minix/lib/libc/include/isc/list.h

121 lines
3.6 KiB
C
Raw Normal View History

/* $NetBSD: list.h,v 1.5 2009/04/12 17:07:16 christos Exp $ */
/*
* Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
* Copyright (c) 1997,1999 by Internet Software Consortium.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
* OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#ifndef LIST_H
#define LIST_H 1
#include <isc/assertions.h>
#define LIST(type) struct { type *head, *tail; }
#define INIT_LIST(list) \
do { (list).head = NULL; (list).tail = NULL; } while (/*CONSTCOND*/0)
#define LINK(type) struct { type *prev, *next; }
#define INIT_LINK_TYPE(elt, link, type) \
do { \
(elt)->link.prev = (type *)(-1); \
(elt)->link.next = (type *)(-1); \
} while (/*CONSTCOND*/0)
#define INIT_LINK(elt, link) \
INIT_LINK_TYPE(elt, link, void)
#define LINKED(elt, link) ((void *)((elt)->link.prev) != (void *)(-1) && \
(void *)((elt)->link.next) != (void *)(-1))
#define HEAD(list) ((list).head)
#define TAIL(list) ((list).tail)
#define EMPTY(list) ((list).head == NULL)
#define PREPEND(list, elt, link) \
do { \
INSIST(!LINKED(elt, link));\
if ((list).head != NULL) \
(list).head->link.prev = (elt); \
else \
(list).tail = (elt); \
(elt)->link.prev = NULL; \
(elt)->link.next = (list).head; \
(list).head = (elt); \
} while (/*CONSTCOND*/0)
#define APPEND(list, elt, link) \
do { \
INSIST(!LINKED(elt, link));\
if ((list).tail != NULL) \
(list).tail->link.next = (elt); \
else \
(list).head = (elt); \
(elt)->link.prev = (list).tail; \
(elt)->link.next = NULL; \
(list).tail = (elt); \
} while (/*CONSTCOND*/0)
#define UNLINK_TYPE(list, elt, link, type) \
do { \
INSIST(LINKED(elt, link));\
if ((elt)->link.next != NULL) \
(elt)->link.next->link.prev = (elt)->link.prev; \
else { \
INSIST((list).tail == (elt)); \
(list).tail = (elt)->link.prev; \
} \
if ((elt)->link.prev != NULL) \
(elt)->link.prev->link.next = (elt)->link.next; \
else { \
INSIST((list).head == (elt)); \
(list).head = (elt)->link.next; \
} \
INIT_LINK_TYPE(elt, link, type); \
} while (/*CONSTCOND*/0)
#define UNLINK(list, elt, link) \
UNLINK_TYPE(list, elt, link, void)
#define PREV(elt, link) ((elt)->link.prev)
#define NEXT(elt, link) ((elt)->link.next)
#define INSERT_BEFORE(list, before, elt, link) \
do { \
INSIST(!LINKED(elt, link));\
if ((before)->link.prev == NULL) \
PREPEND(list, elt, link); \
else { \
(elt)->link.prev = (before)->link.prev; \
(before)->link.prev = (elt); \
(elt)->link.prev->link.next = (elt); \
(elt)->link.next = (before); \
} \
} while (/*CONSTCOND*/0)
#define INSERT_AFTER(list, after, elt, link) \
do { \
INSIST(!LINKED(elt, link));\
if ((after)->link.next == NULL) \
APPEND(list, elt, link); \
else { \
(elt)->link.next = (after)->link.next; \
(after)->link.next = (elt); \
(elt)->link.next->link.prev = (elt); \
(elt)->link.prev = (after); \
} \
} while (/*CONSTCOND*/0)
#define ENQUEUE(list, elt, link) APPEND(list, elt, link)
#define DEQUEUE(list, elt, link) UNLINK(list, elt, link)
#endif /* LIST_H */
/*! \file */