307     item **head, **tail;  in do_item_link_q()  local
311     tail = &tails[it->slabs_clsid];  in do_item_link_q()
313     assert((*head && *tail) || (*head == 0 && *tail == 0));  in do_item_link_q()
318     if (*tail == 0) *tail = it;  in do_item_link_q()
331     item **head, **tail;  in do_item_unlink_q()  local
333     tail = &tails[it->slabs_clsid];  in do_item_unlink_q()
339     if (*tail == it) {  in do_item_unlink_q()
341         *tail = it->prev;  in do_item_unlink_q()
1198     item **head, **tail;  in crawler_link_q()  local
1203     tail = &tails[it->slabs_clsid];  in crawler_link_q()
1204     assert(*tail != 0);  in crawler_link_q()
1205     assert(it != *tail);  in crawler_link_q()
1206     assert((*head && *tail) || (*head == 0 && *tail == 0));  in crawler_link_q()
1207     it->prev = *tail;  in crawler_link_q()
1213     *tail = it;  in crawler_link_q()
1219     item **head, **tail;  in crawler_unlink_q()  local
1221     tail = &tails[it->slabs_clsid];  in crawler_unlink_q()
1227     if (*tail == it) {  in crawler_unlink_q()
1229         *tail = it->prev;  in crawler_unlink_q()
1242     item **head, **tail;  in crawler_crawl_q()  local
1246     tail = &tails[it->slabs_clsid];  in crawler_crawl_q()
1267         if (*tail == it) {  in crawler_crawl_q()
1269             *tail = it->prev;  in crawler_crawl_q()