NewFuzzer::NewFuzzer() :
thrd_last_read_act(),
thrd_last_func_inst(),
+ available_branches_tmp_storage(),
thrd_selected_child_branch(),
thrd_pruned_writes(),
paused_thread_list(),
int NewFuzzer::selectWrite(ModelAction *read, SnapVector<ModelAction *> * rf_set)
{
- return random() % rf_set->size();
+// return random() % rf_set->size();
thread_id_t tid = read->get_tid();
int thread_id = id_to_int(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_store_visibility(curr_pred, read_inst, inst_act_map, 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_store_visibility(curr_pred, read_inst, inst_act_map, rf_set)) {
+ selected_branch = selectBranch(tid, curr_pred, read_inst);
+ break;
+ }
+ }
+ }
+
+ prune_writes(tid, selected_branch, rf_set, inst_act_map);
+ }
if (!failed_predicates.isEmpty())
failed_predicates.reset();
thrd_last_func_inst[thread_id] = read_inst;
}
- // No write satisfies the selected predicate, so pause this thread.
- while ( rf_set->size() == 0 ) {
- Predicate * selected_branch = get_selected_child_branch(tid);
-
- //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++) {
- rf_set->push_back( (*pruned_writes)[i] );
- }
-
- // Reselect a predicate and prune writes
- Predicate * curr_pred = selected_branch->get_parent();
- FuncInst * read_inst = thrd_last_func_inst[thread_id];
- selected_branch = selectBranch(tid, curr_pred, read_inst);
-
- 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);
-
- 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)
+/* For children of curr_pred that matches read_inst.
+ * If any store in rf_set satisfies the a child's predicate,
+ * increment the store visibility count for it.
+ *
+ * @return False if no child matches read_inst
+ */
+bool NewFuzzer::check_store_visibility(Predicate * curr_pred, FuncInst * read_inst,
+inst_act_map_t * inst_act_map, 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++) {
/* The children predicates may have different FuncInsts */
if (branch->get_func_inst() == read_inst) {
PredExprSet * pred_expressions = branch->get_pred_expressions();
+ any_child_match = true;
/* Do not check unset predicates */
- if (pred_expressions->isEmpty())
+ if (pred_expressions->isEmpty()) {
+ available_branches_tmp_storage.push_back(branch);
continue;
+ }
branch->incr_total_checking_count();
/* If one write value satisfies the predicate, go to check the next predicate */
if (satisfy_predicate) {
branch->incr_store_visible_count();
+ available_branches_tmp_storage.push_back(branch);
break;
}
}
}
-
}
-}
+ return any_child_match;
+}
/* Select a random branch from the children of curr_pred
* @return The selected branch
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 ];
+ int index = choose_index(&available_branches_tmp_storage);
+ Predicate * random_branch = available_branches_tmp_storage[ index ];
thrd_selected_child_branch[thread_id] = random_branch;
- // Update predicate tree position
- FuncNode * func_node = history->get_curr_func_node(tid);
- func_node->set_predicate_tree_position(tid, random_branch);
-
return random_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_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++) {
- 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 prob = (double) random() / RAND_MAX;
- double prob_sum = 0;
- int index = 0;
-
- for (uint i = 0; i < factors.size(); i++) {
- index = i;
- prob_sum += (double) (factors[i] / total_factor);
- if (prob_sum > prob) {
- break;
- }
- }
-
- return index;
- */
}
Predicate * NewFuzzer::get_selected_child_branch(thread_id_t tid)
* @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)
+SnapVector<ModelAction *> * rf_set, inst_act_map_t * inst_act_map)
{
if (pred == NULL)
return false;
/* 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;
-
- return false;
- */
-}
-
bool NewFuzzer::has_paused_threads()
{
return paused_thread_list.size() != 0;
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)
+inst_act_map_t * inst_act_map, uint64_t write_val, bool * no_predicate)
{
bool satisfy_predicate = true;
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;
+ 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:
+ // 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)
projects / c11tester.git / blobdiff