queue.h revision 51955
18876Srgrimes/* 21541Srgrimes * Copyright (c) 1991, 1993 31541Srgrimes * The Regents of the University of California. All rights reserved. 41541Srgrimes * 51541Srgrimes * Redistribution and use in source and binary forms, with or without 61541Srgrimes * modification, are permitted provided that the following conditions 71541Srgrimes * are met: 81541Srgrimes * 1. Redistributions of source code must retain the above copyright 91541Srgrimes * notice, this list of conditions and the following disclaimer. 101541Srgrimes * 2. Redistributions in binary form must reproduce the above copyright 111541Srgrimes * notice, this list of conditions and the following disclaimer in the 121541Srgrimes * documentation and/or other materials provided with the distribution. 131541Srgrimes * 3. All advertising materials mentioning features or use of this software 141541Srgrimes * must display the following acknowledgement: 151541Srgrimes * This product includes software developed by the University of 161541Srgrimes * California, Berkeley and its contributors. 171541Srgrimes * 4. Neither the name of the University nor the names of its contributors 181541Srgrimes * may be used to endorse or promote products derived from this software 191541Srgrimes * without specific prior written permission. 201541Srgrimes * 211541Srgrimes * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 221541Srgrimes * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 231541Srgrimes * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 241541Srgrimes * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 251541Srgrimes * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 261541Srgrimes * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 271541Srgrimes * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 281541Srgrimes * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 291541Srgrimes * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 301541Srgrimes * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 311541Srgrimes * SUCH DAMAGE. 321541Srgrimes * 3314492Shsu * @(#)queue.h 8.5 (Berkeley) 8/20/94 3450477Speter * $FreeBSD: head/sys/sys/queue.h 51955 1999-10-05 20:35:32Z n_hibma $ 351541Srgrimes */ 361541Srgrimes 3712592Sbde#ifndef _SYS_QUEUE_H_ 381541Srgrimes#define _SYS_QUEUE_H_ 391541Srgrimes 401541Srgrimes/* 4114940Sgibbs * This file defines five types of data structures: singly-linked lists, 4214940Sgibbs * slingly-linked tail queues, lists, tail queues, and circular queues. 431541Srgrimes * 4414940Sgibbs * A singly-linked list is headed by a single forward pointer. The elements 4514940Sgibbs * are singly linked for minimum space and pointer manipulation overhead at 4614940Sgibbs * the expense of O(n) removal for arbitrary elements. New elements can be 4714940Sgibbs * added to the list after an existing element or at the head of the list. 4814940Sgibbs * Elements being removed from the head of the list should use the explicit 4914940Sgibbs * macro for this purpose for optimum efficiency. A singly-linked list may 5014940Sgibbs * only be traversed in the forward direction. Singly-linked lists are ideal 5114940Sgibbs * for applications with large datasets and few or no removals or for 5214940Sgibbs * implementing a LIFO queue. 