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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 | ||
2a6a4076 MA |
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 | |
72cf2d4f | 120 | #define QLIST_INSERT_AFTER(listelm, elm, field) do { \ |
fc56ef08 BS |
121 | if (((elm)->field.le_next = (listelm)->field.le_next) != NULL) \ |
122 | (listelm)->field.le_next->field.le_prev = \ | |
123 | &(elm)->field.le_next; \ | |
124 | (listelm)->field.le_next = (elm); \ | |
125 | (elm)->field.le_prev = &(listelm)->field.le_next; \ | |
126 | } while (/*CONSTCOND*/0) | |
127 | ||
72cf2d4f | 128 | #define QLIST_INSERT_BEFORE(listelm, elm, field) do { \ |
fc56ef08 BS |
129 | (elm)->field.le_prev = (listelm)->field.le_prev; \ |
130 | (elm)->field.le_next = (listelm); \ | |
131 | *(listelm)->field.le_prev = (elm); \ | |
132 | (listelm)->field.le_prev = &(elm)->field.le_next; \ | |
133 | } while (/*CONSTCOND*/0) | |
134 | ||
72cf2d4f | 135 | #define QLIST_INSERT_HEAD(head, elm, field) do { \ |
fc56ef08 BS |
136 | if (((elm)->field.le_next = (head)->lh_first) != NULL) \ |
137 | (head)->lh_first->field.le_prev = &(elm)->field.le_next;\ | |
138 | (head)->lh_first = (elm); \ | |
139 | (elm)->field.le_prev = &(head)->lh_first; \ | |
140 | } while (/*CONSTCOND*/0) | |
141 | ||
72cf2d4f | 142 | #define QLIST_REMOVE(elm, field) do { \ |
fc56ef08 BS |
143 | if ((elm)->field.le_next != NULL) \ |
144 | (elm)->field.le_next->field.le_prev = \ | |
145 | (elm)->field.le_prev; \ | |
146 | *(elm)->field.le_prev = (elm)->field.le_next; \ | |
147 | } while (/*CONSTCOND*/0) | |
148 | ||
72cf2d4f | 149 | #define QLIST_FOREACH(var, head, field) \ |
fc56ef08 BS |
150 | for ((var) = ((head)->lh_first); \ |
151 | (var); \ | |
152 | (var) = ((var)->field.le_next)) | |
153 | ||
72cf2d4f | 154 | #define QLIST_FOREACH_SAFE(var, head, field, next_var) \ |
bb150dc8 JQ |
155 | for ((var) = ((head)->lh_first); \ |
156 | (var) && ((next_var) = ((var)->field.le_next), 1); \ | |
157 | (var) = (next_var)) | |
158 | ||
fc56ef08 BS |
159 | /* |
160 | * List access methods. | |
161 | */ | |
72cf2d4f BS |
162 | #define QLIST_EMPTY(head) ((head)->lh_first == NULL) |
163 | #define QLIST_FIRST(head) ((head)->lh_first) | |
164 | #define QLIST_NEXT(elm, field) ((elm)->field.le_next) | |
fc56ef08 BS |
165 | |
166 | ||
6095aa88 PB |
167 | /* |
168 | * Singly-linked List definitions. | |
169 | */ | |
170 | #define QSLIST_HEAD(name, type) \ | |
171 | struct name { \ | |
172 | struct type *slh_first; /* first element */ \ | |
173 | } | |
174 | ||
175 | #define QSLIST_HEAD_INITIALIZER(head) \ | |
176 | { NULL } | |
177 | ||
178 | #define QSLIST_ENTRY(type) \ | |
179 | struct { \ | |
180 | struct type *sle_next; /* next element */ \ | |
