[gssapi-openssh.git] / openssh / openbsd-compat / sys-queue.h

/* OPENBSD ORIGINAL: sys/sys/queue.h */

/*	$OpenBSD: queue.h,v 1.23 2003/06/02 23:28:21 millert 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	_FAKE_QUEUE_H_
#define	_FAKE_QUEUE_H_

/*
 * Ignore all <sys/queue.h> since older platforms have broken/incomplete
 * <sys/queue.h> that are too hard to work around.
 */
#undef SLIST_HEAD
#undef SLIST_HEAD_INITIALIZER
#undef SLIST_ENTRY
#undef SLIST_FIRST
#undef SLIST_END
#undef SLIST_EMPTY
#undef SLIST_NEXT
#undef SLIST_FOREACH
#undef SLIST_INIT
#undef SLIST_INSERT_AFTER
#undef SLIST_INSERT_HEAD
#undef SLIST_REMOVE_HEAD
#undef SLIST_REMOVE
#undef LIST_HEAD
#undef LIST_HEAD_INITIALIZER
#undef LIST_ENTRY
#undef LIST_FIRST
#undef LIST_END
#undef LIST_EMPTY
#undef LIST_NEXT
#undef LIST_FOREACH
#undef LIST_INIT
#undef LIST_INSERT_AFTER
#undef LIST_INSERT_BEFORE
#undef LIST_INSERT_HEAD
#undef LIST_REMOVE
#undef LIST_REPLACE
#undef SIMPLEQ_HEAD
#undef SIMPLEQ_HEAD_INITIALIZER
#undef SIMPLEQ_ENTRY
#undef SIMPLEQ_FIRST
#undef SIMPLEQ_END
#undef SIMPLEQ_EMPTY
#undef SIMPLEQ_NEXT
#undef SIMPLEQ_FOREACH
#undef SIMPLEQ_INIT
#undef SIMPLEQ_INSERT_HEAD
#undef SIMPLEQ_INSERT_TAIL
#undef SIMPLEQ_INSERT_AFTER
#undef SIMPLEQ_REMOVE_HEAD
#undef TAILQ_HEAD
#undef TAILQ_HEAD_INITIALIZER
#undef TAILQ_ENTRY
#undef TAILQ_FIRST
#undef TAILQ_END
#undef TAILQ_NEXT
#undef TAILQ_LAST
#undef TAILQ_PREV
#undef TAILQ_EMPTY
#undef TAILQ_FOREACH
#undef TAILQ_FOREACH_REVERSE
#undef TAILQ_INIT
#undef TAILQ_INSERT_HEAD
#undef TAILQ_INSERT_TAIL
#undef TAILQ_INSERT_AFTER
#undef TAILQ_INSERT_BEFORE
#undef TAILQ_REMOVE
#undef TAILQ_REPLACE
#undef CIRCLEQ_HEAD
#undef CIRCLEQ_HEAD_INITIALIZER
#undef CIRCLEQ_ENTRY
#undef CIRCLEQ_FIRST
#undef CIRCLEQ_LAST
#undef CIRCLEQ_END
#undef CIRCLEQ_NEXT
#undef CIRCLEQ_PREV
#undef CIRCLEQ_EMPTY
#undef CIRCLEQ_FOREACH
#undef CIRCLEQ_FOREACH_REVERSE
#undef CIRCLEQ_INIT
#undef CIRCLEQ_INSERT_AFTER
#undef CIRCLEQ_INSERT_BEFORE
#undef CIRCLEQ_INSERT_HEAD
#undef CIRCLEQ_INSERT_TAIL
#undef CIRCLEQ_REMOVE
#undef CIRCLEQ_REPLACE

/*
 * 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	/* !_FAKE_QUEUE_H_ */
Commit	Line	Data
cdd66111	1	/* OPENBSD ORIGINAL: sys/sys/queue.h */
cdd66111	2
0fff78ff	3	/* $OpenBSD: queue.h,v 1.23 2003/06/02 23:28:21 millert Exp $ */
41b2f314	4	/* $NetBSD: queue.h,v 1.11 1996/05/16 05:17:14 mycroft Exp $ */
	5
	6	/*
	7	* Copyright (c) 1991, 1993
	8	* The Regents of the University of California. All rights reserved.
