NFS man page: update nfs(5) with details about IPv6 support
[nfs-utils.git] / utils / idmapd / queue.h
1 /*      $OpenBSD: queue.h,v 1.22 2001/06/23 04:39:35 angelos 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 circular 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 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  * A circle queue is headed by a pair of pointers, one to the head of the
75  * list and the other to the tail of the list. The elements are doubly
76  * linked so that an arbitrary element can be removed without a need to
77  * traverse the list. New elements can be added to the list before or after
78  * an existing element, at the head of the list, or at the end of the list.
79  * A circle queue may be traversed in either direction, but has a more
80  * complex end of list detection.
81  *
82  * For details on the use of these macros, see the queue(3) manual page.
83  */
84
85 /*
86  * Singly-linked List definitions.
87  */
88 #define SLIST_HEAD(name, type)                                          \
89 struct name {                                                           \
90         struct type *slh_first; /* first element */                     \
91 }
92
93 #define SLIST_HEAD_INITIALIZER(head)                                    \
94         { NULL }
95
96 #define SLIST_ENTRY(type)                                               \
97 struct {                                                                \
98         struct type *sle_next;  /* next element */                      \
99 }
100
101 /*
102  * Singly-linked List access methods.
103  */
104 #define SLIST_FIRST(head)       ((head)->slh_first)
105 #define SLIST_END(head)         NULL
106 #define SLIST_EMPTY(head)       (SLIST_FIRST(head) == SLIST_END(head))
107 #define SLIST_NEXT(elm, field)  ((elm)->field.sle_next)
108
109 #define SLIST_FOREACH(var, head, field)                                 \
110         for((var) = SLIST_FIRST(head);                                  \
111             (var) != SLIST_END(head);                                   \
112             (var) = SLIST_NEXT(var, field))
113
114 /*
115  * Singly-linked List functions.
116  */
117 #define SLIST_INIT(head) {                                              \
118         SLIST_FIRST(head) = SLIST_END(head);                            \
119 }
120
121 #define SLIST_INSERT_AFTER(slistelm, elm, field) do {                   \
122         (elm)->field.sle_next = (slistelm)->field.sle_next;             \
123         (slistelm)->field.sle_next = (elm);                             \
124 } while (0)
125
126 #define SLIST_INSERT_HEAD(head, elm, field) do {                        \
127         (elm)->field.sle_next = (head)->slh_first;                      \
128         (head)->slh_first = (elm);                                      \
129 } while (0)
130
131 #define SLIST_REMOVE_HEAD(head, field) do {                             \
132         (head)->slh_first = (head)->slh_first->field.sle_next;          \
133 } while (0)
134
135 #define SLIST_REMOVE(head, elm, type, field) do {                       \
136         if ((head)->slh_first == (elm)) {                               \
137                 SLIST_REMOVE_HEAD((head), field);                       \
138         }                                                               \
139         else {                                                          \
140                 struct type *curelm = (head)->slh_first;                \
141                 while( curelm->field.sle_next != (elm) )                \
142                         curelm = curelm->field.sle_next;                \
143                 curelm->field.sle_next =                                \
144                     curelm->field.sle_next->field.sle_next;             \
145         }                                                               \
146 } while (0)
147
148 /*
149  * List definitions.
150  */
151 #define LIST_HEAD(name, type)                                           \
152 struct name {                                                           \
153         struct type *lh_first;  /* first element */                     \
154 }
155
156 #define LIST_HEAD_INITIALIZER(head)                                     \
157         { NULL }
158
159 #define LIST_ENTRY(type)                                                \
160 struct {                                                                \
161         struct type *le_next;   /* next element */                      \
162         struct type **le_prev;  /* address of previous next element */  \
163 }
164
165 /*
166  * List access methods
167  */
168 #define LIST_FIRST(head)                ((head)->lh_first)
169 #define LIST_END(head)                  NULL
170 #define LIST_EMPTY(head)                (LIST_FIRST(head) == LIST_END(head))
171 #define LIST_NEXT(elm, field)           ((elm)->field.le_next)
172
173 #define LIST_FOREACH(var, head, field)                                  \
174         for((var) = LIST_FIRST(head);                                   \
175             (var)!= LIST_END(head);                                     \
176             (var) = LIST_NEXT(var, field))
177
178 /*
179  * List functions.