181 | } | |
182 | ||
183 | /* | |
184 | * Singly-linked List functions. | |
185 | */ | |
186 | #define QSLIST_INIT(head) do { \ | |
187 | (head)->slh_first = NULL; \ | |
188 | } while (/*CONSTCOND*/0) | |
189 | ||
190 | #define QSLIST_INSERT_AFTER(slistelm, elm, field) do { \ | |
191 | (elm)->field.sle_next = (slistelm)->field.sle_next; \ | |
192 | (slistelm)->field.sle_next = (elm); \ | |
193 | } while (/*CONSTCOND*/0) | |
194 | ||
195 | #define QSLIST_INSERT_HEAD(head, elm, field) do { \ | |
c740ad92 PB |
196 | (elm)->field.sle_next = (head)->slh_first; \ |
197 | (head)->slh_first = (elm); \ | |
198 | } while (/*CONSTCOND*/0) | |
199 | ||
2120465f PB |
200 | #define QSLIST_INSERT_HEAD_ATOMIC(head, elm, field) do { \ |
201 | typeof(elm) save_sle_next; \ | |
202 | do { \ | |
203 | save_sle_next = (elm)->field.sle_next = (head)->slh_first; \ | |
204 | } while (atomic_cmpxchg(&(head)->slh_first, save_sle_next, (elm)) != \ | |
205 | save_sle_next); \ | |
c740ad92 PB |
206 | } while (/*CONSTCOND*/0) |
207 | ||
208 | #define QSLIST_MOVE_ATOMIC(dest, src) do { \ | |
209 | (dest)->slh_first = atomic_xchg(&(src)->slh_first, NULL); \ | |
6095aa88 PB |
210 | } while (/*CONSTCOND*/0) |
211 | ||
212 | #define QSLIST_REMOVE_HEAD(head, field) do { \ | |
213 | (head)->slh_first = (head)->slh_first->field.sle_next; \ | |
214 | } while (/*CONSTCOND*/0) | |
215 | ||
216 | #define QSLIST_REMOVE_AFTER(slistelm, field) do { \ | |
217 | (slistelm)->field.sle_next = \ | |
218 | QSLIST_NEXT(QSLIST_NEXT((slistelm), field), field); \ | |
219 | } while (/*CONSTCOND*/0) | |
220 | ||
221 | #define QSLIST_FOREACH(var, head, field) \ | |
222 | for((var) = (head)->slh_first; (var); (var) = (var)->field.sle_next) | |
223 | ||
224 | #define QSLIST_FOREACH_SAFE(var, head, field, tvar) \ | |
225 | for ((var) = QSLIST_FIRST((head)); \ | |
226 | (var) && ((tvar) = QSLIST_NEXT((var), field), 1); \ | |
227 | (var) = (tvar)) | |
228 | ||
229 | /* | |
230 | * Singly-linked List access methods. | |
231 | */ | |
232 | #define QSLIST_EMPTY(head) ((head)->slh_first == NULL) | |
233 | #define QSLIST_FIRST(head) ((head)->slh_first) | |
234 | #define QSLIST_NEXT(elm, field) ((elm)->field.sle_next) | |
235 | ||
236 | ||
c616bbe1 PR |
237 | /* |
238 | * Simple queue definitions. | |
239 | */ | |
240 | #define QSIMPLEQ_HEAD(name, type) \ | |
241 | struct name { \ | |
242 | struct type *sqh_first; /* first element */ \ | |
243 | struct type **sqh_last; /* addr of last next element */ \ | |
244 | } | |
245 | ||
246 | #define QSIMPLEQ_HEAD_INITIALIZER(head) \ | |
247 | { NULL, &(head).sqh_first } | |
248 | ||
249 | #define QSIMPLEQ_ENTRY(type) \ | |
250 | struct { \ | |
251 | struct type *sqe_next; /* next element */ \ | |
