make scheduler choose fair schedules when threads with priority are sleeping...
[model-checker.git] / schedule.cc
index da6d469..f68cb52 100644 (file)
@@ -131,10 +131,24 @@ Thread * Scheduler::next_thread(Thread *t)
 {
        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;
-                       if (enabled[curr_thread_index]==THREAD_ENABLED) {
-                               t = model->get_thread(int_to_id(curr_thread_index));
+                       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(int_to_id(curr_tid));
                                break;
                        }
                        if (curr_thread_index == old_curr_thread) {