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);
73 prune_writes(tid, selected_branch, rf_set, inst_act_map);
76 if (!failed_predicates.isEmpty())
77 failed_predicates.reset();
79 thrd_last_read_act[thread_id] = read;
80 thrd_last_func_inst[thread_id] = read_inst;
83 ASSERT(rf_set->size() != 0);
84 int random_index = random() % rf_set->size();
89 /* For children of curr_pred that matches read_inst.
90 * If any store in rf_set satisfies the a child's predicate,
91 * increment the store visibility count for it.
93 * @return False if no child matches read_inst
95 bool NewFuzzer::check_store_visibility(Predicate * curr_pred, FuncInst * read_inst,
96 inst_act_map_t * inst_act_map, SnapVector<ModelAction *> * rf_set)
98 available_branches_tmp_storage.clear();
100 ASSERT(!rf_set->empty());
101 if (curr_pred == NULL || read_inst == NULL)
104 ModelVector<Predicate *> * children = curr_pred->get_children();
105 bool any_child_match = false;
107 /* Iterate over all predicate children */
108 for (uint i = 0;i < children->size();i++) {
109 Predicate * branch = (*children)[i];
111 /* The children predicates may have different FuncInsts */
112 if (branch->get_func_inst() == read_inst) {
113 PredExprSet * pred_expressions = branch->get_pred_expressions();
114 any_child_match = true;
116 /* Do not check unset predicates */
117 if (pred_expressions->isEmpty()) {
118 available_branches_tmp_storage.push_back(branch);
122 branch->incr_total_checking_count();
124 /* Iterate over all write actions */
125 for (uint j = 0;j < rf_set->size();j++) {
126 ModelAction * write_act = (*rf_set)[j];
127 uint64_t write_val = write_act->get_write_value();
129 bool satisfy_predicate = check_predicate_expressions(pred_expressions, inst_act_map, write_val, &dummy);
131 /* If one write value satisfies the predicate, go to check the next predicate */
132 if (satisfy_predicate) {
133 branch->incr_store_visible_count();
134 available_branches_tmp_storage.push_back(branch);
141 return any_child_match;
144 /* Select a random branch from the children of curr_pred
145 * @return The selected branch
147 Predicate * NewFuzzer::selectBranch(thread_id_t tid, Predicate * curr_pred, FuncInst * read_inst)
149 int thread_id = id_to_int(tid);
150 if ( thrd_selected_child_branch.size() <= (uint) thread_id)
151 thrd_selected_child_branch.resize(thread_id + 1);
153 if (curr_pred == NULL || read_inst == NULL) {
154 thrd_selected_child_branch[thread_id] = NULL;
158 // predicate children have not been generated
159 if (available_branches_tmp_storage.size() == 0) {
160 thrd_selected_child_branch[thread_id] = NULL;
164 int index = choose_index(&available_branches_tmp_storage);
165 Predicate * random_branch = available_branches_tmp_storage[ index ];
166 thrd_selected_child_branch[thread_id] = random_branch;
168 return random_branch;
172 * @brief Select a branch from the given predicate branch
174 int NewFuzzer::choose_index(SnapVector<Predicate *> * branches)
176 return random() % branches->size();
179 Predicate * NewFuzzer::get_selected_child_branch(thread_id_t tid)
181 int thread_id = id_to_int(tid);
182 if (thrd_selected_child_branch.size() <= (uint) thread_id)
185 return thrd_selected_child_branch[thread_id];
188 /* Remove writes from the rf_set that do not satisfie the selected predicate,
189 * and store them in thrd_pruned_writes
191 * @return true if rf_set is pruned
193 bool NewFuzzer::prune_writes(thread_id_t tid, Predicate * pred,
194 SnapVector<ModelAction *> * rf_set, inst_act_map_t * inst_act_map)
199 PredExprSet * pred_expressions = pred->get_pred_expressions();
200 if (pred_expressions->getSize() == 0) // unset predicates
203 int thread_id = id_to_int(tid);
204 uint old_size = thrd_pruned_writes.size();
205 if (thrd_pruned_writes.size() <= (uint) thread_id) {
206 uint new_size = thread_id + 1;
207 thrd_pruned_writes.resize(new_size);
208 for (uint i = old_size;i < new_size;i++)
209 thrd_pruned_writes[i] = new SnapVector<ModelAction *>();
211 SnapVector<ModelAction *> * pruned_writes = thrd_pruned_writes[thread_id];
212 pruned_writes->clear(); // clear the old pruned_writes set
217 while ( index < rf_set->size() ) {
218 ModelAction * write_act = (*rf_set)[index];
219 uint64_t write_val = write_act->get_write_value();
220 bool no_predicate = false;
221 bool satisfy_predicate = check_predicate_expressions(pred_expressions, inst_act_map, write_val, &no_predicate);
226 if (!satisfy_predicate) {
227 ASSERT(rf_set != NULL);
228 (*rf_set)[index] = rf_set->back();
230 pruned_writes->push_back(write_act);
239 /* @brief Put a thread to sleep because no writes in rf_set satisfies the selected predicate.