180  */
181 #define LIST_INIT(head) do {                                            \
182         LIST_FIRST(head) = LIST_END(head);                              \
183 } while (0)
184
185 #define LIST_INSERT_AFTER(listelm, elm, field) do {                     \
186         if (((elm)->field.le_next = (listelm)->field.le_next) != NULL)  \
187                 (listelm)->field.le_next->field.le_prev =               \
188                     &(elm)->field.le_next;                              \
189         (listelm)->field.le_next = (elm);                               \
190         (elm)->field.le_prev = &(listelm)->field.le_next;               \
191 } while (0)
192
193 #define LIST_INSERT_BEFORE(listelm, elm, field) do {                    \
194         (elm)->field.le_prev = (listelm)->field.le_prev;                \
195         (elm)->field.le_next = (listelm);                               \
196         *(listelm)->field.le_prev = (elm);                              \
197         (listelm)->field.le_prev = &(elm)->field.le_next;               \
198 } while (0)
199
200 #define LIST_INSERT_HEAD(head, elm, field) do {                         \
201         if (((elm)->field.le_next = (head)->lh_first) != NULL)          \
202                 (head)->lh_first->field.le_prev = &(elm)->field.le_next;\
203         (head)->lh_first = (elm);                                       \
204         (elm)->field.le_prev = &(head)->lh_first;                       \
205 } while (0)
206
207 #define LIST_REMOVE(elm, field) do {                                    \
208         if ((elm)->field.le_next != NULL)                               \
209                 (elm)->field.le_next->field.le_prev =                   \
210                     (elm)->field.le_prev;                               \
211         *(elm)->field.le_prev = (elm)->field.le_next;                   \
212 } while (0)
213
214 #define LIST_REPLACE(elm, elm2, field) do {                             \
215         if (((elm2)->field.le_next = (elm)->field.le_next) != NULL)     \
216                 (elm2)->field.le_next->field.le_prev =                  \
217                     &(elm2)->field.le_next;                             \
218         (elm2)->field.le_prev = (elm)->field.le_prev;                   \
219         *(elm2)->field.le_prev = (elm2);                                \
220 } while (0)
221
222 /*
223  * Simple queue definitions.
224  */
225 #define SIMPLEQ_HEAD(name, type)                                        \
226 struct name {                                                           \
227         struct type *sqh_first; /* first element */                     \
228         struct type **sqh_last; /* addr of last next element */         \
229 }
230
231 #define SIMPLEQ_HEAD_INITIALIZER(head)                                  \
232         { NULL, &(head).sqh_first }
233
234 #define SIMPLEQ_ENTRY(type)                                             \
235 struct {                                                                \
236         struct type *sqe_next;  /* next element */                      \
237 }
238
239 /*
240  * Simple queue access methods.
241  */
242 #define SIMPLEQ_FIRST(head)         ((head)->sqh_first)
243 #define SIMPLEQ_END(head)           NULL
244 #define SIMPLEQ_EMPTY(head)         (SIMPLEQ_FIRST(head) == SIMPLEQ_END(head))
245 #define SIMPLEQ_NEXT(elm, field)    ((elm)->field.sqe_next)
246
247 #define SIMPLEQ_FOREACH(var, head, field)                               \
248         for((var) = SIMPLEQ_FIRST(head);                                \
249             (var) != SIMPLEQ_END(head);                                 \
250             (var) = SIMPLEQ_NEXT(var, field))
251
252 /*
253  * Simple queue functions.
