int vcl_session_read_ready (vcl_session_t * session);
int vcl_session_write_ready (vcl_session_t * session);
int vcl_session_alloc_ext_cfg (vcl_session_t *s,
int vcl_session_read_ready (vcl_session_t * session);
int vcl_session_write_ready (vcl_session_t * session);
int vcl_session_alloc_ext_cfg (vcl_session_t *s,