void add_thread(Thread *t);
void remove_thread(Thread *t);
- Thread * get_thread(thread_id_t tid);
- Thread * get_thread(ModelAction *act);
+ Thread * get_thread(thread_id_t tid) const;
+ Thread * get_thread(ModelAction *act) const;
thread_id_t get_next_id();
int get_num_threads();