1/*	$NetBSD: queue.h,v 1.39 2004/04/18 14:25:34 lukem Exp $	*/
2
3/*
4 * Copyright (c) 1991, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 *
31 *	@(#)queue.h	8.5 (Berkeley) 8/20/94
32 */
33
34#ifndef	_MECHQUEUE_H_
35#define	_MECHQUEUE_H_
36
37/*
38 * Singly-linked List definitions.
39 */
40#define	HEIM_SLIST_HEAD(name, type)						\
41struct name {								\
42	struct type *slh_first;	/* first element */			\
43}
44
45#define	HEIM_SLIST_HEAD_INITIALIZER(head)					\
46	{ NULL }
47
48#define	HEIM_SLIST_ENTRY(type)						\
49struct {								\
50	struct type *sle_next;	/* next element */			\
51}
52
53/*
54 * Singly-linked List functions.
55 */
56#define	HEIM_SLIST_INIT(head) do {						\
57	(head)->slh_first = NULL;					\
58} while (/*CONSTCOND*/0)
59
60#define	HEIM_SLIST_INSERT_AFTER(slistelm, elm, field) do {			\
61	(elm)->field.sle_next = (slistelm)->field.sle_next;		\
62	(slistelm)->field.sle_next = (elm);				\
63} while (/*CONSTCOND*/0)
64
65#define	HEIM_SLIST_INSERT_HEAD(head, elm, field) do {			\
66	(elm)->field.sle_next = (head)->slh_first;			\
67	(head)->slh_first = (elm);					\
68} while (/*CONSTCOND*/0)
69
70#define	HEIM_SLIST_REMOVE_HEAD(head, field) do {				\
71	(head)->slh_first = (head)->slh_first->field.sle_next;		\
72} while (/*CONSTCOND*/0)
73
74#define	HEIM_SLIST_REMOVE(head, elm, type, field) do {			\
75	if ((head)->slh_first == (elm)) {				\
76		HEIM_SLIST_REMOVE_HEAD((head), field);			\
77	}								\
78	else {								\
79		struct type *curelm = (head)->slh_first;		\
80		while(curelm->field.sle_next != (elm))			\
81			curelm = curelm->field.sle_next;		\
82		curelm->field.sle_next =				\
83		    curelm->field.sle_next->field.sle_next;		\
84	}								\
85} while (/*CONSTCOND*/0)
86
87#define	HEIM_SLIST_FOREACH(var, head, field)					\
88	for((var) = (head)->slh_first; (var); (var) = (var)->field.sle_next)
89
90/*
91 * Singly-linked List access methods.
92 */
93#define	HEIM_SLIST_EMPTY(head)	((head)->slh_first == NULL)
94#define	HEIM_SLIST_FIRST(head)	((head)->slh_first)
95#define	HEIM_SLIST_NEXT(elm, field)	((elm)->field.sle_next)
96
97#endif	/* !_MECHQUEUE_H_ */
98