5314940Sgibbs * 5414940Sgibbs * A singly-linked tail queue is headed by a pair of pointers, one to the 5514940Sgibbs * head of the list and the other to the tail of the list. The elements are 5614940Sgibbs * singly linked for minimum space and pointer manipulation overhead at the 5714940Sgibbs * expense of O(n) removal for arbitrary elements. New elements can be added 5814940Sgibbs * to the list after an existing element, at the head of the list, or at the 5914940Sgibbs * end of the list. Elements being removed from the head of the tail queue 6014940Sgibbs * should use the explicit macro for this purpose for optimum efficiency. 6114940Sgibbs * A singly-linked tail queue may only be traversed in the forward direction. 6214940Sgibbs * Singly-linked tail queues are ideal for applications with large datasets 6314940Sgibbs * and few or no removals or for implementing a FIFO queue. 6414940Sgibbs * 651541Srgrimes * A list is headed by a single forward pointer (or an array of forward 661541Srgrimes * pointers for a hash table header). The elements are doubly linked 671541Srgrimes * so that an arbitrary element can be removed without a need to 6814492Shsu * traverse the list. New elements can be added to the list before 6914492Shsu * or after an existing element or at the head of the list. A list 7014492Shsu * may only be traversed in the forward direction. 711541Srgrimes * 721541Srgrimes * A tail queue is headed by a pair of pointers, one to the head of the 731541Srgrimes * list and the other to the tail of the list. The elements are doubly 741541Srgrimes * linked so that an arbitrary element can be removed without a need to 7514492Shsu * traverse the list. New elements can be added to the list before or 7614492Shsu * after an existing element, at the head of the list, or at the end of 7714492Shsu * the list. A tail queue may only be traversed in the forward direction. 781541Srgrimes * 791541Srgrimes * A circle queue is headed by a pair of pointers, one to the head of the 801541Srgrimes * list and the other to the tail of the list. The elements are doubly 811541Srgrimes * linked so that an arbitrary element can be removed without a need to 821541Srgrimes * traverse the list. New elements can be added to the list before or after 831541Srgrimes * an existing element, at the head of the list, or at the end of the list. 841541Srgrimes * A circle queue may be traversed in either direction, but has a more 851541Srgrimes * complex end of list detection. 861541Srgrimes * 871541Srgrimes * For details on the use of these macros, see the queue(3) manual page. 8825188Sphk * 8925188Sphk * 9025188Sphk * SLIST LIST STAILQ TAILQ CIRCLEQ 9125188Sphk * _HEAD + + + + + 9225188Sphk * _ENTRY + + + + + 9325188Sphk * _INIT + + + + + 9425188Sphk * _EMPTY + + + + + 9537143Sphk * _FIRST + + + + + 9637143Sphk * _NEXT + + + + + 9725188Sphk * _PREV - - - + + 9837143Sphk * _LAST - - + + + 9950604Sjdp * _FOREACH + + + + + 10025188Sphk * _INSERT_HEAD + + + + + 10125188Sphk * _INSERT_BEFORE - + - + + 10225188Sphk * _INSERT_AFTER + + + + + 10325188Sphk * _INSERT_TAIL - - + + + 10425188Sphk * _REMOVE_HEAD + - + - - 10525188Sphk * _REMOVE + + + + + 10625188Sphk * 1071541Srgrimes */ 1081541Srgrimes 1091541Srgrimes/* 11014940Sgibbs * Singly-linked List definitions. 