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1 | /* $OpenBSD: queue.h,v 1.43 2015/12/28 19:38:40 millert Exp $ */ |
2 | /* $NetBSD: queue.h,v 1.11 1996/05/16 05:17:14 mycroft Exp $ */ | |
3 | ||
4 | /* | |
5 | * Copyright (c) 1991, 1993 | |
6 | * The Regents of the University of California. All rights reserved. | |
7 | * | |
8 | * Redistribution and use in source and binary forms, with or without | |
9 | * modification, are permitted provided that the following conditions | |
10 | * are met: | |
11 | * 1. Redistributions of source code must retain the above copyright | |
12 | * notice, this list of conditions and the following disclaimer. | |
13 | * 2. Redistributions in binary form must reproduce the above copyright | |
14 | * notice, this list of conditions and the following disclaimer in the | |
15 | * documentation and/or other materials provided with the distribution. | |
16 | * 3. Neither the name of the University nor the names of its contributors | |
17 | * may be used to endorse or promote products derived from this software | |
18 | * without specific prior written permission. | |
19 | * | |
20 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND | |
21 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
22 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
23 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE | |
24 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
25 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
26 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
27 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
28 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
29 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
30 | * SUCH DAMAGE. | |
31 | * | |
32 | * @(#)queue.h 8.5 (Berkeley) 8/20/94 | |
33 | */ | |
34 | ||
35 | #ifndef _SYS_QUEUE_H_ | |
36 | #define _SYS_QUEUE_H_ | |
37 | ||
38 | /* | |
39 | * This file defines five types of data structures: singly-linked lists, | |
40 | * lists, simple queues, tail queues and XOR simple queues. | |
41 | * | |
42 | * | |
43 | * A singly-linked list is headed by a single forward pointer. The elements | |
44 | * are singly linked for minimum space and pointer manipulation overhead at | |
45 | * the expense of O(n) removal for arbitrary elements. New elements can be | |
46 | * added to the list after an existing element or at the head of the list. | |
47 | * Elements being removed from the head of the list should use the explicit | |
48 | * macro for this purpose for optimum efficiency. A singly-linked list may | |
49 | * only be traversed in the forward direction. Singly-linked lists are ideal | |
50 | * for applications with large datasets and few or no removals or for | |
51 | * implementing a LIFO queue. | |
52 | * | |
53 | * A list is headed by a single forward pointer (or an array of forward | |
54 | * pointers for a hash table header). The elements are doubly linked | |
55 | * 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 | |
57 | * or after an existing element or at the head of the list. A list | |
