2 #include "threads-model.h"
8 #include "concretepredicate.h"
13 #include "execution.h"
15 NewFuzzer::NewFuzzer() :
18 thrd_selected_child_branch(),
21 paused_thread_table(128)
25 * @brief Register the ModelHistory and ModelExecution engine
27 void NewFuzzer::register_engine(ModelHistory * history, ModelExecution *execution)
29 this->history = history;
30 this->execution = execution;
33 int NewFuzzer::selectWrite(ModelAction *read, SnapVector<ModelAction *> * rf_set)
35 // return random() % rf_set->size();
37 thread_id_t tid = read->get_tid();
38 int thread_id = id_to_int(tid);
40 if (thrd_last_read_act.size() <= (uint) thread_id)
41 thrd_last_read_act.resize(thread_id + 1);
43 // A new read action is encountered, select a random child branch of current predicate
44 if (read != thrd_last_read_act[thread_id]) {
45 thrd_last_read_act[thread_id] = read;
47 FuncNode * func_node = history->get_curr_func_node(tid);
48 Predicate * curr_pred = func_node->get_predicate_tree_position(tid);
49 FuncInst * read_inst = func_node->get_inst(read);
50 Predicate * selected_branch = selectBranch(tid, curr_pred, read_inst);
52 inst_act_map_t * inst_act_map = func_node->get_inst_act_map(tid);
53 prune_writes(tid, selected_branch, rf_set, inst_act_map);
56 // No write satisfies the selected predicate, so pause this thread.
57 if ( rf_set->size() == 0 ) {
58 Thread * read_thread = execution->get_thread(tid);
59 model_print("the %d read action of thread %d at %p is unsuccessful\n", read->get_seq_number(), read_thread->get_id(), read->get_location());
61 // reset thread pending action and revert sequence numbers
62 read_thread->set_pending(read);
63 read->reset_seq_number();
64 execution->restore_last_seq_num();
66 conditional_sleep(read_thread);
70 SnapVector<ModelAction *> * pruned_writes = thrd_pruned_writes[thread_id];
71 for (uint i = 0; i < pruned_writes->size(); i++)
72 rf_set->push_back( (*pruned_writes)[i] );
73 pruned_writes->clear();
77 ASSERT(rf_set->size() != 0);
78 int random_index = random() % rf_set->size();
83 /* Select a random branch from the children of curr_pred
84 * @return The selected branch
86 Predicate * NewFuzzer::selectBranch(thread_id_t tid, Predicate * curr_pred, FuncInst * read_inst)
88 int thread_id = id_to_int(tid);
89 if ( thrd_selected_child_branch.size() <= (uint) thread_id)
90 thrd_selected_child_branch.resize(thread_id + 1);
92 if (curr_pred == NULL || read_inst == NULL) {
93 thrd_selected_child_branch[thread_id] = NULL;
97 ModelVector<Predicate *> * children = curr_pred->get_children();
98 SnapVector<Predicate *> branches;
100 for (uint i = 0; i < children->size(); i++) {
101 Predicate * child = (*children)[i];
102 if (child->get_func_inst() == read_inst)
103 branches.push_back(child);
106 // predicate children have not been generated
107 if (branches.size() == 0) {
108 thrd_selected_child_branch[thread_id] = NULL;
112 // randomly select a branch
113 int random_index = random() % branches.size();
114 Predicate * random_branch = branches[ random_index ];
115 thrd_selected_child_branch[thread_id] = random_branch;
117 return random_branch;
120 Predicate * NewFuzzer::get_selected_child_branch(thread_id_t tid)
122 int thread_id = id_to_int(tid);
123 if (thrd_selected_child_branch.size() <= (uint) thread_id)
126 return thrd_selected_child_branch[thread_id];
129 /* Remove writes from the rf_set that do not satisfie the selected predicate,
130 * and store them in thrd_pruned_writes
132 * @return true if rf_set is pruned
134 bool NewFuzzer::prune_writes(thread_id_t tid, Predicate * pred,
135 SnapVector<ModelAction *> * rf_set, inst_act_map_t * inst_act_map)
140 PredExprSet * pred_expressions = pred->get_pred_expressions();
141 if (pred_expressions->getSize() == 0) // unset predicates
144 int thread_id = id_to_int(tid);
145 uint old_size = thrd_pruned_writes.size();
146 if (thrd_pruned_writes.size() <= (uint) thread_id) {
147 uint new_size = thread_id + 1;
148 thrd_pruned_writes.resize(new_size);
149 for (uint i = old_size; i < new_size; i++)
150 thrd_pruned_writes[i] = new SnapVector<ModelAction *>();
152 SnapVector<ModelAction *> * pruned_writes = thrd_pruned_writes[thread_id];
153 pruned_writes->clear(); // clear the old pruned_writes set
158 ConcretePredicate * concrete_pred = pred->evaluate(inst_act_map, tid);
159 SnapVector<struct concrete_pred_expr> * concrete_exprs = concrete_pred->getExpressions();
161 while ( index < rf_set->size() ) {
162 ModelAction * write_act = (*rf_set)[index];
163 uint64_t write_val = write_act->get_write_value();
164 bool satisfy_predicate = true;
166 for (uint i = 0; i < concrete_exprs->size(); i++) {
167 struct concrete_pred_expr concrete = (*concrete_exprs)[i];
170 switch (concrete.token) {
174 equality = (write_val == concrete.value);
175 if (equality != concrete.equality)
176 satisfy_predicate = false;
179 equality = ((void*)write_val == NULL);
180 if (equality != concrete.equality)
181 satisfy_predicate = false;
184 model_print("unknown predicate token\n");
188 if (!satisfy_predicate)
192 if (!satisfy_predicate) {
193 ASSERT(rf_set != NULL);
194 (*rf_set)[index] = rf_set->back();
196 pruned_writes->push_back(write_act);
202 delete concrete_pred;
207 /* @brief Put a thread to sleep because no writes in rf_set satisfies the selected predicate.
