/* $Csoft: queue.h,v 1.1.1.1 2003/10/16 23:25:17 vedge Exp $ */ /* $OpenBSD: queue.h,v 1.22 2001/06/23 04:39:35 angelos Exp $ */ /* $NetBSD: queue.h,v 1.11 1996/05/16 05:17:14 mycroft Exp $ */ /* * Copyright (c) 1991, 1993 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)queue.h 8.5 (Berkeley) 8/20/94 */ #ifndef _SYS_QUEUE_H_ #define _SYS_QUEUE_H_ /* * This file defines five types of data structures: singly-linked lists, * lists, simple queues, tail queues, and circular queues. * * * A singly-linked list is headed by a single forward pointer. The elements * are singly linked for minimum space and pointer manipulation overhead at * the expense of O(n) removal for arbitrary elements. New elements can be * added to the list after an existing element or at the head of the list. * Elements being removed from the head of the list should use the explicit * macro for this purpose for optimum efficiency. A singly-linked list may * only be traversed in the forward direction. Singly-linked lists are ideal * for applications with large datasets and few or no removals or for * implementing a LIFO queue. * * A list is headed by a single forward pointer (or an array of forward * pointers for a hash table header). The elements are doubly linked * so that an arbitrary element can be removed without a need to * traverse the list. New elements can be added to the list before * or after an existing element or at the head of the list. A list * may only be traversed in the forward direction. * * A simple queue is headed by a pair of pointers, one the head of the * list and the other to the tail of the list. The elements are singly * linked to save space, so elements can only be removed from the * head of the list. New elements can be added to the list before or after * an existing element, at the head of the list, or at the end of the * list. A simple queue may only be traversed in the forward direction. * * A tail queue is headed by a pair of pointers, one to the head of the * list and the other to the tail of the list. The elements are doubly * linked so that an arbitrary element can be removed without a need to * traverse the list. New elements can be added to the list before or * after an existing element, at the head of the list, or at the end of * the list. A tail queue may be traversed in either direction. * * A circle queue is headed by a pair of pointers, one to the head of the * list and the other to the tail of the list. The elements are doubly * linked so that an arbitrary element can be removed without a need to * traverse the list. New elements can be added to the list before or after * an existing element, at the head of the list, or at the end of the list. * A circle queue may be traversed in either direction, but has a more * complex end of list detection. * * For details on the use of these macros, see the queue(3) manual page. */ /* * Singly-linked List definitions. */ #define SLIST_HEAD(name, type) \ struct name { \ struct type *slh_first; /* first element */ \ } #define SLIST_HEAD_INITIALIZER(head) \ { NULL } #define SLIST_ENTRY(type) \ struct { \ struct type *sle_next; /* next element */ \ } /* * Singly-linked List access methods. */ #define SLIST_FIRST(head) ((head)->slh_first) #define SLIST_END(head) NULL #define SLIST_EMPTY(head) (SLIST_FIRST(head) == SLIST_END(head)) #define SLIST_NEXT(elm, field) ((elm)->field.sle_next) #define SLIST_FOREACH(var, head, field) \ for((var) = SLIST_FIRST(head); \ (var) != SLIST_END(head); \ (var) = SLIST_NEXT(var, field)) /* * Singly-linked List functions. */ #define SLIST_INIT(head) { \ SLIST_FIRST(head) = SLIST_END(head); \ } #define SLIST_INSERT_AFTER(slistelm, elm, field) do { \ (elm)->field.sle_next = (slistelm)->field.sle_next; \ (slistelm)->field.sle_next = (elm); \ } while (0) #define SLIST_INSERT_HEAD(head, elm, field) do { \ (elm)->field.sle_next = (head)->slh_first; \ (head)->slh_first = (elm); \ } while (0) #define SLIST_REMOVE_HEAD(head, field) do { \ (head)->slh_first = (head)->slh_first->field.sle_next; \ } while (0) #define SLIST_REMOVE(head, elm, type, field) do { \ if ((head)->slh_first == (elm)) { \ SLIST_REMOVE_HEAD((head), field); \ } \ else { \ struct type *curelm = (head)->slh_first; \ while( curelm->field.sle_next != (elm) ) \ curelm = curelm->field.sle_next; \ curelm->field.sle_next = \ curelm->field.sle_next->field.sle_next; \ } \ } while (0) /* * List definitions. */ #define LIST_HEAD(name, type) \ struct name { \ struct type *lh_first; /* first element */ \ } #define LIST_HEAD_INITIALIZER(head) \ { NULL } #define LIST_ENTRY(type) \ struct { \ struct type *le_next; /* next element */ \ struct type **le_prev; /* address of previous next element */ \ } /* * List access methods */ #define LIST_FIRST(head) ((head)->lh_first) #define LIST_END(head) NULL #define LIST_EMPTY(head) (LIST_FIRST(head) == LIST_END(head)) #define LIST_NEXT(elm, field) ((elm)->field.le_next) #define LIST_FOREACH(var, head, field) \ for((var) = LIST_FIRST(head); \ (var)!= LIST_END(head); \ (var) = LIST_NEXT(var, field)) /* * List functions. */ #define LIST_INIT(head) do { \ LIST_FIRST(head) = LIST_END(head); \ } while (0) #define LIST_INSERT_AFTER(listelm, elm, field) do { \ if (((elm)->field.le_next = (listelm)->field.le_next) != NULL) \ (listelm)->field.le_next->field.le_prev = \ &(elm)->field.le_next; \ (listelm)->field.le_next = (elm); \ (elm)->field.le_prev = &(listelm)->field.le_next; \ } while (0) #define LIST_INSERT_BEFORE(listelm, elm, field) do { \ (elm)->field.le_prev = (listelm)->field.le_prev; \ (elm)->field.le_next = (listelm); \ *(listelm)->field.le_prev = (elm); \ (listelm)->field.le_prev = &(elm)->field.le_next; \ } while (0) #define LIST_INSERT_HEAD(head, elm, field) do { \ if (((elm)->field.le_next = (head)->lh_first) != NULL) \ (head)->lh_first->field.le_prev = &(elm)->field.le_next;\ (head)->lh_first = (elm); \ (elm)->field.le_prev = &(head)->lh_first; \ } while (0) #define LIST_REMOVE(elm, field) do { \ if ((elm)->field.le_next != NULL) \ (elm)->field.le_next->field.le_prev = \ (elm)->field.le_prev; \ *(elm)->field.le_prev = (elm)->field.le_next; \ } while (0) #define LIST_REPLACE(elm, elm2, field) do { \ if (((elm2)->field.le_next = (elm)->field.le_next) != NULL) \ (elm2)->field.le_next->field.le_prev = \ &(elm2)->field.le_next; \ (elm2)->field.le_prev = (elm)->field.le_prev; \ *(elm2)->field.le_prev = (elm2); \ } while (0) /* * Simple queue definitions. */ #define SIMPLEQ_HEAD(name, type) \ struct name { \ struct type *sqh_first; /* first element */ \ struct type **sqh_last; /* addr of last next element */ \ } #define SIMPLEQ_HEAD_INITIALIZER(head) \ { NULL, &(head).sqh_first } #define SIMPLEQ_ENTRY(type) \ struct { \ struct type *sqe_next; /* next element */ \ } /* * Simple queue access methods. */ #define SIMPLEQ_FIRST(head) ((head)->sqh_first) #define SIMPLEQ_END(head) NULL #define SIMPLEQ_EMPTY(head) (SIMPLEQ_FIRST(head) == SIMPLEQ_END(head)) #define SIMPLEQ_NEXT(elm, field) ((elm)->field.sqe_next) #define SIMPLEQ_FOREACH(var, head, field) \ for((var) = SIMPLEQ_FIRST(head); \ (var) != SIMPLEQ_END(head); \ (var) = SIMPLEQ_NEXT(var, field)) /* * Simple queue functions. */ #define SIMPLEQ_INIT(head) do { \ (head)->sqh_first = NULL; \ (head)->sqh_last = &(head)->sqh_first; \ } while (0) #define SIMPLEQ_INSERT_HEAD(head, elm, field) do { \ if (((elm)->field.sqe_next = (head)->sqh_first) == NULL) \ (head)->sqh_last = &(elm)->field.sqe_next; \ (head)->sqh_first = (elm); \ } while (0) #define SIMPLEQ_INSERT_TAIL(head, elm, field) do { \ (elm)->field.sqe_next = NULL; \ *(head)->sqh_last = (elm); \ (head)->sqh_last = &(elm)->field.sqe_next; \ } while (0) #define SIMPLEQ_INSERT_AFTER(head, listelm, elm, field) do { \ if (((elm)->field.sqe_next = (listelm)->field.sqe_next) == NULL)\ (head)->sqh_last = &(elm)->field.sqe_next; \ (listelm)->field.sqe_next = (elm); \ } while (0) #define SIMPLEQ_REMOVE_HEAD(head, elm, field) do { \ if (((head)->sqh_first = (elm)->field.sqe_next) == NULL) \ (head)->sqh_last = &(head)->sqh_first; \ } while (0) /* * Tail queue definitions. */ #define TAILQ_HEAD(name, type) \ struct name { \ struct type *tqh_first; /* first element */ \ struct type **tqh_last; /* addr of last next element */ \ } #define TAILQ_HEAD_INITIALIZER(head) \ { NULL, &(head).tqh_first } #define TAILQ_ENTRY(type) \ struct { \ struct type *tqe_next; /* next element */ \ struct type **tqe_prev; /* address of previous next element */ \ } /* * tail queue access methods */ #define TAILQ_FIRST(head) ((head)->tqh_first) #define TAILQ_END(head) NULL #define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next) #define TAILQ_LAST(head, headname) \ (*(((struct headname *)((head)->tqh_last))->tqh_last)) /* XXX */ #define TAILQ_PREV(elm, headname, field) \ (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last)) #define TAILQ_EMPTY(head) \ (TAILQ_FIRST(head) == TAILQ_END(head)) #define TAILQ_FOREACH(var, head, field) \ for((var) = TAILQ_FIRST(head); \ (var) != TAILQ_END(head); \ (var) = TAILQ_NEXT(var, field)) #define TAILQ_FOREACH_REVERSE(var, head, field, headname) \ for((var) = TAILQ_LAST(head, headname); \ (var) != TAILQ_END(head); \ (var) = TAILQ_PREV(var, headname, field)) /* * Tail queue functions. */ #define TAILQ_INIT(head) do { \ (head)->tqh_first = NULL; \ (head)->tqh_last = &(head)->tqh_first; \ } while (0) #define TAILQ_INSERT_HEAD(head, elm, field) do { \ if (((elm)->field.tqe_next = (head)->tqh_first) != NULL) \ (head)->tqh_first->field.tqe_prev = \ &(elm)->field.tqe_next; \ else \ (head)->tqh_last = &(elm)->field.tqe_next; \ (head)->tqh_first = (elm); \ (elm)->field.tqe_prev = &(head)->tqh_first; \ } while (0) #define TAILQ_INSERT_TAIL(head, elm, field) do { \ (elm)->field.tqe_next = NULL; \ (elm)->field.tqe_prev = (head)->tqh_last; \ *(head)->tqh_last = (elm); \ (head)->tqh_last = &(elm)->field.tqe_next; \ } while (0) #define TAILQ_INSERT_AFTER(head, listelm, elm, field) do { \ if (((elm)->field.tqe_next = (listelm)->field.tqe_next) != NULL)\ (elm)->field.tqe_next->field.tqe_prev = \ &(elm)->field.tqe_next; \ else \ (head)->tqh_last = &(elm)->field.tqe_next; \ (listelm)->field.tqe_next = (elm); \ (elm)->field.tqe_prev = &(listelm)->field.tqe_next; \ } while (0) #define TAILQ_INSERT_BEFORE(listelm, elm, field) do { \ (elm)->field.tqe_prev = (listelm)->field.tqe_prev; \ (elm)->field.tqe_next = (listelm); \ *(listelm)->field.tqe_prev = (elm); \ (listelm)->field.tqe_prev = &(elm)->field.tqe_next; \ } while (0) #define TAILQ_REMOVE(head, elm, field) do { \ if (((elm)->field.tqe_next) != NULL) \ (elm)->field.tqe_next->field.tqe_prev = \ (elm)->field.tqe_prev; \ else \ (head)->tqh_last = (elm)->field.tqe_prev; \ *(elm)->field.tqe_prev = (elm)->field.tqe_next; \ } while (0) #define TAILQ_REPLACE(head, elm, elm2, field) do { \ if (((elm2)->field.tqe_next = (elm)->field.tqe_next) != NULL) \ (elm2)->field.tqe_next->field.tqe_prev = \ &(elm2)->field.tqe_next; \ else \ (head)->tqh_last = &(elm2)->field.tqe_next; \ (elm2)->field.tqe_prev = (elm)->field.tqe_prev; \ *(elm2)->field.tqe_prev = (elm2); \ } while (0) /* * Circular queue definitions. */ #define CIRCLEQ_HEAD(name, type) \ struct name { \ struct type *cqh_first; /* first element */ \ struct type *cqh_last; /* last element */ \ } #define CIRCLEQ_HEAD_INITIALIZER(head) \ { CIRCLEQ_END(&head), CIRCLEQ_END(&head) } #define CIRCLEQ_ENTRY(type) \ struct { \ struct type *cqe_next; /* next element */ \ struct type *cqe_prev; /* previous element */ \ } /* * Circular queue access methods */ #define CIRCLEQ_FIRST(head) ((head)->cqh_first) #define CIRCLEQ_LAST(head) ((head)->cqh_last) #define CIRCLEQ_END(head) ((void *)(head)) #define CIRCLEQ_NEXT(elm, field) ((elm)->field.cqe_next) #define CIRCLEQ_PREV(elm, field) ((elm)->field.cqe_prev) #define CIRCLEQ_EMPTY(head) \ (CIRCLEQ_FIRST(head) == CIRCLEQ_END(head)) #define CIRCLEQ_FOREACH(var, head, field) \ for((var) = CIRCLEQ_FIRST(head); \ (var) != CIRCLEQ_END(head); \ (var) = CIRCLEQ_NEXT(var, field)) #define CIRCLEQ_FOREACH_REVERSE(var, head, field) \ for((var) = CIRCLEQ_LAST(head); \ (var) != CIRCLEQ_END(head); \ (var) = CIRCLEQ_PREV(var, field)) /* * Circular queue functions. */ #define CIRCLEQ_INIT(head) do { \ (head)->cqh_first = CIRCLEQ_END(head); \ (head)->cqh_last = CIRCLEQ_END(head); \ } while (0) #define CIRCLEQ_INSERT_AFTER(head, listelm, elm, field) do { \ (elm)->field.cqe_next = (listelm)->field.cqe_next; \ (elm)->field.cqe_prev = (listelm); \ if ((listelm)->field.cqe_next == CIRCLEQ_END(head)) \ (head)->cqh_last = (elm); \ else \ (listelm)->field.cqe_next->field.cqe_prev = (elm); \ (listelm)->field.cqe_next = (elm); \ } while (0) #define CIRCLEQ_INSERT_BEFORE(head, listelm, elm, field) do { \ (elm)->field.cqe_next = (listelm); \ (elm)->field.cqe_prev = (listelm)->field.cqe_prev; \ if ((listelm)->field.cqe_prev == CIRCLEQ_END(head)) \ (head)->cqh_first = (elm); \ else \ (listelm)->field.cqe_prev->field.cqe_next = (elm); \ (listelm)->field.cqe_prev = (elm); \ } while (0) #define CIRCLEQ_INSERT_HEAD(head, elm, field) do { \ (elm)->field.cqe_next = (head)->cqh_first; \ (elm)->field.cqe_prev = CIRCLEQ_END(head); \ if ((head)->cqh_last == CIRCLEQ_END(head)) \ (head)->cqh_last = (elm); \ else \ (head)->cqh_first->field.cqe_prev = (elm); \ (head)->cqh_first = (elm); \ } while (0) #define CIRCLEQ_INSERT_TAIL(head, elm, field) do { \ (elm)->field.cqe_next = CIRCLEQ_END(head); \ (elm)->field.cqe_prev = (head)->cqh_last; \ if ((head)->cqh_first == CIRCLEQ_END(head)) \ (head)->cqh_first = (elm); \ else \ (head)->cqh_last->field.cqe_next = (elm); \ (head)->cqh_last = (elm); \ } while (0) #define CIRCLEQ_REMOVE(head, elm, field) do { \ if ((elm)->field.cqe_next == CIRCLEQ_END(head)) \ (head)->cqh_last = (elm)->field.cqe_prev; \ else \ (elm)->field.cqe_next->field.cqe_prev = \ (elm)->field.cqe_prev; \ if ((elm)->field.cqe_prev == CIRCLEQ_END(head)) \ (head)->cqh_first = (elm)->field.cqe_next; \ else \ (elm)->field.cqe_prev->field.cqe_next = \ (elm)->field.cqe_next; \ } while (0) #define CIRCLEQ_REPLACE(head, elm, elm2, field) do { \ if (((elm2)->field.cqe_next = (elm)->field.cqe_next) == \ CIRCLEQ_END(head)) \ (head).cqh_last = (elm2); \ else \ (elm2)->field.cqe_next->field.cqe_prev = (elm2); \ if (((elm2)->field.cqe_prev = (elm)->field.cqe_prev) == \ CIRCLEQ_END(head)) \ (head).cqh_first = (elm2); \ else \ (elm2)->field.cqe_prev->field.cqe_next = (elm2); \ } while (0) #endif /* !_SYS_QUEUE_H_ */