252 | } | |
253 | ||
254 | /* | |
255 | * Simple queue functions. | |
256 | */ | |
257 | #define QSIMPLEQ_INIT(head) do { \ | |
258 | (head)->sqh_first = NULL; \ | |
259 | (head)->sqh_last = &(head)->sqh_first; \ | |
260 | } while (/*CONSTCOND*/0) | |
261 | ||
262 | #define QSIMPLEQ_INSERT_HEAD(head, elm, field) do { \ | |
263 | if (((elm)->field.sqe_next = (head)->sqh_first) == NULL) \ | |
264 | (head)->sqh_last = &(elm)->field.sqe_next; \ | |
265 | (head)->sqh_first = (elm); \ | |
266 | } while (/*CONSTCOND*/0) | |
267 | ||
268 | #define QSIMPLEQ_INSERT_TAIL(head, elm, field) do { \ | |
269 | (elm)->field.sqe_next = NULL; \ | |
270 | *(head)->sqh_last = (elm); \ | |
271 | (head)->sqh_last = &(elm)->field.sqe_next; \ | |
272 | } while (/*CONSTCOND*/0) | |
273 | ||
274 | #define QSIMPLEQ_INSERT_AFTER(head, listelm, elm, field) do { \ | |
275 | if (((elm)->field.sqe_next = (listelm)->field.sqe_next) == NULL) \ | |
276 | (head)->sqh_last = &(elm)->field.sqe_next; \ | |
277 | (listelm)->field.sqe_next = (elm); \ | |
278 | } while (/*CONSTCOND*/0) | |
279 | ||
280 | #define QSIMPLEQ_REMOVE_HEAD(head, field) do { \ | |
281 | if (((head)->sqh_first = (head)->sqh_first->field.sqe_next) == NULL)\ | |
282 | (head)->sqh_last = &(head)->sqh_first; \ | |
283 | } while (/*CONSTCOND*/0) | |
284 | ||
82595da8 PB |
285 | #define QSIMPLEQ_SPLIT_AFTER(head, elm, field, removed) do { \ |
286 | QSIMPLEQ_INIT(removed); \ | |
287 | if (((removed)->sqh_first = (head)->sqh_first) != NULL) { \ | |
288 | if (((head)->sqh_first = (elm)->field.sqe_next) == NULL) { \ | |
289 | (head)->sqh_last = &(head)->sqh_first; \ | |
290 | } \ | |
291 | (removed)->sqh_last = &(elm)->field.sqe_next; \ | |
292 | (elm)->field.sqe_next = NULL; \ | |
293 | } \ | |
294 | } while (/*CONSTCOND*/0) | |
295 | ||
c616bbe1 PR |
296 | #define QSIMPLEQ_REMOVE(head, elm, type, field) do { \ |
297 | if ((head)->sqh_first == (elm)) { \ | |
298 | QSIMPLEQ_REMOVE_HEAD((head), field); \ | |
299 | } else { \ | |
300 | struct type *curelm = (head)->sqh_first; \ | |
301 | while (curelm->field.sqe_next != (elm)) \ | |
302 | curelm = curelm->field.sqe_next; \ | |
303 | if ((curelm->field.sqe_next = \ | |
304 | curelm->field.sqe_next->field.sqe_next) == NULL) \ | |
305 | (head)->sqh_last = &(curelm)->field.sqe_next; \ | |
306 | } \ | |
307 | } while (/*CONSTCOND*/0) | |
308 | ||
309 | #define QSIMPLEQ_FOREACH(var, head, field) \ | |
310 | for ((var) = ((head)->sqh_first); \ | |
311 | (var); \ | |
312 | (var) = ((var)->field.sqe_next)) | |
313 | ||
314 | #define QSIMPLEQ_FOREACH_SAFE(var, head, field, next) \ | |
315 | for ((var) = ((head)->sqh_first); \ | |
316 | (var) && ((next = ((var)->field.sqe_next)), 1); \ | |