	9	*
	10	* Redistribution and use in source and binary forms, with or without
	11	* modification, are permitted provided that the following conditions
	12	* are met:
	13	* 1. Redistributions of source code must retain the above copyright
	14	* notice, this list of conditions and the following disclaimer.
	15	* 2. Redistributions in binary form must reproduce the above copyright
	16	* notice, this list of conditions and the following disclaimer in the
	17	* documentation and/or other materials provided with the distribution.
0fff78ff	18	* 3. Neither the name of the University nor the names of its contributors
41b2f314	19	* may be used to endorse or promote products derived from this software
	20	* without specific prior written permission.
	21	*
	22	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	23	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	24	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	25	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	26	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	27	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	28	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	29	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	30	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	31	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	32	* SUCH DAMAGE.
	33	*
	34	* @(#)queue.h 8.5 (Berkeley) 8/20/94
	35	*/
	36
	37	#ifndef _FAKE_QUEUE_H_
	38	#define _FAKE_QUEUE_H_
	39
	40	/*
	41	* Ignore all <sys/queue.h> since older platforms have broken/incomplete
	42	* <sys/queue.h> that are too hard to work around.
	43	*/
	44	#undef SLIST_HEAD
	45	#undef SLIST_HEAD_INITIALIZER
	46	#undef SLIST_ENTRY
	47	#undef SLIST_FIRST
	48	#undef SLIST_END
	49	#undef SLIST_EMPTY
	50	#undef SLIST_NEXT
	51	#undef SLIST_FOREACH
	52	#undef SLIST_INIT
	53	#undef SLIST_INSERT_AFTER
	54	#undef SLIST_INSERT_HEAD
	55	#undef SLIST_REMOVE_HEAD
	56	#undef SLIST_REMOVE
	57	#undef LIST_HEAD
	58	#undef LIST_HEAD_INITIALIZER
	59	#undef LIST_ENTRY
	60	#undef LIST_FIRST
	61	#undef LIST_END
	62	#undef LIST_EMPTY
	63	#undef LIST_NEXT
	64	#undef LIST_FOREACH
	65	#undef LIST_INIT
	66	#undef LIST_INSERT_AFTER
	67	#undef LIST_INSERT_BEFORE
	68	#undef LIST_INSERT_HEAD
	69	#undef LIST_REMOVE
	70	#undef LIST_REPLACE
	71	#undef SIMPLEQ_HEAD
	72	#undef SIMPLEQ_HEAD_INITIALIZER
	73	#undef SIMPLEQ_ENTRY
	74	#undef SIMPLEQ_FIRST
	75	#undef SIMPLEQ_END
	76	#undef SIMPLEQ_EMPTY
	77	#undef SIMPLEQ_NEXT
	78	#undef SIMPLEQ_FOREACH
	79	#undef SIMPLEQ_INIT
	80	#undef SIMPLEQ_INSERT_HEAD
	81	#undef SIMPLEQ_INSERT_TAIL
	82	#undef SIMPLEQ_INSERT_AFTER
83	#undef SIMPLEQ_REMOVE_HEAD
84	#undef TAILQ_HEAD
85	#undef TAILQ_HEAD_INITIALIZER
86	#undef TAILQ_ENTRY
87	#undef TAILQ_FIRST
88	#undef TAILQ_END
89	#undef TAILQ_NEXT
90	#undef TAILQ_LAST
91	#undef TAILQ_PREV
92	#undef TAILQ_EMPTY
93	#undef TAILQ_FOREACH
94	#undef TAILQ_FOREACH_REVERSE
95	#undef TAILQ_INIT
96	#undef TAILQ_INSERT_HEAD
97	#undef TAILQ_INSERT_TAIL
98	#undef TAILQ_INSERT_AFTER
99	#undef TAILQ_INSERT_BEFORE
100	#undef TAILQ_REMOVE
101	#undef TAILQ_REPLACE
102	#undef CIRCLEQ_HEAD
103	#undef CIRCLEQ_HEAD_INITIALIZER
104	#undef CIRCLEQ_ENTRY
105	#undef CIRCLEQ_FIRST
106	#undef CIRCLEQ_LAST
107	#undef CIRCLEQ_END
108	#undef CIRCLEQ_NEXT
109	#undef CIRCLEQ_PREV
110	#undef CIRCLEQ_EMPTY
111	#undef CIRCLEQ_FOREACH
112	#undef CIRCLEQ_FOREACH_REVERSE
113	#undef CIRCLEQ_INIT
114	#undef CIRCLEQ_INSERT_AFTER
115	#undef CIRCLEQ_INSERT_BEFORE
116	#undef CIRCLEQ_INSERT_HEAD
117	#undef CIRCLEQ_INSERT_TAIL
118	#undef CIRCLEQ_REMOVE
119	#undef CIRCLEQ_REPLACE
120
121	/*
122	* This file defines five types of data structures: singly-linked lists,
123	* lists, simple queues, tail queues, and circular queues.
