ModelChecker::ModelChecker() :
/* Initialize default scheduler */
params(),
- restart_flag(false),
scheduler(new Scheduler()),
history(new ModelHistory()),
execution(new ModelExecution(this, scheduler)),
* @return If there are more executions to explore, return true. Otherwise,
* return false.
*/
-bool ModelChecker::next_execution()
+void ModelChecker::finish_execution(bool more_executions)
{
DBG();
/* Is this execution a feasible execution that's worth bug-checking? */
else
clear_program_output();
- if (restart_flag) {
- do_restart();
- return true;
- }
// test code
execution_number ++;
- reset_to_initial_state();
+ if (more_executions)
+ reset_to_initial_state();
history->set_new_exec_flag();
- return false;
}
/** @brief Run trace analyses on complete trace */
return old->get_return_value();
}
+void ModelChecker::continueExecution(Thread *old)
+{
+ if (params.traceminsize != 0 &&
+ execution->get_curr_seq_num() > checkfree) {
+ checkfree += params.checkthreshold;
+ execution->collectActions();
+ }
+ thread_chosen = false;
+ curr_thread_num = 1;
+ Thread *thr = getNextThread();
+ if (thr != nullptr) {
+ scheduler->set_current_thread(thr);
+ if (Thread::swap(old, thr) < 0) {
+ perror("swap threads");
+ exit(EXIT_FAILURE);
+ }
+ } else
+ handleChosenThread(old);
+}
+
+Thread* ModelChecker::getNextThread()
+{
+ Thread *thr = nullptr;
+ for (unsigned int i = curr_thread_num; i < get_num_threads(); i++) {
+ thread_id_t tid = int_to_id(i);
+ thr = get_thread(tid);
+
+ if (!thr->is_complete() && !thr->get_pending()) {
+ curr_thread_num = i;
+ break;
+ }
+ ModelAction *act = thr->get_pending();
+
+ if (act && execution->is_enabled(thr) && !execution->check_action_enabled(act)) {
+ scheduler->sleep(thr);
+ }
+
+ chooseThread(act, thr);
+ }
+ return thr;
+}
+
+void ModelChecker::finishExecution(Thread *old)
+{
+ scheduler->set_current_thread(NULL);
+ if (Thread::swap(old, &system_context) < 0) {
+ perror("swap threads");
+ exit(EXIT_FAILURE);
+ }
+}
+
+void ModelChecker::consumeAction()
+{
+ ModelAction *curr = chosen_thread->get_pending();
+ chosen_thread->set_pending(NULL);
+ chosen_thread = execution->take_step(curr);
+}
+
+void ModelChecker::chooseThread(ModelAction *act, Thread *old)
+{
+ if (!thread_chosen && act && execution->is_enabled(old) && (old->get_state() != THREAD_BLOCKED) ) {
+ if (act->is_write()) {
+ std::memory_order order = act->get_mo();
+ if (order == std::memory_order_relaxed || \
+ order == std::memory_order_release) {
+ chosen_thread = old;
+ thread_chosen = true;
+ }
+ } else if (act->get_type() == THREAD_CREATE || \
+ act->get_type() == PTHREAD_CREATE || \
+ act->get_type() == THREAD_START || \
+ act->get_type() == THREAD_FINISH) {
+ chosen_thread = old;
+ thread_chosen = true;
+ }
+ }
+}
+
+uint64_t ModelChecker::switch_thread(ModelAction *act)
+{
+ if (modellock) {
+ static bool fork_message_printed = false;
+
+ if (!fork_message_printed) {
+ model_print("Fork handler or dead thread trying to call into model checker...\n");
+ fork_message_printed = true;
+ }
+ delete act;
+ return 0;
+ }
+ DBG();
+ Thread *old = thread_current();
+ ASSERT(!old->get_pending());
+
+ if (inspect_plugin != NULL) {
+ inspect_plugin->inspectModelAction(act);
+ }
+
+ old->set_pending(act);
+
+ curr_thread_num++;
+ Thread* next = getNextThread();
+ if (next != nullptr)
+ handleNewValidThread(old, next);
+ else
+ handleChosenThread(old);
+
+ return old->get_return_value();
+}
+
+void ModelChecker::handleNewValidThread(Thread *old, Thread *next)
+{
+ if (old->is_waiting_on(old))
+ assert_bug("Deadlock detected (thread %u)", curr_thread_num-1);
+
+ ModelAction *act = old->get_pending();
+
+ if (act && execution->is_enabled(old) && !execution->check_action_enabled(act)) {
+ scheduler->sleep(old);
+ }
+ chooseThread(act, old);
+
+ scheduler->set_current_thread(next);
+
+ if (Thread::swap(old, next) < 0) {
+ perror("swap threads");
+ exit(EXIT_FAILURE);
+ }
+}
+
+void ModelChecker::handleChosenThread(Thread *old)
+{
+ if (execution->has_asserted())
