NewFuzzer::NewFuzzer() :
thrd_last_read_act(),
thrd_last_func_inst(),
+ available_branches_tmp_storage(),
thrd_selected_child_branch(),
thrd_pruned_writes(),
paused_thread_list(),
paused_thread_table(128),
- failed_predicates(32),
dist_info_vec()
{}
/**
* @brief Register the ModelHistory and ModelExecution engine
*/
-void NewFuzzer::register_engine(ModelHistory * history, ModelExecution *execution)
+void NewFuzzer::register_engine(ModelChecker *_model, ModelExecution *execution)
{
- this->history = history;
+ this->history = _model->get_history();
this->execution = execution;
}
FuncNode * func_node = history->get_curr_func_node(tid);
Predicate * curr_pred = func_node->get_predicate_tree_position(tid);
FuncInst * read_inst = func_node->get_inst(read);
- inst_act_map_t * inst_act_map = func_node->get_inst_act_map(tid);
- check_store_visibility(curr_pred, read_inst, inst_act_map, rf_set);
- Predicate * selected_branch = selectBranch(tid, curr_pred, read_inst);
- prune_writes(tid, selected_branch, rf_set, inst_act_map);
+ if (curr_pred != NULL) {
+ Predicate * selected_branch = NULL;
+
+ if (check_branch_inst(curr_pred, read_inst, rf_set))
+ selected_branch = selectBranch(tid, curr_pred, read_inst);
+ else {
+ // no child of curr_pred matches read_inst, check back edges
+ PredSet * back_edges = curr_pred->get_backedges();
+ PredSetIter * it = back_edges->iterator();
+
+ while (it->hasNext()) {
+ curr_pred = it->next();
+ if (check_branch_inst(curr_pred, read_inst, rf_set)) {
+ selected_branch = selectBranch(tid, curr_pred, read_inst);
+ break;
+ }
+ }
+
+ delete it;
+ }
- if (!failed_predicates.isEmpty())
- failed_predicates.reset();
+ thrd_selected_child_branch[thread_id] = selected_branch;
+ prune_writes(tid, selected_branch, rf_set);
+ }
thrd_last_read_act[thread_id] = read;
thrd_last_func_inst[thread_id] = read_inst;
}
- // No write satisfies the selected predicate, so pause this thread.
+ // The chosen branch fails, reselect new branches
while ( rf_set->size() == 0 ) {
Predicate * selected_branch = get_selected_child_branch(tid);
+ FuncNode * func_node = history->get_curr_func_node(tid);
+
+ // Increment failure count
+ selected_branch->incr_fail_count();
+ func_node->add_predicate_to_trace(tid, selected_branch); // For updating predicate weight
//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());
SnapVector<ModelAction *> * pruned_writes = thrd_pruned_writes[thread_id];
- for (uint i = 0; i < pruned_writes->size(); i++) {
+ for (uint i = 0;i < pruned_writes->size();i++) {
rf_set->push_back( (*pruned_writes)[i] );
}
Predicate * curr_pred = selected_branch->get_parent();
FuncInst * read_inst = thrd_last_func_inst[thread_id];
selected_branch = selectBranch(tid, curr_pred, read_inst);
+ thrd_selected_child_branch[thread_id] = selected_branch;
- FuncNode * func_node = history->get_curr_func_node(tid);
- inst_act_map_t * inst_act_map = func_node->get_inst_act_map(tid);
- prune_writes(tid, selected_branch, rf_set, inst_act_map);
+ prune_writes(tid, selected_branch, rf_set);
ASSERT(selected_branch);
}
- ASSERT(rf_set->size() != 0);
int random_index = random() % rf_set->size();
return random_index;
}
-void NewFuzzer::check_store_visibility(Predicate * curr_pred, FuncInst * read_inst,
- inst_act_map_t * inst_act_map, SnapVector<ModelAction *> * rf_set)
+/* Check if children of curr_pred match read_inst.