317 | (var) = (next)) | |
318 | ||
319 | #define QSIMPLEQ_CONCAT(head1, head2) do { \ | |
320 | if (!QSIMPLEQ_EMPTY((head2))) { \ | |
321 | *(head1)->sqh_last = (head2)->sqh_first; \ | |
322 | (head1)->sqh_last = (head2)->sqh_last; \ | |
323 | QSIMPLEQ_INIT((head2)); \ | |
324 | } \ | |
325 | } while (/*CONSTCOND*/0) | |
326 | ||
327 | #define QSIMPLEQ_LAST(head, type, field) \ | |
328 | (QSIMPLEQ_EMPTY((head)) ? \ | |
329 | NULL : \ | |
330 | ((struct type *)(void *) \ | |
331 | ((char *)((head)->sqh_last) - offsetof(struct type, field)))) | |
332 | ||
333 | /* | |
334 | * Simple queue access methods. | |
335 | */ | |
336 | #define QSIMPLEQ_EMPTY(head) ((head)->sqh_first == NULL) | |
337 | #define QSIMPLEQ_FIRST(head) ((head)->sqh_first) | |
338 | #define QSIMPLEQ_NEXT(elm, field) ((elm)->field.sqe_next) | |
339 | ||
340 | ||
fc56ef08 BS |
341 | /* |
342 | * Tail queue definitions. | |
343 | */ | |
72cf2d4f | 344 | #define Q_TAILQ_HEAD(name, type, qual) \ |
fc56ef08 BS |
345 | struct name { \ |
346 | qual type *tqh_first; /* first element */ \ | |
347 | qual type *qual *tqh_last; /* addr of last next element */ \ | |
348 | } | |
72cf2d4f | 349 | #define QTAILQ_HEAD(name, type) Q_TAILQ_HEAD(name, struct type,) |
fc56ef08 | 350 | |
72cf2d4f | 351 | #define QTAILQ_HEAD_INITIALIZER(head) \ |
fc56ef08 BS |
352 | { NULL, &(head).tqh_first } |
353 | ||
72cf2d4f | 354 | #define Q_TAILQ_ENTRY(type, qual) \ |
fc56ef08 BS |
355 | struct { \ |
356 | qual type *tqe_next; /* next element */ \ | |
357 | qual type *qual *tqe_prev; /* address of previous next element */\ | |
358 | } | |
72cf2d4f | 359 | #define QTAILQ_ENTRY(type) Q_TAILQ_ENTRY(struct type,) |
fc56ef08 BS |
360 | |
361 | /* | |
362 | * Tail queue functions. | |
363 | */ | |
72cf2d4f | 364 | #define QTAILQ_INIT(head) do { \ |
fc56ef08 BS |
365 | (head)->tqh_first = NULL; \ |
366 | (head)->tqh_last = &(head)->tqh_first; \ | |
367 | } while (/*CONSTCOND*/0) | |
368 | ||
72cf2d4f | 369 | #define QTAILQ_INSERT_HEAD(head, elm, field) do { \ |
fc56ef08 BS |
370 | if (((elm)->field.tqe_next = (head)->tqh_first) != NULL) \ |
371 | (head)->tqh_first->field.tqe_prev = \ | |
372 | &(elm)->field.tqe_next; \ | |
373 | else \ | |
374 | (head)->tqh_last = &(elm)->field.tqe_next; \ | |
375 | (head)->tqh_first = (elm); \ | |
376 | (elm)->field.tqe_prev = &(head)->tqh_first; \ | |
377 | } while (/*CONSTCOND*/0) | |
378 | ||
72cf2d4f | 379 | #define QTAILQ_INSERT_TAIL(head, elm, field) do { \ |
fc56ef08 BS |
380 | (elm)->field.tqe_next = NULL; \ |
381 | (elm)->field.tqe_prev = (head)->tqh_last; \ | |
382 | *(head)->tqh_last = (elm); \ | |
383 | (head)->tqh_last = &(elm)->field.tqe_next; \ | |
384 | } while (/*CONSTCOND*/0) | |
