+XBT_PUBLIC void sg_actor_migrate(sg_actor_t process, sg_host_t host);
+XBT_PUBLIC void sg_actor_join(sg_actor_t actor, double timeout);
+XBT_PUBLIC void sg_actor_kill(sg_actor_t actor);
+XBT_PUBLIC void sg_actor_set_kill_time(sg_actor_t actor, double kill_time);