1/*	$NetBSD: queue.h,v 1.38 2004/04/18 14:12:05 lukem Exp $	*/
2/*	$Id$ */
3
4/*
5 * Copyright (c) 1991, 1993
6 *	The Regents of the University of California.  All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the University nor the names of its contributors
17 *    may be used to endorse or promote products derived from this software
18 *    without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 *
32 *	@(#)queue.h	8.5 (Berkeley) 8/20/94
33 */
34
35#ifndef	_HEIM_QUEUE_H_
36#define	_HEIM_QUEUE_H_
37
38/*
39 * Tail queue definitions.
40 */
41#define	HEIM_TAILQ_HEAD(name, type)					\
42struct name {								\
43	struct type *tqh_first;	/* first element */			\
44	struct type **tqh_last;	/* addr of last next element */		\
45}
46
47#define	HEIM_TAILQ_HEAD_INITIALIZER(head)				\
48	{ NULL, &(head).tqh_first }
49#define	HEIM_TAILQ_ENTRY(type)						\
50struct {								\
51	struct type *tqe_next;	/* next element */			\
52	struct type **tqe_prev;	/* address of previous next element */	\
53}
54
55/*
56 * Tail queue functions.
57 */
58#if defined(_KERNEL) && defined(QUEUEDEBUG)
59#define	QUEUEDEBUG_HEIM_TAILQ_INSERT_HEAD(head, elm, field)		\
60	if ((head)->tqh_first &&					\
61	    (head)->tqh_first->field.tqe_prev != &(head)->tqh_first)	\
62		panic("HEIM_TAILQ_INSERT_HEAD %p %s:%d", (head), __FILE__, __LINE__);
63#define	QUEUEDEBUG_HEIM_TAILQ_INSERT_TAIL(head, elm, field)		\
64	if (*(head)->tqh_last != NULL)					\
65		panic("HEIM_TAILQ_INSERT_TAIL %p %s:%d", (head), __FILE__, __LINE__);
66#define	QUEUEDEBUG_HEIM_TAILQ_OP(elm, field)				\
67	if ((elm)->field.tqe_next &&					\
68	    (elm)->field.tqe_next->field.tqe_prev !=			\
69	    &(elm)->field.tqe_next)					\
70		panic("HEIM_TAILQ_* forw %p %s:%d", (elm), __FILE__, __LINE__);\
71	if (*(elm)->field.tqe_prev != (elm))				\
72		panic("HEIM_TAILQ_* back %p %s:%d", (elm), __FILE__, __LINE__);
73#define	QUEUEDEBUG_HEIM_TAILQ_PREREMOVE(head, elm, field)		\
74	if ((elm)->field.tqe_next == NULL &&				\
75	    (head)->tqh_last != &(elm)->field.tqe_next)			\
76		panic("HEIM_TAILQ_PREREMOVE head %p elm %p %s:%d",	\
77		      (head), (elm), __FILE__, __LINE__);
78#define	QUEUEDEBUG_HEIM_TAILQ_POSTREMOVE(elm, field)			\
79	(elm)->field.tqe_next = (void *)1L;				\
80	(elm)->field.tqe_prev = (void *)1L;
81#else
82#define	QUEUEDEBUG_HEIM_TAILQ_INSERT_HEAD(head, elm, field)
83#define	QUEUEDEBUG_HEIM_TAILQ_INSERT_TAIL(head, elm, field)
84#define	QUEUEDEBUG_HEIM_TAILQ_OP(elm, field)
85#define	QUEUEDEBUG_HEIM_TAILQ_PREREMOVE(head, elm, field)
86#define	QUEUEDEBUG_HEIM_TAILQ_POSTREMOVE(elm, field)
87#endif
88
89#define	HEIM_TAILQ_INIT(head) do {					\
90	(head)->tqh_first = NULL;					\
91	(head)->tqh_last = &(head)->tqh_first;				\
92} while (/*CONSTCOND*/0)
93
94#define	HEIM_TAILQ_INSERT_HEAD(head, elm, field) do {			\
95	QUEUEDEBUG_HEIM_TAILQ_INSERT_HEAD((head), (elm), field)		\
