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 * modified for flow-tools to prevent conflicts with sys/queue.h on some
34 * systems.
35 *
36 * @(#)queue.h 8.5 (Berkeley) 8/20/94
37 * $Id: ftqueue.h,v 1.2 2001/04/08 13:43:01 maf Exp $
38 */
39
40 #ifndef _FT_QUEUE_H_
41 #define _FT_QUEUE_H_
42
43 /*
44 * This file defines five types of data structures: singly-linked lists,
45 * slingly-linked tail queues, lists, tail queues, and circular queues.
46 *
47 * A singly-linked list is headed by a single forward pointer. The elements
48 * are singly linked for minimum space and pointer manipulation overhead at
49 * the expense of O(n) removal for arbitrary elements. New elements can be
50 * added to the list after an existing element or at the head of the list.
51 * Elements being removed from the head of the list should use the explicit
52 * macro for this purpose for optimum efficiency. A singly-linked list may
53 * only be traversed in the forward direction. Singly-linked lists are ideal
54 * for applications with large datasets and few or no removals or for
55 * implementing a LIFO queue.
56 *
57 * A singly-linked tail queue is headed by a pair of pointers, one to the
58 * head of the list and the other to the tail of the list. The elements are
59 * singly linked for minimum space and pointer manipulation overhead at the
60 * expense of O(n) removal for arbitrary elements. New elements can be added
61 * to the list after an existing element, at the head of the list, or at the
62 * end of the list. Elements being removed from the head of the tail queue
63 * should use the explicit macro for this purpose for optimum efficiency.
64 * A singly-linked tail queue may only be traversed in the forward direction.
65 * Singly-linked tail queues are ideal for applications with large datasets
66 * and few or no removals or for implementing a FIFO queue.
67 *
68 * A list is headed by a single forward pointer (or an array of forward
69 * pointers for a hash table header). The elements are doubly linked
70 * so that an arbitrary element can be removed without a need to
71 * traverse the list. New elements can be added to the list before
72 * or after an existing element or at the head of the list. A list
73 * may only be traversed in the forward direction.
74 *
75 * A tail queue is headed by a pair of pointers, one to the head of the
76 * list and the other to the tail of the list. The elements are doubly
77 * linked so that an arbitrary element can be removed without a need to
78 * traverse the list. New elements can be added to the list before or
79 * after an existing element, at the head of the list, or at the end of
80 * the list. A tail queue may only be traversed in the forward direction.
81 *
82 * A circle queue is headed by a pair of pointers, one to the head of the
83 * list and the other to the tail of the list. The elements are doubly
84 * linked so that an arbitrary element can be removed without a need to
85 * traverse the list. New elements can be added to the list before or after
86 * an existing element, at the head of the list, or at the end of the list.
87 * A circle queue may be traversed in either direction, but has a more
88 * complex end of list detection.
89 *
90 * For details on the use of these macros, see the queue(3) manual page.
91 *
92 *
93 * SLIST LIST STAILQ TAILQ CIRCLEQ
94 * _HEAD + + + + +
95 * _ENTRY + + + + +
96 * _INIT + + + + +
97 * _EMPTY + + + + +
98 * _FIRST + + - + +
99 * _NEXT + + - + +
100 * _PREV - - - + +
101 * _LAST - - - + +
102 * _FOREACH + + - + -
103 * _INSERT_HEAD + + + + +
104 * _INSERT_BEFORE - + - + +
105 * _INSERT_AFTER + + + + +
106 * _INSERT_TAIL - - + + +
107 * _REMOVE_HEAD + - + - -
108 * _REMOVE + + + + +
109 *
110 */
111
112 /*
113 * Singly-linked List definitions.
114 */
115 #define FT_SLIST_HEAD(name, type) \
116 struct name { \
117 struct type *slh_first; /* first element */ \
118 }
119
120 #define FT_SLIST_ENTRY(type) \
121 struct { \
122 struct type *sle_next; /* next element */ \
123 }
124
125 /*
126 * Singly-linked List functions.
