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c616bbe1 | 1 | /* $NetBSD: queue.h,v 1.52 2009/04/20 09:56:08 mschuett Exp $ */ |
fc56ef08 BS |
2 | |
3 | /* | |
5cbdb3a3 | 4 | * QEMU version: Copy from netbsd, removed debug code, removed some of |
6095aa88 | 5 | * the implementations. Left in singly-linked lists, lists, simple |
cf904cfa | 6 | * queues, and tail queues. |
fc56ef08 BS |
7 | */ |
8 | ||
9 | /* | |
10 | * Copyright (c) 1991, 1993 | |
11 | * The Regents of the University of California. All rights reserved. | |
12 | * | |
13 | * Redistribution and use in source and binary forms, with or without | |
14 | * modification, are permitted provided that the following conditions | |
15 | * are met: | |
16 | * 1. Redistributions of source code must retain the above copyright | |
17 | * notice, this list of conditions and the following disclaimer. | |
18 | * 2. Redistributions in binary form must reproduce the above copyright | |
19 | * notice, this list of conditions and the following disclaimer in the | |
20 | * documentation and/or other materials provided with the distribution. | |
21 | * 3. Neither the name of the University nor the names of its contributors | |
22 | * may be used to endorse or promote products derived from this software | |
23 | * without specific prior written permission. | |
24 | * | |
25 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND | |
26 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
27 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
28 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE | |
29 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
30 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
31 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
32 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
33 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
34 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
35 | * SUCH DAMAGE. | |
36 | * | |
37 | * @(#)queue.h 8.5 (Berkeley) 8/20/94 | |
38 | */ | |
39 | ||
72cf2d4f BS |
40 | #ifndef QEMU_SYS_QUEUE_H_ |
41 | #define QEMU_SYS_QUEUE_H_ | |
fc56ef08 BS |
42 | |
43 | /* | |
cf904cfa PB |
44 | * This file defines four types of data structures: singly-linked lists, |
45 | * lists, simple queues, and tail queues. | |
fc56ef08 | 46 | * |
6095aa88 PB |
47 | * A singly-linked list is headed by a single forward pointer. The |
48 | * elements are singly linked for minimum space and pointer manipulation | |
49 | * overhead at the expense of O(n) removal for arbitrary elements. New | |
50 | * elements can be added to the list after an existing element or at the | |
51 | * head of the list. Elements being removed from the head of the list | |
52 | * should use the explicit macro for this purpose for optimum | |
53 | * efficiency. A singly-linked list may only be traversed in the forward | |
54 | * direction. Singly-linked lists are ideal for applications with large | |
55 | * datasets and few or no removals or for implementing a LIFO queue. | |
56 | * | |
fc56ef08 BS |
57 | * A list is headed by a single forward pointer (or an array of forward |
58 | * pointers for a hash table header). The elements are doubly linked | |
