1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
|
/* SPDX-License-Identifier: BSD-3-Clause */
/* $NetBSD: queue.h,v 1.52 2009/04/20 09:56:08 mschuett Exp $ */
/*
* slirp version: Copy from QEMU, removed all but tail queues.
*/
/*
* 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 QTAILQ_H
#define QTAILQ_H
/*
* 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.
*/
typedef struct QTailQLink {
void *tql_next;
struct QTailQLink *tql_prev;
} QTailQLink;
/*
* Tail queue definitions. The union acts as a poor man template, as if
* it were QTailQLink<type>.
*/
#define QTAILQ_HEAD(name, type) \
union name { \
struct type *tqh_first; /* first element */ \
QTailQLink tqh_circ; /* link for circular backwards list */ \
}
#define QTAILQ_HEAD_INITIALIZER(head) \
{ .tqh_circ = { NULL, &(head).tqh_circ } }
#define QTAILQ_ENTRY(type) \
union { \
struct type *tqe_next; /* next element */ \
QTailQLink tqe_circ; /* link for circular backwards list */ \
}
#define QTAILQ_INIT(head) do { \
(head)->tqh_first = NULL; \
(head)->tqh_circ.tql_prev = &(head)->tqh_circ; \
} while (/*CONSTCOND*/0)
#define QTAILQ_INSERT_HEAD(head, elm, field) do { \
if (((elm)->field.tqe_next = (head)->tqh_first) != NULL) \
(head)->tqh_first->field.tqe_circ.tql_prev = \
&(elm)->field.tqe_circ; \
else \
(head)->tqh_circ.tql_prev = &(elm)->field.tqe_circ; \
(head)->tqh_first = (elm); \
(elm)->field.tqe_circ.tql_prev = &(head)->tqh_circ; \
} while (/*CONSTCOND*/0)
#define QTAILQ_INSERT_TAIL(head, elm, field) do { \
(elm)->field.tqe_next = NULL; \
(elm)->field.tqe_circ.tql_prev = (head)->tqh_circ.tql_prev; \
(head)->tqh_circ.tql_prev->tql_next = (elm); \
(head)->tqh_circ.tql_prev = &(elm)->field.tqe_circ; \
} while (/*CONSTCOND*/0)
#define QTAILQ_INSERT_AFTER(head, listelm, elm, field) do { \
if (((elm)->field.tqe_next = (listelm)->field.tqe_next) != NULL)\
(elm)->field.tqe_next->field.tqe_circ.tql_prev = \
&(elm)->field.tqe_circ; \
else \
(head)->tqh_circ.tql_prev = &(elm)->field.tqe_circ; \
(listelm)->field.tqe_next = (elm); \
(elm)->field.tqe_circ.tql_prev = &(listelm)->field.tqe_circ; \
} while (/*CONSTCOND*/0)
#define QTAILQ_INSERT_BEFORE(listelm, elm, field) do { \
(elm)->field.tqe_circ.tql_prev = (listelm)->field.tqe_circ.tql_prev; \
(elm)->field.tqe_next = (listelm); \
(listelm)->field.tqe_circ.tql_prev->tql_next = (elm); \
(listelm)->field.tqe_circ.tql_prev = &(elm)->field.tqe_circ; \
} while (/*CONSTCOND*/0)
#define QTAILQ_REMOVE(head, elm, field) do { \
if (((elm)->field.tqe_next) != NULL) \
(elm)->field.tqe_next->field.tqe_circ.tql_prev = \
(elm)->field.tqe_circ.tql_prev; \
else \
(head)->tqh_circ.tql_prev = (elm)->field.tqe_circ.tql_prev; \
(elm)->field.tqe_circ.tql_prev->tql_next = (elm)->field.tqe_next; \
(elm)->field.tqe_circ.tql_prev = NULL; \
} while (/*CONSTCOND*/0)
#define QTAILQ_FOREACH(var, head, field) \
for ((var) = ((head)->tqh_first); \
(var); \
(var) = ((var)->field.tqe_next))
#define QTAILQ_FOREACH_SAFE(var, head, field, next_var) \
for ((var) = ((head)->tqh_first); \
(var) && ((next_var) = ((var)->field.tqe_next), 1); \
(var) = (next_var))
#define QTAILQ_FOREACH_REVERSE(var, head, field) \
for ((var) = QTAILQ_LAST(head); \
(var); \
(var) = QTAILQ_PREV(var, field))
#define QTAILQ_FOREACH_REVERSE_SAFE(var, head, field, prev_var) \
for ((var) = QTAILQ_LAST(head); \
(var) && ((prev_var) = QTAILQ_PREV(var, field)); \
(var) = (prev_var))
/*
* Tail queue access methods.
*/
#define QTAILQ_EMPTY(head) ((head)->tqh_first == NULL)
#define QTAILQ_FIRST(head) ((head)->tqh_first)
#define QTAILQ_NEXT(elm, field) ((elm)->field.tqe_next)
#define QTAILQ_IN_USE(elm, field) ((elm)->field.tqe_circ.tql_prev != NULL)
#define QTAILQ_LINK_PREV(link) \
((link).tql_prev->tql_prev->tql_next)
#define QTAILQ_LAST(head) \
((typeof((head)->tqh_first)) QTAILQ_LINK_PREV((head)->tqh_circ))
#define QTAILQ_PREV(elm, field) \
((typeof((elm)->field.tqe_next)) QTAILQ_LINK_PREV((elm)->field.tqe_circ))
#define field_at_offset(base, offset, type) \
((type *) (((char *) (base)) + (offset)))
/*
* Raw access of elements of a tail queue head. Offsets are all zero
* because it's a union.
*/
#define QTAILQ_RAW_FIRST(head) \
field_at_offset(head, 0, void *)
#define QTAILQ_RAW_TQH_CIRC(head) \
field_at_offset(head, 0, QTailQLink)
/*
* Raw access of elements of a tail entry
*/
#define QTAILQ_RAW_NEXT(elm, entry) \
field_at_offset(elm, entry, void *)
#define QTAILQ_RAW_TQE_CIRC(elm, entry) \
field_at_offset(elm, entry, QTailQLink)
/*
* Tail queue traversal using pointer arithmetic.
*/
#define QTAILQ_RAW_FOREACH(elm, head, entry) \
for ((elm) = *QTAILQ_RAW_FIRST(head); \
(elm); \
(elm) = *QTAILQ_RAW_NEXT(elm, entry))
/*
* Tail queue insertion using pointer arithmetic.
*/
#define QTAILQ_RAW_INSERT_TAIL(head, elm, entry) do { \
*QTAILQ_RAW_NEXT(elm, entry) = NULL; \
QTAILQ_RAW_TQE_CIRC(elm, entry)->tql_prev = QTAILQ_RAW_TQH_CIRC(head)->tql_prev; \
QTAILQ_RAW_TQH_CIRC(head)->tql_prev->tql_next = (elm); \
QTAILQ_RAW_TQH_CIRC(head)->tql_prev = QTAILQ_RAW_TQE_CIRC(elm, entry); \
} while (/*CONSTCOND*/0)
#endif /* QTAILQ_H */
|