+ * @return False if no child matches read_inst
+ */
+bool NewFuzzer::check_branch_inst(Predicate * curr_pred, FuncInst * read_inst,
+ SnapVector<ModelAction *> * rf_set)
{
+ available_branches_tmp_storage.clear();
+
ASSERT(!rf_set->empty());
if (curr_pred == NULL || read_inst == NULL)
- return;
+ return false;
ModelVector<Predicate *> * children = curr_pred->get_children();
+ bool any_child_match = false;
/* Iterate over all predicate children */
- for (uint i = 0; i < children->size(); i++) {
+ for (uint i = 0;i < children->size();i++) {
Predicate * branch = (*children)[i];
/* The children predicates may have different FuncInsts */
if (branch->get_func_inst() == read_inst) {
- PredExprSet * pred_expressions = branch->get_pred_expressions();
-
- /* Do not check unset predicates */
- if (pred_expressions->isEmpty())
- continue;
-
+ any_child_match = true;
branch->incr_total_checking_count();
-
- /* Iterate over all write actions */
- for (uint j = 0; j < rf_set->size(); j++) {
- ModelAction * write_act = (*rf_set)[j];
- uint64_t write_val = write_act->get_write_value();
- bool dummy = true;
- bool satisfy_predicate = check_predicate_expressions(pred_expressions, inst_act_map, write_val, &dummy);
-
- /* If one write value satisfies the predicate, go to check the next predicate */
- if (satisfy_predicate) {
- branch->incr_store_visible_count();
- break;
- }
- }
+ available_branches_tmp_storage.push_back(branch);
}
-
}
-}
+ return any_child_match;
+}
-/* Select a random branch from the children of curr_pred
+/* Select a random branch from the children of curr_pred
* @return The selected branch
*/
Predicate * NewFuzzer::selectBranch(thread_id_t tid, Predicate * curr_pred, FuncInst * read_inst)
return NULL;
}
- ModelVector<Predicate *> * children = curr_pred->get_children();
- SnapVector<Predicate *> branches;
-
- for (uint i = 0; i < children->size(); i++) {
- Predicate * child = (*children)[i];
- if (child->get_func_inst() == read_inst && !failed_predicates.contains(child)) {
- branches.push_back(child);
- }
- }
-
// predicate children have not been generated
- if (branches.size() == 0) {
+ if (available_branches_tmp_storage.size() == 0) {
thrd_selected_child_branch[thread_id] = NULL;
return NULL;
}
- int index = choose_index(&branches, 0);
- Predicate * random_branch = branches[ index ];
- thrd_selected_child_branch[thread_id] = random_branch;
+ int index = choose_branch_index(&available_branches_tmp_storage);
+ Predicate * selected_branch = available_branches_tmp_storage[ index ];
- // Update predicate tree position
- FuncNode * func_node = history->get_curr_func_node(tid);
- func_node->set_predicate_tree_position(tid, random_branch);
+ /* Remove the chosen branch from vec in case that this
+ * branch fails and need to choose another one */
+ available_branches_tmp_storage[index] = available_branches_tmp_storage.back();
+ available_branches_tmp_storage.pop_back();
- return random_branch;
+ return selected_branch;
}
/**
- * @brief Select a branch from the given predicate branches based
- * on their exploration counts.
- *
- * Let b_1, ..., b_n be branches with exploration counts c_1, ..., c_n
- * M := max(c_1, ..., c_n) + 1
- * Factor f_i := M / (c_i + 1)
- * The probability p_i that branch b_i is selected:
- * p_i := f_i / (f_1 + ... + f_n)
- * = \fraction{ 1/(c_i + 1) }{ 1/(c_1 + 1) + ... + 1/(c_n + 1) }
- *
- * Note: (1) c_i + 1 is used because counts may be 0.
- * (2) The numerator of f_i is chosen to reduce the effect of underflow
- *
- * @param numerator is M defined above
+ * @brief Select a branch from the given predicate branch
*/
-int NewFuzzer::choose_index(SnapVector<Predicate *> * branches, uint32_t numerator)
+int NewFuzzer::choose_branch_index(SnapVector<Predicate *> * branches)
{
- return random() % branches->size();
-/*--
if (branches->size() == 1)
return 0;
- double total_factor = 0;
- SnapVector<double> factors = SnapVector<double>( branches->size() + 1 );
- for (uint i = 0; i < branches->size(); i++) {
+ double total_weight = 0;
+ SnapVector<double> weights;
+ for (uint i = 0;i < branches->size();i++) {
Predicate * branch = (*branches)[i];
- double factor = (double) numerator / (branch->get_expl_count() + 5 * branch->get_fail_count() + 1);
- total_factor += factor;
- factors.push_back(factor);
+ double weight = branch->get_weight();
+ total_weight += weight;
+ weights.push_back(weight);
}
double prob = (double) random() / RAND_MAX;
double prob_sum = 0;