59 | * 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 | |
61 | * or after an existing element or at the head of the list. A list | |
62 | * may only be traversed in the forward direction. | |
63 | * | |
c616bbe1 PR |
64 | * A simple queue is headed by a pair of pointers, one the head of the |
65 | * list and the other to the tail of the list. The elements are singly | |
66 | * linked to save space, so elements can only be removed from the | |
67 | * head of the list. New elements can be added to the list after | |
68 | * an existing element, at the head of the list, or at the end of the | |
69 | * list. A simple queue may only be traversed in the forward direction. | |
70 | * | |
fc56ef08 BS |
71 | * A tail queue is headed by a pair of pointers, one to the head of the |
72 | * list and the other to the tail of the list. The elements are doubly | |
73 | * linked so that an arbitrary element can be removed without a need to | |
74 | * traverse the list. New elements can be added to the list before or | |
75 | * after an existing element, at the head of the list, or at the end of | |
76 | * the list. A tail queue may be traversed in either direction. | |
77 | * | |
fc56ef08 BS |
78 | * For details on the use of these macros, see the queue(3) manual page. |
79 | */ | |
80 | ||
1de7afc9 | 81 | #include "qemu/atomic.h" /* for smp_wmb() */ |
5f7d05ec | 82 | |
fc56ef08 BS |
83 | /* |
84 | * List definitions. | |
85 | */ | |
72cf2d4f | 86 | #define QLIST_HEAD(name, type) \ |
fc56ef08 BS |
87 | struct name { \ |
88 | struct type *lh_first; /* first element */ \ | |
89 | } | |
90 | ||
72cf2d4f | 91 | #define QLIST_HEAD_INITIALIZER(head) \ |
fc56ef08 BS |
92 | { NULL } |
93 | ||
72cf2d4f | 94 | #define QLIST_ENTRY(type) \ |
fc56ef08 BS |
95 | struct { \ |
96 | struct type *le_next; /* next element */ \ | |
97 | struct type **le_prev; /* address of previous next element */ \ | |
98 | } | |
99 | ||
100 | /* | |
101 | * List functions. | |
102 | */ | |
72cf2d4f | 103 | #define QLIST_INIT(head) do { \ |
fc56ef08 BS |
104 | (head)->lh_first = NULL; \ |
105 | } while (/*CONSTCOND*/0) | |
7911747b PB |
106 | |
107 | #define QLIST_SWAP(dstlist, srclist, field) do { \ | |
108 | void *tmplist; \ | |
109 | tmplist = (srclist)->lh_first; \ | |
110 | (srclist)->lh_first = (dstlist)->lh_first; \ | |
111 | if ((srclist)->lh_first != NULL) { \ | |
112 | (srclist)->lh_first->field.le_prev = &(srclist)->lh_first; \ | |
113 | } \ | |
114 | (dstlist)->lh_first = tmplist; \ | |
115 | if ((dstlist)->lh_first != NULL) { \ | |
116 | (dstlist)->lh_first->field.le_prev = &(dstlist)->lh_first; \ | |
117 | } \ | |
118 | } while (/*CONSTCOND*/0) | |
fc56ef08 | 119 | |
ae816930 KW |
120 | #define QLIST_FIX_HEAD_PTR(head, field) do { \ |
121 | if ((head)->lh_first != NULL) { \ | |
122 | (head)->lh_first->field.le_prev = &(head)->lh_first; \ | |
123 | } \ | |
124 | } while (/*CONSTCOND*/0) | |
125 | ||
72cf2d4f | 126 | #define QLIST_INSERT_AFTER(listelm, elm, field) do { \ |
fc56ef08 BS |
127 | if (((elm)->field.le_next = (listelm)->field.le_next) != NULL) \ |
128 | (listelm)->field.le_next->field.le_prev = \ | |
129 | &(elm)->field.le_next; \ | |
130 | (listelm)->field.le_next = (elm); \ | |
131 | (elm)->field.le_prev = &(listelm)->field.le_next; \ | |
