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Diffstat (limited to 'contrib/sendmail/include/sm/tailq.h')
| -rw-r--r-- | contrib/sendmail/include/sm/tailq.h | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/contrib/sendmail/include/sm/tailq.h b/contrib/sendmail/include/sm/tailq.h new file mode 100644 index 000000000000..b49466eae301 --- /dev/null +++ b/contrib/sendmail/include/sm/tailq.h @@ -0,0 +1,157 @@ +/* $OpenBSD: queue.h,v 1.30 2005/10/25 06:37:47 otto 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. 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 SM_TAILQ_H_ +#define SM_TAILQ_H_ + +/* + * $Id: tailq.h,v 1.3 2012-01-21 00:12:14 ashish Exp $ + * + * This file is a modified copy of queue.h from a BSD system: + * we only need tail queues here. + * We do not use queue.h directly because there is a conflict with + * some versions of that file on some OSs. + * + * 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. + */ + +/* + * Tail queue definitions. + */ +#define SM_TAILQ_HEAD(name, type) \ +struct name { \ + struct type *tqh_first; /* first element */ \ + struct type **tqh_last; /* addr of last next element */ \ +} + +#define SM_TAILQ_HEAD_INITIALIZER(head) \ + { NULL, &(head).tqh_first } + +#define SM_TAILQ_ENTRY(type) \ +struct { \ + struct type *tqe_next; /* next element */ \ + struct type **tqe_prev; /* address of previous next element */ \ +} + +/* + * tail queue access methods + */ +#define SM_TAILQ_FIRST(head) ((head)->tqh_first) +#define SM_TAILQ_END(head) NULL +#define SM_TAILQ_NEXT(elm, field) ((elm)->field.tqe_next) +#define SM_TAILQ_LAST(head, headname) \ + (*(((struct headname *)((head)->tqh_last))->tqh_last)) +/* XXX */ +#define SM_TAILQ_PREV(elm, headname, field) \ + (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last)) +#define SM_TAILQ_EMPTY(head) \ + (SM_TAILQ_FIRST(head) == SM_TAILQ_END(head)) + +#define SM_TAILQ_FOREACH(var, head, field) \ + for((var) = SM_TAILQ_FIRST(head); \ + (var) != SM_TAILQ_END(head); \ + (var) = SM_TAILQ_NEXT(var, field)) + +#define SM_TAILQ_FOREACH_REVERSE(var, head, headname, field) \ + for((var) = SM_TAILQ_LAST(head, headname); \ + (var) != SM_TAILQ_END(head); \ + (var) = SM_TAILQ_PREV(var, headname, field)) + +/* + * Tail queue functions. + */ +#define SM_TAILQ_INIT(head) do { \ + (head)->tqh_first = NULL; \ + (head)->tqh_last = &(head)->tqh_first; \ +} while (0) + +#define SM_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 SM_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 SM_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 SM_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 SM_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 SM_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) + +#endif /* !SM_TAILQ_H_ */ |