124	*
125	*
126	* A singly-linked list is headed by a single forward pointer. The elements
127	* are singly linked for minimum space and pointer manipulation overhead at
128	* the expense of O(n) removal for arbitrary elements. New elements can be
129	* added to the list after an existing element or at the head of the list.
130	* Elements being removed from the head of the list should use the explicit
131	* macro for this purpose for optimum efficiency. A singly-linked list may
132	* only be traversed in the forward direction. Singly-linked lists are ideal
133	* for applications with large datasets and few or no removals or for
134	* implementing a LIFO queue.
135	*
136	* A list is headed by a single forward pointer (or an array of forward
137	* pointers for a hash table header). The elements are doubly linked
138	* so that an arbitrary element can be removed without a need to
139	* traverse the list. New elements can be added to the list before
140	* or after an existing element or at the head of the list. A list
141	* may only be traversed in the forward direction.
142	*
143	* A simple queue is headed by a pair of pointers, one the head of the
144	* list and the other to the tail of the list. The elements are singly
145	* linked to save space, so elements can only be removed from the
146	* head of the list. New elements can be added to the list before or after
147	* an existing element, at the head of the list, or at the end of the
148	* list. A simple queue may only be traversed in the forward direction.
149	*
150	* A tail queue is headed by a pair of pointers, one to the head of the
151	* list and the other to the tail of the list. The elements are doubly
152	* linked so that an arbitrary element can be removed without a need to
153	* traverse the list. New elements can be added to the list before or
154	* after an existing element, at the head of the list, or at the end of
155	* the list. A tail queue may be traversed in either direction.
156	*
157	* A circle queue is headed by a pair of pointers, one to the head of the
158	* list and the other to the tail of the list. The elements are doubly
159	* linked so that an arbitrary element can be removed without a need to
160	* traverse the list. New elements can be added to the list before or after
161	* an existing element, at the head of the list, or at the end of the list.
162	* A circle queue may be traversed in either direction, but has a more
163	* complex end of list detection.
164	*
165	* For details on the use of these macros, see the queue(3) manual page.
166	*/
167
168	/*
169	* Singly-linked List definitions.
170	*/
171	#define SLIST_HEAD(name, type) \
172	struct name { \
173	struct type slh_first; / first element */ \
174	}
175
176	#define SLIST_HEAD_INITIALIZER(head) \
177	{ NULL }
178
179	#define SLIST_ENTRY(type) \
180	struct { \
181	struct type sle_next; / next element */ \
182	}
183
184	/*
185	* Singly-linked List access methods.
186	*/
187	#define SLIST_FIRST(head) ((head)->slh_first)
188	#define SLIST_END(head) NULL
189	#define SLIST_EMPTY(head) (SLIST_FIRST(head) == SLIST_END(head))
190	#define SLIST_NEXT(elm, field) ((elm)->field.sle_next)
191
192	#define SLIST_FOREACH(var, head, field) \
193	for((var) = SLIST_FIRST(head); \
194	(var) != SLIST_END(head); \
195	(var) = SLIST_NEXT(var, field))
196
197	/*
198	* Singly-linked List functions.