132 | } while (/*CONSTCOND*/0) | |
133 | ||
72cf2d4f | 134 | #define QLIST_INSERT_BEFORE(listelm, elm, field) do { \ |
fc56ef08 BS |
135 | (elm)->field.le_prev = (listelm)->field.le_prev; \ |
136 | (elm)->field.le_next = (listelm); \ | |
137 | *(listelm)->field.le_prev = (elm); \ | |
138 | (listelm)->field.le_prev = &(elm)->field.le_next; \ | |
139 | } while (/*CONSTCOND*/0) | |
140 | ||
72cf2d4f | 141 | #define QLIST_INSERT_HEAD(head, elm, field) do { \ |
fc56ef08 BS |
142 | if (((elm)->field.le_next = (head)->lh_first) != NULL) \ |
143 | (head)->lh_first->field.le_prev = &(elm)->field.le_next;\ | |
144 | (head)->lh_first = (elm); \ | |
145 | (elm)->field.le_prev = &(head)->lh_first; \ | |
146 | } while (/*CONSTCOND*/0) | |
147 | ||
72cf2d4f | 148 | #define QLIST_REMOVE(elm, field) do { \ |
fc56ef08 BS |
149 | if ((elm)->field.le_next != NULL) \ |
150 | (elm)->field.le_next->field.le_prev = \ | |
151 | (elm)->field.le_prev; \ | |
152 | *(elm)->field.le_prev = (elm)->field.le_next; \ | |
153 | } while (/*CONSTCOND*/0) | |
154 | ||
72cf2d4f | 155 | #define QLIST_FOREACH(var, head, field) \ |
fc56ef08 BS |
156 | for ((var) = ((head)->lh_first); \ |
157 | (var); \ | |
158 | (var) = ((var)->field.le_next)) | |
159 | ||
72cf2d4f | 160 | #define QLIST_FOREACH_SAFE(var, head, field, next_var) \ |
bb150dc8 JQ |
161 | for ((var) = ((head)->lh_first); \ |
162 | (var) && ((next_var) = ((var)->field.le_next), 1); \ | |
163 | (var) = (next_var)) | |
164 | ||
fc56ef08 BS |
165 | /* |
166 | * List access methods. | |
167 | */ | |
72cf2d4f BS |
168 | #define QLIST_EMPTY(head) ((head)->lh_first == NULL) |
169 | #define QLIST_FIRST(head) ((head)->lh_first) | |
170 | #define QLIST_NEXT(elm, field) ((elm)->field.le_next) | |
fc56ef08 BS |
171 | |
172 | ||
6095aa88 PB |
173 | /* |
174 | * Singly-linked List definitions. | |
175 | */ | |
176 | #define QSLIST_HEAD(name, type) \ | |
177 | struct name { \ | |
178 | struct type *slh_first; /* first element */ \ | |
179 | } | |
180 | ||
181 | #define QSLIST_HEAD_INITIALIZER(head) \ | |
182 | { NULL } | |
183 | ||
184 | #define QSLIST_ENTRY(type) \ | |
185 | struct { \ | |
186 | struct type *sle_next; /* next element */ \ | |
187 | } | |
188 | ||
189 | /* | |
190 | * Singly-linked List functions. | |
191 | */ | |
192 | #define QSLIST_INIT(head) do { \ | |
193 | (head)->slh_first = NULL; \ | |
194 | } while (/*CONSTCOND*/0) | |
195 | ||
196 | #define QSLIST_INSERT_AFTER(slistelm, elm, field) do { \ | |
197 | (elm)->field.sle_next = (slistelm)->field.sle_next; \ | |
198 | (slistelm)->field.sle_next = (elm); \ | |
199 | } while (/*CONSTCOND*/0) | |
200 | ||
201 | #define QSLIST_INSERT_HEAD(head, elm, field) do { \ | |
c740ad92 PB |
202 | (elm)->field.sle_next = (head)->slh_first; \ |
203 | (head)->slh_first = (elm); \ | |
204 | } while (/*CONSTCOND*/0) | |
205 | ||
2120465f PB |
206 | #define QSLIST_INSERT_HEAD_ATOMIC(head, elm, field) do { \ |
207 | typeof(elm) save_sle_next; \ | |
208 | do { \ | |
209 | save_sle_next = (elm)->field.sle_next = (head)->slh_first; \ | |
210 | } while (atomic_cmpxchg(&(head)->slh_first, save_sle_next, (elm)) != \ | |
211 | save_sle_next); \ | |
c740ad92 PB |
212 | } while (/*CONSTCOND*/0) |
