1 /*
2 * Copyright (c) 2002, Stockholms Universitet
3 * (Stockholm University, Stockholm Sweden)
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 *
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 *
17 * 3. Neither the name of the university nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
22 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
25 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
26 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
27 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
28 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
29 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
30 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
31 * POSSIBILITY OF SUCH DAMAGE.
32 */
33
34 /* $arla: xfs_queue.h,v 1.1 2002/11/28 06:24:23 lha Exp $ */
35
36 /* Inspirered by the queue macros in BSD. */
37
38 #ifndef NNPFS_QUEUE_H
39 #define NNPFS_QUEUE_H 1
40
41 /* Define a head. */
42 #define NNPQUEUE_HEAD(name, type) \
43 struct name { \
44 struct type *nnpq_first; \
45 struct type **nnpq_last; \
46 }
47
48 /* Defining a entry. */
49 #define NNPQUEUE_ENTRY(type) \
50 struct { \
51 struct type *nnpq_next, **nnpq_prev; \
52 }
53
54 /* Is the queue empty. */
55 #define NNPQUEUE_EMPTY(head) \
56 ((head)->nnpq_first == NULL)
57
58 /* Init head. */
59 #define NNPQUEUE_INIT(head) do { \
60 (head)->nnpq_first = NULL; \
61 (head)->nnpq_last = &(head)->nnpq_first; \
62 } while (0)
63
64 /* Insert elm after listelm, field is named. */
65 #define NNPQUEUE_INSERT_HEAD(head, elm, field) do { \
66 if (((elm)->field.nnpq_next = (head)->nnpq_first) != NULL) \
67 (head)->nnpq_first->field.nnpq_prev = \
68 &(elm)->field.nnpq_next; \
69 else \
70 (head)->nnpq_last = &(elm)->field.nnpq_next; \
71 (head)->nnpq_first = (elm); \
72 (elm)->field.nnpq_prev = &(head)->nnpq_first; \
73 } while (0)
74
75 /* Remove an entry. */
76 #define NNPQUEUE_REMOVE(elm,head,field) do { \
77 if (((elm)->field.nnpq_next) != NULL) \
78 (elm)->field.nnpq_next->field.nnpq_prev = \
79 (elm)->field.nnpq_prev; \
80 else \
81 (head)->nnpq_last = (elm)->field.nnpq_prev; \
82 *(elm)->field.nnpq_prev = (elm)->field.nnpq_next; \
83 } while(0)
84
85 /* Iterate over the list. */
86 #define NNPQUEUE_FOREACH(var,head,field) \
87 for ((var) = ((head)->nnpq_first); \
88 (var); \
89 (var) = ((var)->field.nnpq_next))
90
91 #endif /* NNPFS_QUEUE_H */