X-Git-Url: http://plrg.eecs.uci.edu/git/?p=c11tester.git;a=blobdiff_plain;f=newfuzzer.cc;h=cb25d7635f2cb728ffe9317dae6cac55daf66722;hp=1fdc7d85f91f2b5b121b242b9c84ece0e987594d;hb=e102155b9b54d88cf310d8eba39a42aa51a1aec2;hpb=02060a26c266ffad07c29327431621e611c09065 diff --git a/newfuzzer.cc b/newfuzzer.cc index 1fdc7d85..cb25d763 100644 --- a/newfuzzer.cc +++ b/newfuzzer.cc @@ -1,18 +1,25 @@ #include "newfuzzer.h" #include "threads-model.h" -#include "model.h" #include "action.h" -#include "execution.h" +#include "history.h" #include "funcnode.h" -#include "schedule.h" +#include "funcinst.h" +#include "predicate.h" #include "concretepredicate.h" +#include "waitobj.h" + +#include "model.h" +#include "schedule.h" +#include "execution.h" 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_list(), + paused_thread_table(128), + failed_predicates(32) {} /** @@ -31,42 +38,70 @@ int NewFuzzer::selectWrite(ModelAction *read, SnapVector * rf_set 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; - - SnapVector * thrd_func_list = execution->get_thrd_func_list(); - uint32_t func_id = (*thrd_func_list)[thread_id].back(); - FuncNode * func_node = history->get_func_node(func_id); - inst_act_map_t * inst_act_map = func_node->get_inst_act_map(tid); + 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); + 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); prune_writes(tid, selected_branch, rf_set, inst_act_map); + + if (!failed_predicates.isEmpty()) + failed_predicates.reset(); + + thrd_last_read_act[thread_id] = read; + thrd_last_func_inst[thread_id] = read_inst; } - // No write satisfies the selected predicate - if ( rf_set->size() == 0 ) { + // No write satisfies the selected predicate, so pause this thread. + while ( rf_set->size() == 0 ) { Thread * read_thread = execution->get_thread(tid); - model_print("the %d read action of thread %d is unsuccessful\n", read->get_seq_number(), read_thread->get_id()); - - // reset thread pending action and revert sequence numbers - read_thread->set_pending(read); - read->reset_seq_number(); - execution->restore_last_seq_num(); - - conditional_sleep(read_thread); - return -1; -/* - SnapVector * pruned_writes = thrd_pruned_writes[thread_id]; - for (uint i = 0; i < pruned_writes->size(); i++) - rf_set->push_back( (*pruned_writes)[i] ); - pruned_writes->clear(); -*/ + Predicate * selected_branch = get_selected_child_branch(tid); + bool should_reselect_predicate = false; + //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 (!find_threads(read)) { + update_predicate_score(selected_branch, SLEEP_FAIL_TYPE1); + should_reselect_predicate = true; + } else if (!should_conditional_sleep(selected_branch)) { + update_predicate_score(selected_branch, SLEEP_FAIL_TYPE2); + should_reselect_predicate = true; + } else { + // reset thread pending action and revert sequence numbers + read_thread->set_pending(read); + read->reset_seq_number(); + execution->restore_last_seq_num(); + + conditional_sleep(read_thread); + // Returning -1 stops the while loop of ModelExecution::process_read + return -1; + } + + if (should_reselect_predicate) { + SnapVector * 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); @@ -91,11 +126,17 @@ Predicate * NewFuzzer::selectBranch(thread_id_t tid, Predicate * curr_pred, Func ModelVector * children = curr_pred->get_children(); SnapVector branches; + uint32_t numerator = 1; 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); + + // max of (exploration counts + 1) + if (child->get_expl_count() + 1 > numerator) + numerator = child->get_expl_count() + 1; + } } // predicate children have not been generated @@ -105,13 +146,65 @@ Predicate * NewFuzzer::selectBranch(thread_id_t tid, Predicate * curr_pred, Func } // randomly select a branch - int random_index = random() % branches.size(); - Predicate * random_branch = branches[ random_index ]; + // int random_index = random() % branches.size(); + // Predicate * random_branch = branches[ random_index ]; + + int index = choose_index(&branches, numerator); + 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) +{ + 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); @@ -149,28 +242,36 @@ bool NewFuzzer::prune_writes(thread_id_t tid, Predicate * pred, bool pruned = false; uint index = 0; - SnapVector concrete_exprs = pred->evaluate(inst_act_map); 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]; + PredExprSetIter * pred_expr_it = pred_expressions->iterator(); + while (pred_expr_it->hasNext()) { + struct pred_expr * expression = pred_expr_it->next(); bool equality; - switch (concrete.token) { + switch (expression->token) { case NOPREDICATE: return false; case EQUALITY: - equality = (write_val == concrete.value); - if (equality != concrete.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 != concrete.equality) + if (equality != expression->value) satisfy_predicate = false; break; default: @@ -201,48 +302,170 @@ bool NewFuzzer::prune_writes(thread_id_t tid, Predicate * pred, */ void NewFuzzer::conditional_sleep(Thread * thread) { + 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 */ + 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); + + Predicate * selected_branch = get_selected_child_branch(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 */ +} + +bool NewFuzzer::should_conditional_sleep(Predicate *) +{ + return true; } 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\n", numthreads); - model_print("active t id: %d\n", 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 */ +/* Force waking up one of threads paused by Fuzzer, because otherwise + * the Fuzzer is not making progress + */ 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); - paused_thread_set[random_index] = paused_thread_set.back(); - 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", thread->get_id()); - threadlist[*numthreads] = thread->get_id(); + 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); } -/* Notify one of conditional sleeping threads if the desired write is available */ -bool NewFuzzer::notify_conditional_sleep(Thread * thread) +/* Wake up conditional sleeping threads if the desired write is available */ +void NewFuzzer::notify_paused_thread(Thread * thread) { - + ASSERT(paused_thread_table.contains(thread)); + + int index = paused_thread_table.get(thread); + model->getScheduler()->remove_sleep(thread); + + 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 + * @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++) { + FuncNode * target_node = (*func_node_list)[i]; + for (uint i = 1; i < execution->get_num_threads(); i++) { + thread_id_t tid = int_to_id(i); + if (tid == self_id) + continue; + + FuncNode * node = history->get_curr_func_node(tid); + /* It is possible that thread tid is not in any FuncNode */ + if (node == NULL) + continue; + + int distance = node->compute_distance(target_node); + if (distance != -1) { + history->add_waiting_thread(self_id, tid, target_node, 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); + } + } + } + + 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->decr_sleep_score(1); + failed_predicates.put(predicate, true); + break; + case SLEEP_FAIL_TYPE3: + predicate->incr_fail_count(); + predicate->incr_sleep_score(10); + break; + case SLEEP_SUCCESS: + predicate->decr_sleep_score(10); + break; + default: + model_print("unknown predicate result type.\n"); + break; + } } bool NewFuzzer::shouldWait(const ModelAction * act)