58 | * may only be traversed in the forward direction. | |
59 | * | |
60 | * A simple 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 singly | |
62 | * linked to save space, so elements can only be removed from the | |
63 | * head of 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 | |
65 | * list. A simple queue may only be traversed in the forward direction. | |
66 | * | |
67 | * A tail queue is headed by a pair of pointers, one to the head of the | |
68 | * list and the other to the tail of the list. The elements are doubly | |
69 | * linked so that an arbitrary element can be removed without a need to | |
70 | * traverse the list. New elements can be added to the list before or | |
71 | * after an existing element, at the head of the list, or at the end of | |
72 | * the list. A tail queue may be traversed in either direction. | |
73 | * | |
74 | * An XOR simple queue is used in the same way as a regular simple queue. | |
75 | * The difference is that the head structure also includes a "cookie" that | |
76 | * is XOR'd with the queue pointer (first, last or next) to generate the | |
77 | * real pointer value. | |
78 | * | |
79 | * For details on the use of these macros, see the queue(3) manual page. | |
80 | */ | |
81 | ||
82 | #if defined(QUEUE_MACRO_DEBUG) || (defined(_KERNEL) && defined(DIAGNOSTIC)) | |
83 | #define _Q_INVALIDATE(a) (a) = ((void *)-1) | |
84 | #else | |
85 | #define _Q_INVALIDATE(a) | |
86 | #endif | |
87 | ||
88 | /* | |
89 | * Singly-linked List definitions. | |
90 | */ | |
91 | #define SLIST_HEAD(name, type) \ | |
92 | struct name { \ | |
93 | struct type *slh_first; /* first element */ \ | |
94 | } | |
95 | ||
96 | #define SLIST_HEAD_INITIALIZER(head) \ | |
97 | { NULL } | |
98 | ||
99 | #define SLIST_ENTRY(type) \ | |
100 | struct { \ | |
101 | struct type *sle_next; /* next element */ \ | |
102 | } | |
103 | ||
104 | /* | |
105 | * Singly-linked List access methods. | |
106 | */ | |
107 | #define SLIST_FIRST(head) ((head)->slh_first) | |
108 | #define SLIST_END(head) NULL | |
109 | #define SLIST_EMPTY(head) (SLIST_FIRST(head) == SLIST_END(head)) | |
110 | #define SLIST_NEXT(elm, field) ((elm)->field.sle_next) | |
111 | ||
112 | #define SLIST_FOREACH(var, head, field) \ | |
113 | for((var) = SLIST_FIRST(head); \ | |
114 | (var) != SLIST_END(head); \ | |
115 | (var) = SLIST_NEXT(var, field)) | |
116 | ||
117 | #define SLIST_FOREACH_SAFE(var, head, field, tvar) \ | |
118 | for ((var) = SLIST_FIRST(head); \ | |
119 | (var) && ((tvar) = SLIST_NEXT(var, field), 1); \ | |
120 | (var) = (tvar)) | |
121 | ||
122 | /* | |
123 | * Singly-linked List functions. | |
124 | */ | |
125 | #define SLIST_INIT(head) { \ | |
126 | SLIST_FIRST(head) = SLIST_END(head); \ | |
127 | } | |
128 | ||
129 | #define SLIST_INSERT_AFTER(slistelm, elm, field) do { \ | |
130 | (elm)->field.sle_next = (slistelm)->field.sle_next; \ | |
131 | (slistelm)->field.sle_next = (elm); \ | |
132 | } while (0) | |
133 | ||
134 | #define SLIST_INSERT_HEAD(head, elm, field) do { \ | |
135 | (elm)->field.sle_next = (head)->slh_first; \ | |
136 | (head)->slh_first = (elm); \ | |