+ finishExecution(old);
+ if (!chosen_thread)
+ chosen_thread = get_next_thread();
+ if (!chosen_thread || chosen_thread->is_model_thread())
+ finishExecution(old);
+ if (chosen_thread->just_woken_up()) {
+ chosen_thread->set_wakeup_state(false);
+ chosen_thread->set_pending(NULL);
+ chosen_thread = NULL;
+ // Allow this thread to stash the next pending action
+ if (should_terminate_execution())
+ finishExecution(old);
+ else
+ continueExecution(old);
+ } else {
+ /* Consume the next action for a Thread */
+ consumeAction();
+
+ if (should_terminate_execution())
+ finishExecution(old);
+ else
+ continueExecution(old);
+ }
+}
+
static void runChecker() {
model->run();
delete model;
return false;
}
-/** @brief Restart ModelChecker upon returning to the run loop of the
- * model checker. */
-void ModelChecker::restart()
-{
- restart_flag = true;
-}
-
-void ModelChecker::do_restart()
-{
- restart_flag = false;
- reset_to_initial_state();
- memset(&stats,0,sizeof(struct execution_stats));
- execution_number = 1;
-}
-
/** @brief Run ModelChecker for the user program */
void ModelChecker::run()
{
//Need to initial random number generator state to avoid resets on rollback
char random_state[256];
initstate(423121, random_state, sizeof(random_state));
- modelclock_t checkfree = params.checkthreshold;
+ checkfree = params.checkthreshold;
for(int exec = 0;exec < params.maxexecutions;exec++) {
- Thread * t = init_thread;
-
- do {
- /* Check whether we need to free model actions. */
-
- if (params.traceminsize != 0 &&
- execution->get_curr_seq_num() > checkfree) {
- checkfree += params.checkthreshold;
- execution->collectActions();
- }
-
- /*
- * Stash next pending action(s) for thread(s). There
- * should only need to stash one thread's action--the
- * thread which just took a step--plus the first step
- * for any newly-created thread
- */
- for (unsigned int i = 0;i < get_num_threads();i++) {
- thread_id_t tid = int_to_id(i);
- Thread *thr = get_thread(tid);
- if (!thr->is_model_thread() && !thr->is_complete() && !thr->get_pending()) {
- switch_from_master(thr);
- if (thr->is_waiting_on(thr))
- assert_bug("Deadlock detected (thread %u)", i);
- }
- }
-
- /* Don't schedule threads which should be disabled */
- for (unsigned int i = 0;i < get_num_threads();i++) {
- Thread *th = get_thread(int_to_id(i));
- ModelAction *act = th->get_pending();
- if (act && execution->is_enabled(th) && !execution->check_action_enabled(act)) {
- scheduler->sleep(th);
- }
- }
-
- for (unsigned int i = 1;i < get_num_threads();i++) {
- Thread *th = get_thread(int_to_id(i));
- ModelAction *act = th->get_pending();
- if (act && execution->is_enabled(th) && (th->get_state() != THREAD_BLOCKED) ) {
- if (act->is_write()) {
- std::memory_order order = act->get_mo();
- if (order == std::memory_order_relaxed || \
- order == std::memory_order_release) {
- t = th;
- break;
- }
- } else if (act->get_type() == THREAD_CREATE || \
- act->get_type() == PTHREAD_CREATE || \
- act->get_type() == THREAD_START || \
- act->get_type() == THREAD_FINISH) {
- t = th;
- break;
- }
- }
- }
-
- /* Catch assertions from prior take_step or from
- * between-ModelAction bugs (e.g., data races) */
-
- if (execution->has_asserted())
- break;
- if (!t)
- t = get_next_thread();
- if (!t || t->is_model_thread())
- break;
- if (t->just_woken_up()) {
- t->set_wakeup_state(false);
- t->set_pending(NULL);
- t = NULL;
- continue; // Allow this thread to stash the next pending action
- }
-
- /* Consume the next action for a Thread */
- ModelAction *curr = t->get_pending();
- t->set_pending(NULL);
- t = execution->take_step(curr);
- } while (!should_terminate_execution());
- next_execution();
+ chosen_thread = init_thread;
+ thread_chosen = false;
+ curr_thread_num = 1;
+ thread_id_t tid = int_to_id(1);
+ Thread *thr = get_thread(tid);
+ switch_from_master(thr);
+ finish_execution((exec+1) < params.maxexecutions);
//restore random number generator state after rollback
setstate(random_state);
}