
202                 return;
203
204         HashTable<void *, value_set_t *, uintptr_t, 0> * write_history = history->getWriteHistory();
205
206         /* build inst_list from act_list for later processing */
207 //      func_inst_list_t inst_list;
208
209         FuncInst * func_inst = get_inst(act);
210         void * loc = act->get_location();
211
212         if (func_inst == NULL)
213                 return;
214
215 //      inst_list.push_back(func_inst);
216
217         if (act->is_write()) {
218                 if (!write_locations->contains(loc)) {
219                         write_locations->add(loc);
220                         history->update_loc_wr_func_nodes_map(loc, this);
221                 }
222         }
223
224         if (act->is_read()) {
225
226                 /* If func_inst may only read_from a single location, then:
227                  *
228                  * The first time an action reads from some location,
229                  * import all the values that have been written to this
230                  * location from ModelHistory and notify ModelHistory
231                  * that this FuncNode may read from this location.
232                  */
233                 if (!read_locations->contains(loc) && func_inst->is_single_location()) {
234                         read_locations->add(loc);
235                         value_set_t * write_values = write_history->get(loc);
236                         add_to_val_loc_map(write_values, loc);
237                         history->update_loc_rd_func_nodes_map(loc, this);
238                 }
239         }
240
241 //      update_inst_tree(&inst_list); TODO
242
243         update_predicate_tree(act);
244
245 //      print_predicate_tree();
246 }
247
248 /**
249  * @brief Link FuncInsts in inst_list  - add one FuncInst to another's predecessors and successors
250  * @param inst_list A list of FuncInsts
251  */
252 void FuncNode::update_inst_tree(func_inst_list_t * inst_list)
253 {
254         if (inst_list == NULL)
255                 return;
256         else if (inst_list->size() == 0)
257                 return;
258
259         /* start linking */
260         sllnode<FuncInst *>* it = inst_list->begin();
261         sllnode<FuncInst *>* prev;
262
263         /* add the first instruction to the list of entry insts */
264         FuncInst * entry_inst = it->getVal();
265         add_entry_inst(entry_inst);
266
267         it = it->getNext();
268         while (it != NULL) {
269                 prev = it->getPrev();
270
271                 FuncInst * prev_inst = prev->getVal();
272                 FuncInst * curr_inst = it->getVal();
273
274                 prev_inst->add_succ(curr_inst);
275                 curr_inst->add_pred(prev_inst);
276
277                 it = it->getNext();
278         }
279 }
280
281 void FuncNode::update_predicate_tree(ModelAction * next_act)
282 {
283         thread_id_t tid = next_act->get_tid();
284         int thread_id = id_to_int(tid);
285         uint32_t this_marker = thrd_markers[thread_id]->back();
286         int recursion_depth = thrd_recursion_depth[thread_id];
287
288         loc_inst_map_t * loc_inst_map = thrd_loc_inst_maps[thread_id]->back();
289         inst_pred_map_t * inst_pred_map = thrd_inst_pred_maps[thread_id]->back();
290         inst_id_map_t * inst_id_map = thrd_inst_id_maps[thread_id]->back();
291
292         Predicate * curr_pred = get_predicate_tree_position(tid);
293         NewFuzzer * fuzzer = (NewFuzzer *)model->get_execution()->getFuzzer();
294         Predicate * selected_branch = fuzzer->get_selected_child_branch(tid);
295
296         bool amended;
297         while (true) {
298                 FuncInst * next_inst = get_inst(next_act);
299
300                 Predicate * unset_predicate = NULL;
301                 bool branch_found = follow_branch(&curr_pred, next_inst, next_act, &unset_predicate);
302
303                 // A branch with unset predicate expression is detected
304                 if (!branch_found && unset_predicate != NULL) {
305                         amended = amend_predicate_expr(curr_pred, next_inst, next_act);
306                         if (amended)
307                                 continue;
308                         else {
309                                 curr_pred = unset_predicate;
310                                 branch_found = true;
311                         }
312                 }
313
314                 // Detect loops
315                 if (!branch_found && inst_id_map->contains(next_inst)) {
316                         FuncInst * curr_inst = curr_pred->get_func_inst();
317                         uint32_t curr_id = inst_id_map->get(curr_inst);
318                         uint32_t next_id = inst_id_map->get(next_inst);
319