int index = 0;
- for (uint i = 0; i < factors.size(); i++) {
+ for (uint i = 0;i < weights.size();i++) {
index = i;
- prob_sum += (double) (factors[i] / total_factor);
+ prob_sum += (double) (weights[i] / total_weight);
if (prob_sum > prob) {
break;
}
}
return index;
-*/
+// return random() % branches->size();
}
Predicate * NewFuzzer::get_selected_child_branch(thread_id_t tid)
return thrd_selected_child_branch[thread_id];
}
-/* Remove writes from the rf_set that do not satisfie the selected predicate,
+/* Remove writes from the rf_set that do not satisfie the selected predicate,
* and store them in thrd_pruned_writes
*
* @return true if rf_set is pruned
*/
-bool NewFuzzer::prune_writes(thread_id_t tid, Predicate * pred,
- SnapVector<ModelAction *> * rf_set, inst_act_map_t * inst_act_map)
+bool NewFuzzer::prune_writes(thread_id_t tid, Predicate * pred, SnapVector<ModelAction *> * rf_set)
{
if (pred == NULL)
return false;
if (thrd_pruned_writes.size() <= (uint) thread_id) {
uint new_size = thread_id + 1;
thrd_pruned_writes.resize(new_size);
- for (uint i = old_size; i < new_size; i++)
+ for (uint i = old_size;i < new_size;i++)
thrd_pruned_writes[i] = new SnapVector<ModelAction *>();
}
SnapVector<ModelAction *> * pruned_writes = thrd_pruned_writes[thread_id];
pruned_writes->clear(); // clear the old pruned_writes set
bool pruned = false;
- uint index = 0;
+ uint rf_index = 0;
- while ( index < rf_set->size() ) {
- ModelAction * write_act = (*rf_set)[index];
+ while ( rf_index < rf_set->size() ) {
+ ModelAction * write_act = (*rf_set)[rf_index];
uint64_t write_val = write_act->get_write_value();
bool no_predicate = false;
- bool satisfy_predicate = check_predicate_expressions(pred_expressions, inst_act_map, write_val, &no_predicate);
+ bool satisfy_predicate = true;
+
+ // Check if the write value satisfies the predicates
+ PredExprSetIter * pred_expr_it = pred_expressions->iterator();
+ while (pred_expr_it->hasNext()) {
+ struct pred_expr * expression = pred_expr_it->next();
+ bool equality;
+
+ switch (expression->token) {
+ case NOPREDICATE:
+ no_predicate = true;
+ break;
+ case EQUALITY:
+ FuncInst * to_be_compared;
+ FuncNode * func_node;
+ uint64_t last_read;
+
+ to_be_compared = expression->func_inst;
+ func_node = history->get_curr_func_node(tid);
+ last_read = func_node->get_associated_read(tid, to_be_compared);
+ ASSERT(last_read != VALUE_NONE);
+
+ equality = (write_val == last_read);
+ if (equality != expression->value)
+ satisfy_predicate = false;
+ break;
+ case NULLITY:
+ // TODO: implement likely to be null
+ equality = ((void*) (write_val & 0xffffffff) == NULL);
+ if (equality != expression->value)
+ satisfy_predicate = false;
+ break;
+ default:
+ model_print("unknown predicate token\n");
+ break;
+ }
+
+ if (!satisfy_predicate)
+ break;
+ }
+ delete pred_expr_it;
if (no_predicate)
return false;
if (!satisfy_predicate) {
ASSERT(rf_set != NULL);
- (*rf_set)[index] = rf_set->back();
+ (*rf_set)[rf_index] = rf_set->back();
rf_set->pop_back();
pruned_writes->push_back(write_act);
pruned = true;
} else
- index++;
+ rf_index++;
}
return pruned;
}
-/* @brief Put a thread to sleep because no writes in rf_set satisfies the selected predicate.
+/* @brief Put a thread to sleep because no writes in rf_set satisfies the selected predicate.
*
* @param thread A thread whose last action is a read
*/
void NewFuzzer::conditional_sleep(Thread * thread)
{
+/*
int index = paused_thread_list.size();
model->getScheduler()->add_sleep(thread);
paused_thread_list.push_back(thread);
paused_thread_table.put(thread, index); // Update table
- /* Add the waiting condition to ModelHistory */
+ // Add the waiting condition to ModelHistory
ModelAction * read = thread->get_pending();
thread_id_t tid = thread->get_id();
FuncNode * func_node = history->get_curr_func_node(tid);
- inst_act_map_t * inst_act_map = func_node->get_inst_act_map(tid);
+// inst_act_map_t * inst_act_map = func_node->get_inst_act_map(tid);
Predicate * selected_branch = get_selected_child_branch(tid);
- ConcretePredicate * concrete = selected_branch->evaluate(inst_act_map, tid);
+// ConcretePredicate * concrete = selected_branch->evaluate(inst_act_map, tid);
concrete->set_location(read->get_location());
- history->add_waiting_write(concrete);
- /* history->add_waiting_thread is already called in find_threads */
-}
-
-/**
- * Decides whether a thread should condition sleep based on
- * the sleep score of the chosen predicate.
