2 #include "threads-model.h"
7 #include "concretepredicate.h"
12 #include "execution.h"
14 NewFuzzer::NewFuzzer() :
16 thrd_last_func_inst(),
17 available_branches_tmp_storage(),
18 thrd_selected_child_branch(),
21 paused_thread_table(128),
22 failed_predicates(32),
27 * @brief Register the ModelHistory and ModelExecution engine
29 void NewFuzzer::register_engine(ModelHistory * history, ModelExecution *execution)
31 this->history = history;
32 this->execution = execution;
35 int NewFuzzer::selectWrite(ModelAction *read, SnapVector<ModelAction *> * rf_set)
37 // return random() % rf_set->size();
39 thread_id_t tid = read->get_tid();
40 int thread_id = id_to_int(tid);
42 if (thrd_last_read_act.size() <= (uint) thread_id) {
43 thrd_last_read_act.resize(thread_id + 1);
44 thrd_last_func_inst.resize(thread_id + 1);
47 // A new read action is encountered, select a random child branch of current predicate
48 if (read != thrd_last_read_act[thread_id]) {
49 FuncNode * func_node = history->get_curr_func_node(tid);
50 Predicate * curr_pred = func_node->get_predicate_tree_position(tid);
51 FuncInst * read_inst = func_node->get_inst(read);
52 inst_act_map_t * inst_act_map = func_node->get_inst_act_map(tid);
54 if (curr_pred != NULL) {
55 Predicate * selected_branch = NULL;
57 if (check_store_visibility(curr_pred, read_inst, inst_act_map, rf_set))
58 selected_branch = selectBranch(tid, curr_pred, read_inst);
60 // no child of curr_pred matches read_inst, check back edges
61 PredSet * back_edges = curr_pred->get_backedges();
62 PredSetIter * it = back_edges->iterator();
64 while (it->hasNext()) {
65 curr_pred = it->next();
66 if (check_store_visibility(curr_pred, read_inst, inst_act_map, rf_set)) {
67 selected_branch = selectBranch(tid, curr_pred, read_inst);
75 prune_writes(tid, selected_branch, rf_set, inst_act_map);
78 if (!failed_predicates.isEmpty())
79 failed_predicates.reset();
81 thrd_last_read_act[thread_id] = read;
82 thrd_last_func_inst[thread_id] = read_inst;
85 ASSERT(rf_set->size() != 0);
86 int random_index = random() % rf_set->size();
91 /* For children of curr_pred that matches read_inst.
92 * If any store in rf_set satisfies the a child's predicate,
93 * increment the store visibility count for it.
95 * @return False if no child matches read_inst
97 bool NewFuzzer::check_store_visibility(Predicate * curr_pred, FuncInst * read_inst,
98 inst_act_map_t * inst_act_map, SnapVector<ModelAction *> * rf_set)
100 available_branches_tmp_storage.clear();
102 ASSERT(!rf_set->empty());
103 if (curr_pred == NULL || read_inst == NULL)
106 ModelVector<Predicate *> * children = curr_pred->get_children();
107 bool any_child_match = false;
109 /* Iterate over all predicate children */
110 for (uint i = 0;i < children->size();i++) {
111 Predicate * branch = (*children)[i];
113 /* The children predicates may have different FuncInsts */
114 if (branch->get_func_inst() == read_inst) {
115 PredExprSet * pred_expressions = branch->get_pred_expressions();
116 any_child_match = true;
118 branch->incr_total_checking_count();
120 if (pred_expressions->isEmpty()) {
121 /* Do not check predicate expression of unset predicates */
122 available_branches_tmp_storage.push_back(branch);
123 branch->incr_store_visible_count();
127 /* Iterate over all write actions */
128 for (uint j = 0;j < rf_set->size();j++) {
129 ModelAction * write_act = (*rf_set)[j];
130 uint64_t write_val = write_act->get_write_value();
132 bool satisfy_predicate = check_predicate_expressions(pred_expressions, inst_act_map, write_val, &dummy);
134 /* If one write value satisfies the predicate, go to check the next predicate */
135 if (satisfy_predicate) {
136 branch->incr_store_visible_count();
137 available_branches_tmp_storage.push_back(branch);
144 return any_child_match;
147 /* Select a random branch from the children of curr_pred
148 * @return The selected branch
150 Predicate * NewFuzzer::selectBranch(thread_id_t tid, Predicate * curr_pred, FuncInst * read_inst)