320                         if (curr_id >= next_id) {
321                                 Predicate * old_pred = inst_pred_map->get(next_inst);
322                                 Predicate * back_pred = old_pred->get_parent();
323
324                                 // Add to the set of backedges
325                                 curr_pred->add_backedge(back_pred);
326                                 curr_pred = back_pred;
327
328                                 continue;
329                         }
330                 }
331
332                 // Generate new branches
333                 if (!branch_found) {
334                         SnapVector<struct half_pred_expr *> half_pred_expressions;
335                         infer_predicates(next_inst, next_act, &half_pred_expressions);
336                         generate_predicates(curr_pred, next_inst, &half_pred_expressions);
337                         continue;
338                 }
339
340                 if (next_act->is_write()) {
341                         curr_pred->set_write(true);
342                 }
343
344                 if (next_act->is_read()) {
345                         /* Only need to store the locations of read actions */
346                         loc_inst_map->put(next_act->get_location(), next_inst);
347                 }
348
349                 inst_pred_map->put(next_inst, curr_pred);
350                 set_predicate_tree_position(tid, curr_pred);
351
352                 if (!inst_id_map->contains(next_inst))
353                         inst_id_map->put(next_inst, inst_counter++);
354
355                 curr_pred->incr_expl_count();
356                 add_predicate_to_trace(tid, curr_pred);
357                 if (next_act->is_read())
358                         next_inst->set_associated_read(tid, recursion_depth, this_marker, next_act->get_reads_from_value());
359
360                 break;
361         }
362
363         // A check
364         if (next_act->is_read()) {
365                 if (selected_branch != NULL && !amended)
366                         ASSERT(selected_branch == curr_pred);
367         }
368 }
369
370 /* Given curr_pred and next_inst, find the branch following curr_pred that
371  * contains next_inst and the correct predicate.
372  * @return true if branch found, false otherwise.
373  */
374 bool FuncNode::follow_branch(Predicate ** curr_pred, FuncInst * next_inst,
375                                                                                                                  ModelAction * next_act, Predicate ** unset_predicate)
376 {
377         /* Check if a branch with func_inst and corresponding predicate exists */
378         bool branch_found = false;
379         thread_id_t tid = next_act->get_tid();
380
381         ModelVector<Predicate *> * branches = (*curr_pred)->get_children();
382         for (uint i = 0;i < branches->size();i++) {
383                 Predicate * branch = (*branches)[i];
384                 if (branch->get_func_inst() != next_inst)
385                         continue;
386
387                 /* Check against predicate expressions */
388                 bool predicate_correct = true;
389                 PredExprSet * pred_expressions = branch->get_pred_expressions();
390
391                 /* Only read and rmw actions my have unset predicate expressions */
392                 if (pred_expressions->getSize() == 0) {
393                         predicate_correct = false;
394
395                         if (*unset_predicate == NULL)
396                                 *unset_predicate = branch;
397                         else
398                                 ASSERT(false);
399
400                         continue;
401                 }
402
403                 PredExprSetIter * pred_expr_it = pred_expressions->iterator();
404                 while (pred_expr_it->hasNext()) {
405                         pred_expr * pred_expression = pred_expr_it->next();
406                         uint64_t last_read, next_read;
407                         bool equality;
408
409                         switch(pred_expression->token) {
410                         case NOPREDICATE:
411                                 predicate_correct = true;
412                                 break;
413                         case EQUALITY:
414                                 FuncInst * to_be_compared;
415                                 to_be_compared = pred_expression->func_inst;
416
417                                 last_read = get_associated_read(tid, to_be_compared);
418                                 ASSERT(last_read != VALUE_NONE);
419
420                                 next_read = next_act->get_reads_from_value();
421                                 equality = (last_read == next_read);
422                                 if (equality != pred_expression->value)