199	*/
200	#define SLIST_INIT(head) { \
201	SLIST_FIRST(head) = SLIST_END(head); \
202	}
203
204	#define SLIST_INSERT_AFTER(slistelm, elm, field) do { \
205	(elm)->field.sle_next = (slistelm)->field.sle_next; \
206	(slistelm)->field.sle_next = (elm); \
207	} while (0)
208
209	#define SLIST_INSERT_HEAD(head, elm, field) do { \
210	(elm)->field.sle_next = (head)->slh_first; \
211	(head)->slh_first = (elm); \
212	} while (0)
213
214	#define SLIST_REMOVE_HEAD(head, field) do { \
215	(head)->slh_first = (head)->slh_first->field.sle_next; \
216	} while (0)
217
218	#define SLIST_REMOVE(head, elm, type, field) do { \
219	if ((head)->slh_first == (elm)) { \
220	SLIST_REMOVE_HEAD((head), field); \
221	} \
222	else { \
223	struct type *curelm = (head)->slh_first; \
224	while( curelm->field.sle_next != (elm) ) \
225	curelm = curelm->field.sle_next; \
226	curelm->field.sle_next = \
227	curelm->field.sle_next->field.sle_next; \
228	} \
229	} while (0)
230
231	/*
232	* List definitions.
233	*/
234	#define LIST_HEAD(name, type) \
235	struct name { \
236	struct type lh_first; / first element */ \
237	}
238
239	#define LIST_HEAD_INITIALIZER(head) \
240	{ NULL }
241
242	#define LIST_ENTRY(type) \
243	struct { \
244	struct type le_next; / next element */ \
245	struct type *le_prev; / address of previous next element */ \
246	}
247
248	/*
249	* List access methods
250	*/
251	#define LIST_FIRST(head) ((head)->lh_first)
252	#define LIST_END(head) NULL
253	#define LIST_EMPTY(head) (LIST_FIRST(head) == LIST_END(head))
254	#define LIST_NEXT(elm, field) ((elm)->field.le_next)
255
256	#define LIST_FOREACH(var, head, field) \
257	for((var) = LIST_FIRST(head); \
258	(var)!= LIST_END(head); \
259	(var) = LIST_NEXT(var, field))
260
261	/*
262	* List functions.
263	*/
264	#define LIST_INIT(head) do { \
265	LIST_FIRST(head) = LIST_END(head); \
266	} while (0)
267
268	#define LIST_INSERT_AFTER(listelm, elm, field) do { \
269	if (((elm)->field.le_next = (listelm)->field.le_next) != NULL) \
270	(listelm)->field.le_next->field.le_prev = \
271	&(elm)->field.le_next; \
272	(listelm)->field.le_next = (elm); \
273	(elm)->field.le_prev = &(listelm)->field.le_next; \
274	} while (0)
275
276	#define LIST_INSERT_BEFORE(listelm, elm, field) do { \
277	(elm)->field.le_prev = (listelm)->field.le_prev; \
278	(elm)->field.le_next = (listelm); \
279	*(listelm)->field.le_prev = (elm); \
280	(listelm)->field.le_prev = &(elm)->field.le_next; \
281	} while (0)
282
283	#define LIST_INSERT_HEAD(head, elm, field) do { \
284	if (((elm)->field.le_next = (head)->lh_first) != NULL) \
285	(head)->lh_first->field.le_prev = &(elm)->field.le_next;\
286	(head)->lh_first = (elm); \
287	(elm)->field.le_prev = &(head)->lh_first; \
288	} while (0)
289
290	#define LIST_REMOVE(elm, field) do { \
291	if ((elm)->field.le_next != NULL) \
292	(elm)->field.le_next->field.le_prev = \
293	(elm)->field.le_prev; \
294	*(elm)->field.le_prev = (elm)->field.le_next; \
295	} while (0)
296
297	#define LIST_REPLACE(elm, elm2, field) do { \
298	if (((elm2)->field.le_next = (elm)->field.le_next) != NULL) \
299	(elm2)->field.le_next->field.le_prev = \
300	&(elm2)->field.le_next; \
301	(elm2)->field.le_prev = (elm)->field.le_prev; \
302	*(elm2)->field.le_prev = (elm2); \
303	} while (0)
304
305	/*
306	* Simple queue definitions.