96	if (((elm)->field.tqe_next = (head)->tqh_first) != NULL)	\
97		(head)->tqh_first->field.tqe_prev =			\
98		    &(elm)->field.tqe_next;				\
99	else								\
100		(head)->tqh_last = &(elm)->field.tqe_next;		\
101	(head)->tqh_first = (elm);					\
102	(elm)->field.tqe_prev = &(head)->tqh_first;			\
103} while (/*CONSTCOND*/0)
104
105#define	HEIM_TAILQ_INSERT_TAIL(head, elm, field) do {			\
106	QUEUEDEBUG_HEIM_TAILQ_INSERT_TAIL((head), (elm), field)		\
107	(elm)->field.tqe_next = NULL;					\
108	(elm)->field.tqe_prev = (head)->tqh_last;			\
109	*(head)->tqh_last = (elm);					\
110	(head)->tqh_last = &(elm)->field.tqe_next;			\
111} while (/*CONSTCOND*/0)
112
113#define	HEIM_TAILQ_INSERT_AFTER(head, listelm, elm, field) do {		\
114	QUEUEDEBUG_HEIM_TAILQ_OP((listelm), field)			\
115	if (((elm)->field.tqe_next = (listelm)->field.tqe_next) != NULL)\
116		(elm)->field.tqe_next->field.tqe_prev = 		\
117		    &(elm)->field.tqe_next;				\
118	else								\
119		(head)->tqh_last = &(elm)->field.tqe_next;		\
120	(listelm)->field.tqe_next = (elm);				\
121	(elm)->field.tqe_prev = &(listelm)->field.tqe_next;		\
122} while (/*CONSTCOND*/0)
123
124#define	HEIM_TAILQ_INSERT_BEFORE(listelm, elm, field) do {		\
125	QUEUEDEBUG_HEIM_TAILQ_OP((listelm), field)			\
126	(elm)->field.tqe_prev = (listelm)->field.tqe_prev;		\
127	(elm)->field.tqe_next = (listelm);				\
128	*(listelm)->field.tqe_prev = (elm);				\
129	(listelm)->field.tqe_prev = &(elm)->field.tqe_next;		\
130} while (/*CONSTCOND*/0)
131
132#define	HEIM_TAILQ_REMOVE(head, elm, field) do {			\
133	QUEUEDEBUG_HEIM_TAILQ_PREREMOVE((head), (elm), field)		\
134	QUEUEDEBUG_HEIM_TAILQ_OP((elm), field)				\
135	if (((elm)->field.tqe_next) != NULL)				\
136		(elm)->field.tqe_next->field.tqe_prev = 		\
137		    (elm)->field.tqe_prev;				\
138	else								\
139		(head)->tqh_last = (elm)->field.tqe_prev;		\
140	*(elm)->field.tqe_prev = (elm)->field.tqe_next;			\
141	QUEUEDEBUG_HEIM_TAILQ_POSTREMOVE((elm), field);			\
142} while (/*CONSTCOND*/0)
143
144#define	HEIM_TAILQ_FOREACH(var, head, field)				\
145	for ((var) = ((head)->tqh_first);				\
146		(var);							\
147		(var) = ((var)->field.tqe_next))
148
149#define	HEIM_TAILQ_FOREACH_REVERSE(var, head, headname, field)		\
150	for ((var) = (*(((struct headname *)((head)->tqh_last))->tqh_last)); \
151		(var);							\
152		(var) = (*(((struct headname *)((var)->field.tqe_prev))->tqh_last)))
153
154/*
155 * Tail queue access methods.
156 */
157#define	HEIM_TAILQ_EMPTY(head)		((head)->tqh_first == NULL)
158#define	HEIM_TAILQ_FIRST(head)		((head)->tqh_first)
159#define	HEIM_TAILQ_NEXT(elm, field)		((elm)->field.tqe_next)
160
161#define	HEIM_TAILQ_LAST(head, headname) \
162	(*(((struct headname *)((head)->tqh_last))->tqh_last))
163#define	HEIM_TAILQ_PREV(elm, headname, field) \
164	(*(((struct headname *)((elm)->field.tqe_prev))->tqh_last))
165
166
167#endif	/* !_HEIM_QUEUE_H_ */
168