423                                         predicate_correct = false;
424
425                                 break;
426                         case NULLITY:
427                                 next_read = next_act->get_reads_from_value();
428                                 // TODO: implement likely to be null
429                                 equality = ( (void*) (next_read & 0xffffffff) == NULL);
430                                 if (equality != pred_expression->value)
431                                         predicate_correct = false;
432                                 break;
433                         default:
434                                 predicate_correct = false;
435                                 model_print("unkown predicate token\n");
436                                 break;
437                         }
438                 }
439
440                 delete pred_expr_it;
441
442                 if (predicate_correct) {
443                         *curr_pred = branch;
444                         branch_found = true;
445                         break;
446                 }
447         }
448
449         return branch_found;
450 }
451
452 /* Infer predicate expressions, which are generated in FuncNode::generate_predicates */
453 void FuncNode::infer_predicates(FuncInst * next_inst, ModelAction * next_act,
454                                                                                                                                 SnapVector<struct half_pred_expr *> * half_pred_expressions)
455 {
456         void * loc = next_act->get_location();
457         int thread_id = id_to_int(next_act->get_tid());
458         loc_inst_map_t * loc_inst_map = thrd_loc_inst_maps[thread_id]->back();
459
460         if (next_inst->is_read()) {
461                 /* read + rmw */
462                 if ( loc_inst_map->contains(loc) ) {
463                         FuncInst * last_inst = loc_inst_map->get(loc);
464                         struct half_pred_expr * expression = new half_pred_expr(EQUALITY, last_inst);
465                         half_pred_expressions->push_back(expression);
466                 } else if ( next_inst->is_single_location() ) {
467                         loc_set_t * loc_may_equal = loc_may_equal_map->get(loc);
468
469                         if (loc_may_equal != NULL) {
470                                 loc_set_iter * loc_it = loc_may_equal->iterator();
471                                 while (loc_it->hasNext()) {
472                                         void * neighbor = loc_it->next();
473                                         if (loc_inst_map->contains(neighbor)) {
474                                                 FuncInst * last_inst = loc_inst_map->get(neighbor);
475
476                                                 struct half_pred_expr * expression = new half_pred_expr(EQUALITY, last_inst);
477                                                 half_pred_expressions->push_back(expression);
478                                         }
479                                 }
480
481                                 delete loc_it;
482                         }
483                 } else {
484                         // next_inst is not single location
485                         uint64_t read_val = next_act->get_reads_from_value();
486
487                         // only infer NULLITY predicate when it is actually NULL.
488                         if ( (void*)read_val == NULL) {
489                                 struct half_pred_expr * expression = new half_pred_expr(NULLITY, NULL);
490                                 half_pred_expressions->push_back(expression);
491                         }
492                 }
493         } else {
494                 /* Pure writes */
495                 // TODO: do anything here?
496         }
497 }
498
499 /* Able to generate complex predicates when there are multiple predciate expressions */
500 void FuncNode::generate_predicates(Predicate * curr_pred, FuncInst * next_inst,
501                                                                                                                                          SnapVector<struct half_pred_expr *> * half_pred_expressions)
502 {
503         if (half_pred_expressions->size() == 0) {
504                 Predicate * new_pred = new Predicate(next_inst);
505                 curr_pred->add_child(new_pred);
506                 new_pred->set_parent(curr_pred);
507
508                 /* entry predicates and predicates containing pure write actions
509                  * have no predicate expressions */
510                 if ( curr_pred->is_entry_predicate() )
511                         new_pred->add_predicate_expr(NOPREDICATE, NULL, true);