152 int thread_id = id_to_int(tid);
153 if ( thrd_selected_child_branch.size() <= (uint) thread_id)
154 thrd_selected_child_branch.resize(thread_id + 1);
156 if (curr_pred == NULL || read_inst == NULL) {
157 thrd_selected_child_branch[thread_id] = NULL;
161 // predicate children have not been generated
162 if (available_branches_tmp_storage.size() == 0) {
163 thrd_selected_child_branch[thread_id] = NULL;
167 int index = choose_index(&available_branches_tmp_storage);
168 Predicate * random_branch = available_branches_tmp_storage[ index ];
169 thrd_selected_child_branch[thread_id] = random_branch;
171 return random_branch;
175 * @brief Select a branch from the given predicate branch
177 int NewFuzzer::choose_index(SnapVector<Predicate *> * branches)
179 return random() % branches->size();
182 Predicate * NewFuzzer::get_selected_child_branch(thread_id_t tid)
184 int thread_id = id_to_int(tid);
185 if (thrd_selected_child_branch.size() <= (uint) thread_id)
188 return thrd_selected_child_branch[thread_id];
191 /* Remove writes from the rf_set that do not satisfie the selected predicate,
192 * and store them in thrd_pruned_writes
194 * @return true if rf_set is pruned
196 bool NewFuzzer::prune_writes(thread_id_t tid, Predicate * pred,
197 SnapVector<ModelAction *> * rf_set, inst_act_map_t * inst_act_map)
202 PredExprSet * pred_expressions = pred->get_pred_expressions();
203 if (pred_expressions->getSize() == 0) // unset predicates
206 int thread_id = id_to_int(tid);
207 uint old_size = thrd_pruned_writes.size();
208 if (thrd_pruned_writes.size() <= (uint) thread_id) {
209 uint new_size = thread_id + 1;
210 thrd_pruned_writes.resize(new_size);
211 for (uint i = old_size;i < new_size;i++)
212 thrd_pruned_writes[i] = new SnapVector<ModelAction *>();
214 SnapVector<ModelAction *> * pruned_writes = thrd_pruned_writes[thread_id];
215 pruned_writes->clear(); // clear the old pruned_writes set
220 while ( index < rf_set->size() ) {
221 ModelAction * write_act = (*rf_set)[index];
222 uint64_t write_val = write_act->get_write_value();
223 bool no_predicate = false;
224 bool satisfy_predicate = check_predicate_expressions(pred_expressions, inst_act_map, write_val, &no_predicate);
229 if (!satisfy_predicate) {
230 ASSERT(rf_set != NULL);
231 (*rf_set)[index] = rf_set->back();
233 pruned_writes->push_back(write_act);
242 /* @brief Put a thread to sleep because no writes in rf_set satisfies the selected predicate.
244 * @param thread A thread whose last action is a read
246 void NewFuzzer::conditional_sleep(Thread * thread)
248 int index = paused_thread_list.size();
250 model->getScheduler()->add_sleep(thread);
251 paused_thread_list.push_back(thread);
252 paused_thread_table.put(thread, index); // Update table
254 /* Add the waiting condition to ModelHistory */
255 ModelAction * read = thread->get_pending();
256 thread_id_t tid = thread->get_id();
257 FuncNode * func_node = history->get_curr_func_node(tid);
258 inst_act_map_t * inst_act_map = func_node->get_inst_act_map(tid);
260 Predicate * selected_branch = get_selected_child_branch(tid);
261 ConcretePredicate * concrete = selected_branch->evaluate(inst_act_map, tid);
262 concrete->set_location(read->get_location());
264 history->add_waiting_write(concrete);
265 /* history->add_waiting_thread is already called in find_threads */
268 bool NewFuzzer::has_paused_threads()
270 return paused_thread_list.size() != 0;
273 Thread * NewFuzzer::selectThread(int * threadlist, int numthreads)
275 if (numthreads == 0 && has_paused_threads()) {
276 wake_up_paused_threads(threadlist, &numthreads);
277 //model_print("list size: %d, active t id: %d\n", numthreads, threadlist[0]);
280 int random_index = random() % numthreads;
281 int thread = threadlist[random_index];
282 thread_id_t curr_tid = int_to_id(thread);
283 return execution->get_thread(curr_tid);
286 /* Force waking up one of threads paused by Fuzzer, because otherwise