241 * @param thread A thread whose last action is a read
243 void NewFuzzer::conditional_sleep(Thread * thread)
245 int index = paused_thread_list.size();
247 model->getScheduler()->add_sleep(thread);
248 paused_thread_list.push_back(thread);
249 paused_thread_table.put(thread, index); // Update table
251 /* Add the waiting condition to ModelHistory */
252 ModelAction * read = thread->get_pending();
253 thread_id_t tid = thread->get_id();
254 FuncNode * func_node = history->get_curr_func_node(tid);
255 inst_act_map_t * inst_act_map = func_node->get_inst_act_map(tid);
257 Predicate * selected_branch = get_selected_child_branch(tid);
258 ConcretePredicate * concrete = selected_branch->evaluate(inst_act_map, tid);
259 concrete->set_location(read->get_location());
261 history->add_waiting_write(concrete);
262 /* history->add_waiting_thread is already called in find_threads */
265 bool NewFuzzer::has_paused_threads()
267 return paused_thread_list.size() != 0;
270 Thread * NewFuzzer::selectThread(int * threadlist, int numthreads)
272 if (numthreads == 0 && has_paused_threads()) {
273 wake_up_paused_threads(threadlist, &numthreads);
274 //model_print("list size: %d, active t id: %d\n", numthreads, threadlist[0]);
277 int random_index = random() % numthreads;
278 int thread = threadlist[random_index];
279 thread_id_t curr_tid = int_to_id(thread);
280 return execution->get_thread(curr_tid);
283 /* Force waking up one of threads paused by Fuzzer, because otherwise
284 * the Fuzzer is not making progress
286 void NewFuzzer::wake_up_paused_threads(int * threadlist, int * numthreads)
288 int random_index = random() % paused_thread_list.size();
289 Thread * thread = paused_thread_list[random_index];
290 model->getScheduler()->remove_sleep(thread);
292 Thread * last_thread = paused_thread_list.back();
293 paused_thread_list[random_index] = last_thread;
294 paused_thread_list.pop_back();
295 paused_thread_table.put(last_thread, random_index); // Update table
296 paused_thread_table.remove(thread);
298 thread_id_t tid = thread->get_id();
299 history->remove_waiting_write(tid);
300 history->remove_waiting_thread(tid);
302 threadlist[*numthreads] = tid;
306 Predicate * selected_branch = get_selected_child_branch(tid);
307 update_predicate_score(selected_branch, SLEEP_FAIL_TYPE3);
310 model_print("thread %d is woken up\n", tid);
313 /* Wake up conditional sleeping threads if the desired write is available */
314 void NewFuzzer::notify_paused_thread(Thread * thread)
316 ASSERT(paused_thread_table.contains(thread));
318 int index = paused_thread_table.get(thread);
319 model->getScheduler()->remove_sleep(thread);
321 Thread * last_thread = paused_thread_list.back();
322 paused_thread_list[index] = last_thread;
323 paused_thread_list.pop_back();
324 paused_thread_table.put(last_thread, index); // Update table
325 paused_thread_table.remove(thread);
327 thread_id_t tid = thread->get_id();
328 history->remove_waiting_write(tid);
329 history->remove_waiting_thread(tid);
332 Predicate * selected_branch = get_selected_child_branch(tid);
333 update_predicate_score(selected_branch, SLEEP_SUCCESS);
336 model_print("** thread %d is woken up\n", tid);
339 /* Find threads that may write values that the pending read action is waiting for.
340 * Side effect: waiting thread related info are stored in dist_info_vec
342 * @return True if any thread is found
344 bool NewFuzzer::find_threads(ModelAction * pending_read)
346 ASSERT(pending_read->is_read());
348 void * location = pending_read->get_location();
349 thread_id_t self_id = pending_read->get_tid();
350 bool finds_waiting_for = false;
352 SnapVector<FuncNode *> * func_node_list = history->getWrFuncNodes(location);
353 for (uint i = 0;i < func_node_list->size();i++) {
354 FuncNode * target_node = (*func_node_list)[i];
355 for (uint i = 1;i < execution->get_num_threads();i++) {
356 thread_id_t tid = int_to_id(i);
360 FuncNode * node = history->get_curr_func_node(tid);
361 /* It is possible that thread tid is not in any FuncNode */
365 int distance = node->compute_distance(target_node);
366 if (distance != -1) {
367 finds_waiting_for = true;
368 //model_print("thread: %d; distance from node %d to node %d: %d\n", tid, node->get_func_id(), target_node->get_func_id(), distance);
370 dist_info_vec.push_back(node_dist_info(tid, target_node, distance));
375 return finds_waiting_for;
378 bool NewFuzzer::check_predicate_expressions(PredExprSet * pred_expressions,
379 inst_act_map_t * inst_act_map, uint64_t write_val, bool * no_predicate)
381 bool satisfy_predicate = true;
383 PredExprSetIter * pred_expr_it = pred_expressions->iterator();
384 while (pred_expr_it->hasNext()) {
385 struct pred_expr * expression = pred_expr_it->next();
388 switch (expression->token) {
390 *no_predicate = true;
393 FuncInst * to_be_compared;
394 ModelAction * last_act;
397 to_be_compared = expression->func_inst;
398 last_act = inst_act_map->get(to_be_compared);
399 last_read = last_act->get_reads_from_value();
401 equality = (write_val == last_read);
402 if (equality != expression->value)
403 satisfy_predicate = false;
406 // TODO: implement likely to be null
407 equality = ((void*) (write_val & 0xffffffff) == NULL);
408 if (equality != expression->value)
409 satisfy_predicate = false;
412 model_print("unknown predicate token\n");
416 if (!satisfy_predicate)
420 return satisfy_predicate;
423 bool NewFuzzer::shouldWait(const ModelAction * act)