int session_set_watch(struct session *s, int what, session_watchfun fun, void *data, struct http_channel *c);
int session_active_clients(struct session *s);
int session_is_preferred_clients_ready(struct session *s);
int session_set_watch(struct session *s, int what, session_watchfun fun, void *data, struct http_channel *c);
int session_active_clients(struct session *s);
int session_is_preferred_clients_ready(struct session *s);