Disable preadv/pwritev support
[qemu-kvm/fedora.git] / sys-queue.h
blobcb6a4c89063fa29fd94566903dc808565b4ef075
1 /* $NetBSD: queue.h,v 1.45.14.1 2007/07/18 20:13:24 liamjfoy Exp $ */
3 /*
4 * Qemu version: Copy from netbsd, removed debug code, removed some of
5 * the implementations. Left in lists, tail queues and circular queues.
6 */
8 /*
9 * Copyright (c) 1991, 1993
10 * The Regents of the University of California. All rights reserved.
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
36 * @(#)queue.h 8.5 (Berkeley) 8/20/94
39 #ifndef _SYS_QUEUE_H_
40 #define _SYS_QUEUE_H_
43 * This file defines three types of data structures:
44 * lists, tail queues, and circular queues.
46 * A list is headed by a single forward pointer (or an array of forward
47 * pointers for a hash table header). The elements are doubly linked
48 * so that an arbitrary element can be removed without a need to
49 * traverse the list. New elements can be added to the list before
50 * or after an existing element or at the head of the list. A list
51 * may only be traversed in the forward direction.
53 * A tail queue is headed by a pair of pointers, one to the head of the
54 * list and the other to the tail of the list. The elements are doubly
55 * linked so that an arbitrary element can be removed without a need to
56 * traverse the list. New elements can be added to the list before or
57 * after an existing element, at the head of the list, or at the end of
58 * the list. A tail queue may be traversed in either direction.
60 * A circle queue is headed by a pair of pointers, one to the head of the
61 * list and the other to the tail of the list. The elements are doubly
62 * linked so that an arbitrary element can be removed without a need to
63 * traverse the list. New elements can be added to the list before or after
64 * an existing element, at the head of the list, or at the end of the list.
65 * A circle queue may be traversed in either direction, but has a more
66 * complex end of list detection.
68 * For details on the use of these macros, see the queue(3) manual page.
72 * List definitions.
74 #define LIST_HEAD(name, type) \
75 struct name { \
76 struct type *lh_first; /* first element */ \
79 #define LIST_HEAD_INITIALIZER(head) \
80 { NULL }
82 #define LIST_ENTRY(type) \
83 struct { \
84 struct type *le_next; /* next element */ \
85 struct type **le_prev; /* address of previous next element */ \
89 * List functions.
91 #define LIST_INIT(head) do { \
92 (head)->lh_first = NULL; \
93 } while (/*CONSTCOND*/0)
95 #define LIST_INSERT_AFTER(listelm, elm, field) do { \
96 if (((elm)->field.le_next = (listelm)->field.le_next) != NULL) \
97 (listelm)->field.le_next->field.le_prev = \
98 &(elm)->field.le_next; \
99 (listelm)->field.le_next = (elm); \
100 (elm)->field.le_prev = &(listelm)->field.le_next; \
101 } while (/*CONSTCOND*/0)
103 #define LIST_INSERT_BEFORE(listelm, elm, field) do { \
104 (elm)->field.le_prev = (listelm)->field.le_prev; \
105 (elm)->field.le_next = (listelm); \
106 *(listelm)->field.le_prev = (elm); \
107 (listelm)->field.le_prev = &(elm)->field.le_next; \
108 } while (/*CONSTCOND*/0)
110 #define LIST_INSERT_HEAD(head, elm, field) do { \
111 if (((elm)->field.le_next = (head)->lh_first) != NULL) \
112 (head)->lh_first->field.le_prev = &(elm)->field.le_next;\
113 (head)->lh_first = (elm); \
114 (elm)->field.le_prev = &(head)->lh_first; \
115 } while (/*CONSTCOND*/0)
117 #define LIST_REMOVE(elm, field) do { \
118 if ((elm)->field.le_next != NULL) \
119 (elm)->field.le_next->field.le_prev = \
120 (elm)->field.le_prev; \
121 *(elm)->field.le_prev = (elm)->field.le_next; \
122 } while (/*CONSTCOND*/0)
124 #define LIST_FOREACH(var, head, field) \
125 for ((var) = ((head)->lh_first); \
126 (var); \
127 (var) = ((var)->field.le_next))
130 * List access methods.
132 #define LIST_EMPTY(head) ((head)->lh_first == NULL)
133 #define LIST_FIRST(head) ((head)->lh_first)
134 #define LIST_NEXT(elm, field) ((elm)->field.le_next)
138 * Tail queue definitions.