512                 else if (next_inst->is_write()) {
513                         /* next_inst->is_write() <==> pure writes */
514                         new_pred->add_predicate_expr(NOPREDICATE, NULL, true);
515                 }
516
517                 return;
518         }
519
520         SnapVector<Predicate *> predicates;
521
522         struct half_pred_expr * half_expr = (*half_pred_expressions)[0];
523         predicates.push_back(new Predicate(next_inst));
524         predicates.push_back(new Predicate(next_inst));
525
526         predicates[0]->add_predicate_expr(half_expr->token, half_expr->func_inst, true);
527         predicates[1]->add_predicate_expr(half_expr->token, half_expr->func_inst, false);
528
529         for (uint i = 1;i < half_pred_expressions->size();i++) {
530                 half_expr = (*half_pred_expressions)[i];
531
532                 uint old_size = predicates.size();
533                 for (uint j = 0;j < old_size;j++) {
534                         Predicate * pred = predicates[j];
535                         Predicate * new_pred = new Predicate(next_inst);
536                         new_pred->copy_predicate_expr(pred);
537
538                         pred->add_predicate_expr(half_expr->token, half_expr->func_inst, true);
539                         new_pred->add_predicate_expr(half_expr->token, half_expr->func_inst, false);
540
541                         predicates.push_back(new_pred);
542                 }
543         }
544
545         for (uint i = 0;i < predicates.size();i++) {
546                 Predicate * pred= predicates[i];
547                 curr_pred->add_child(pred);
548                 pred->set_parent(curr_pred);
549         }
550
551         /* Free memories allocated by infer_predicate */
552         for (uint i = 0;i < half_pred_expressions->size();i++) {
553                 struct half_pred_expr * tmp = (*half_pred_expressions)[i];
554                 snapshot_free(tmp);
555         }
556 }
557
558 /* Amend predicates that contain no predicate expressions. Currenlty only amend with NULLITY predicates */
559 bool FuncNode::amend_predicate_expr(Predicate * curr_pred, FuncInst * next_inst, ModelAction * next_act)
560 {
561         ModelVector<Predicate *> * children = curr_pred->get_children();
562
563         Predicate * unset_pred = NULL;
564         for (uint i = 0;i < children->size();i++) {
565                 Predicate * child = (*children)[i];
566                 if (child->get_func_inst() == next_inst) {
567                         unset_pred = child;
568                         break;
569                 }
570         }
571
572         uint64_t read_val = next_act->get_reads_from_value();
573
574         // only generate NULLITY predicate when it is actually NULL.
575         if ( !next_inst->is_single_location() && (void*)read_val == NULL ) {
576                 Predicate * new_pred = new Predicate(next_inst);
577
578                 curr_pred->add_child(new_pred);
579                 new_pred->set_parent(curr_pred);
580
581                 unset_pred->add_predicate_expr(NULLITY, NULL, false);
582                 new_pred->add_predicate_expr(NULLITY, NULL, true);
583
584                 return true;
585         }
586
587         return false;
588 }
589
590 void FuncNode::add_to_val_loc_map(uint64_t val, void * loc)
591 {
592         loc_set_t * locations = val_loc_map->get(val);
593
594         if (locations == NULL) {
595                 locations = new loc_set_t();
596                 val_loc_map->put(val, locations);
597         }
598
599         update_loc_may_equal_map(loc, locations);
600         locations->add(loc);
601         // values_may_read_from->add(val);
602 }
603
604 void FuncNode::add_to_val_loc_map(value_set_t * values, void * loc)
605 {
606         if (values == NULL)
607                 return;
608
609         value_set_iter * it = values->iterator();
610         while (it->hasNext()) {
611                 uint64_t val = it->next();
612                 add_to_val_loc_map(val, loc);
613         }
614
615         delete it;
616 }
617
618 void FuncNode::update_loc_may_equal_map(void * new_loc, loc_set_t * old_locations)
619 {
620         if ( old_locations->contains(new_loc) )
621                 return;
622
623         loc_set_t * neighbors = loc_may_equal_map->get(new_loc);
624
625         if (neighbors == NULL) {
626                 neighbors = new loc_set_t();
627                 loc_may_equal_map->put(new_loc, neighbors);
628         }
629
630         loc_set_iter * loc_it = old_locations->iterator();
631         while (loc_it->hasNext()) {
632                 // new_loc: { old_locations, ... }
633                 void * member = loc_it->next();
634                 neighbors->add(member);
635
636                 // for each i in old_locations, i : { new_loc, ... }
