X-Git-Url: http://plrg.eecs.uci.edu/git/?p=c11tester.git;a=blobdiff_plain;f=newfuzzer.cc;h=e76d8961e47d3357360be5ee09270e4b0d75f01e;hp=69f1ce148bb3c2eb70f2252c1f8cba07b7722888;hb=e296778cb3574eeafdd20e0c25a4081c8d1ab0dc;hpb=dc255d1dd25f734bc6b1aae2f39418381c0823b5 diff --git a/newfuzzer.cc b/newfuzzer.cc index 69f1ce14..e76d8961 100644 --- a/newfuzzer.cc +++ b/newfuzzer.cc @@ -4,7 +4,6 @@ #include "history.h" #include "funcnode.h" #include "funcinst.h" -#include "predicate.h" #include "concretepredicate.h" #include "waitobj.h" @@ -14,11 +13,13 @@ NewFuzzer::NewFuzzer() : thrd_last_read_act(), - thrd_curr_pred(), + thrd_last_func_inst(), thrd_selected_child_branch(), thrd_pruned_writes(), - paused_thread_set(), - paused_thread_table(128) + paused_thread_list(), + paused_thread_table(128), + failed_predicates(32), + dist_info_vec() {} /** @@ -32,48 +33,55 @@ void NewFuzzer::register_engine(ModelHistory * history, ModelExecution *executio int NewFuzzer::selectWrite(ModelAction *read, SnapVector * 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); - if (thrd_last_read_act.size() <= (uint) thread_id) + if (thrd_last_read_act.size() <= (uint) thread_id) { thrd_last_read_act.resize(thread_id + 1); + thrd_last_func_inst.resize(thread_id + 1); + } // A new read action is encountered, select a random child branch of current predicate if (read != thrd_last_read_act[thread_id]) { - thrd_last_read_act[thread_id] = read; - 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); - Predicate * selected_branch = selectBranch(tid, curr_pred, read_inst); - 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); - } - // No write satisfies the selected predicate, so pause this thread. - if ( rf_set->size() == 0 ) { - Thread * read_thread = execution->get_thread(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()); + if (!failed_predicates.isEmpty()) + failed_predicates.reset(); - // reset thread pending action and revert sequence numbers - read_thread->set_pending(read); - read->reset_seq_number(); - execution->restore_last_seq_num(); + thrd_last_read_act[thread_id] = read; + thrd_last_func_inst[thread_id] = read_inst; + } - conditional_sleep(read_thread); + // No write satisfies the selected predicate, so pause this thread. + while ( rf_set->size() == 0 ) { + Predicate * selected_branch = get_selected_child_branch(tid); - find_threads(read); + //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()); - return -1; -/* SnapVector * 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] ); - pruned_writes->clear(); -*/ + } + + // 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); @@ -82,6 +90,48 @@ int NewFuzzer::selectWrite(ModelAction *read, SnapVector * rf_set return random_index; } +void NewFuzzer::check_store_visibility(Predicate * curr_pred, FuncInst * read_inst, + inst_act_map_t * inst_act_map, SnapVector * rf_set) +{ + ASSERT(!rf_set->empty()); + if (curr_pred == NULL || read_inst == NULL) + return; + + ModelVector * children = curr_pred->get_children(); + + /* Iterate over all predicate children */ + 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; + + 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; + } + } + } + + } +} + + /* Select a random branch from the children of curr_pred * @return The selected branch */ @@ -101,8 +151,9 @@ Predicate * NewFuzzer::selectBranch(thread_id_t tid, Predicate * curr_pred, Func for (uint i = 0; i < children->size(); i++) { Predicate * child = (*children)[i]; - if (child->get_func_inst() == read_inst) + if (child->get_func_inst() == read_inst && !failed_predicates.contains(child)) { branches.push_back(child); + } } // predicate children have not been generated @@ -111,14 +162,65 @@ Predicate * NewFuzzer::selectBranch(thread_id_t tid, Predicate * curr_pred, Func return NULL; } - // randomly select a branch - int random_index = random() % branches.size(); - Predicate * random_branch = branches[ random_index ]; + int index = choose_index(&branches, 0); + Predicate * random_branch = branches[ 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 + */ +int NewFuzzer::choose_index(SnapVector * branches, uint32_t numerator) +{ + return random() % branches->size(); +/*-- + if (branches->size() == 1) + return 0; + + double total_factor = 0; + SnapVector factors = SnapVector( 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) { int thread_id = id_to_int(tid); @@ -157,39 +259,14 @@ bool NewFuzzer::prune_writes(thread_id_t tid, Predicate * pred, bool pruned = false; uint index = 0; - ConcretePredicate * concrete_pred = pred->evaluate(inst_act_map, tid); - SnapVector * concrete_exprs = concrete_pred->getExpressions(); - while ( index < rf_set->size() ) { ModelAction * write_act = (*rf_set)[index]; uint64_t write_val = write_act->get_write_value(); - bool satisfy_predicate = true; - - for (uint i = 0; i < concrete_exprs->size(); i++) { - struct concrete_pred_expr concrete = (*concrete_exprs)[i]; - bool equality; - - switch (concrete.token) { - case NOPREDICATE: - return false; - case EQUALITY: - equality = (write_val == concrete.value); - if (equality != concrete.equality) - satisfy_predicate = false; - break; - case NULLITY: - equality = ((void*)write_val == NULL); - if (equality != concrete.equality) - satisfy_predicate = false; - break; - default: - model_print("unknown predicate token\n"); - break; - } + bool no_predicate = false; + bool satisfy_predicate = check_predicate_expressions(pred_expressions, inst_act_map, write_val, &no_predicate); - if (!satisfy_predicate) - break; - } + if (no_predicate) + return false; if (!satisfy_predicate) { ASSERT(rf_set != NULL); @@ -201,8 +278,6 @@ bool NewFuzzer::prune_writes(thread_id_t tid, Predicate * pred, index++; } - delete concrete_pred; - return pruned; } @@ -212,10 +287,10 @@ bool NewFuzzer::prune_writes(thread_id_t tid, Predicate * pred, */ void NewFuzzer::conditional_sleep(Thread * thread) { - int index = paused_thread_set.size(); + int index = paused_thread_list.size(); model->getScheduler()->add_sleep(thread); - paused_thread_set.push_back(thread); + paused_thread_list.push_back(thread); paused_thread_table.put(thread, index); // Update table /* Add the waiting condition to ModelHistory */ @@ -229,24 +304,47 @@ void NewFuzzer::conditional_sleep(Thread * thread) 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; + + return false; + */ } bool NewFuzzer::has_paused_threads() { - return paused_thread_set.size() != 0; + return paused_thread_list.size() != 0; } Thread * NewFuzzer::selectThread(int * threadlist, int numthreads) { if (numthreads == 0 && has_paused_threads()) { wake_up_paused_threads(threadlist, &numthreads); - model_print("list size: %d, active t id: %d\n", numthreads, threadlist[0]); + //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); - return model->get_thread(curr_tid); + return execution->get_thread(curr_tid); } /* Force waking up one of threads paused by Fuzzer, because otherwise @@ -254,22 +352,29 @@ Thread * NewFuzzer::selectThread(int * threadlist, int numthreads) */ void NewFuzzer::wake_up_paused_threads(int * threadlist, int * numthreads) { - int random_index = random() % paused_thread_set.size(); - Thread * thread = paused_thread_set[random_index]; + int random_index = random() % paused_thread_list.size(); + Thread * thread = paused_thread_list[random_index]; model->getScheduler()->remove_sleep(thread); - Thread * last_thread = paused_thread_set.back(); - paused_thread_set[random_index] = last_thread; - paused_thread_set.pop_back(); + Thread * last_thread = paused_thread_list.back(); + paused_thread_list[random_index] = last_thread; + paused_thread_list.pop_back(); paused_thread_table.put(last_thread, random_index); // Update table paused_thread_table.remove(thread); thread_id_t tid = thread->get_id(); history->remove_waiting_write(tid); + history->remove_waiting_thread(tid); - model_print("thread %d is woken up\n", tid); threadlist[*numthreads] = tid; (*numthreads)++; + +/*-- + 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); } /* Wake up conditional sleeping threads if the desired write is available */ @@ -280,21 +385,36 @@ void NewFuzzer::notify_paused_thread(Thread * thread) int index = paused_thread_table.get(thread); model->getScheduler()->remove_sleep(thread); - Thread * last_thread = paused_thread_set.back(); - paused_thread_set[index] = last_thread; - paused_thread_set.pop_back(); + Thread * last_thread = paused_thread_list.back(); + paused_thread_list[index] = last_thread; + paused_thread_list.pop_back(); paused_thread_table.put(last_thread, index); // Update table paused_thread_table.remove(thread); thread_id_t tid = thread->get_id(); history->remove_waiting_write(tid); + history->remove_waiting_thread(tid); + +/*-- + Predicate * selected_branch = get_selected_child_branch(tid); + update_predicate_score(selected_branch, SLEEP_SUCCESS); +*/ + + model_print("** thread %d is woken up\n", tid); } -/* Find threads that may write values that the pending read action is waiting for */ -void NewFuzzer::find_threads(ModelAction * pending_read) +/* Find threads that may write values that the pending read action is waiting for. + * Side effect: waiting thread related info are stored in dist_info_vec + * + * @return True if any thread is found + */ +bool NewFuzzer::find_threads(ModelAction * pending_read) { + ASSERT(pending_read->is_read()); + void * location = pending_read->get_location(); thread_id_t self_id = pending_read->get_tid(); + bool finds_waiting_for = false; SnapVector * func_node_list = history->getWrFuncNodes(location); for (uint i = 0; i < func_node_list->size(); i++) { @@ -311,13 +431,97 @@ void NewFuzzer::find_threads(ModelAction * pending_read) int distance = node->compute_distance(target_node); if (distance != -1) { - history->add_waiting_thread(self_id, tid, distance); - model_print("thread: %d; distance from node %d to node %d: %d\n", tid, node->get_func_id(), target_node->get_func_id(), distance); + finds_waiting_for = true; + //model_print("thread: %d; distance from node %d to node %d: %d\n", tid, node->get_func_id(), target_node->get_func_id(), distance); + dist_info_vec.push_back(node_dist_info(tid, target_node, distance)); } + } + } + + 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)