127 */
128 #define FT_SLIST_EMPTY(head) ((head)->slh_first == NULL)
129
130 #define FT_SLIST_FIRST(head) ((head)->slh_first)
131
132 #define FT_SLIST_FOREACH(var, head, field) \
133 for((var) = (head)->slh_first; (var); (var) = (var)->field.sle_next)
134
135 #define FT_SLIST_INIT(head) { \
136 (head)->slh_first = NULL; \
137 }
138
139 #define FT_SLIST_INSERT_AFTER(slistelm, elm, field) do { \
140 (elm)->field.sle_next = (slistelm)->field.sle_next; \
141 (slistelm)->field.sle_next = (elm); \
142 } while (0)
143
144 #define FT_SLIST_INSERT_HEAD(head, elm, field) do { \
145 (elm)->field.sle_next = (head)->slh_first; \
146 (head)->slh_first = (elm); \
147 } while (0)
148
149 #define FT_SLIST_NEXT(elm, field) ((elm)->field.sle_next)
150
151 #define FT_SLIST_REMOVE_HEAD(head, field) do { \
152 (head)->slh_first = (head)->slh_first->field.sle_next; \
153 } while (0)
154
155 #define FT_SLIST_REMOVE(head, elm, type, field) do { \
156 if ((head)->slh_first == (elm)) { \
157 FT_SLIST_REMOVE_HEAD((head), field); \
158 } \
159 else { \
160 struct type *curelm = (head)->slh_first; \
161 while( curelm->field.sle_next != (elm) ) \
162 curelm = curelm->field.sle_next; \
163 curelm->field.sle_next = \
164 curelm->field.sle_next->field.sle_next; \
165 } \
166 } while (0)
167
168 /*
169 * Singly-linked Tail queue definitions.
170 */
171 #define FT_STAILQ_HEAD(name, type) \
172 struct name { \
173 struct type *stqh_first;/* first element */ \
174 struct type **stqh_last;/* addr of last next element */ \
175 }
176
177 #define FT_STAILQ_ENTRY(type) \
178 struct { \
179 struct type *stqe_next; /* next element */ \
180 }
181
182 /*
183 * Singly-linked Tail queue functions.
184 */
185 #define FT_STAILQ_EMPTY(head) ((head)->stqh_first == NULL)
186
187 #define FT_STAILQ_INIT(head) do { \
188 (head)->stqh_first = NULL; \
189 (head)->stqh_last = &(head)->stqh_first; \
190 } while (0)
191
192 #define FT_STAILQ_FIRST(head) ((head)->stqh_first)
193 #define FT_STAILQ_LAST(head) (*(head)->stqh_last)
194
195 #define FT_STAILQ_INSERT_HEAD(head, elm, field) do { \
196 if (((elm)->field.stqe_next = (head)->stqh_first) == NULL) \
197 (head)->stqh_last = &(elm)->field.stqe_next; \
198 (head)->stqh_first = (elm); \
199 } while (0)
200
201 #define FT_STAILQ_INSERT_TAIL(head, elm, field) do { \
202 (elm)->field.stqe_next = NULL; \
203 *(head)->stqh_last = (elm); \
204 (head)->stqh_last = &(elm)->field.stqe_next; \
205 } while (0)
206
207 #define FT_STAILQ_INSERT_AFTER(head, tqelm, elm, field) do { \
208 if (((elm)->field.stqe_next = (tqelm)->field.stqe_next) == NULL)\
209 (head)->stqh_last = &(elm)->field.stqe_next; \
210 (tqelm)->field.stqe_next = (elm); \
211 } while (0)
212
213 #define FT_STAILQ_NEXT(elm, field) ((elm)->field.stqe_next)
214
215 #define FT_STAILQ_FOREACH(var, head, field) \
216 for (var = FT_STAILQ_FIRST(head); var; var = FT_STAILQ_NEXT(var, field))
217
218 #define FT_STAILQ_REMOVE_HEAD(head, field) do { \
219 if (((head)->stqh_first = \
220 (head)->stqh_first->field.stqe_next) == NULL) \
221 (head)->stqh_last = &(head)->stqh_first; \
222 } while (0)
223
224 #define FT_STAILQ_REMOVE(head, elm, type, field) do { \
225 if ((head)->stqh_first == (elm)) { \
226 FT_STAILQ_REMOVE_HEAD(head, field); \
227 } \
228 else { \
229 struct type *curelm = (head)->stqh_first; \
230 while( curelm->field.stqe_next != (elm) ) \
231 curelm = curelm->field.stqe_next; \
232 if((curelm->field.stqe_next = \
233 curelm->field.stqe_next->field.stqe_next) == NULL) \
234 (head)->stqh_last = &(curelm)->field.stqe_next; \
235 } \
236 } while (0)
237
238 /*
239 * List definitions.
