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)						\
41 struct 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)						\
49 struct {								\
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