307	*/
308	#define SIMPLEQ_HEAD(name, type) \
309	struct name { \
310	struct type sqh_first; / first element */ \
311	struct type *sqh_last; / addr of last next element */ \
312	}
313
314	#define SIMPLEQ_HEAD_INITIALIZER(head) \
315	{ NULL, &(head).sqh_first }
316
317	#define SIMPLEQ_ENTRY(type) \
318	struct { \
319	struct type sqe_next; / next element */ \
320	}
321
322	/*
323	* Simple queue access methods.
324	*/
325	#define SIMPLEQ_FIRST(head) ((head)->sqh_first)
326	#define SIMPLEQ_END(head) NULL
327	#define SIMPLEQ_EMPTY(head) (SIMPLEQ_FIRST(head) == SIMPLEQ_END(head))
328	#define SIMPLEQ_NEXT(elm, field) ((elm)->field.sqe_next)
329
330	#define SIMPLEQ_FOREACH(var, head, field) \
331	for((var) = SIMPLEQ_FIRST(head); \
332	(var) != SIMPLEQ_END(head); \
333	(var) = SIMPLEQ_NEXT(var, field))
334
335	/*
336	* Simple queue functions.
337	*/
338	#define SIMPLEQ_INIT(head) do { \
339	(head)->sqh_first = NULL; \
340	(head)->sqh_last = &(head)->sqh_first; \
341	} while (0)
342
343	#define SIMPLEQ_INSERT_HEAD(head, elm, field) do { \
344	if (((elm)->field.sqe_next = (head)->sqh_first) == NULL) \
345	(head)->sqh_last = &(elm)->field.sqe_next; \
346	(head)->sqh_first = (elm); \
347	} while (0)
348
349	#define SIMPLEQ_INSERT_TAIL(head, elm, field) do { \
350	(elm)->field.sqe_next = NULL; \
351	*(head)->sqh_last = (elm); \
352	(head)->sqh_last = &(elm)->field.sqe_next; \
353	} while (0)
354
355	#define SIMPLEQ_INSERT_AFTER(head, listelm, elm, field) do { \
356	if (((elm)->field.sqe_next = (listelm)->field.sqe_next) == NULL)\
357	(head)->sqh_last = &(elm)->field.sqe_next; \
358	(listelm)->field.sqe_next = (elm); \
359	} while (0)
360
361	#define SIMPLEQ_REMOVE_HEAD(head, elm, field) do { \
362	if (((head)->sqh_first = (elm)->field.sqe_next) == NULL) \
363	(head)->sqh_last = &(head)->sqh_first; \
364	} while (0)
365
366	/*
367	* Tail queue definitions.
368	*/
369	#define TAILQ_HEAD(name, type) \
370	struct name { \
371	struct type tqh_first; / first element */ \
372	struct type *tqh_last; / addr of last next element */ \
373	}
374
375	#define TAILQ_HEAD_INITIALIZER(head) \
376	{ NULL, &(head).tqh_first }
377
378	#define TAILQ_ENTRY(type) \
379	struct { \
380	struct type tqe_next; / next element */ \
381	struct type *tqe_prev; / address of previous next element */ \
382	}
383
384	/*
385	* tail queue access methods
386	*/
387	#define TAILQ_FIRST(head) ((head)->tqh_first)
388	#define TAILQ_END(head) NULL
389	#define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next)
390	#define TAILQ_LAST(head, headname) \
391	((((struct headname )((head)->tqh_last))->tqh_last))
392	/* XXX */
393	#define TAILQ_PREV(elm, headname, field) \
394	((((struct headname )((elm)->field.tqe_prev))->tqh_last))
395	#define TAILQ_EMPTY(head) \
396	(TAILQ_FIRST(head) == TAILQ_END(head))
397
398	#define TAILQ_FOREACH(var, head, field) \
399	for((var) = TAILQ_FIRST(head); \
400	(var) != TAILQ_END(head); \
401	(var) = TAILQ_NEXT(var, field))
402
403	#define TAILQ_FOREACH_REVERSE(var, head, field, headname) \
404	for((var) = TAILQ_LAST(head, headname); \
405	(var) != TAILQ_END(head); \
406	(var) = TAILQ_PREV(var, headname, field))
407
408	/*
409	* Tail queue functions.