637                 loc_set_t * _neighbors = loc_may_equal_map->get(member);
638                 if (_neighbors == NULL) {
639                         _neighbors = new loc_set_t();
640                         loc_may_equal_map->put(member, _neighbors);
641                 }
642                 _neighbors->add(new_loc);
643         }
644
645         delete loc_it;
646 }
647
648 void FuncNode::set_predicate_tree_position(thread_id_t tid, Predicate * pred)
649 {
650         int thread_id = id_to_int(tid);
651         ModelVector<Predicate *> * stack = thrd_predicate_tree_position[thread_id];
652         (*stack)[stack->size() - 1] = pred;
653 }
654
655 /* @return The position of a thread in a predicate tree */
656 Predicate * FuncNode::get_predicate_tree_position(thread_id_t tid)
657 {
658         int thread_id = id_to_int(tid);
659         return thrd_predicate_tree_position[thread_id]->back();
660 }
661
662 void FuncNode::add_predicate_to_trace(thread_id_t tid, Predicate * pred)
663 {
664         int thread_id = id_to_int(tid);
665         thrd_predicate_trace[thread_id]->back()->push_back(pred);
666 }
667
668 void FuncNode::init_marker(thread_id_t tid)
669 {
670         marker++;
671
672         int thread_id = id_to_int(tid);
673         int old_size = thrd_markers.size();
674
675         if (old_size < thread_id + 1) {
676                 thrd_markers.resize(thread_id + 1);
677
678                 for (int i = old_size; i < thread_id + 1; i++) {
679                         thrd_markers[i] = new ModelVector<uint32_t>();
680                         thrd_recursion_depth.push_back(-1);
681                 }
682         }
683
684         thrd_markers[thread_id]->push_back(marker);
685         thrd_recursion_depth[thread_id]++;
686 }
687
688 uint64_t FuncNode::get_associated_read(thread_id_t tid, FuncInst * inst)
689 {
690         int thread_id = id_to_int(tid);
691         int recursion_depth = thrd_recursion_depth[thread_id];
692         uint marker = thrd_markers[thread_id]->back();
693
694         return inst->get_associated_read(tid, recursion_depth, marker);
695 }
696
697 /* Make sure elements of maps are initialized properly when threads enter functions */
698 void FuncNode::init_local_maps(thread_id_t tid)
699 {
700         int thread_id = id_to_int(tid);
701         int old_size = thrd_loc_inst_maps.size();
702
703         if (old_size < thread_id + 1) {
704                 int new_size = thread_id + 1;
705
706                 thrd_loc_inst_maps.resize(new_size);
707                 thrd_inst_id_maps.resize(new_size);
708                 thrd_inst_pred_maps.resize(new_size);
709
710                 for (int i = old_size; i < new_size; i++) {
711                         thrd_loc_inst_maps[i] = new ModelVector<loc_inst_map_t *>;
712                         thrd_inst_id_maps[i] = new ModelVector<inst_id_map_t *>;
713                         thrd_inst_pred_maps[i] = new ModelVector<inst_pred_map_t *>;
714                 }
715         }
716
717         ModelVector<loc_inst_map_t *> * map = thrd_loc_inst_maps[thread_id];
718         int index = thrd_recursion_depth[thread_id];
719
720         // If there are recursive calls, push more hashtables into the vector.
721         if (map->size() < (uint) index + 1) {
722                 thrd_loc_inst_maps[thread_id]->push_back(new loc_inst_map_t(64));
723                 thrd_inst_id_maps[thread_id]->push_back(new inst_id_map_t(64));
724                 thrd_inst_pred_maps[thread_id]->push_back(new inst_pred_map_t(64));
725         }
726
727         ASSERT(map->size() == (uint) index + 1);
728 }
729
730 /* Reset elements of maps when threads exit functions */
731 void FuncNode::reset_local_maps(thread_id_t tid)
732 {
733         int thread_id = id_to_int(tid);
734         int index = thrd_recursion_depth[thread_id];
735
736         // When recursive call ends, keep only one hashtable in the vector
737         if (index > 0) {
738                 delete thrd_loc_inst_maps[thread_id]->back();
739                 delete thrd_inst_id_maps[thread_id]->back();
740                 delete thrd_inst_pred_maps[thread_id]->back();
741
742                 thrd_loc_inst_maps[thread_id]->pop_back();
743                 thrd_inst_id_maps[thread_id]->pop_back();
744                 thrd_inst_pred_maps[thread_id]->pop_back();
745         } else {
746                 thrd_loc_inst_maps[thread_id]->back()->reset();
747                 thrd_inst_id_maps[thread_id]->back()->reset();
748                 thrd_inst_pred_maps[thread_id]->back()->reset();
749         }
750 }
751
752 void FuncNode::init_predicate_tree_data_structure(thread_id_t tid)
753 {
754         int thread_id = id_to_int(tid);
755         int old_size = thrd_predicate_tree_position.size();
756
757         if (old_size < thread_id + 1) {