11114940Sgibbs */ 11214940Sgibbs#define SLIST_HEAD(name, type) \ 11314940Sgibbsstruct name { \ 11414940Sgibbs struct type *slh_first; /* first element */ \ 11514940Sgibbs} 11651955Sn_hibma 11751955Sn_hibma#define SLIST_HEAD_INITIALIZER(head) \ 11851955Sn_hibma { NULL } 11914940Sgibbs 12014940Sgibbs#define SLIST_ENTRY(type) \ 12114940Sgibbsstruct { \ 12214940Sgibbs struct type *sle_next; /* next element */ \ 12314940Sgibbs} 12414940Sgibbs 12514940Sgibbs/* 12614940Sgibbs * Singly-linked List functions. 12714940Sgibbs */ 12821029Sphk#define SLIST_EMPTY(head) ((head)->slh_first == NULL) 12921029Sphk 13021029Sphk#define SLIST_FIRST(head) ((head)->slh_first) 13121029Sphk 13228730Sphk#define SLIST_FOREACH(var, head, field) \ 13328730Sphk for((var) = (head)->slh_first; (var); (var) = (var)->field.sle_next) 13428730Sphk 13514940Sgibbs#define SLIST_INIT(head) { \ 13614940Sgibbs (head)->slh_first = NULL; \ 13714940Sgibbs} 13814940Sgibbs 13942359Sn_hibma#define SLIST_INSERT_AFTER(slistelm, elm, field) do { \ 14014940Sgibbs (elm)->field.sle_next = (slistelm)->field.sle_next; \ 14114940Sgibbs (slistelm)->field.sle_next = (elm); \ 14233793Sjulian} while (0) 14314940Sgibbs 14433793Sjulian#define SLIST_INSERT_HEAD(head, elm, field) do { \ 14514940Sgibbs (elm)->field.sle_next = (head)->slh_first; \ 14614940Sgibbs (head)->slh_first = (elm); \ 14733793Sjulian} while (0) 14814940Sgibbs 14921029Sphk#define SLIST_NEXT(elm, field) ((elm)->field.sle_next) 15021029Sphk 15133793Sjulian#define SLIST_REMOVE_HEAD(head, field) do { \ 15214940Sgibbs (head)->slh_first = (head)->slh_first->field.sle_next; \ 15333793Sjulian} while (0) 15414940Sgibbs 15533793Sjulian#define SLIST_REMOVE(head, elm, type, field) do { \ 15614940Sgibbs if ((head)->slh_first == (elm)) { \ 15714940Sgibbs SLIST_REMOVE_HEAD((head), field); \ 15814940Sgibbs } \ 15914940Sgibbs else { \ 16014940Sgibbs struct type *curelm = (head)->slh_first; \ 16114940Sgibbs while( curelm->field.sle_next != (elm) ) \ 16214940Sgibbs curelm = curelm->field.sle_next; \ 16314940Sgibbs curelm->field.sle_next = \ 16414940Sgibbs curelm->field.sle_next->field.sle_next; \ 16514940Sgibbs } \ 16633793Sjulian} while (0) 16714940Sgibbs 16814940Sgibbs/* 16914940Sgibbs * Singly-linked Tail queue definitions. 17014940Sgibbs */ 17114940Sgibbs#define STAILQ_HEAD(name, type) \ 17214940Sgibbsstruct name { \ 17314940Sgibbs struct type *stqh_first;/* first element */ \ 17414940Sgibbs struct type **stqh_last;/* addr of last next element */ \ 17514940Sgibbs} 17614940Sgibbs 17742359Sn_hibma#define STAILQ_HEAD_INITIALIZER(head) \ 17842359Sn_hibma { NULL, &(head).stqh_first } 17942359Sn_hibma 18014940Sgibbs#define STAILQ_ENTRY(type) \ 18114940Sgibbsstruct { \ 18214940Sgibbs struct type *stqe_next; /* next element */ \ 18314940Sgibbs} 18414940Sgibbs 18514940Sgibbs/* 18614940Sgibbs * Singly-linked Tail queue functions. 18714940Sgibbs */ 18825188Sphk#define STAILQ_EMPTY(head) ((head)->stqh_first == NULL) 18925188Sphk 19033793Sjulian#define STAILQ_INIT(head) do { \ 19114940Sgibbs (head)->stqh_first = NULL; \ 19214940Sgibbs (head)->stqh_last = &(head)->stqh_first; \ 19333793Sjulian} while (0) 19414940Sgibbs 19525536Sdfr#define STAILQ_FIRST(head) ((head)->stqh_first) 19625536Sdfr#define STAILQ_LAST(head) (*(head)->stqh_last) 19725536Sdfr 19850604Sjdp#define STAILQ_FOREACH(var, head, field) \ 19950604Sjdp for((var) = (head)->stqh_first; (var); (var) = (var)->field.stqe_next) 20050604Sjdp 20133793Sjulian#define STAILQ_INSERT_HEAD(head, elm, field) do { \ 20214940Sgibbs if (((elm)->field.stqe_next = (head)->stqh_first) == NULL) \ 20314940Sgibbs (head)->stqh_last = &(elm)->field.stqe_next; \ 20414940Sgibbs (head)->stqh_first = (elm); \ 20533793Sjulian} while (0) 20614940Sgibbs 20733793Sjulian#define STAILQ_INSERT_TAIL(head, elm, field) do { \ 20814940Sgibbs (elm)->field.stqe_next = NULL; \ 20914940Sgibbs *(head)->stqh_last = (elm); \ 21014940Sgibbs (head)->stqh_last = &(elm)->field.stqe_next; \ 21133793Sjulian} while (0) 21214940Sgibbs 21333793Sjulian#define STAILQ_INSERT_AFTER(head, tqelm, elm, field) do { \ 21414940Sgibbs if (((elm)->field.stqe_next = (tqelm)->field.stqe_next) == NULL)\ 21514940Sgibbs (head)->stqh_last = &(elm)->field.stqe_next; \ 21614940Sgibbs (tqelm)->field.stqe_next = (elm); \ 21733793Sjulian} while (0) 21814940Sgibbs 21925536Sdfr#define STAILQ_NEXT(elm, field) ((elm)->field.stqe_next) 22025536Sdfr 22133793Sjulian#define STAILQ_REMOVE_HEAD(head, field) do { \ 22214940Sgibbs if (((head)->stqh_first = \ 22314940Sgibbs (head)->stqh_first->field.stqe_next) == NULL) \ 22414940Sgibbs (head)->stqh_last = &(head)->stqh_first; \ 22533793Sjulian} while (0) 22614940Sgibbs 22742359Sn_hibma 22833793Sjulian#define STAILQ_REMOVE(head, elm, type, field) do { \ 22914940Sgibbs if ((head)->stqh_first == (elm)) { \ 23014940Sgibbs STAILQ_REMOVE_HEAD(head, field); \ 23114940Sgibbs } \ 23214940Sgibbs else { \ 23314940Sgibbs struct type *curelm = (head)->stqh_first; \ 23414940Sgibbs while( curelm->field.stqe_next != (elm) ) \ 23514940Sgibbs curelm = curelm->field.stqe_next; \ 23614940Sgibbs if((curelm->field.stqe_next = \ 23714940Sgibbs curelm->field.stqe_next->field.stqe_next) == NULL) \ 23814940Sgibbs (head)->stqh_last = &(curelm)->field.stqe_next; \ 23914940Sgibbs } \ 24033793Sjulian} while (0) 24114940Sgibbs 24214940Sgibbs/* 2431541Srgrimes * List definitions. 2441541Srgrimes */ 2451541Srgrimes#define LIST_HEAD(name, type) \ 2461541Srgrimesstruct name { \ 2471541Srgrimes struct type *lh_first; /* first element */ \ 2481541Srgrimes} 2491541Srgrimes 25048641Sn_hibma#define LIST_HEAD_INITIALIZER(head) \ 25142359Sn_hibma { NULL } 25242359Sn_hibma 2531541Srgrimes#define LIST_ENTRY(type) \ 2541541Srgrimesstruct { \ 2551541Srgrimes struct type *le_next; /* next element */ \ 2561541Srgrimes struct type **le_prev; /* address of previous next element */ \ 2571541Srgrimes} 2581541Srgrimes 2591541Srgrimes/* 2601541Srgrimes * List functions. 2611541Srgrimes */ 26225188Sphk 26325188Sphk#define LIST_EMPTY(head) ((head)->lh_first == NULL) 26425188Sphk 26524935Sphk#define LIST_FIRST(head) ((head)->lh_first) 26624935Sphk 26724935Sphk#define LIST_FOREACH(var, head, field) \ 26824935Sphk for((var) = (head)->lh_first; (var); (var) = (var)->field.le_next) 26924935Sphk 27033793Sjulian#define LIST_INIT(head) do { \ 2711541Srgrimes (head)->lh_first = NULL; \ 27233793Sjulian} while (0) 2731541Srgrimes 27433793Sjulian#define LIST_INSERT_AFTER(listelm, elm, field) do { \ 2751541Srgrimes if (((elm)->field.le_next = (listelm)->field.le_next) != NULL) \ 2761541Srgrimes (listelm)->field.le_next->field.le_prev = \ 2771541Srgrimes &(elm)->field.le_next; \ 2781541Srgrimes (listelm)->field.le_next = (elm); \ 2791541Srgrimes (elm)->field.le_prev = &(listelm)->field.le_next; \ 28033793Sjulian} while (0) 2811541Srgrimes 28233793Sjulian#define