410	*/
411	#define TAILQ_INIT(head) do { \
412	(head)->tqh_first = NULL; \
413	(head)->tqh_last = &(head)->tqh_first; \
414	} while (0)
415
416	#define TAILQ_INSERT_HEAD(head, elm, field) do { \
417	if (((elm)->field.tqe_next = (head)->tqh_first) != NULL) \
418	(head)->tqh_first->field.tqe_prev = \
419	&(elm)->field.tqe_next; \
420	else \
421	(head)->tqh_last = &(elm)->field.tqe_next; \
422	(head)->tqh_first = (elm); \
423	(elm)->field.tqe_prev = &(head)->tqh_first; \
424	} while (0)
425
426	#define TAILQ_INSERT_TAIL(head, elm, field) do { \
427	(elm)->field.tqe_next = NULL; \
428	(elm)->field.tqe_prev = (head)->tqh_last; \
429	*(head)->tqh_last = (elm); \
430	(head)->tqh_last = &(elm)->field.tqe_next; \
431	} while (0)
432
433	#define TAILQ_INSERT_AFTER(head, listelm, elm, field) do { \
434	if (((elm)->field.tqe_next = (listelm)->field.tqe_next) != NULL)\
435	(elm)->field.tqe_next->field.tqe_prev = \
436	&(elm)->field.tqe_next; \
437	else \
438	(head)->tqh_last = &(elm)->field.tqe_next; \
439	(listelm)->field.tqe_next = (elm); \
440	(elm)->field.tqe_prev = &(listelm)->field.tqe_next; \
441	} while (0)
442
443	#define TAILQ_INSERT_BEFORE(listelm, elm, field) do { \
444	(elm)->field.tqe_prev = (listelm)->field.tqe_prev; \
445	(elm)->field.tqe_next = (listelm); \
446	*(listelm)->field.tqe_prev = (elm); \
447	(listelm)->field.tqe_prev = &(elm)->field.tqe_next; \
448	} while (0)
449
450	#define TAILQ_REMOVE(head, elm, field) do { \
451	if (((elm)->field.tqe_next) != NULL) \
452	(elm)->field.tqe_next->field.tqe_prev = \
453	(elm)->field.tqe_prev; \
454	else \
455	(head)->tqh_last = (elm)->field.tqe_prev; \
456	*(elm)->field.tqe_prev = (elm)->field.tqe_next; \
457	} while (0)
458
459	#define TAILQ_REPLACE(head, elm, elm2, field) do { \
460	if (((elm2)->field.tqe_next = (elm)->field.tqe_next) != NULL) \
461	(elm2)->field.tqe_next->field.tqe_prev = \
462	&(elm2)->field.tqe_next; \
463	else \
464	(head)->tqh_last = &(elm2)->field.tqe_next; \
465	(elm2)->field.tqe_prev = (elm)->field.tqe_prev; \
466	*(elm2)->field.tqe_prev = (elm2); \
467	} while (0)
468
469	/*
470	* Circular queue definitions.
471	*/
472	#define CIRCLEQ_HEAD(name, type) \
473	struct name { \
474	struct type cqh_first; / first element */ \
475	struct type cqh_last; / last element */ \
476	}
477
478	#define CIRCLEQ_HEAD_INITIALIZER(head) \
479	{ CIRCLEQ_END(&head), CIRCLEQ_END(&head) }
480
481	#define CIRCLEQ_ENTRY(type) \
482	struct { \
483	struct type cqe_next; / next element */ \
484	struct type cqe_prev; / previous element */ \
485	}
486
487	/*
488	* Circular queue access methods
489	*/
490	#define CIRCLEQ_FIRST(head) ((head)->cqh_first)
491	#define CIRCLEQ_LAST(head) ((head)->cqh_last)
492	#define CIRCLEQ_END(head) ((void *)(head))
493	#define CIRCLEQ_NEXT(elm, field) ((elm)->field.cqe_next)
494	#define CIRCLEQ_PREV(elm, field) ((elm)->field.cqe_prev)
495	#define CIRCLEQ_EMPTY(head) \
496	(CIRCLEQ_FIRST(head) == CIRCLEQ_END(head))
497
498	#define CIRCLEQ_FOREACH(var, head, field) \
499	for((var) = CIRCLEQ_FIRST(head); \
500	(var) != CIRCLEQ_END(head); \
501	(var) = CIRCLEQ_NEXT(var, field))
502
503	#define CIRCLEQ_FOREACH_REVERSE(var, head, field) \
504	for((var) = CIRCLEQ_LAST(head); \
505	(var) != CIRCLEQ_END(head); \
506	(var) = CIRCLEQ_PREV(var, field))
507
508	/*
509	* Circular queue functions.