287 * the Fuzzer is not making progress
289 void NewFuzzer::wake_up_paused_threads(int * threadlist, int * numthreads)
291 int random_index = random() % paused_thread_list.size();
292 Thread * thread = paused_thread_list[random_index];
293 model->getScheduler()->remove_sleep(thread);
295 Thread * last_thread = paused_thread_list.back();
296 paused_thread_list[random_index] = last_thread;
297 paused_thread_list.pop_back();
298 paused_thread_table.put(last_thread, random_index); // Update table
299 paused_thread_table.remove(thread);
301 thread_id_t tid = thread->get_id();
302 history->remove_waiting_write(tid);
303 history->remove_waiting_thread(tid);
305 threadlist[*numthreads] = tid;
309 Predicate * selected_branch = get_selected_child_branch(tid);
310 update_predicate_score(selected_branch, SLEEP_FAIL_TYPE3);
313 model_print("thread %d is woken up\n", tid);
316 /* Wake up conditional sleeping threads if the desired write is available */
317 void NewFuzzer::notify_paused_thread(Thread * thread)
319 ASSERT(paused_thread_table.contains(thread));
321 int index = paused_thread_table.get(thread);
322 model->getScheduler()->remove_sleep(thread);
324 Thread * last_thread = paused_thread_list.back();
325 paused_thread_list[index] = last_thread;
326 paused_thread_list.pop_back();
327 paused_thread_table.put(last_thread, index); // Update table
328 paused_thread_table.remove(thread);
330 thread_id_t tid = thread->get_id();
331 history->remove_waiting_write(tid);
332 history->remove_waiting_thread(tid);
335 Predicate * selected_branch = get_selected_child_branch(tid);
336 update_predicate_score(selected_branch, SLEEP_SUCCESS);
339 model_print("** thread %d is woken up\n", tid);
342 /* Find threads that may write values that the pending read action is waiting for.
343 * Side effect: waiting thread related info are stored in dist_info_vec
345 * @return True if any thread is found
347 bool NewFuzzer::find_threads(ModelAction * pending_read)
349 ASSERT(pending_read->is_read());
351 void * location = pending_read->get_location();
352 thread_id_t self_id = pending_read->get_tid();
353 bool finds_waiting_for = false;
355 SnapVector<FuncNode *> * func_node_list = history->getWrFuncNodes(location);
356 for (uint i = 0;i < func_node_list->size();i++) {
357 FuncNode * target_node = (*func_node_list)[i];
358 for (uint i = 1;i < execution->get_num_threads();i++) {
359 thread_id_t tid = int_to_id(i);
363 FuncNode * node = history->get_curr_func_node(tid);
364 /* It is possible that thread tid is not in any FuncNode */
368 int distance = node->compute_distance(target_node);
369 if (distance != -1) {
370 finds_waiting_for = true;
371 //model_print("thread: %d; distance from node %d to node %d: %d\n", tid, node->get_func_id(), target_node->get_func_id(), distance);
373 dist_info_vec.push_back(node_dist_info(tid, target_node, distance));
378 return finds_waiting_for;
381 bool NewFuzzer::check_predicate_expressions(PredExprSet * pred_expressions,
382 inst_act_map_t * inst_act_map, uint64_t write_val, bool * no_predicate)
384 bool satisfy_predicate = true;
386 PredExprSetIter * pred_expr_it = pred_expressions->iterator();
387 while (pred_expr_it->hasNext()) {
388 struct pred_expr * expression = pred_expr_it->next();
391 switch (expression->token) {
393 *no_predicate = true;
396 FuncInst * to_be_compared;
397 ModelAction * last_act;
400 to_be_compared = expression->func_inst;
401 last_act = inst_act_map->get(to_be_compared);
402 last_read = last_act->get_reads_from_value();
404 equality = (write_val == last_read);
405 if (equality != expression->value)
406 satisfy_predicate = false;
409 // TODO: implement likely to be null
410 equality = ((void*) (write_val & 0xffffffff) == NULL);
411 if (equality != expression->value)
412 satisfy_predicate = false;
415 model_print("unknown predicate token\n");
419 if (!satisfy_predicate)
424 return satisfy_predicate;
427 bool NewFuzzer::shouldWait(const ModelAction * act)