Commit | Line | Data |
---|---|---|
ed54eb82 NW |
1 | /* |
2 | * Copyright (c) 1991, 1993 | |
3 | * The Regents of the University of California. All rights reserved. | |
4 | * | |
5 | * Redistribution and use in source and binary forms, with or without | |
6 | * modification, are permitted provided that the following conditions | |
7 | * are met: | |
8 | * 1. Redistributions of source code must retain the above copyright | |
9 | * notice, this list of conditions and the following disclaimer. | |
10 | * 2. Redistributions in binary form must reproduce the above copyright | |
11 | * notice, this list of conditions and the following disclaimer in the | |
12 | * documentation and/or other materials provided with the distribution. | |
13 | * 3. All advertising materials mentioning features or use of this software | |
14 | * must display the following acknowledgement: | |
15 | * This product includes software developed by the University of | |
16 | * California, Berkeley and its contributors. | |
17 | * 4. 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 REGENTS AND CONTRIBUTORS ``AS IS'' AND | |
22 | * 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 REGENTS OR CONTRIBUTORS BE LIABLE | |
25 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
26 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
27 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
28 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
29 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
30 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
31 | * SUCH DAMAGE. | |
32 | * | |
33 | * @(#)queue.h 8.3 (Berkeley) 12/13/93 | |
34 | */ | |
35 | ||
36 | #ifndef _QUEUE_H_ | |
37 | #define _QUEUE_H_ | |
38 | ||
39 | /* | |
40 | * This file defines three types of data structures: lists, tail queues, | |
41 | * and circular queues. | |
42 | * | |
43 | * A list is headed by a single forward pointer (or an array of forward | |
44 | * pointers for a hash table header). The elements are doubly linked | |
45 | * so that an arbitrary element can be removed without a need to | |
46 | * traverse the list. New elements can be added to the list after | |
47 | * an existing element or at the head of the list. A list may only be | |
48 | * traversed in the forward direction. | |
49 | * | |
50 | * A tail queue is headed by a pair of pointers, one to the head of the | |
51 | * list and the other to the tail of the list. The elements are doubly | |
52 | * linked so that an arbitrary element can be removed without a need to | |
53 | * traverse the list. New elements can be added to the list after | |
54 | * an existing element, at the head of the list, or at the end of the | |
55 | * list. A tail queue may only be traversed in the forward direction. | |
56 | * | |
57 | * A circle queue is headed by a pair of pointers, one to the head of the | |
58 | * list and the other to the tail of the list. The elements are doubly | |
59 | * linked so that an arbitrary element can be removed without a need to | |
60 | * traverse the list. New elements can be added to the list before or after | |
61 | * an existing element, at the head of the list, or at the end of the list. | |
62 | * A circle queue may be traversed in either direction, but has a more | |