137 | } while (0) | |
138 | ||
139 | #define SLIST_REMOVE_AFTER(elm, field) do { \ | |
140 | (elm)->field.sle_next = (elm)->field.sle_next->field.sle_next; \ | |
141 | } while (0) | |
142 | ||
143 | #define SLIST_REMOVE_HEAD(head, field) do { \ | |
144 | (head)->slh_first = (head)->slh_first->field.sle_next; \ | |
145 | } while (0) | |
146 | ||
147 | #define SLIST_REMOVE(head, elm, type, field) do { \ | |
148 | if ((head)->slh_first == (elm)) { \ | |
149 | SLIST_REMOVE_HEAD((head), field); \ | |
150 | } else { \ | |
151 | struct type *curelm = (head)->slh_first; \ | |
152 | \ | |
153 | while (curelm->field.sle_next != (elm)) \ | |
154 | curelm = curelm->field.sle_next; \ | |
155 | curelm->field.sle_next = \ | |
156 | curelm->field.sle_next->field.sle_next; \ | |
157 | } \ | |
158 | _Q_INVALIDATE((elm)->field.sle_next); \ | |
159 | } while (0) | |
160 | ||
161 | /* | |
162 | * List definitions. | |
163 | */ | |
164 | #define LIST_HEAD(name, type) \ | |
165 | struct name { \ | |
166 | struct type *lh_first; /* first element */ \ | |
167 | } | |
168 | ||
169 | #define LIST_HEAD_INITIALIZER(head) \ | |
170 | { NULL } | |
171 | ||
172 | #define LIST_ENTRY(type) \ | |
173 | struct { \ | |
174 | struct type *le_next; /* next element */ \ | |
175 | struct type **le_prev; /* address of previous next element */ \ | |
176 | } | |
177 | ||
178 | /* | |
179 | * List access methods. | |
180 | */ | |
181 | #define LIST_FIRST(head) ((head)->lh_first) | |
182 | #define LIST_END(head) NULL | |
183 | #define LIST_EMPTY(head) (LIST_FIRST(head) == LIST_END(head)) | |
184 | #define LIST_NEXT(elm, field) ((elm)->field.le_next) | |
185 | ||
186 | #define LIST_FOREACH(var, head, field) \ | |
187 | for((var) = LIST_FIRST(head); \ | |
188 | (var)!= LIST_END(head); \ | |
189 | (var) = LIST_NEXT(var, field)) | |
190 | ||
191 | #define LIST_FOREACH_SAFE(var, head, field, tvar) \ | |
192 | for ((var) = LIST_FIRST(head); \ | |
193 | (var) && ((tvar) = LIST_NEXT(var, field), 1); \ | |
194 | (var) = (tvar)) | |
195 | ||
196 | /* | |
197 | * List functions. | |
198 | */ | |
199 | #define LIST_INIT(head) do { \ | |
200 | LIST_FIRST(head) = LIST_END(head); \ | |
201 | } while (0) | |
202 | ||
203 | #define LIST_INSERT_AFTER(listelm, elm, field) do { \ | |
204 | if (((elm)->field.le_next = (listelm)->field.le_next) != NULL) \ | |
205 | (listelm)->field.le_next->field.le_prev = \ | |
206 | &(elm)->field.le_next; \ | |
207 | (listelm)->field.le_next = (elm); \ | |
208 | (elm)->field.le_prev = &(listelm)->field.le_next; \ | |
209 | } while (0) | |
210 | ||
211 | #define LIST_INSERT_BEFORE(listelm, elm, field) do { \ | |
212 | (elm)->field.le_prev = (listelm)->field.le_prev; \ | |
213 | (elm)->field.le_next = (listelm); \ | |
214 | *(listelm)->field.le_prev = (elm); \ | |
215 | (listelm)->field.le_prev = &(elm)->field.le_next; \ | |
216 | } while (0) | |
217 | ||
218 | #define LIST_INSERT_HEAD(head, elm, field) do { \ | |
219 | if (((elm)->field.le_next = (head)->lh_first) != NULL) \ | |
220 | (head)->lh_first->field.le_prev = &(elm)->field.le_next;\ | |
221 | (head)->lh_first = (elm); \ | |
