w->close = oss_close;
w->pre_select = oss_pre_select;
w->post_select = oss_post_select;
w->parse_config_or_die = oss_parse_config_or_die;
w->free_config = oss_free_config;
w->close = oss_close;
w->pre_select = oss_pre_select;
w->post_select = oss_post_select;
w->parse_config_or_die = oss_parse_config_or_die;
w->free_config = oss_free_config;