240 */
241 #define FT_LIST_HEAD(name, type) \
242 struct name { \
243 struct type *lh_first; /* first element */ \
244 }
245
246 #define FT_LIST_ENTRY(type) \
247 struct { \
248 struct type *le_next; /* next element */ \
249 struct type **le_prev; /* address of previous next element */ \
250 }
251
252 /*
253 * List functions.
254 */
255
256 #define FT_LIST_EMPTY(head) ((head)->lh_first == NULL)
257
258 #define FT_LIST_FIRST(head) ((head)->lh_first)
259
260 #define FT_LIST_FOREACH(var, head, field) \
261 for((var) = (head)->lh_first; (var); (var) = (var)->field.le_next)
262
263 #define FT_LIST_INIT(head) do { \
264 (head)->lh_first = NULL; \
265 } while (0)
266
267 #define FT_LIST_INSERT_AFTER(listelm, elm, field) do { \
268 if (((elm)->field.le_next = (listelm)->field.le_next) != NULL) \
269 (listelm)->field.le_next->field.le_prev = \
270 &(elm)->field.le_next; \
271 (listelm)->field.le_next = (elm); \
272 (elm)->field.le_prev = &(listelm)->field.le_next; \
273 } while (0)
274
275 #define FT_LIST_INSERT_BEFORE(listelm, elm, field) do { \
276 (elm)->field.le_prev = (listelm)->field.le_prev; \
277 (elm)->field.le_next = (listelm); \
278 *(listelm)->field.le_prev = (elm); \
279 (listelm)->field.le_prev = &(elm)->field.le_next; \
280 } while (0)
281
282 #define FT_LIST_INSERT_HEAD(head, elm, field) do { \
283 if (((elm)->field.le_next = (head)->lh_first) != NULL) \
284 (head)->lh_first->field.le_prev = &(elm)->field.le_next;\
285 (head)->lh_first = (elm); \
286 (elm)->field.le_prev = &(head)->lh_first; \
287 } while (0)
288
289 #define FT_LIST_NEXT(elm, field) ((elm)->field.le_next)
290
291 #define FT_LIST_REMOVE(elm, field) do { \
292 if ((elm)->field.le_next != NULL) \
293 (elm)->field.le_next->field.le_prev = \
294 (elm)->field.le_prev; \
295 *(elm)->field.le_prev = (elm)->field.le_next; \
296 } while (0)
297
298 /*
299 * Tail queue definitions.
300 */
301 #define FT_TAILQ_HEAD(name, type) \
302 struct name { \
303 struct type *tqh_first; /* first element */ \
304 struct type **tqh_last; /* addr of last next element */ \
305 }
306
307 #define FT_TAILQ_HEAD_INITIALIZER(head) \
308 { NULL, &(head).tqh_first }
309
310 #define FT_TAILQ_ENTRY(type) \
311 struct { \
312 struct type *tqe_next; /* next element */ \
313 struct type **tqe_prev; /* address of previous next element */ \
314 }
315
316 /*
317 * Tail queue functions.