222 | (elm)->field.le_prev = &(head)->lh_first; \ | |
223 | } while (0) | |
224 | ||
225 | #define LIST_REMOVE(elm, field) do { \ | |
226 | if ((elm)->field.le_next != NULL) \ | |
227 | (elm)->field.le_next->field.le_prev = \ | |
228 | (elm)->field.le_prev; \ | |
229 | *(elm)->field.le_prev = (elm)->field.le_next; \ | |
230 | _Q_INVALIDATE((elm)->field.le_prev); \ | |
231 | _Q_INVALIDATE((elm)->field.le_next); \ | |
232 | } while (0) | |
233 | ||
234 | #define LIST_REPLACE(elm, elm2, field) do { \ | |
235 | if (((elm2)->field.le_next = (elm)->field.le_next) != NULL) \ | |
236 | (elm2)->field.le_next->field.le_prev = \ | |
237 | &(elm2)->field.le_next; \ | |
238 | (elm2)->field.le_prev = (elm)->field.le_prev; \ | |
239 | *(elm2)->field.le_prev = (elm2); \ | |
240 | _Q_INVALIDATE((elm)->field.le_prev); \ | |
241 | _Q_INVALIDATE((elm)->field.le_next); \ | |
242 | } while (0) | |
243 | ||
244 | /* | |
245 | * Simple queue definitions. | |
246 | */ | |
247 | #define SIMPLEQ_HEAD(name, type) \ | |
248 | struct name { \ | |
249 | struct type *sqh_first; /* first element */ \ | |
250 | struct type **sqh_last; /* addr of last next element */ \ | |
251 | } | |
252 | ||
253 | #define SIMPLEQ_HEAD_INITIALIZER(head) \ | |
254 | { NULL, &(head).sqh_first } | |
255 | ||
256 | #define SIMPLEQ_ENTRY(type) \ | |
257 | struct { \ | |
258 | struct type *sqe_next; /* next element */ \ | |
259 | } | |
260 | ||
261 | /* | |
262 | * Simple queue access methods. | |
263 | */ | |
264 | #define SIMPLEQ_FIRST(head) ((head)->sqh_first) | |
265 | #define SIMPLEQ_END(head) NULL | |
266 | #define SIMPLEQ_EMPTY(head) (SIMPLEQ_FIRST(head) == SIMPLEQ_END(head)) | |
267 | #define SIMPLEQ_NEXT(elm, field) ((elm)->field.sqe_next) | |
268 | ||
269 | #define SIMPLEQ_FOREACH(var, head, field) \ | |
270 | for((var) = SIMPLEQ_FIRST(head); \ | |
271 | (var) != SIMPLEQ_END(head); \ | |
272 | (var) = SIMPLEQ_NEXT(var, field)) | |
273 | ||
274 | #define SIMPLEQ_FOREACH_SAFE(var, head, field, tvar) \ | |
275 | for ((var) = SIMPLEQ_FIRST(head); \ | |
276 | (var) && ((tvar) = SIMPLEQ_NEXT(var, field), 1); \ | |
277 | (var) = (tvar)) | |
278 | ||
279 | /* | |
280 | * Simple queue functions. | |
281 | */ | |
282 | #define SIMPLEQ_INIT(head) do { \ | |
283 | (head)->sqh_first = NULL; \ | |
284 | (head)->sqh_last = &(head)->sqh_first; \ | |
285 | } while (0) | |
286 | ||
287 | #define SIMPLEQ_INSERT_HEAD(head, elm, field) do { \ | |
288 | if (((elm)->field.sqe_next = (head)->sqh_first) == NULL) \ | |
289 | (head)->sqh_last = &(elm)->field.sqe_next; \ | |
290 | (head)->sqh_first = (elm); \ | |
291 | } while (0) | |
292 | ||
293 | #define SIMPLEQ_INSERT_TAIL(head, elm, field) do { \ | |
294 | (elm)->field.sqe_next = NULL; \ | |
295 | *(head)->sqh_last = (elm); \ | |
296 | (head)->sqh_last = &(elm)->field.sqe_next; \ | |
297 | } while (0) | |
298 | ||
299 | #define SIMPLEQ_INSERT_AFTER(head, listelm, elm, field) do { \ | |
300 | if (((elm)->field.sqe_next = (listelm)->field.sqe_next) == NULL)\ | |
301 | (head)->sqh_last = &(elm)->field.sqe_next; \ | |
302 | (listelm)->field.sqe_next = (elm); \ | |