385 | ||
72cf2d4f | 386 | #define QTAILQ_INSERT_AFTER(head, listelm, elm, field) do { \ |
fc56ef08 BS |
387 | if (((elm)->field.tqe_next = (listelm)->field.tqe_next) != NULL)\ |
388 | (elm)->field.tqe_next->field.tqe_prev = \ | |
389 | &(elm)->field.tqe_next; \ | |
390 | else \ | |
391 | (head)->tqh_last = &(elm)->field.tqe_next; \ | |
392 | (listelm)->field.tqe_next = (elm); \ | |
393 | (elm)->field.tqe_prev = &(listelm)->field.tqe_next; \ | |
394 | } while (/*CONSTCOND*/0) | |
395 | ||
72cf2d4f | 396 | #define QTAILQ_INSERT_BEFORE(listelm, elm, field) do { \ |
fc56ef08 BS |
397 | (elm)->field.tqe_prev = (listelm)->field.tqe_prev; \ |
398 | (elm)->field.tqe_next = (listelm); \ | |
399 | *(listelm)->field.tqe_prev = (elm); \ | |
400 | (listelm)->field.tqe_prev = &(elm)->field.tqe_next; \ | |
401 | } while (/*CONSTCOND*/0) | |
402 | ||
72cf2d4f | 403 | #define QTAILQ_REMOVE(head, elm, field) do { \ |
fc56ef08 BS |
404 | if (((elm)->field.tqe_next) != NULL) \ |
405 | (elm)->field.tqe_next->field.tqe_prev = \ | |
406 | (elm)->field.tqe_prev; \ | |
407 | else \ | |
408 | (head)->tqh_last = (elm)->field.tqe_prev; \ | |
409 | *(elm)->field.tqe_prev = (elm)->field.tqe_next; \ | |
3b8c1761 | 410 | (elm)->field.tqe_prev = NULL; \ |
fc56ef08 BS |
411 | } while (/*CONSTCOND*/0) |
412 | ||
72cf2d4f | 413 | #define QTAILQ_FOREACH(var, head, field) \ |
fc56ef08 BS |
414 | for ((var) = ((head)->tqh_first); \ |
415 | (var); \ | |
416 | (var) = ((var)->field.tqe_next)) | |
417 | ||
72cf2d4f | 418 | #define QTAILQ_FOREACH_SAFE(var, head, field, next_var) \ |
fc56ef08 BS |
419 | for ((var) = ((head)->tqh_first); \ |
420 | (var) && ((next_var) = ((var)->field.tqe_next), 1); \ | |
421 | (var) = (next_var)) | |
422 | ||
72cf2d4f | 423 | #define QTAILQ_FOREACH_REVERSE(var, head, headname, field) \ |
fc56ef08 BS |
424 | for ((var) = (*(((struct headname *)((head)->tqh_last))->tqh_last)); \ |
425 | (var); \ | |
426 | (var) = (*(((struct headname *)((var)->field.tqe_prev))->tqh_last))) | |
427 | ||
428 | /* | |
429 | * Tail queue access methods. | |
430 | */ | |
72cf2d4f BS |
431 | #define QTAILQ_EMPTY(head) ((head)->tqh_first == NULL) |
432 | #define QTAILQ_FIRST(head) ((head)->tqh_first) | |
433 | #define QTAILQ_NEXT(elm, field) ((elm)->field.tqe_next) | |
3b8c1761 | 434 | #define QTAILQ_IN_USE(elm, field) ((elm)->field.tqe_prev != NULL) |
fc56ef08 | 435 | |
72cf2d4f | 436 | #define QTAILQ_LAST(head, headname) \ |
fc56ef08 | 437 | (*(((struct headname *)((head)->tqh_last))->tqh_last)) |
72cf2d4f | 438 | #define QTAILQ_PREV(elm, headname, field) \ |
fc56ef08 BS |
439 | (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last)) |
440 | ||
2a6a4076 | 441 | #endif /* QEMU_SYS_QUEUE_H */ |