- *
- * sleep_score = 0: never sleeps
- * sleep_score = 100: always sleeps
- **/
-bool NewFuzzer::should_conditional_sleep(Predicate * predicate)
-{
- return false;
- /*
- int sleep_score = predicate->get_sleep_score();
- int random_num = random() % 100;
-
- // should sleep if random_num falls within [0, sleep_score)
- if (random_num < sleep_score)
- return true;
+ ASSERT(false);
- return false;
- */
+// history->add_waiting_write(concrete);
+ // history->add_waiting_thread is already called in find_threads
+*/
}
bool NewFuzzer::has_paused_threads()
wake_up_paused_threads(threadlist, &numthreads);
//model_print("list size: %d, active t id: %d\n", numthreads, threadlist[0]);
}
-
int random_index = random() % numthreads;
int thread = threadlist[random_index];
thread_id_t curr_tid = int_to_id(thread);
(*numthreads)++;
/*--
- Predicate * selected_branch = get_selected_child_branch(tid);
- update_predicate_score(selected_branch, SLEEP_FAIL_TYPE3);
-*/
+ Predicate * selected_branch = get_selected_child_branch(tid);
+ update_predicate_score(selected_branch, SLEEP_FAIL_TYPE3);
+ */
model_print("thread %d is woken up\n", tid);
}
history->remove_waiting_thread(tid);
/*--
- Predicate * selected_branch = get_selected_child_branch(tid);
- update_predicate_score(selected_branch, SLEEP_SUCCESS);
-*/
+ Predicate * selected_branch = get_selected_child_branch(tid);
+ update_predicate_score(selected_branch, SLEEP_SUCCESS);
+ */
model_print("** thread %d is woken up\n", tid);
}
bool finds_waiting_for = false;
SnapVector<FuncNode *> * func_node_list = history->getWrFuncNodes(location);
- for (uint i = 0; i < func_node_list->size(); i++) {
+ for (uint i = 0;i < func_node_list->size();i++) {
FuncNode * target_node = (*func_node_list)[i];
- for (uint i = 1; i < execution->get_num_threads(); i++) {
+ for (uint i = 1;i < execution->get_num_threads();i++) {
thread_id_t tid = int_to_id(i);
if (tid == self_id)
continue;
return finds_waiting_for;
}
-/* Update predicate counts and scores (asynchronous) when the read value is not available
- *
- * @param type
- * type 1: find_threads return false
- * type 2: find_threads return true, but the fuzzer decides that that thread shall not sleep based on sleep score
- * type 3: threads are put to sleep but woken up before the waited value appears
- * type 4: threads are put to sleep and the waited vaule appears (success)
- */
-
-/*--
-void NewFuzzer::update_predicate_score(Predicate * predicate, sleep_result_t type)
-{
- switch (type) {
- case SLEEP_FAIL_TYPE1:
- predicate->incr_fail_count();
-
- // Do not choose this predicate when reselecting a new branch
- failed_predicates.put(predicate, true);
- break;
- case SLEEP_FAIL_TYPE2:
- predicate->incr_fail_count();
- predicate->incr_sleep_score(1);
- failed_predicates.put(predicate, true);
- break;
- case SLEEP_FAIL_TYPE3:
- predicate->incr_fail_count();
- predicate->decr_sleep_score(10);
- break;
- case SLEEP_SUCCESS:
- predicate->incr_sleep_score(10);
- break;
- default:
- model_print("unknown predicate result type.\n");
- break;
- }
-}
-*/
-
-bool NewFuzzer::check_predicate_expressions(PredExprSet * pred_expressions,
- inst_act_map_t * inst_act_map, uint64_t write_val, bool * no_predicate)
-{
- bool satisfy_predicate = true;
-
- PredExprSetIter * pred_expr_it = pred_expressions->iterator();
- while (pred_expr_it->hasNext()) {
- struct pred_expr * expression = pred_expr_it->next();
- bool equality;
-
- switch (expression->token) {
- case NOPREDICATE:
- *no_predicate = true;
- break;
- case EQUALITY:
- FuncInst * to_be_compared;
- ModelAction * last_act;
- uint64_t last_read;
-
- to_be_compared = expression->func_inst;
- last_act = inst_act_map->get(to_be_compared);
- last_read = last_act->get_reads_from_value();
-
- equality = (write_val == last_read);
- if (equality != expression->value)
- satisfy_predicate = false;
- break;
- case NULLITY:
- equality = ((void*)write_val == NULL);
- if (equality != expression->value)
- satisfy_predicate = false;
- break;
- default:
- model_print("unknown predicate token\n");
- break;
- }
-
- if (!satisfy_predicate)
- break;
- }
-
- return satisfy_predicate;
-}
-
bool NewFuzzer::shouldWait(const ModelAction * act)
{
- return random() & 1;
+ return true;
}