254  */
255 #define SIMPLEQ_INIT(head) do {                                         \
256         (head)->sqh_first = NULL;                                       \
257         (head)->sqh_last = &(head)->sqh_first;                          \
258 } while (0)
259
260 #define SIMPLEQ_INSERT_HEAD(head, elm, field) do {                      \
261         if (((elm)->field.sqe_next = (head)->sqh_first) == NULL)        \
262                 (head)->sqh_last = &(elm)->field.sqe_next;              \
263         (head)->sqh_first = (elm);                                      \
264 } while (0)
265
266 #define SIMPLEQ_INSERT_TAIL(head, elm, field) do {                      \
267         (elm)->field.sqe_next = NULL;                                   \
268         *(head)->sqh_last = (elm);                                      \
269         (head)->sqh_last = &(elm)->field.sqe_next;                      \
270 } while (0)
271
272 #define SIMPLEQ_INSERT_AFTER(head, listelm, elm, field) do {            \
273         if (((elm)->field.sqe_next = (listelm)->field.sqe_next) == NULL)\
274                 (head)->sqh_last = &(elm)->field.sqe_next;              \
275         (listelm)->field.sqe_next = (elm);                              \
276 } while (0)
277
278 #define SIMPLEQ_REMOVE_HEAD(head, elm, field) do {                      \
279         if (((head)->sqh_first = (elm)->field.sqe_next) == NULL)        \
280                 (head)->sqh_last = &(head)->sqh_first;                  \
281 } while (0)
282
283 /*
284  * Tail queue definitions.
285  */
286 #define TAILQ_HEAD(name, type)                                          \
287 struct name {                                                           \
288         struct type *tqh_first; /* first element */                     \
289         struct type **tqh_last; /* addr of last next element */         \
290 }
291
292 #define TAILQ_HEAD_INITIALIZER(head)                                    \
293         { NULL, &(head).tqh_first }
294
295 #define TAILQ_ENTRY(type)                                               \
296 struct {                                                                \
297         struct type *tqe_next;  /* next element */                      \
298         struct type **tqe_prev; /* address of previous next element */  \
299 }
300
301 /*
302  * tail queue access methods
303  */
304 #define TAILQ_FIRST(head)               ((head)->tqh_first)
305 #define TAILQ_END(head)                 NULL
306 #define TAILQ_NEXT(elm, field)          ((elm)->field.tqe_next)
307 #define TAILQ_LAST(head, headname)                                      \
308         (*(((struct headname *)((head)->tqh_last))->tqh_last))
309 /* XXX */
310 #define TAILQ_PREV(elm, headname, field)                                \
311         (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last))
312 #define TAILQ_EMPTY(head)                                               \
313         (TAILQ_FIRST(head) == TAILQ_END(head))
314
315 #define TAILQ_FOREACH(var, head, field)                                 \
316         for((var) = TAILQ_FIRST(head);                                  \
317             (var) != TAILQ_END(head);                                   \
318             (var) = TAILQ_NEXT(var, field))
319
320 #define TAILQ_FOREACH_REVERSE(var, head, field, headname)               \
321         for((var) = TAILQ_LAST(head, headname);                         \
322             (var) != TAILQ_END(head);                                   \
323             (var) = TAILQ_PREV(var, headname, field))
324
325 /*
326  * Tail queue functions.
