+ if ( t == NULL ) {
+ int old_curr_thread = curr_thread_index;
+ bool have_enabled_thread_with_priority=false;
+ Node *n=model->get_curr_node();
+
+ for(int i=0;i<enabled_len;i++) {
+ thread_id_t tid=int_to_id(i);
+ if (n->has_priority(tid)) {
+ //Have a thread with priority
+ if (enabled[i]!=THREAD_DISABLED)
+ have_enabled_thread_with_priority=true;
+ }
+ }
+
+ while(true) {
+ curr_thread_index = (curr_thread_index+1) % enabled_len;
+ thread_id_t curr_tid=int_to_id(curr_thread_index);
+ if (enabled[curr_thread_index]==THREAD_ENABLED&&
+ (!have_enabled_thread_with_priority||n->has_priority(curr_tid))) {
+ t = model->get_thread(curr_tid);
+ break;
+ }
+ if (curr_thread_index == old_curr_thread) {
+ print();
+ return NULL;
+ }
+ }
+ } else if (t->is_model_thread()) {
+ /* model-checker threads never run */
+ t = NULL;
+ } else {
+ curr_thread_index = id_to_int(t->get_id());
+ }
+
+ current = t;
+ print();
+ return t;