213 | ||
214 | #define QSLIST_MOVE_ATOMIC(dest, src) do { \ | |
215 | (dest)->slh_first = atomic_xchg(&(src)->slh_first, NULL); \ | |
6095aa88 PB |
216 | } while (/*CONSTCOND*/0) |
217 | ||
218 | #define QSLIST_REMOVE_HEAD(head, field) do { \ | |
219 | (head)->slh_first = (head)->slh_first->field.sle_next; \ | |
220 | } while (/*CONSTCOND*/0) | |
221 | ||
222 | #define QSLIST_REMOVE_AFTER(slistelm, field) do { \ | |
223 | (slistelm)->field.sle_next = \ | |
224 | QSLIST_NEXT(QSLIST_NEXT((slistelm), field), field); \ | |
225 | } while (/*CONSTCOND*/0) | |
226 | ||
227 | #define QSLIST_FOREACH(var, head, field) \ | |
228 | for((var) = (head)->slh_first; (var); (var) = (var)->field.sle_next) | |
229 | ||
230 | #define QSLIST_FOREACH_SAFE(var, head, field, tvar) \ | |
231 | for ((var) = QSLIST_FIRST((head)); \ | |
232 | (var) && ((tvar) = QSLIST_NEXT((var), field), 1); \ | |
233 | (var) = (tvar)) | |
234 | ||
235 | /* | |
236 | * Singly-linked List access methods. | |
237 | */ | |
238 | #define QSLIST_EMPTY(head) ((head)->slh_first == NULL) | |
239 | #define QSLIST_FIRST(head) ((head)->slh_first) | |
240 | #define QSLIST_NEXT(elm, field) ((elm)->field.sle_next) | |
241 | ||
242 | ||
c616bbe1 PR |
243 | /* |
244 | * Simple queue definitions. | |
245 | */ | |
246 | #define QSIMPLEQ_HEAD(name, type) \ | |
247 | struct name { \ | |
248 | struct type *sqh_first; /* first element */ \ | |
249 | struct type **sqh_last; /* addr of last next element */ \ | |
250 | } | |
251 | ||
252 | #define QSIMPLEQ_HEAD_INITIALIZER(head) \ | |
253 | { NULL, &(head).sqh_first } | |
254 | ||
255 | #define QSIMPLEQ_ENTRY(type) \ | |
256 | struct { \ | |
257 | struct type *sqe_next; /* next element */ \ | |
258 | } | |
259 | ||
260 | /* | |
261 | * Simple queue functions. | |
262 | */ | |
263 | #define QSIMPLEQ_INIT(head) do { \ | |
264 | (head)->sqh_first = NULL; \ | |
265 | (head)->sqh_last = &(head)->sqh_first; \ | |
266 | } while (/*CONSTCOND*/0) | |
267 | ||
268 | #define QSIMPLEQ_INSERT_HEAD(head, elm, field) do { \ | |
269 | if (((elm)->field.sqe_next = (head)->sqh_first) == NULL) \ | |
270 | (head)->sqh_last = &(elm)->field.sqe_next; \ | |
271 | (head)->sqh_first = (elm); \ | |
272 | } while (/*CONSTCOND*/0) | |
273 | ||
274 | #define QSIMPLEQ_INSERT_TAIL(head, elm, field) do { \ | |
275 | (elm)->field.sqe_next = NULL; \ | |
276 | *(head)->sqh_last = (elm); \ | |
277 | (head)->sqh_last = &(elm)->field.sqe_next; \ | |
278 | } while (/*CONSTCOND*/0) | |
279 | ||
280 | #define QSIMPLEQ_INSERT_AFTER(head, listelm, elm, field) do { \ | |
281 | if (((elm)->field.sqe_next = (listelm)->field.sqe_next) == NULL) \ | |
282 | (head)->sqh_last = &(elm)->field.sqe_next; \ | |
283 | (listelm)->field.sqe_next = (elm); \ | |
284 | } while (/*CONSTCOND*/0) | |
285 | ||
286 | #define QSIMPLEQ_REMOVE_HEAD(head, field) do { \ | |
287 | if (((head)->sqh_first = (head)->sqh_first->field.sqe_next) == NULL)\ | |
288 | (head)->sqh_last = &(head)->sqh_first; \ | |
289 | } while (/*CONSTCOND*/0) | |
290 | ||
82595da8 PB |
291 | #define QSIMPLEQ_SPLIT_AFTER(head, elm, field, removed) do { \ |
292 | QSIMPLEQ_INIT(removed); \ | |
293 | if (((removed)->sqh_first = (head)->sqh_first) != NULL) { \ | |