327  */
328 #define TAILQ_INIT(head) do {                                           \
329         (head)->tqh_first = NULL;                                       \
330         (head)->tqh_last = &(head)->tqh_first;                          \
331 } while (0)
332
333 #define TAILQ_INSERT_HEAD(head, elm, field) do {                        \
334         if (((elm)->field.tqe_next = (head)->tqh_first) != NULL)        \
335                 (head)->tqh_first->field.tqe_prev =                     \
336                     &(elm)->field.tqe_next;                             \
337         else                                                            \
338                 (head)->tqh_last = &(elm)->field.tqe_next;              \
339         (head)->tqh_first = (elm);                                      \
340         (elm)->field.tqe_prev = &(head)->tqh_first;                     \
341 } while (0)
342
343 #define TAILQ_INSERT_TAIL(head, elm, field) do {                        \
344         (elm)->field.tqe_next = NULL;                                   \
345         (elm)->field.tqe_prev = (head)->tqh_last;                       \
346         *(head)->tqh_last = (elm);                                      \
347         (head)->tqh_last = &(elm)->field.tqe_next;                      \
348 } while (0)
349
350 #define TAILQ_INSERT_AFTER(head, listelm, elm, field) do {              \
351         if (((elm)->field.tqe_next = (listelm)->field.tqe_next) != NULL)\
352                 (elm)->field.tqe_next->field.tqe_prev =                 \
353                     &(elm)->field.tqe_next;                             \
354         else                                                            \
355                 (head)->tqh_last = &(elm)->field.tqe_next;              \
356         (listelm)->field.tqe_next = (elm);                              \
357         (elm)->field.tqe_prev = &(listelm)->field.tqe_next;             \
358 } while (0)
359
360 #define TAILQ_INSERT_BEFORE(listelm, elm, field) do {                   \
361         (elm)->field.tqe_prev = (listelm)->field.tqe_prev;              \
362         (elm)->field.tqe_next = (listelm);                              \
363         *(listelm)->field.tqe_prev = (elm);                             \
364         (listelm)->field.tqe_prev = &(elm)->field.tqe_next;             \
365 } while (0)
366
367 #define TAILQ_REMOVE(head, elm, field) do {                             \
368         if (((elm)->field.tqe_next) != NULL)                            \
369                 (elm)->field.tqe_next->field.tqe_prev =                 \
370                     (elm)->field.tqe_prev;                              \
371         else                                                            \
372                 (head)->tqh_last = (elm)->field.tqe_prev;               \
373         *(elm)->field.tqe_prev = (elm)->field.tqe_next;                 \
374 } while (0)
375
376 #define TAILQ_REPLACE(head, elm, elm2, field) do {                      \
377         if (((elm2)->field.tqe_next = (elm)->field.tqe_next) != NULL)   \
378                 (elm2)->field.tqe_next->field.tqe_prev =                \
379                     &(elm2)->field.tqe_next;                            \
380         else                                                            \
381                 (head)->tqh_last = &(elm2)->field.tqe_next;             \
382         (elm2)->field.tqe_prev = (elm)->field.tqe_prev;                 \
383         *(elm2)->field.tqe_prev = (elm2);                               \
384 } while (0)
385
386 /*
387  * Circular queue definitions.
388  */
389 #define CIRCLEQ_HEAD(name, type)                                        \
390 struct name {                                                           \
391         struct type *cqh_first;         /* first element */             \
392         struct type *cqh_last;          /* last element */              \
393 }
394
395 #define CIRCLEQ_HEAD_INITIALIZER(head)                                  \
396         { CIRCLEQ_END(&head), CIRCLEQ_END(&head) }
397
398 #define CIRCLEQ_ENTRY(type)                                             \
399 struct {                                                                \
400         struct type *cqe_next;          /* next element */              \
401         struct type *cqe_prev;          /* previous element */          \
402 }
403
404 /*
405  * Circular queue access methods
406  */
407 #define CIRCLEQ_FIRST(head)             ((head)->cqh_first)
408 #define CIRCLEQ_LAST(head)              ((head)->cqh_last)
409 #define CIRCLEQ_END(head)               ((void *)(head))
410 #define CIRCLEQ_NEXT(elm, field)        ((elm)->field.cqe_next)
411 #define CIRCLEQ_PREV(elm, field)        ((elm)->field.cqe_prev)
412 #define CIRCLEQ_EMPTY(head)                                             \
413         (CIRCLEQ_FIRST(head) == CIRCLEQ_END(head))
414
415 #define CIRCLEQ_FOREACH(var, head, field)                               \
416         for((var) = CIRCLEQ_FIRST(head);                                \
417             (var) != CIRCLEQ_END(head);                                 \
418             (var) = CIRCLEQ_NEXT(var, field))
419
420 #define CIRCLEQ_FOREACH_REVERSE(var, head, field)                       \
421         for((var) = CIRCLEQ_LAST(head);                                 \
422             (var) != CIRCLEQ_END(head);                                 \
423             (var) = CIRCLEQ_PREV(var, field))
424
425 /*
426  * Circular queue functions.
