surf_action_t(*sleep) (void *workstation, double duration);
e_surf_cpu_state_t(*get_state) (void *workstation);
surf_action_t(*communicate) (void *workstation_src,
surf_action_t(*sleep) (void *workstation, double duration);
e_surf_cpu_state_t(*get_state) (void *workstation);
surf_action_t(*communicate) (void *workstation_src,