209 * @param thread A thread whose last action is a read
211 void NewFuzzer::conditional_sleep(Thread * thread)
213 int index = paused_thread_set.size();
215 model->getScheduler()->add_sleep(thread);
216 paused_thread_set.push_back(thread);
217 paused_thread_table.put(thread, index); // Update table
219 /* Add the waiting condition to ModelHistory */
220 ModelAction * read = thread->get_pending();
221 thread_id_t tid = thread->get_id();
222 FuncNode * func_node = history->get_curr_func_node(tid);
223 inst_act_map_t * inst_act_map = func_node->get_inst_act_map(tid);
225 Predicate * selected_branch = get_selected_child_branch(tid);
226 ConcretePredicate * concrete = selected_branch->evaluate(inst_act_map, tid);
227 concrete->set_location(read->get_location());
229 history->add_waiting_write(concrete);
231 /* history->add_waiting_thread is called in find_threads */
235 bool NewFuzzer::has_paused_threads()
237 return paused_thread_set.size() != 0;
240 Thread * NewFuzzer::selectThread(int * threadlist, int numthreads)
242 if (numthreads == 0 && has_paused_threads()) {
243 wake_up_paused_threads(threadlist, &numthreads);
244 //model_print("list size: %d, active t id: %d\n", numthreads, threadlist[0]);
247 int random_index = random() % numthreads;
248 int thread = threadlist[random_index];
249 thread_id_t curr_tid = int_to_id(thread);
250 return model->get_thread(curr_tid);
253 /* Force waking up one of threads paused by Fuzzer, because otherwise
254 * the Fuzzer is not making progress
256 void NewFuzzer::wake_up_paused_threads(int * threadlist, int * numthreads)
258 int random_index = random() % paused_thread_set.size();
259 Thread * thread = paused_thread_set[random_index];
260 model->getScheduler()->remove_sleep(thread);
262 Thread * last_thread = paused_thread_set.back();
263 paused_thread_set[random_index] = last_thread;
264 paused_thread_set.pop_back();
265 paused_thread_table.put(last_thread, random_index); // Update table
266 paused_thread_table.remove(thread);
268 thread_id_t tid = thread->get_id();
269 history->remove_waiting_write(tid);
270 history->remove_waiting_thread(tid);
272 model_print("thread %d is woken up\n", tid);
273 threadlist[*numthreads] = tid;
277 /* Wake up conditional sleeping threads if the desired write is available */
278 void NewFuzzer::notify_paused_thread(Thread * thread)
280 ASSERT(paused_thread_table.contains(thread));
282 int index = paused_thread_table.get(thread);
283 model->getScheduler()->remove_sleep(thread);
285 Thread * last_thread = paused_thread_set.back();
286 paused_thread_set[index] = last_thread;
287 paused_thread_set.pop_back();
288 paused_thread_table.put(last_thread, index); // Update table
289 paused_thread_table.remove(thread);
291 thread_id_t tid = thread->get_id();
292 history->remove_waiting_write(tid);
293 history->remove_waiting_thread(tid);
296 /* Find threads that may write values that the pending read action is waiting for */
297 void NewFuzzer::find_threads(ModelAction * pending_read)
299 ASSERT(pending_read->is_read());
301 void * location = pending_read->get_location();
302 thread_id_t self_id = pending_read->get_tid();
304 SnapVector<FuncNode *> * func_node_list = history->getWrFuncNodes(location);
305 for (uint i = 0; i < func_node_list->size(); i++) {
306 FuncNode * target_node = (*func_node_list)[i];
307 for (uint i = 1; i < execution->get_num_threads(); i++) {
308 thread_id_t tid = int_to_id(i);
312 FuncNode * node = history->get_curr_func_node(tid);
313 /* It is possible that thread tid is not in any FuncNode */
317 int distance = node->compute_distance(target_node);
318 if (distance != -1) {
319 history->add_waiting_thread(self_id, tid, distance);
320 model_print("thread: %d; distance from node %d to node %d: %d\n", tid, node->get_func_id(), target_node->get_func_id(), distance);
328 bool NewFuzzer::shouldWait(const ModelAction * act)