318 */
319 #define FT_TAILQ_EMPTY(head) ((head)->tqh_first == NULL)
320
321 #define FT_TAILQ_FOREACH(var, head, field) \
322 for (var = FT_TAILQ_FIRST(head); var; var = FT_TAILQ_NEXT(var, field))
323
324 #define FT_TAILQ_FIRST(head) ((head)->tqh_first)
325
326 #define FT_TAILQ_LAST(head, headname) \
327 (*(((struct headname *)((head)->tqh_last))->tqh_last))
328
329 #define FT_TAILQ_NEXT(elm, field) ((elm)->field.tqe_next)
330
331 #define FT_TAILQ_PREV(elm, headname, field) \
332 (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last))
333
334 #define FT_TAILQ_INIT(head) do { \
335 (head)->tqh_first = NULL; \
336 (head)->tqh_last = &(head)->tqh_first; \
337 } while (0)
338
339 #define FT_TAILQ_INSERT_HEAD(head, elm, field) do { \
340 if (((elm)->field.tqe_next = (head)->tqh_first) != NULL) \
341 (head)->tqh_first->field.tqe_prev = \
342 &(elm)->field.tqe_next; \
343 else \
344 (head)->tqh_last = &(elm)->field.tqe_next; \
345 (head)->tqh_first = (elm); \
346 (elm)->field.tqe_prev = &(head)->tqh_first; \
347 } while (0)
348
349 #define FT_TAILQ_INSERT_TAIL(head, elm, field) do { \
350 (elm)->field.tqe_next = NULL; \
351 (elm)->field.tqe_prev = (head)->tqh_last; \
352 *(head)->tqh_last = (elm); \
353 (head)->tqh_last = &(elm)->field.tqe_next; \
354 } while (0)
355
356 #define FT_TAILQ_INSERT_AFTER(head, listelm, elm, field) do { \
357 if (((elm)->field.tqe_next = (listelm)->field.tqe_next) != NULL)\
358 (elm)->field.tqe_next->field.tqe_prev = \
359 &(elm)->field.tqe_next; \
360 else \
361 (head)->tqh_last = &(elm)->field.tqe_next; \
362 (listelm)->field.tqe_next = (elm); \
363 (elm)->field.tqe_prev = &(listelm)->field.tqe_next; \
364 } while (0)
365
366 #define FT_TAILQ_INSERT_BEFORE(listelm, elm, field) do { \
367 (elm)->field.tqe_prev = (listelm)->field.tqe_prev; \
368 (elm)->field.tqe_next = (listelm); \
369 *(listelm)->field.tqe_prev = (elm); \
370 (listelm)->field.tqe_prev = &(elm)->field.tqe_next; \
371 } while (0)
372
373 #define FT_TAILQ_REMOVE(head, elm, field) do { \
374 if (((elm)->field.tqe_next) != NULL) \
375 (elm)->field.tqe_next->field.tqe_prev = \
376 (elm)->field.tqe_prev; \
377 else \
378 (head)->tqh_last = (elm)->field.tqe_prev; \
379 *(elm)->field.tqe_prev = (elm)->field.tqe_next; \
380 } while (0)
381
382 /*
383 * Circular queue definitions.
384 */
385 #define FT_CIRCLEQ_HEAD(name, type) \
386 struct name { \
387 struct type *cqh_first; /* first element */ \
388 struct type *cqh_last; /* last element */ \
389 }
390
391 #define FT_CIRCLEQ_ENTRY(type) \
392 struct { \
393 struct type *cqe_next; /* next element */ \
394 struct type *cqe_prev; /* previous element */ \
395 }
396
397 /*
398 * Circular queue functions.
