X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=model.cc;h=856a33d2cdfa13d2db741797d4fc0f1681a9fd04;hb=09c3eb5539455e82dcb357fbce82bf5974c3a37c;hp=c832b03710fc360ab17bcb5b3afe7a5920c1cfa6;hpb=3e520de48b5be0b0d4fa4a5f033e207b17c4496d;p=model-checker.git

diff --git a/model.cc b/model.cc
index c832b03..856a33d 100644
--- a/model.cc
+++ b/model.cc
@@ -159,6 +159,14 @@ void ModelChecker::reset_to_initial_state()
 	/* Print all model-checker output before rollback */
 	fflush(model_out);
 
+	/**
+	 * FIXME: if we utilize partial rollback, we will need to free only
+	 * those pending actions which were NOT pending before the rollback
+	 * point
+	 */
+	for (unsigned int i = 0; i < get_num_threads(); i++)
+		delete get_thread(int_to_id(i))->get_pending();
+
 	snapshot_backtrack_before(0);
 }
 
@@ -293,9 +301,7 @@ void ModelChecker::execute_sleep_set()
 	for (unsigned int i = 0; i < get_num_threads(); i++) {
 		thread_id_t tid = int_to_id(i);
 		Thread *thr = get_thread(tid);
-		if (scheduler->is_sleep_set(thr) && thr->get_pending() == NULL) {
-			scheduler->next_thread(thr);
-			Thread::swap(&system_context, thr);
+		if (scheduler->is_sleep_set(thr) && thr->get_pending()) {
 			thr->get_pending()->set_sleep_flag();
 		}
 	}
@@ -321,11 +327,22 @@ void ModelChecker::set_bad_synchronization()
 	priv->bad_synchronization = true;
 }
 
+/**
+ * Check whether the current trace has triggered an assertion which should halt
+ * its execution.
+ *
+ * @return True, if the execution should be aborted; false otherwise
+ */
 bool ModelChecker::has_asserted() const
 {
 	return priv->asserted;
 }
 
+/**
+ * Trigger a trace assertion which should cause this execution to be halted.
+ * This can be due to a detected bug or due to an infeasibility that should
+ * halt ASAP.
+ */
 void ModelChecker::set_assert()
 {
 	priv->asserted = true;
@@ -2665,6 +2682,7 @@ uint64_t ModelChecker::switch_to_master(ModelAction *act)
 {
 	DBG();
 	Thread *old = thread_current();
+	ASSERT(!old->get_pending());
 	old->set_pending(act);
 	if (Thread::swap(old, &system_context) < 0) {
 		perror("swap threads");
@@ -2681,9 +2699,6 @@ uint64_t ModelChecker::switch_to_master(ModelAction *act)
  */
 Thread * ModelChecker::take_step(ModelAction *curr)
 {
-	if (has_asserted())
-		return NULL;
-
 	Thread *curr_thrd = get_thread(curr);
 	ASSERT(curr_thrd->get_state() == THREAD_READY);
 
@@ -2751,8 +2766,25 @@ void ModelChecker::run()
 		add_thread(t);
 
 		do {
-			scheduler->next_thread(t);
-			Thread::swap(&system_context, t);
+			/*
+			 * 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()) {
+					scheduler->next_thread(thr);
+					Thread::swap(&system_context, thr);
+				}
+			}
+
+			/* Catch assertions from prior take_step or from
+			 * between-ModelAction bugs (e.g., data races) */
+			if (has_asserted())
+				break;
 
 			/* Consume the next action for a Thread */
 			ModelAction *curr = t->get_pending();