X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=model.cc;h=843034d31acec815eb8c8943d6910eb074103f0b;hb=ac8e176cd4a8756244c12dbbcaf961d27bfc8a74;hp=1d3e0c4901b19095dda5091ba662d1b92f1a5aeb;hpb=43974636b8a2773c4cd8f6f1a2537e5d52b3145b;p=model-checker.git

diff --git a/model.cc b/model.cc
index 1d3e0c4..843034d 100644
--- a/model.cc
+++ b/model.cc
@@ -254,8 +254,9 @@ Thread * ModelChecker::get_next_thread(ModelAction *curr)
 			tid = next->get_tid();
 			node_stack->pop_restofstack(2);
 		} else {
+			ASSERT(prevnode);
 			/* Make a different thread execute for next step */
-			scheduler->add_sleep(thread_map->get(id_to_int(next->get_tid())));
+			scheduler->add_sleep(get_thread(next->get_tid()));
 			tid = prevnode->get_next_backtrack();
 			/* Make sure the backtracked thread isn't sleeping. */
 			node_stack->pop_restofstack(1);
@@ -1295,7 +1296,7 @@ void ModelChecker::check_curr_backtracking(ModelAction *curr)
 	Node *currnode = curr->get_node();
 	Node *parnode = currnode->get_parent();
 
-	if (!parnode->backtrack_empty() ||
+	if ((parnode && !parnode->backtrack_empty()) ||
 			 !currnode->misc_empty() ||
 			 !currnode->read_from_empty() ||
 			 !currnode->future_value_empty() ||