510	*/
511	#define CIRCLEQ_INIT(head) do { \
512	(head)->cqh_first = CIRCLEQ_END(head); \
513	(head)->cqh_last = CIRCLEQ_END(head); \
514	} while (0)
515
516	#define CIRCLEQ_INSERT_AFTER(head, listelm, elm, field) do { \
517	(elm)->field.cqe_next = (listelm)->field.cqe_next; \
518	(elm)->field.cqe_prev = (listelm); \
519	if ((listelm)->field.cqe_next == CIRCLEQ_END(head)) \
520	(head)->cqh_last = (elm); \
521	else \
522	(listelm)->field.cqe_next->field.cqe_prev = (elm); \
523	(listelm)->field.cqe_next = (elm); \
524	} while (0)
525
526	#define CIRCLEQ_INSERT_BEFORE(head, listelm, elm, field) do { \
527	(elm)->field.cqe_next = (listelm); \
528	(elm)->field.cqe_prev = (listelm)->field.cqe_prev; \
529	if ((listelm)->field.cqe_prev == CIRCLEQ_END(head)) \
530	(head)->cqh_first = (elm); \
531	else \
532	(listelm)->field.cqe_prev->field.cqe_next = (elm); \
533	(listelm)->field.cqe_prev = (elm); \
534	} while (0)
535
536	#define CIRCLEQ_INSERT_HEAD(head, elm, field) do { \
537	(elm)->field.cqe_next = (head)->cqh_first; \
538	(elm)->field.cqe_prev = CIRCLEQ_END(head); \
539	if ((head)->cqh_last == CIRCLEQ_END(head)) \
540	(head)->cqh_last = (elm); \
541	else \
542	(head)->cqh_first->field.cqe_prev = (elm); \
543	(head)->cqh_first = (elm); \
544	} while (0)
545
546	#define CIRCLEQ_INSERT_TAIL(head, elm, field) do { \
547	(elm)->field.cqe_next = CIRCLEQ_END(head); \
548	(elm)->field.cqe_prev = (head)->cqh_last; \
549	if ((head)->cqh_first == CIRCLEQ_END(head)) \
550	(head)->cqh_first = (elm); \
551	else \
552	(head)->cqh_last->field.cqe_next = (elm); \
553	(head)->cqh_last = (elm); \
554	} while (0)
555
556	#define CIRCLEQ_REMOVE(head, elm, field) do { \
557	if ((elm)->field.cqe_next == CIRCLEQ_END(head)) \
558	(head)->cqh_last = (elm)->field.cqe_prev; \
559	else \
560	(elm)->field.cqe_next->field.cqe_prev = \
561	(elm)->field.cqe_prev; \
562	if ((elm)->field.cqe_prev == CIRCLEQ_END(head)) \
563	(head)->cqh_first = (elm)->field.cqe_next; \
564	else \
565	(elm)->field.cqe_prev->field.cqe_next = \
566	(elm)->field.cqe_next; \
567	} while (0)
568
569	#define CIRCLEQ_REPLACE(head, elm, elm2, field) do { \
570	if (((elm2)->field.cqe_next = (elm)->field.cqe_next) == \
571	CIRCLEQ_END(head)) \
572	(head).cqh_last = (elm2); \
573	else \
574	(elm2)->field.cqe_next->field.cqe_prev = (elm2); \
575	if (((elm2)->field.cqe_prev = (elm)->field.cqe_prev) == \
576	CIRCLEQ_END(head)) \
577	(head).cqh_first = (elm2); \
578	else \
579	(elm2)->field.cqe_prev->field.cqe_next = (elm2); \
580	} while (0)
581
582	#endif /* !_FAKE_QUEUE_H_ */