303 | } while (0) | |
304 | ||
305 | #define SIMPLEQ_REMOVE_HEAD(head, field) do { \ | |
306 | if (((head)->sqh_first = (head)->sqh_first->field.sqe_next) == NULL) \ | |
307 | (head)->sqh_last = &(head)->sqh_first; \ | |
308 | } while (0) | |
309 | ||
310 | #define SIMPLEQ_REMOVE_AFTER(head, elm, field) do { \ | |
311 | if (((elm)->field.sqe_next = (elm)->field.sqe_next->field.sqe_next) \ | |
312 | == NULL) \ | |
313 | (head)->sqh_last = &(elm)->field.sqe_next; \ | |
314 | } while (0) | |
315 | ||
316 | #define SIMPLEQ_CONCAT(head1, head2) do { \ | |
317 | if (!SIMPLEQ_EMPTY((head2))) { \ | |
318 | *(head1)->sqh_last = (head2)->sqh_first; \ | |
319 | (head1)->sqh_last = (head2)->sqh_last; \ | |
320 | SIMPLEQ_INIT((head2)); \ | |
321 | } \ | |
322 | } while (0) | |
323 | ||
324 | /* | |
325 | * XOR Simple queue definitions. | |
326 | */ | |
327 | #define XSIMPLEQ_HEAD(name, type) \ | |
328 | struct name { \ | |
329 | struct type *sqx_first; /* first element */ \ | |
330 | struct type **sqx_last; /* addr of last next element */ \ | |
331 | unsigned long sqx_cookie; \ | |
332 | } | |
333 | ||
334 | #define XSIMPLEQ_ENTRY(type) \ | |
335 | struct { \ | |
336 | struct type *sqx_next; /* next element */ \ | |
337 | } | |
338 | ||
339 | /* | |
340 | * XOR Simple queue access methods. | |
341 | */ | |
342 | #define XSIMPLEQ_XOR(head, ptr) ((__typeof(ptr))((head)->sqx_cookie ^ \ | |
343 | (unsigned long)(ptr))) | |
344 | #define XSIMPLEQ_FIRST(head) XSIMPLEQ_XOR(head, ((head)->sqx_first)) | |
345 | #define XSIMPLEQ_END(head) NULL | |
346 | #define XSIMPLEQ_EMPTY(head) (XSIMPLEQ_FIRST(head) == XSIMPLEQ_END(head)) | |
347 | #define XSIMPLEQ_NEXT(head, elm, field) XSIMPLEQ_XOR(head, ((elm)->field.sqx_next)) | |
348 | ||
349 | ||
350 | #define XSIMPLEQ_FOREACH(var, head, field) \ | |
351 | for ((var) = XSIMPLEQ_FIRST(head); \ | |
352 | (var) != XSIMPLEQ_END(head); \ | |
353 | (var) = XSIMPLEQ_NEXT(head, var, field)) | |
354 | ||
355 | #define XSIMPLEQ_FOREACH_SAFE(var, head, field, tvar) \ | |
356 | for ((var) = XSIMPLEQ_FIRST(head); \ | |
357 | (var) && ((tvar) = XSIMPLEQ_NEXT(head, var, field), 1); \ | |
358 | (var) = (tvar)) | |
359 | ||
360 | /* | |
361 | * XOR Simple queue functions. | |
362 | */ | |
363 | #define XSIMPLEQ_INIT(head) do { \ | |
364 | arc4random_buf(&(head)->sqx_cookie, sizeof((head)->sqx_cookie)); \ | |
365 | (head)->sqx_first = XSIMPLEQ_XOR(head, NULL); \ | |
366 | (head)->sqx_last = XSIMPLEQ_XOR(head, &(head)->sqx_first); \ | |
367 | } while (0) | |
368 | ||
369 | #define XSIMPLEQ_INSERT_HEAD(head, elm, field) do { \ | |
370 | if (((elm)->field.sqx_next = (head)->sqx_first) == \ | |
371 | XSIMPLEQ_XOR(head, NULL)) \ | |
372 | (head)->sqx_last = XSIMPLEQ_XOR(head, &(elm)->field.sqx_next); \ | |
373 | (head)->sqx_first = XSIMPLEQ_XOR(head, (elm)); \ | |
374 | } while (0) | |
375 | ||
376 | #define XSIMPLEQ_INSERT_TAIL(head, elm, field) do { \ | |
377 | (elm)->field.sqx_next = XSIMPLEQ_XOR(head, NULL); \ | |
378 | *(XSIMPLEQ_XOR(head, (head)->sqx_last)) = XSIMPLEQ_XOR(head, (elm)); \ | |
379 | (head)->sqx_last = XSIMPLEQ_XOR(head, &(elm)->field.sqx_next); \ | |