427  */
428 #define CIRCLEQ_INIT(head) do {                                         \
429         (head)->cqh_first = CIRCLEQ_END(head);                          \
430         (head)->cqh_last = CIRCLEQ_END(head);                           \
431 } while (0)
432
433 #define CIRCLEQ_INSERT_AFTER(head, listelm, elm, field) do {            \
434         (elm)->field.cqe_next = (listelm)->field.cqe_next;              \
435         (elm)->field.cqe_prev = (listelm);                              \
436         if ((listelm)->field.cqe_next == CIRCLEQ_END(head))             \
437                 (head)->cqh_last = (elm);                               \
438         else                                                            \
439                 (listelm)->field.cqe_next->field.cqe_prev = (elm);      \
440         (listelm)->field.cqe_next = (elm);                              \
441 } while (0)
442
443 #define CIRCLEQ_INSERT_BEFORE(head, listelm, elm, field) do {           \
444         (elm)->field.cqe_next = (listelm);                              \
445         (elm)->field.cqe_prev = (listelm)->field.cqe_prev;              \
446         if ((listelm)->field.cqe_prev == CIRCLEQ_END(head))             \
447                 (head)->cqh_first = (elm);                              \
448         else                                                            \
449                 (listelm)->field.cqe_prev->field.cqe_next = (elm);      \
450         (listelm)->field.cqe_prev = (elm);                              \
451 } while (0)
452
453 #define CIRCLEQ_INSERT_HEAD(head, elm, field) do {                      \
454         (elm)->field.cqe_next = (head)->cqh_first;                      \
455         (elm)->field.cqe_prev = CIRCLEQ_END(head);                      \
456         if ((head)->cqh_last == CIRCLEQ_END(head))                      \
457                 (head)->cqh_last = (elm);                               \
458         else                                                            \
459                 (head)->cqh_first->field.cqe_prev = (elm);              \
460         (head)->cqh_first = (elm);                                      \
461 } while (0)
462
463 #define CIRCLEQ_INSERT_TAIL(head, elm, field) do {                      \
464         (elm)->field.cqe_next = CIRCLEQ_END(head);                      \
465         (elm)->field.cqe_prev = (head)->cqh_last;                       \
466         if ((head)->cqh_first == CIRCLEQ_END(head))                     \
467                 (head)->cqh_first = (elm);                              \
468         else                                                            \
469                 (head)->cqh_last->field.cqe_next = (elm);               \
470         (head)->cqh_last = (elm);                                       \
471 } while (0)
472
473 #define CIRCLEQ_REMOVE(head, elm, field) do {                           \
474         if ((elm)->field.cqe_next == CIRCLEQ_END(head))                 \
475                 (head)->cqh_last = (elm)->field.cqe_prev;               \
476         else                                                            \
477                 (elm)->field.cqe_next->field.cqe_prev =                 \
478                     (elm)->field.cqe_prev;                              \
479         if ((elm)->field.cqe_prev == CIRCLEQ_END(head))                 \
480                 (head)->cqh_first = (elm)->field.cqe_next;              \
481         else                                                            \
482                 (elm)->field.cqe_prev->field.cqe_next =                 \
483                     (elm)->field.cqe_next;                              \
484 } while (0)
485
486 #define CIRCLEQ_REPLACE(head, elm, elm2, field) do {                    \
487         if (((elm2)->field.cqe_next = (elm)->field.cqe_next) ==         \
488             CIRCLEQ_END(head))                                          \
489                 (head).cqh_last = (elm2);                               \
490         else                                                            \
491                 (elm2)->field.cqe_next->field.cqe_prev = (elm2);        \
492         if (((elm2)->field.cqe_prev = (elm)->field.cqe_prev) ==         \
493             CIRCLEQ_END(head))                                          \
494                 (head).cqh_first = (elm2);                              \
495         else                                                            \
496                 (elm2)->field.cqe_prev->field.cqe_next = (elm2);        \
497 } while (0)
498
499 #endif  /* !_SYS_QUEUE_H_ */