63 | * complex end of list detection. | |
64 | * | |
65 | * For details on the use of these macros, see the queue(3) manual page. | |
66 | */ | |
67 | ||
68 | /* | |
69 | * List definitions. | |
70 | */ | |
71 | #define LIST_HEAD(name, type) \ | |
72 | struct name { \ | |
73 | struct type *lh_first; /* first element */ \ | |
74 | } | |
75 | ||
76 | #define LIST_ENTRY(type) \ | |
77 | struct { \ | |
78 | struct type *le_next; /* next element */ \ | |
79 | struct type **le_prev; /* address of previous next element */ \ | |
80 | } | |
81 | ||
82 | /* | |
83 | * List functions. | |
84 | */ | |
85 | #define LIST_INIT(head) { \ | |
86 | (head)->lh_first = NULL; \ | |
87 | } | |
88 | ||
89 | #define LIST_INSERT_AFTER(listelm, elm, field) { \ | |
90 | if (((elm)->field.le_next = (listelm)->field.le_next) != NULL) \ | |
91 | (listelm)->field.le_next->field.le_prev = \ | |
92 | &(elm)->field.le_next; \ | |
93 | (listelm)->field.le_next = (elm); \ | |
94 | (elm)->field.le_prev = &(listelm)->field.le_next; \ | |
95 | } | |
96 | ||
97 | #define LIST_INSERT_HEAD(head, elm, field) { \ | |
98 | if (((elm)->field.le_next = (head)->lh_first) != NULL) \ | |
99 | (head)->lh_first->field.le_prev = &(elm)->field.le_next;\ | |
100 | (head)->lh_first = (elm); \ | |
101 | (elm)->field.le_prev = &(head)->lh_first; \ | |
102 | } | |
103 | ||
104 | #define LIST_REMOVE(elm, field) { \ | |
105 | if ((elm)->field.le_next != NULL) \ | |
106 | (elm)->field.le_next->field.le_prev = \ | |
107 | (elm)->field.le_prev; \ | |
108 | *(elm)->field.le_prev = (elm)->field.le_next; \ | |
109 | } | |
110 | ||
111 | /* | |
112 | * Tail queue definitions. | |
113 | */ | |
114 | #define TAILQ_HEAD(name, type) \ | |
115 | struct name { \ | |
116 | struct type *tqh_first; /* first element */ \ | |
117 | struct type **tqh_last; /* addr of last next element */ \ | |
118 | } | |
119 | ||
120 | #define TAILQ_ENTRY(type) \ | |
121 | struct { \ | |
122 | struct type *tqe_next; /* next element */ \ | |
123 | struct type **tqe_prev; /* address of previous next element */ \ | |
124 | } | |
125 | ||
126 | /* | |
127 | * Tail queue functions. | |
128 | */ | |
129 | #define TAILQ_INIT(head) { \ | |
130 | (head)->tqh_first = NULL; \ | |
131 | (head)->tqh_last = &(head)->tqh_first; \ | |
132 | } | |
133 | ||
134 | #define TAILQ_INSERT_HEAD(head, elm, field) { \ | |
135 | if (((elm)->field.tqe_next = (head)->tqh_first) != NULL) \ | |
136 | (elm)->field.tqe_next->field.tqe_prev = \ | |
137 | &(elm)->field.tqe_next; \ | |
138 | else \ | |
139 | (head)->tqh_last = &(elm)->field.tqe_next; \ | |
140 | (head)->tqh_first = (elm); \ | |
141 | (elm)->field.tqe_prev = &(head)->tqh_first; \ | |
142 | } | |
143 | ||
144 | #define TAILQ_INSERT_TAIL(head, elm, field) { \ | |
145 | (elm)->field.tqe_next = NULL; \ | |
146 | (elm)->field.tqe_prev = (head)->tqh_last; \ | |
147 | *(head)->tqh_last = (elm); \ | |
148 | (head)->tqh_last = &(elm)->field.tqe_next; \ | |
149 | } | |
150 | ||
151 | #define TAILQ_INSERT_AFTER(head, listelm, elm, field) { \ | |
152 | if (((elm)->field.tqe_next = (listelm)->field.tqe_next) != NULL)\ | |
153 | (elm)->field.tqe_next->field.tqe_prev = \ | |
154 | &(elm)->field.tqe_next; \ | |
155 | else \ | |
156 | (head)->tqh_last = &(elm)->field.tqe_next; \ | |
157 | (listelm)->field.tqe_next = (elm); \ | |