140 #define _TAILQ_HEAD(name, type, qual) \
141 struct name { \
142 qual type *tqh_first; /* first element */ \
143 qual type *qual *tqh_last; /* addr of last next element */ \
145 #define TAILQ_HEAD(name, type) _TAILQ_HEAD(name, struct type,)
147 #define TAILQ_HEAD_INITIALIZER(head) \
148 { NULL, &(head).tqh_first }
150 #define _TAILQ_ENTRY(type, qual) \
151 struct { \
152 qual type *tqe_next; /* next element */ \
153 qual type *qual *tqe_prev; /* address of previous next element */\
155 #define TAILQ_ENTRY(type) _TAILQ_ENTRY(struct type,)
158 * Tail queue functions.
160 #define TAILQ_INIT(head) do { \
161 (head)->tqh_first = NULL; \
162 (head)->tqh_last = &(head)->tqh_first; \
163 } while (/*CONSTCOND*/0)
165 #define TAILQ_INSERT_HEAD(head, elm, field) do { \
166 if (((elm)->field.tqe_next = (head)->tqh_first) != NULL) \
167 (head)->tqh_first->field.tqe_prev = \
168 &(elm)->field.tqe_next; \
169 else \
170 (head)->tqh_last = &(elm)->field.tqe_next; \
171 (head)->tqh_first = (elm); \
172 (elm)->field.tqe_prev = &(head)->tqh_first; \
173 } while (/*CONSTCOND*/0)
175 #define TAILQ_INSERT_TAIL(head, elm, field) do { \
176 (elm)->field.tqe_next = NULL; \
177 (elm)->field.tqe_prev = (head)->tqh_last; \
178 *(head)->tqh_last = (elm); \
179 (head)->tqh_last = &(elm)->field.tqe_next; \
180 } while (/*CONSTCOND*/0)
182 #define TAILQ_INSERT_AFTER(head, listelm, elm, field) do { \
183 if (((elm)->field.tqe_next = (listelm)->field.tqe_next) != NULL)\
184 (elm)->field.tqe_next->field.tqe_prev = \
185 &(elm)->field.tqe_next; \
186 else \
187 (head)->tqh_last = &(elm)->field.tqe_next; \
188 (listelm)->field.tqe_next = (elm); \
189 (elm)->field.tqe_prev = &(listelm)->field.tqe_next; \
190 } while (/*CONSTCOND*/0)
192 #define TAILQ_INSERT_BEFORE(listelm, elm, field) do { \
193 (elm)->field.tqe_prev = (listelm)->field.tqe_prev; \
194 (elm)->field.tqe_next = (listelm); \
195 *(listelm)->field.tqe_prev = (elm); \
196 (listelm)->field.tqe_prev = &(elm)->field.tqe_next; \
197 } while (/*CONSTCOND*/0)
199 #define TAILQ_REMOVE(head, elm, field) do { \
200 if (((elm)->field.tqe_next) != NULL) \
201 (elm)->field.tqe_next->field.tqe_prev = \
202 (elm)->field.tqe_prev; \
203 else \
204 (head)->tqh_last = (elm)->field.tqe_prev; \
205 *(elm)->field.tqe_prev = (elm)->field.tqe_next; \
206 } while (/*CONSTCOND*/0)
208 #define TAILQ_FOREACH(var, head, field) \
209 for ((var) = ((head)->tqh_first); \
210 (var); \
211 (var) = ((var)->field.tqe_next))
213 #define TAILQ_FOREACH_SAFE(var, head, field, next_var) \
214 for ((var) = ((head)->tqh_first); \
215 (var) && ((next_var) = ((var)->field.tqe_next), 1); \
216 (var) = (next_var))
218 #define TAILQ_FOREACH_REVERSE(var, head, headname, field) \
219 for ((var) = (*(((struct headname *)((head)->tqh_last))->tqh_last)); \
220 (var); \
221 (var) = (*(((struct headname *)((var)->field.tqe_prev))->tqh_last)))
224 * Tail queue access methods.
226 #define TAILQ_EMPTY(head) ((head)->tqh_first == NULL)
227 #define TAILQ_FIRST(head) ((head)->tqh_first)
228 #define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next)
230 #define TAILQ_LAST(head, headname) \
231 (*(((struct headname *)((head)->tqh_last))->tqh_last))
232 #define TAILQ_PREV(elm, headname, field) \
233 (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last))
237 * Circular queue definitions.
239 #define CIRCLEQ_HEAD(name, type) \
240 struct name { \
241 struct type *cqh_first; /* first element */ \
242 struct type *cqh_last; /* last element */ \
245 #define CIRCLEQ_HEAD_INITIALIZER(head) \
246 { (void *)&head, (void *)&head }
248 #define CIRCLEQ_ENTRY(type) \
249 struct { \
250 struct type *cqe_next; /* next element */ \
251 struct type *cqe_prev; /* previous element */ \
255 * Circular queue functions.