399 */
400 #define FT_CIRCLEQ_EMPTY(head) ((head)->cqh_first == (void *)(head))
401
402 #define FT_CIRCLEQ_FIRST(head) ((head)->cqh_first)
403
404 #define FT_CIRCLEQ_FOREACH(var, head, field) \
405 for((var) = (head)->cqh_first; \
406 (var) != (void *)(head); \
407 (var) = (var)->field.cqe_next)
408
409 #define FT_CIRCLEQ_INIT(head) do { \
410 (head)->cqh_first = (void *)(head); \
411 (head)->cqh_last = (void *)(head); \
412 } while (0)
413
414 #define FT_CIRCLEQ_INSERT_AFTER(head, listelm, elm, field) do { \
415 (elm)->field.cqe_next = (listelm)->field.cqe_next; \
416 (elm)->field.cqe_prev = (listelm); \
417 if ((listelm)->field.cqe_next == (void *)(head)) \
418 (head)->cqh_last = (elm); \
419 else \
420 (listelm)->field.cqe_next->field.cqe_prev = (elm); \
421 (listelm)->field.cqe_next = (elm); \
422 } while (0)
423
424 #define FT_CIRCLEQ_INSERT_BEFORE(head, listelm, elm, field) do { \
425 (elm)->field.cqe_next = (listelm); \
426 (elm)->field.cqe_prev = (listelm)->field.cqe_prev; \
427 if ((listelm)->field.cqe_prev == (void *)(head)) \
428 (head)->cqh_first = (elm); \
429 else \
430 (listelm)->field.cqe_prev->field.cqe_next = (elm); \
431 (listelm)->field.cqe_prev = (elm); \
432 } while (0)
433
434 #define FT_CIRCLEQ_INSERT_HEAD(head, elm, field) do { \
435 (elm)->field.cqe_next = (head)->cqh_first; \
436 (elm)->field.cqe_prev = (void *)(head); \
437 if ((head)->cqh_last == (void *)(head)) \
438 (head)->cqh_last = (elm); \
439 else \
440 (head)->cqh_first->field.cqe_prev = (elm); \
441 (head)->cqh_first = (elm); \
442 } while (0)
443
444 #define FT_CIRCLEQ_INSERT_TAIL(head, elm, field) do { \
445 (elm)->field.cqe_next = (void *)(head); \
446 (elm)->field.cqe_prev = (head)->cqh_last; \
447 if ((head)->cqh_first == (void *)(head)) \
448 (head)->cqh_first = (elm); \
449 else \
450 (head)->cqh_last->field.cqe_next = (elm); \
451 (head)->cqh_last = (elm); \
452 } while (0)
453
454 #define FT_CIRCLEQ_LAST(head) ((head)->cqh_last)
455
456 #define FT_CIRCLEQ_NEXT(elm,field) ((elm)->field.cqe_next)
457
458 #define FT_CIRCLEQ_PREV(elm,field) ((elm)->field.cqe_prev)
459
460 #define FT_CIRCLEQ_REMOVE(head, elm, field) do { \
461 if ((elm)->field.cqe_next == (void *)(head)) \
462 (head)->cqh_last = (elm)->field.cqe_prev; \
463 else \
464 (elm)->field.cqe_next->field.cqe_prev = \
465 (elm)->field.cqe_prev; \
466 if ((elm)->field.cqe_prev == (void *)(head)) \
467 (head)->cqh_first = (elm)->field.cqe_next; \
468 else \
469 (elm)->field.cqe_prev->field.cqe_next = \
470 (elm)->field.cqe_next; \
471 } while (0)
472
473 #ifdef KERNEL
474
475 /*
476 * XXX insque() and remque() are an old way of handling certain queues.
477 * They bogusly assumes that all queue heads look alike.
478 */
479
480 struct quehead {
481 struct quehead *qh_link;
482 struct quehead *qh_rlink;
483 };
484
485 #ifdef __GNUC__
486
487 static __inline void
insque(void * a,void * b)488 insque(void *a, void *b)
489 {
490 struct quehead *element = a, *head = b;
491
492 element->qh_link = head->qh_link;
493 element->qh_rlink = head;
494 head->qh_link = element;
495 element->qh_link->qh_rlink = element;
496 }
497
498 static __inline void
remque(void * a)499 remque(void *a)
500 {
501 struct quehead *element = a;
502
503 element->qh_link->qh_rlink = element->qh_rlink;
504 element->qh_rlink->qh_link = element->qh_link;
505 element->qh_rlink = 0;
506 }
507
508 #else /* !__GNUC__ */
509
510 void insque __P((void *a, void *b));
511 void remque __P((void *a));
512
513 #endif /* __GNUC__ */
514
515 #endif /* KERNEL */
516
517 #endif /* !_FT_QUEUE_H_ */
518