/* * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC") * Copyright (c) 1997-2003 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. * *   Internet Systems Consortium, Inc. *   950 Charter Street *   Redwood City, CA 94063 *   <info@isc.org> *   http://www.isc.org/ */#ifndef ISC_LIST_H#define ISC_LIST_H 1#define ISC_LIST(type) struct { type *head, *tail; }#define ISC_LIST_INIT(list) \	do { (list).head = NULL; (list).tail = NULL; } while (0)#define ISC_LINK(type) struct { type *prev, *next; }#define ISC_LINK_INIT(elt, link) \	do { \		(elt)->link.prev = (void *)(-1); \		(elt)->link.next = (void *)(-1); \	} while (0)#define ISC_LINK_LINKED(elt, link) ((elt)->link.prev != (void *)(-1))#define ISC_LIST_HEAD(list) ((list).head)#define ISC_LIST_TAIL(list) ((list).tail)#define ISC_LIST_EMPTY(list) ((list).head == NULL)#define ISC_LIST_PREPEND(list, elt, link) \	do { \		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 (0)#define ISC_LIST_APPEND(list, elt, link) \	do { \		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 (0)#define ISC_LIST_UNLINK(list, elt, link) \	do { \		if ((elt)->link.next != NULL) \			(elt)->link.next->link.prev = (elt)->link.prev; \		else \			(list).tail = (elt)->link.prev; \		if ((elt)->link.prev != NULL) \			(elt)->link.prev->link.next = (elt)->link.next; \		else \			(list).head = (elt)->link.next; \		(elt)->link.prev = (void *)(-1); \		(elt)->link.next = (void *)(-1); \	} while (0)#define ISC_LIST_PREV(elt, link) ((elt)->link.prev)#define ISC_LIST_NEXT(elt, link) ((elt)->link.next)#define ISC_LIST_INSERTBEFORE(list, before, elt, link) \	do { \		if ((before)->link.prev == NULL) \			ISC_LIST_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 (0)#define ISC_LIST_INSERTAFTER(list, after, elt, link) \	do { \		if ((after)->link.next == NULL) \			ISC_LIST_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 (0)#define ISC_LIST_APPENDLIST(list1, list2, link) \	do { \		if (ISC_LIST_EMPTY(list1)) \			(list1) = (list2); \		else if (!ISC_LIST_EMPTY(list2)) { \			(list1).tail->link.next = (list2).head; \			(list2).head->link.prev = (list1).tail; \			(list1).tail = (list2).tail; \			(list2).head = NULL; \			(list2).tail = NULL; \		} \	} while (0)#define ISC_LIST_ENQUEUE(list, elt, link) ISC_LIST_APPEND(list, elt, link)#define ISC_LIST_DEQUEUE(list, elt, link) ISC_LIST_UNLINK(list, elt, link)#endif /* ISC_LIST_H */