257 #define CIRCLEQ_INIT(head) do { \
258 (head)->cqh_first = (void *)(head); \
259 (head)->cqh_last = (void *)(head); \
260 } while (/*CONSTCOND*/0)
262 #define CIRCLEQ_INSERT_AFTER(head, listelm, elm, field) do { \
263 (elm)->field.cqe_next = (listelm)->field.cqe_next; \
264 (elm)->field.cqe_prev = (listelm); \
265 if ((listelm)->field.cqe_next == (void *)(head)) \
266 (head)->cqh_last = (elm); \
267 else \
268 (listelm)->field.cqe_next->field.cqe_prev = (elm); \
269 (listelm)->field.cqe_next = (elm); \
270 } while (/*CONSTCOND*/0)
272 #define CIRCLEQ_INSERT_BEFORE(head, listelm, elm, field) do { \
273 (elm)->field.cqe_next = (listelm); \
274 (elm)->field.cqe_prev = (listelm)->field.cqe_prev; \
275 if ((listelm)->field.cqe_prev == (void *)(head)) \
276 (head)->cqh_first = (elm); \
277 else \
278 (listelm)->field.cqe_prev->field.cqe_next = (elm); \
279 (listelm)->field.cqe_prev = (elm); \
280 } while (/*CONSTCOND*/0)
282 #define CIRCLEQ_INSERT_HEAD(head, elm, field) do { \
283 (elm)->field.cqe_next = (head)->cqh_first; \
284 (elm)->field.cqe_prev = (void *)(head); \
285 if ((head)->cqh_last == (void *)(head)) \
286 (head)->cqh_last = (elm); \
287 else \
288 (head)->cqh_first->field.cqe_prev = (elm); \
289 (head)->cqh_first = (elm); \
290 } while (/*CONSTCOND*/0)
292 #define CIRCLEQ_INSERT_TAIL(head, elm, field) do { \
293 (elm)->field.cqe_next = (void *)(head); \
294 (elm)->field.cqe_prev = (head)->cqh_last; \
295 if ((head)->cqh_first == (void *)(head)) \
296 (head)->cqh_first = (elm); \
297 else \
298 (head)->cqh_last->field.cqe_next = (elm); \
299 (head)->cqh_last = (elm); \
300 } while (/*CONSTCOND*/0)
302 #define CIRCLEQ_REMOVE(head, elm, field) do { \
303 if ((elm)->field.cqe_next == (void *)(head)) \
304 (head)->cqh_last = (elm)->field.cqe_prev; \
305 else \
306 (elm)->field.cqe_next->field.cqe_prev = \
307 (elm)->field.cqe_prev; \
308 if ((elm)->field.cqe_prev == (void *)(head)) \
309 (head)->cqh_first = (elm)->field.cqe_next; \
310 else \
311 (elm)->field.cqe_prev->field.cqe_next = \
312 (elm)->field.cqe_next; \
313 } while (/*CONSTCOND*/0)
315 #define CIRCLEQ_FOREACH(var, head, field) \
316 for ((var) = ((head)->cqh_first); \
317 (var) != (const void *)(head); \
318 (var) = ((var)->field.cqe_next))
320 #define CIRCLEQ_FOREACH_REVERSE(var, head, field) \
321 for ((var) = ((head)->cqh_last); \
322 (var) != (const void *)(head); \
323 (var) = ((var)->field.cqe_prev))
326 * Circular queue access methods.
328 #define CIRCLEQ_EMPTY(head) ((head)->cqh_first == (void *)(head))
329 #define CIRCLEQ_FIRST(head) ((head)->cqh_first)
330 #define CIRCLEQ_LAST(head) ((head)->cqh_last)
331 #define CIRCLEQ_NEXT(elm, field) ((elm)->field.cqe_next)
332 #define CIRCLEQ_PREV(elm, field) ((elm)->field.cqe_prev)
334 #define CIRCLEQ_LOOP_NEXT(head, elm, field) \
335 (((elm)->field.cqe_next == (void *)(head)) \
336 ? ((head)->cqh_first) \
337 : (elm->field.cqe_next))
338 #define CIRCLEQ_LOOP_PREV(head, elm, field) \
339 (((elm)->field.cqe_prev == (void *)(head)) \
340 ? ((head)->cqh_last) \
341 : (elm->field.cqe_prev))
343 #endif /* !_SYS_QUEUE_H_ */