158 | (elm)->field.tqe_prev = &(listelm)->field.tqe_next; \ | |
159 | } | |
160 | ||
161 | #define TAILQ_REMOVE(head, elm, field) { \ | |
162 | if (((elm)->field.tqe_next) != NULL) \ | |
163 | (elm)->field.tqe_next->field.tqe_prev = \ | |
164 | (elm)->field.tqe_prev; \ | |
165 | else \ | |
166 | (head)->tqh_last = (elm)->field.tqe_prev; \ | |
167 | *(elm)->field.tqe_prev = (elm)->field.tqe_next; \ | |
168 | } | |
169 | ||
170 | /* | |
171 | * Circular queue definitions. | |
172 | */ | |
173 | #define CIRCLEQ_HEAD(name, type) \ | |
174 | struct name { \ | |
175 | struct type *cqh_first; /* first element */ \ | |
176 | struct type *cqh_last; /* last element */ \ | |
177 | } | |
178 | ||
179 | #define CIRCLEQ_ENTRY(type) \ | |
180 | struct { \ | |
181 | struct type *cqe_next; /* next element */ \ | |
182 | struct type *cqe_prev; /* previous element */ \ | |
183 | } | |
184 | ||
185 | /* | |
186 | * Circular queue functions. | |
187 | */ | |
188 | #define CIRCLEQ_INIT(head) { \ | |
189 | (head)->cqh_first = (void *)(head); \ | |
190 | (head)->cqh_last = (void *)(head); \ | |
191 | } | |
192 | ||
193 | #define CIRCLEQ_INSERT_AFTER(head, listelm, elm, field) { \ | |
194 | (elm)->field.cqe_next = (listelm)->field.cqe_next; \ | |
195 | (elm)->field.cqe_prev = (listelm); \ | |
196 | if ((listelm)->field.cqe_next == (void *)(head)) \ | |
197 | (head)->cqh_last = (elm); \ | |
198 | else \ | |
199 | (listelm)->field.cqe_next->field.cqe_prev = (elm); \ | |
200 | (listelm)->field.cqe_next = (elm); \ | |
201 | } | |
202 | ||
203 | #define CIRCLEQ_INSERT_BEFORE(head, listelm, elm, field) { \ | |
204 | (elm)->field.cqe_next = (listelm); \ | |
205 | (elm)->field.cqe_prev = (listelm)->field.cqe_prev; \ | |
206 | if ((listelm)->field.cqe_prev == (void *)(head)) \ | |
207 | (head)->cqh_first = (elm); \ | |
208 | else \ | |
209 | (listelm)->field.cqe_prev->field.cqe_next = (elm); \ | |
210 | (listelm)->field.cqe_prev = (elm); \ | |
211 | } | |
212 | ||
213 | #define CIRCLEQ_INSERT_HEAD(head, elm, field) { \ | |
214 | (elm)->field.cqe_next = (head)->cqh_first; \ | |
215 | (elm)->field.cqe_prev = (void *)(head); \ | |
216 | if ((head)->cqh_last == (void *)(head)) \ | |
217 | (head)->cqh_last = (elm); \ | |
218 | else \ | |
219 | (head)->cqh_first->field.cqe_prev = (elm); \ | |
220 | (head)->cqh_first = (elm); \ | |
221 | } | |
222 | ||
223 | #define CIRCLEQ_INSERT_TAIL(head, elm, field) { \ | |
224 | (elm)->field.cqe_next = (void *)(head); \ | |
225 | (elm)->field.cqe_prev = (head)->cqh_last; \ | |
226 | if ((head)->cqh_first == (void *)(head)) \ | |
227 | (head)->cqh_first = (elm); \ | |
228 | else \ | |
229 | (head)->cqh_last->field.cqe_next = (elm); \ | |
230 | (head)->cqh_last = (elm); \ | |
231 | } | |
232 | ||
233 | #define CIRCLEQ_REMOVE(head, elm, field) { \ | |
234 | if ((elm)->field.cqe_next == (void *)(head)) \ | |
235 | (head)->cqh_last = (elm)->field.cqe_prev; \ | |
236 | else \ | |
237 | (elm)->field.cqe_next->field.cqe_prev = \ | |
238 | (elm)->field.cqe_prev; \ | |
239 | if ((elm)->field.cqe_prev == (void *)(head)) \ | |
240 | (head)->cqh_first = (elm)->field.cqe_next; \ | |
241 | else \ | |
242 | (elm)->field.cqe_prev->field.cqe_next = \ | |
243 | (elm)->field.cqe_next; \ | |
244 | } | |
245 | #endif /* !_QUEUE_H_ */ |