294 | if (((head)->sqh_first = (elm)->field.sqe_next) == NULL) { \ | |
295 | (head)->sqh_last = &(head)->sqh_first; \ | |
296 | } \ | |
297 | (removed)->sqh_last = &(elm)->field.sqe_next; \ | |
298 | (elm)->field.sqe_next = NULL; \ | |
299 | } \ | |
300 | } while (/*CONSTCOND*/0) | |
301 | ||
c616bbe1 PR |
302 | #define QSIMPLEQ_REMOVE(head, elm, type, field) do { \ |
303 | if ((head)->sqh_first == (elm)) { \ | |
304 | QSIMPLEQ_REMOVE_HEAD((head), field); \ | |
305 | } else { \ | |
306 | struct type *curelm = (head)->sqh_first; \ | |
307 | while (curelm->field.sqe_next != (elm)) \ | |
308 | curelm = curelm->field.sqe_next; \ | |
309 | if ((curelm->field.sqe_next = \ | |
310 | curelm->field.sqe_next->field.sqe_next) == NULL) \ | |
311 | (head)->sqh_last = &(curelm)->field.sqe_next; \ | |
312 | } \ | |
313 | } while (/*CONSTCOND*/0) | |
314 | ||
315 | #define QSIMPLEQ_FOREACH(var, head, field) \ | |
316 | for ((var) = ((head)->sqh_first); \ | |
317 | (var); \ | |
318 | (var) = ((var)->field.sqe_next)) | |
319 | ||
320 | #define QSIMPLEQ_FOREACH_SAFE(var, head, field, next) \ | |
321 | for ((var) = ((head)->sqh_first); \ | |
322 | (var) && ((next = ((var)->field.sqe_next)), 1); \ | |
323 | (var) = (next)) | |
324 | ||
325 | #define QSIMPLEQ_CONCAT(head1, head2) do { \ | |
326 | if (!QSIMPLEQ_EMPTY((head2))) { \ | |
327 | *(head1)->sqh_last = (head2)->sqh_first; \ | |
328 | (head1)->sqh_last = (head2)->sqh_last; \ | |
329 | QSIMPLEQ_INIT((head2)); \ | |
330 | } \ | |
331 | } while (/*CONSTCOND*/0) | |
332 | ||
333 | #define QSIMPLEQ_LAST(head, type, field) \ | |
334 | (QSIMPLEQ_EMPTY((head)) ? \ | |
335 | NULL : \ | |
336 | ((struct type *)(void *) \ | |
337 | ((char *)((head)->sqh_last) - offsetof(struct type, field)))) | |
338 | ||
339 | /* | |
340 | * Simple queue access methods. | |
341 | */ | |
342 | #define QSIMPLEQ_EMPTY(head) ((head)->sqh_first == NULL) | |
343 | #define QSIMPLEQ_FIRST(head) ((head)->sqh_first) | |
344 | #define QSIMPLEQ_NEXT(elm, field) ((elm)->field.sqe_next) | |
345 | ||
346 | ||
fc56ef08 BS |
347 | /* |
348 | * Tail queue definitions. | |
349 | */ | |
72cf2d4f | 350 | #define Q_TAILQ_HEAD(name, type, qual) \ |
fc56ef08 BS |
351 | struct name { \ |
352 | qual type *tqh_first; /* first element */ \ | |
353 | qual type *qual *tqh_last; /* addr of last next element */ \ | |
354 | } | |
72cf2d4f | 355 | #define QTAILQ_HEAD(name, type) Q_TAILQ_HEAD(name, struct type,) |
fc56ef08 | 356 | |
72cf2d4f | 357 | #define QTAILQ_HEAD_INITIALIZER(head) \ |
fc56ef08 BS |
358 | { NULL, &(head).tqh_first } |
359 | ||
72cf2d4f | 360 | #define Q_TAILQ_ENTRY(type, qual) \ |
fc56ef08 BS |
361 | struct { \ |
362 | qual type *tqe_next; /* next element */ \ | |
363 | qual type *qual *tqe_prev; /* address of previous next element */\ | |
364 | } | |
72cf2d4f | 365 | #define QTAILQ_ENTRY(type) Q_TAILQ_ENTRY(struct type,) |
fc56ef08 BS |
366 | |
367 | /* | |
368 | * Tail queue functions. | |
369 | */ | |
72cf2d4f | 370 | #define QTAILQ_INIT(head) do { \ |
fc56ef08 BS |
371 | (head)->tqh_first = NULL; \ |
372 | (head)->tqh_last = &(head)->tqh_first; \ | |
373 | } while (/*CONSTCOND*/0) | |
374 | ||
72cf2d4f | 375 | #define QTAILQ_INSERT_HEAD(head, elm, field) do { \ |
fc56ef08 BS |