758                 thrd_predicate_tree_position.resize(thread_id + 1);
759                 thrd_predicate_trace.resize(thread_id + 1);
760
761                 for (int i = old_size; i < thread_id + 1; i++) {
762                         thrd_predicate_tree_position[i] = new ModelVector<Predicate *>();
763                         thrd_predicate_trace[i] = new ModelVector<predicate_trace_t *>();
764                 }
765         }
766
767         thrd_predicate_tree_position[thread_id]->push_back(predicate_tree_entry);
768         thrd_predicate_trace[thread_id]->push_back(new predicate_trace_t());
769 }
770
771 void FuncNode::reset_predicate_tree_data_structure(thread_id_t tid)
772 {
773         int thread_id = id_to_int(tid);
774         thrd_predicate_tree_position[thread_id]->pop_back();
775
776         // Free memories allocated in init_predicate_tree_data_structure
777         delete thrd_predicate_trace[thread_id]->back();
778         thrd_predicate_trace[thread_id]->pop_back();
779 }
780
781 /* Add FuncNodes that this node may follow */
782 void FuncNode::add_out_edge(FuncNode * other)
783 {
784         if ( !edge_table.contains(other) ) {
785                 edge_table.put(other, OUT_EDGE);
786                 out_edges.push_back(other);
787                 return;
788         }
789
790         edge_type_t edge = edge_table.get(other);
791         if (edge == IN_EDGE) {
792                 edge_table.put(other, BI_EDGE);
793                 out_edges.push_back(other);
794         }
795 }
796
797 /* Compute the distance between this FuncNode and the target node.
798  * Return -1 if the target node is unreachable or the actual distance
799  * is greater than max_step.
800  */
801 int FuncNode::compute_distance(FuncNode * target, int max_step)
802 {
803         if (target == NULL)
804                 return -1;
805         else if (target == this)
806                 return 0;
807
808         SnapList<FuncNode *> queue;
809         HashTable<FuncNode *, int, uintptr_t, 0> distances(128);
810
811         queue.push_back(this);
812         distances.put(this, 0);
813
814         while (!queue.empty()) {
815                 FuncNode * curr = queue.front();
816                 queue.pop_front();
817                 int dist = distances.get(curr);
818
819                 if (max_step <= dist)
820                         return -1;
821
822                 ModelList<FuncNode *> * outEdges = curr->get_out_edges();
823                 mllnode<FuncNode *> * it;
824                 for (it = outEdges->begin();it != NULL;it = it->getNext()) {
825                         FuncNode * out_node = it->getVal();
826
827                         /* This node has not been visited before */
828                         if ( !distances.contains(out_node) ) {
829                                 if (out_node == target)
830                                         return dist + 1;
831
832                                 queue.push_back(out_node);
833                                 distances.put(out_node, dist + 1);
834                         }
835                 }
836         }
837
838         /* Target node is unreachable */
839         return -1;
840 }
841
842 void FuncNode::update_predicate_tree_weight(thread_id_t tid)
843 {
844         predicate_trace_t * trace = thrd_predicate_trace[id_to_int(tid)]->back();
845
846         // Update predicate weights based on prediate trace
847         for (mllnode<Predicate *> * rit = trace->end(); rit != NULL; rit = rit->getPrev()) {
848                 Predicate * node = rit->getVal();
849                 ModelVector<Predicate *> * children = node->get_children();
850
851                 if (children->size() == 0) {
852                         double weight = 100.0 / sqrt(node->get_expl_count() + node->get_fail_count() + 1);
853                         node->set_weight(weight);
854                 } else {
855                         double weight_sum = 0.0;
856                         for (uint i = 0;i < children->size();i++) {
857                                 Predicate * child = (*children)[i];
858                                 double weight = child->get_weight();
859                                 weight_sum += weight;
860                         }
861
862                         double average_weight = (double) weight_sum / (double) children->size();
863                         double weight = average_weight * pow(0.9, node->get_depth());
864                         node->set_weight(weight);
865                 }
866         }
867 }
868
869 void FuncNode::print_predicate_tree()
870 {
871         model_print("digraph function_%s {\n", func_name);
872         predicate_tree_entry->print_pred_subtree();
873         predicate_tree_exit->print_predicate();
874         model_print("}\n");     // end of graph
875 }