380 | } while (0) | |
381 | ||
382 | #define XSIMPLEQ_INSERT_AFTER(head, listelm, elm, field) do { \ | |
383 | if (((elm)->field.sqx_next = (listelm)->field.sqx_next) == \ | |
384 | XSIMPLEQ_XOR(head, NULL)) \ | |
385 | (head)->sqx_last = XSIMPLEQ_XOR(head, &(elm)->field.sqx_next); \ | |
386 | (listelm)->field.sqx_next = XSIMPLEQ_XOR(head, (elm)); \ | |
387 | } while (0) | |
388 | ||
389 | #define XSIMPLEQ_REMOVE_HEAD(head, field) do { \ | |
390 | if (((head)->sqx_first = XSIMPLEQ_XOR(head, \ | |
391 | (head)->sqx_first)->field.sqx_next) == XSIMPLEQ_XOR(head, NULL)) \ | |
392 | (head)->sqx_last = XSIMPLEQ_XOR(head, &(head)->sqx_first); \ | |
393 | } while (0) | |
394 | ||
395 | #define XSIMPLEQ_REMOVE_AFTER(head, elm, field) do { \ | |
396 | if (((elm)->field.sqx_next = XSIMPLEQ_XOR(head, \ | |
397 | (elm)->field.sqx_next)->field.sqx_next) \ | |
398 | == XSIMPLEQ_XOR(head, NULL)) \ | |
399 | (head)->sqx_last = \ | |
400 | XSIMPLEQ_XOR(head, &(elm)->field.sqx_next); \ | |
401 | } while (0) | |
402 | ||
403 | ||
404 | /* | |
405 | * Tail queue definitions. | |
406 | */ | |
407 | #define TAILQ_HEAD(name, type) \ | |
408 | struct name { \ | |
409 | struct type *tqh_first; /* first element */ \ | |
410 | struct type **tqh_last; /* addr of last next element */ \ | |
411 | } | |
412 | ||
413 | #define TAILQ_HEAD_INITIALIZER(head) \ | |
414 | { NULL, &(head).tqh_first } | |
415 | ||
416 | #define TAILQ_ENTRY(type) \ | |
417 | struct { \ | |
418 | struct type *tqe_next; /* next element */ \ | |
419 | struct type **tqe_prev; /* address of previous next element */ \ | |
420 | } | |
421 | ||
422 | /* | |
423 | * Tail queue access methods. | |
424 | */ | |
425 | #define TAILQ_FIRST(head) ((head)->tqh_first) | |
426 | #define TAILQ_END(head) NULL | |
427 | #define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next) | |
428 | #define TAILQ_LAST(head, headname) \ | |
429 | (*(((struct headname *)((head)->tqh_last))->tqh_last)) | |
430 | /* XXX */ | |
431 | #define TAILQ_PREV(elm, headname, field) \ | |
432 | (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last)) | |
433 | #define TAILQ_EMPTY(head) \ | |
434 | (TAILQ_FIRST(head) == TAILQ_END(head)) | |
435 | ||
436 | #define TAILQ_FOREACH(var, head, field) \ | |
437 | for((var) = TAILQ_FIRST(head); \ | |
438 | (var) != TAILQ_END(head); \ | |
439 | (var) = TAILQ_NEXT(var, field)) | |
440 | ||
441 | #define TAILQ_FOREACH_SAFE(var, head, field, tvar) \ | |
442 | for ((var) = TAILQ_FIRST(head); \ | |
443 | (var) != TAILQ_END(head) && \ | |
444 | ((tvar) = TAILQ_NEXT(var, field), 1); \ | |
445 | (var) = (tvar)) | |
446 | ||
447 | ||
448 | #define TAILQ_FOREACH_REVERSE(var, head, headname, field) \ | |
449 | for((var) = TAILQ_LAST(head, headname); \ | |
450 | (var) != TAILQ_END(head); \ | |
451 | (var) = TAILQ_PREV(var, headname, field)) | |
452 | ||
453 | #define TAILQ_FOREACH_REVERSE_SAFE(var, head, headname, field, tvar) \ | |
454 | for ((var) = TAILQ_LAST(head, headname); \ | |
455 | (var) != TAILQ_END(head) && \ | |
456 | ((tvar) = TAILQ_PREV(var, headname, field), 1); \ | |