LIST_INSERT_BEFORE(listelm, elm, field) do { \ 28313697Sgibbs (elm)->field.le_prev = (listelm)->field.le_prev; \ 28413697Sgibbs (elm)->field.le_next = (listelm); \ 28513697Sgibbs *(listelm)->field.le_prev = (elm); \ 28613697Sgibbs (listelm)->field.le_prev = &(elm)->field.le_next; \ 28733793Sjulian} while (0) 28813697Sgibbs 28933793Sjulian#define LIST_INSERT_HEAD(head, elm, field) do { \ 2901541Srgrimes if (((elm)->field.le_next = (head)->lh_first) != NULL) \ 2911541Srgrimes (head)->lh_first->field.le_prev = &(elm)->field.le_next;\ 2921541Srgrimes (head)->lh_first = (elm); \ 2931541Srgrimes (elm)->field.le_prev = &(head)->lh_first; \ 29433793Sjulian} while (0) 2951541Srgrimes 29624935Sphk#define LIST_NEXT(elm, field) ((elm)->field.le_next) 29724935Sphk 29833793Sjulian#define LIST_REMOVE(elm, field) do { \ 2991541Srgrimes if ((elm)->field.le_next != NULL) \ 3001541Srgrimes (elm)->field.le_next->field.le_prev = \ 3011541Srgrimes (elm)->field.le_prev; \ 3021541Srgrimes *(elm)->field.le_prev = (elm)->field.le_next; \ 30333793Sjulian} while (0) 3041541Srgrimes 3051541Srgrimes/* 3061541Srgrimes * Tail queue definitions. 3071541Srgrimes */ 3081541Srgrimes#define TAILQ_HEAD(name, type) \ 3091541Srgrimesstruct name { \ 3101541Srgrimes struct type *tqh_first; /* first element */ \ 3111541Srgrimes struct type **tqh_last; /* addr of last next element */ \ 3121541Srgrimes} 3131541Srgrimes 31429683Sgibbs#define TAILQ_HEAD_INITIALIZER(head) \ 31529683Sgibbs { NULL, &(head).tqh_first } 31629683Sgibbs 3171541Srgrimes#define TAILQ_ENTRY(type) \ 3181541Srgrimesstruct { \ 3191541Srgrimes struct type *tqe_next; /* next element */ \ 3201541Srgrimes struct type **tqe_prev; /* address of previous next element */ \ 3211541Srgrimes} 3221541Srgrimes 3231541Srgrimes/* 3241541Srgrimes * Tail queue functions. 3251541Srgrimes */ 32615138Sphk#define TAILQ_EMPTY(head) ((head)->tqh_first == NULL) 32715138Sphk 32825188Sphk#define TAILQ_FOREACH(var, head, field) \ 32925188Sphk for (var = TAILQ_FIRST(head); var; var = TAILQ_NEXT(var, field)) 33025188Sphk 33115138Sphk#define TAILQ_FIRST(head) ((head)->tqh_first) 33215138Sphk 33333793Sjulian#define TAILQ_LAST(head, headname) \ 33433793Sjulian (*(((struct headname *)((head)->tqh_last))->tqh_last)) 33515138Sphk 33615809Sdyson#define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next) 33715138Sphk 33833793Sjulian#define TAILQ_PREV(elm, headname, field) \ 33933793Sjulian (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last)) 34015809Sdyson 34133793Sjulian#define TAILQ_INIT(head) do { \ 3421541Srgrimes (head)->tqh_first = NULL; \ 3431541Srgrimes (head)->tqh_last = &(head)->tqh_first; \ 34433793Sjulian} while (0) 3451541Srgrimes 34633793Sjulian#define TAILQ_INSERT_HEAD(head, elm, field) do { \ 3471541Srgrimes if (((elm)->field.tqe_next = (head)->tqh_first) != NULL) \ 34814492Shsu (head)->tqh_first->field.tqe_prev = \ 3491541Srgrimes &(elm)->field.tqe_next; \ 3501541Srgrimes else \ 3511541Srgrimes (head)->tqh_last = &(elm)->field.tqe_next; \ 3521541Srgrimes (head)->tqh_first = (elm); \ 3531541Srgrimes (elm)->field.tqe_prev = &(head)->tqh_first; \ 35433793Sjulian} while (0) 3551541Srgrimes 35633793Sjulian#define TAILQ_INSERT_TAIL(head, elm, field) do { \ 3571541Srgrimes (elm)->field.tqe_next = NULL; \ 3581541Srgrimes (elm)->field.tqe_prev = (head)->tqh_last; \ 3591541Srgrimes *(head)->tqh_last = (elm); \ 3601541Srgrimes (head)->tqh_last = &(elm)->field.tqe_next; \ 36133793Sjulian} while (0) 3621541Srgrimes 36333793Sjulian#define TAILQ_INSERT_AFTER(head, listelm, elm, field) do { \ 3641541Srgrimes if (((elm)->field.tqe_next = (listelm)->field.tqe_next) != NULL)\ 3651541Srgrimes (elm)->field.tqe_next->field.tqe_prev = \ 3661541Srgrimes &(elm)->field.tqe_next; \ 3671541Srgrimes else \ 3681541Srgrimes (head)->tqh_last = &(elm)->field.tqe_next; \ 3691541Srgrimes (listelm)->field.tqe_next = (elm); \ 3701541Srgrimes (elm)->field.tqe_prev = &(listelm)->field.tqe_next; \ 37133793Sjulian} while (0) 3721541Srgrimes 37333793Sjulian#define TAILQ_INSERT_BEFORE(listelm, elm, field) do { \ 37413697Sgibbs (elm)->field.tqe_prev = (listelm)->field.tqe_prev; \ 37513697Sgibbs (elm)->field.tqe_next = (listelm); \ 37613697Sgibbs *(listelm)->field.tqe_prev = (elm); \ 37713697Sgibbs (listelm)->field.tqe_prev = &(elm)->field.tqe_next; \ 37833793Sjulian} while (0) 37913697Sgibbs 38033793Sjulian#define TAILQ_REMOVE(head, elm, field) do { \ 3811541Srgrimes if (((elm)->field.tqe_next) != NULL) \ 3821541Srgrimes (elm)->field.tqe_next->field.tqe_prev = \ 3831541Srgrimes (elm)->field.tqe_prev; \ 3841541Srgrimes else \ 3851541Srgrimes (head)->tqh_last = (elm)->field.tqe_prev; \ 3861541Srgrimes *(elm)->field.tqe_prev = (elm)->field.tqe_next; \ 38733793Sjulian} while (0) 3881541Srgrimes 3891541Srgrimes/* 3901541Srgrimes * Circular queue definitions. 3911541Srgrimes */ 3921541Srgrimes#define CIRCLEQ_HEAD(name, type) \ 3931541Srgrimesstruct name { \ 3941541Srgrimes struct type *cqh_first; /* first element */ \ 3951541Srgrimes struct type *cqh_last; /* last element */ \ 3961541Srgrimes} 3971541Srgrimes 3981541Srgrimes#define CIRCLEQ_ENTRY(type) \ 3991541Srgrimesstruct { \ 4001541Srgrimes struct type *cqe_next; /* next element */ \ 4011541Srgrimes struct type *cqe_prev; /* previous element */ \ 4021541Srgrimes} 4031541Srgrimes 4041541Srgrimes/* 4051541Srgrimes * Circular queue functions. 4061541Srgrimes */ 40730897Sgibbs#define CIRCLEQ_EMPTY(head) ((head)->cqh_first == (void *)(head)) 40825188Sphk 40925188Sphk#define CIRCLEQ_FIRST(head) ((head)->cqh_first) 41025188Sphk 41125188Sphk#define CIRCLEQ_FOREACH(var, head, field) \ 41235957Sgibbs for((var) = (head)->cqh_first; \ 41335957Sgibbs (var) != (void *)(head); \ 41435957Sgibbs (var) = (var)->field.cqe_next) 41525188Sphk 41633793Sjulian#define CIRCLEQ_INIT(head) do { \ 4171541Srgrimes (head)->cqh_first = (void *)(head); \ 4181541Srgrimes (head)->cqh_last = (void *)(head); \ 41933793Sjulian} while (0) 4201541Srgrimes 42133793Sjulian#define CIRCLEQ_INSERT_AFTER(head, listelm, elm, field) do { \ 4221541Srgrimes (elm)->field.cqe_next = (listelm)->field.cqe_next; \ 4231541Srgrimes (elm)->field.cqe_prev = (listelm); \ 4241541Srgrimes if ((listelm)->field.cqe_next == (void *)(head)) \ 4251541Srgrimes (head)->cqh_last = (elm); \ 4261541Srgrimes else \ 4271541Srgrimes (listelm)->field.cqe_next->field.cqe_prev = (elm); \ 4281541Srgrimes (listelm)->field.cqe_next = (elm); \ 42933793Sjulian} while (0) 4301541Srgrimes 43133793Sjulian#define CIRCLEQ_INSERT_BEFORE(head, listelm, elm, field) do { \ 4321541Srgrimes (elm)->field.cqe_next = (listelm); \ 4331541Srgrimes (elm)->field.cqe_prev = (listelm)->field.cqe_prev; \ 4341541Srgrimes if ((listelm)->field.cqe_prev == (void *)(head)) \ 4351541Srgrimes (head)->cqh_first = (elm); \ 4361541Srgrimes else \ 4371541Srgrimes (listelm)->field.cqe_prev->field.cqe_next = (elm); \ 4381541Srgrimes (listelm)->field.cqe_prev = (elm); \ 43933793Sjulian} while (0) 4401541Srgrimes 44133793Sjulian#define CIRCLEQ_INSERT_HEAD(head, elm, field) do { \ 4421541Srgrimes (elm)->field.cqe_next = (head)->cqh_first; \ 4431541Srgrimes (elm)->field.cqe_prev = (void *)(head); \ 4441541Srgrimes if ((head)->cqh_last == (void *)(head)) \ 4451541Srgrimes (head)->cqh_last = (elm); \ 4461541Srgrimes else \ 4471541Srgrimes (head)->cqh_first->field.cqe_prev = (elm); \ 4481541Srgrimes (head)->cqh_first = (elm); \ 44933793Sjulian} while (0) 4501541Srgrimes 45133793Sjulian#define CIRCLEQ_INSERT_TAIL(head, elm, field) do { \ 4521541Srgrimes (elm)->field.cqe_next = (void *)(head); \ 4531541Srgrimes (elm)->field.cqe_prev = (head)->cqh_last; \ 4541541Srgrimes if ((head)->cqh_first == (void *)(head)) \ 4551541Srgrimes (head)->cqh_first = (elm); \ 4561541Srgrimes else \ 4571541Srgrimes (head)->cqh_last->field.cqe_next = (elm); \ 4581541Srgrimes (head)->cqh_last = (elm); \ 45933793Sjulian} while (0) 4601541Srgrimes 46125188Sphk#define CIRCLEQ_LAST(head) ((head)->cqh_last) 46225188Sphk 46325188Sphk#define CIRCLEQ_NEXT(elm,field) ((elm)->field.cqe_next) 46425188Sphk 46525188Sphk#define CIRCLEQ_PREV(elm,field) ((elm)->field.cqe_prev) 46625188Sphk 46733793Sjulian#define CIRCLEQ_REMOVE(head, elm, field) do { \ 4681541Srgrimes if ((elm)->field.cqe_next == (void *)(head)) \ 4691541Srgrimes (head)->cqh_last = (elm)->field.cqe_prev; \ 4701541Srgrimes else \ 4711541Srgrimes (elm)->field.cqe_next->field.cqe_prev = \ 4721541Srgrimes (elm)->field.cqe_prev; \ 4731541Srgrimes if ((elm)->field.cqe_prev == (void *)(head)) \ 4741541Srgrimes (head)->cqh_first = (elm)->field.cqe_next; \ 4751541Srgrimes else \ 4761541Srgrimes (elm)->field.cqe_prev->field.cqe_next = \ 4771541Srgrimes (elm)->field.cqe_next; \ 47833793Sjulian} while (0) 47912592Sbde 48012592Sbde#ifdef KERNEL 48112592Sbde 48212592Sbde/* 48312592Sbde * XXX insque() and remque() are an old way of handling certain queues. 48412592Sbde * They bogusly assumes that all queue heads look alike. 48512592Sbde */ 48612592Sbde 48712592Sbdestruct quehead { 48812592Sbde struct quehead *qh_link; 48912592Sbde struct quehead *qh_rlink; 49012592Sbde}; 49112592Sbde 49212592Sbde#ifdef __GNUC__ 49312592Sbde 49412592Sbdestatic __inline void 49512592Sbdeinsque(void *a, void *b) 49612592Sbde{ 49712592Sbde struct quehead *element = a, *head = b; 49812592Sbde 49912592Sbde element->qh_link = head->qh_link; 50012592Sbde element->qh_rlink = head; 50112592Sbde head->qh_link = element; 50212592Sbde element->qh_link->qh_rlink = element; 50312592Sbde} 50412592Sbde 50512592Sbdestatic __inline void 50612592Sbderemque(void *a) 50712592Sbde{ 50812592Sbde struct quehead *element = a; 50912592Sbde 51012592Sbde element->qh_link->qh_rlink = element->qh_rlink; 51112592Sbde element->qh_rlink->qh_link = element->qh_link; 51212592Sbde element->qh_rlink = 0; 51312592Sbde} 51412592Sbde 51512592Sbde#else /* !__GNUC__ */ 51612592Sbde 51712592Sbdevoid insque __P((void *a, void *b)); 51812592Sbdevoid remque __P((void *a)); 51912592Sbde 52012592Sbde#endif /* __GNUC__ */ 52112592Sbde 52212592Sbde#endif /* KERNEL */ 52312592Sbde 52412592Sbde#endif /* !_SYS_QUEUE_H_ */ 525