376 | if (((elm)->field.tqe_next = (head)->tqh_first) != NULL) \ |
377 | (head)->tqh_first->field.tqe_prev = \ | |
378 | &(elm)->field.tqe_next; \ | |
379 | else \ | |
380 | (head)->tqh_last = &(elm)->field.tqe_next; \ | |
381 | (head)->tqh_first = (elm); \ | |
382 | (elm)->field.tqe_prev = &(head)->tqh_first; \ | |
383 | } while (/*CONSTCOND*/0) | |
384 | ||
72cf2d4f | 385 | #define QTAILQ_INSERT_TAIL(head, elm, field) do { \ |
fc56ef08 BS |
386 | (elm)->field.tqe_next = NULL; \ |
387 | (elm)->field.tqe_prev = (head)->tqh_last; \ | |
388 | *(head)->tqh_last = (elm); \ | |
389 | (head)->tqh_last = &(elm)->field.tqe_next; \ | |
390 | } while (/*CONSTCOND*/0) | |
391 | ||
72cf2d4f | 392 | #define QTAILQ_INSERT_AFTER(head, listelm, elm, field) do { \ |
fc56ef08 BS |
393 | if (((elm)->field.tqe_next = (listelm)->field.tqe_next) != NULL)\ |
394 | (elm)->field.tqe_next->field.tqe_prev = \ | |
395 | &(elm)->field.tqe_next; \ | |
396 | else \ | |
397 | (head)->tqh_last = &(elm)->field.tqe_next; \ | |
398 | (listelm)->field.tqe_next = (elm); \ | |
399 | (elm)->field.tqe_prev = &(listelm)->field.tqe_next; \ | |
400 | } while (/*CONSTCOND*/0) | |
401 | ||
72cf2d4f | 402 | #define QTAILQ_INSERT_BEFORE(listelm, elm, field) do { \ |
fc56ef08 BS |
403 | (elm)->field.tqe_prev = (listelm)->field.tqe_prev; \ |
404 | (elm)->field.tqe_next = (listelm); \ | |
405 | *(listelm)->field.tqe_prev = (elm); \ | |
406 | (listelm)->field.tqe_prev = &(elm)->field.tqe_next; \ | |
407 | } while (/*CONSTCOND*/0) | |
408 | ||
72cf2d4f | 409 | #define QTAILQ_REMOVE(head, elm, field) do { \ |
fc56ef08 BS |
410 | if (((elm)->field.tqe_next) != NULL) \ |
411 | (elm)->field.tqe_next->field.tqe_prev = \ | |
412 | (elm)->field.tqe_prev; \ | |
413 | else \ | |
414 | (head)->tqh_last = (elm)->field.tqe_prev; \ | |
415 | *(elm)->field.tqe_prev = (elm)->field.tqe_next; \ | |
416 | } while (/*CONSTCOND*/0) | |
417 | ||
72cf2d4f | 418 | #define QTAILQ_FOREACH(var, head, field) \ |
fc56ef08 BS |
419 | for ((var) = ((head)->tqh_first); \ |
420 | (var); \ | |
421 | (var) = ((var)->field.tqe_next)) | |
422 | ||
72cf2d4f | 423 | #define QTAILQ_FOREACH_SAFE(var, head, field, next_var) \ |
fc56ef08 BS |
424 | for ((var) = ((head)->tqh_first); \ |
425 | (var) && ((next_var) = ((var)->field.tqe_next), 1); \ | |
426 | (var) = (next_var)) | |
427 | ||
72cf2d4f | 428 | #define QTAILQ_FOREACH_REVERSE(var, head, headname, field) \ |
fc56ef08 BS |
429 | for ((var) = (*(((struct headname *)((head)->tqh_last))->tqh_last)); \ |
430 | (var); \ | |
431 | (var) = (*(((struct headname *)((var)->field.tqe_prev))->tqh_last))) | |
432 | ||
433 | /* | |
434 | * Tail queue access methods. | |
435 | */ | |
72cf2d4f BS |
436 | #define QTAILQ_EMPTY(head) ((head)->tqh_first == NULL) |
437 | #define QTAILQ_FIRST(head) ((head)->tqh_first) | |
438 | #define QTAILQ_NEXT(elm, field) ((elm)->field.tqe_next) | |
fc56ef08 | 439 | |
72cf2d4f | 440 | #define QTAILQ_LAST(head, headname) \ |
fc56ef08 | 441 | (*(((struct headname *)((head)->tqh_last))->tqh_last)) |
72cf2d4f | 442 | #define QTAILQ_PREV(elm, headname, field) \ |
fc56ef08 BS |
443 | (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last)) |
444 | ||
72cf2d4f | 445 | #endif /* !QEMU_SYS_QUEUE_H_ */ |