457 | (var) = (tvar)) | |
458 | ||
459 | /* | |
460 | * Tail queue functions. | |
461 | */ | |
462 | #define TAILQ_INIT(head) do { \ | |
463 | (head)->tqh_first = NULL; \ | |
464 | (head)->tqh_last = &(head)->tqh_first; \ | |
465 | } while (0) | |
466 | ||
467 | #define TAILQ_INSERT_HEAD(head, elm, field) do { \ | |
468 | if (((elm)->field.tqe_next = (head)->tqh_first) != NULL) \ | |
469 | (head)->tqh_first->field.tqe_prev = \ | |
470 | &(elm)->field.tqe_next; \ | |
471 | else \ | |
472 | (head)->tqh_last = &(elm)->field.tqe_next; \ | |
473 | (head)->tqh_first = (elm); \ | |
474 | (elm)->field.tqe_prev = &(head)->tqh_first; \ | |
475 | } while (0) | |
476 | ||
477 | #define TAILQ_INSERT_TAIL(head, elm, field) do { \ | |
478 | (elm)->field.tqe_next = NULL; \ | |
479 | (elm)->field.tqe_prev = (head)->tqh_last; \ | |
480 | *(head)->tqh_last = (elm); \ | |
481 | (head)->tqh_last = &(elm)->field.tqe_next; \ | |
482 | } while (0) | |
483 | ||
484 | #define TAILQ_INSERT_AFTER(head, listelm, elm, field) do { \ | |
485 | if (((elm)->field.tqe_next = (listelm)->field.tqe_next) != NULL)\ | |
486 | (elm)->field.tqe_next->field.tqe_prev = \ | |
487 | &(elm)->field.tqe_next; \ | |
488 | else \ | |
489 | (head)->tqh_last = &(elm)->field.tqe_next; \ | |
490 | (listelm)->field.tqe_next = (elm); \ | |
491 | (elm)->field.tqe_prev = &(listelm)->field.tqe_next; \ | |
492 | } while (0) | |
493 | ||
494 | #define TAILQ_INSERT_BEFORE(listelm, elm, field) do { \ | |
495 | (elm)->field.tqe_prev = (listelm)->field.tqe_prev; \ | |
496 | (elm)->field.tqe_next = (listelm); \ | |
497 | *(listelm)->field.tqe_prev = (elm); \ | |
498 | (listelm)->field.tqe_prev = &(elm)->field.tqe_next; \ | |
499 | } while (0) | |
500 | ||
501 | #define TAILQ_REMOVE(head, elm, field) do { \ | |
502 | if (((elm)->field.tqe_next) != NULL) \ | |
503 | (elm)->field.tqe_next->field.tqe_prev = \ | |
504 | (elm)->field.tqe_prev; \ | |
505 | else \ | |
506 | (head)->tqh_last = (elm)->field.tqe_prev; \ | |
507 | *(elm)->field.tqe_prev = (elm)->field.tqe_next; \ | |
508 | _Q_INVALIDATE((elm)->field.tqe_prev); \ | |
509 | _Q_INVALIDATE((elm)->field.tqe_next); \ | |
510 | } while (0) | |
511 | ||
512 | #define TAILQ_REPLACE(head, elm, elm2, field) do { \ | |
513 | if (((elm2)->field.tqe_next = (elm)->field.tqe_next) != NULL) \ | |
514 | (elm2)->field.tqe_next->field.tqe_prev = \ | |
515 | &(elm2)->field.tqe_next; \ | |
516 | else \ | |
517 | (head)->tqh_last = &(elm2)->field.tqe_next; \ | |
518 | (elm2)->field.tqe_prev = (elm)->field.tqe_prev; \ | |
519 | *(elm2)->field.tqe_prev = (elm2); \ | |
520 | _Q_INVALIDATE((elm)->field.tqe_prev); \ | |
521 | _Q_INVALIDATE((elm)->field.tqe_next); \ | |
522 | } while (0) | |
523 | ||
524 | #define TAILQ_CONCAT(head1, head2, field) do { \ | |
525 | if (!TAILQ_EMPTY(head2)) { \ | |
526 | *(head1)->tqh_last = (head2)->tqh_first; \ | |
527 | (head2)->tqh_first->field.tqe_prev = (head1)->tqh_last; \ | |
528 | (head1)->tqh_last = (head2)->tqh_last; \ | |
529 | TAILQ_INIT((head2)); \ | |
530 | } \ | |
531 | } while (0) | |
532 | ||
533 | #endif /* !_SYS_QUEUE_H_ */ |