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1 805e39bf 2021-07-22 op /* $OpenBSD: queue.h,v 1.46 2020/12/30 13:33:12 millert Exp $ */
2 805e39bf 2021-07-22 op /* $NetBSD: queue.h,v 1.11 1996/05/16 05:17:14 mycroft Exp $ */
3 805e39bf 2021-07-22 op
4 805e39bf 2021-07-22 op /*
5 805e39bf 2021-07-22 op * Copyright (c) 1991, 1993
6 805e39bf 2021-07-22 op * The Regents of the University of California. All rights reserved.
7 805e39bf 2021-07-22 op *
8 805e39bf 2021-07-22 op * Redistribution and use in source and binary forms, with or without
9 805e39bf 2021-07-22 op * modification, are permitted provided that the following conditions
10 805e39bf 2021-07-22 op * are met:
11 805e39bf 2021-07-22 op * 1. Redistributions of source code must retain the above copyright
12 805e39bf 2021-07-22 op * notice, this list of conditions and the following disclaimer.
13 805e39bf 2021-07-22 op * 2. Redistributions in binary form must reproduce the above copyright
14 805e39bf 2021-07-22 op * notice, this list of conditions and the following disclaimer in the
15 805e39bf 2021-07-22 op * documentation and/or other materials provided with the distribution.
16 805e39bf 2021-07-22 op * 3. Neither the name of the University nor the names of its contributors
17 805e39bf 2021-07-22 op * may be used to endorse or promote products derived from this software
18 805e39bf 2021-07-22 op * without specific prior written permission.
19 805e39bf 2021-07-22 op *
20 805e39bf 2021-07-22 op * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 805e39bf 2021-07-22 op * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 805e39bf 2021-07-22 op * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 805e39bf 2021-07-22 op * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 805e39bf 2021-07-22 op * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 805e39bf 2021-07-22 op * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 805e39bf 2021-07-22 op * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 805e39bf 2021-07-22 op * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 805e39bf 2021-07-22 op * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 805e39bf 2021-07-22 op * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 805e39bf 2021-07-22 op * SUCH DAMAGE.
31 805e39bf 2021-07-22 op *
32 805e39bf 2021-07-22 op * @(#)queue.h 8.5 (Berkeley) 8/20/94
33 805e39bf 2021-07-22 op */
34 805e39bf 2021-07-22 op
35 805e39bf 2021-07-22 op #ifndef _SYS_QUEUE_H_
36 805e39bf 2021-07-22 op #define _SYS_QUEUE_H_
37 805e39bf 2021-07-22 op
38 805e39bf 2021-07-22 op /*
39 805e39bf 2021-07-22 op * This file defines five types of data structures: singly-linked lists,
40 805e39bf 2021-07-22 op * lists, simple queues, tail queues and XOR simple queues.
41 805e39bf 2021-07-22 op *
42 805e39bf 2021-07-22 op *
43 805e39bf 2021-07-22 op * A singly-linked list is headed by a single forward pointer. The elements
44 805e39bf 2021-07-22 op * are singly linked for minimum space and pointer manipulation overhead at
45 805e39bf 2021-07-22 op * the expense of O(n) removal for arbitrary elements. New elements can be
46 805e39bf 2021-07-22 op * added to the list after an existing element or at the head of the list.
47 805e39bf 2021-07-22 op * Elements being removed from the head of the list should use the explicit
48 805e39bf 2021-07-22 op * macro for this purpose for optimum efficiency. A singly-linked list may
49 805e39bf 2021-07-22 op * only be traversed in the forward direction. Singly-linked lists are ideal
50 805e39bf 2021-07-22 op * for applications with large datasets and few or no removals or for
51 805e39bf 2021-07-22 op * implementing a LIFO queue.
52 805e39bf 2021-07-22 op *
53 805e39bf 2021-07-22 op * A list is headed by a single forward pointer (or an array of forward
54 805e39bf 2021-07-22 op * pointers for a hash table header). The elements are doubly linked
55 805e39bf 2021-07-22 op * so that an arbitrary element can be removed without a need to
56 805e39bf 2021-07-22 op * traverse the list. New elements can be added to the list before
57 805e39bf 2021-07-22 op * or after an existing element or at the head of the list. A list
58 805e39bf 2021-07-22 op * may only be traversed in the forward direction.
59 805e39bf 2021-07-22 op *
60 805e39bf 2021-07-22 op * A simple queue is headed by a pair of pointers, one to the head of the
61 805e39bf 2021-07-22 op * list and the other to the tail of the list. The elements are singly
62 805e39bf 2021-07-22 op * linked to save space, so elements can only be removed from the
63 805e39bf 2021-07-22 op * head of the list. New elements can be added to the list before or after
64 805e39bf 2021-07-22 op * an existing element, at the head of the list, or at the end of the
65 805e39bf 2021-07-22 op * list. A simple queue may only be traversed in the forward direction.
66 805e39bf 2021-07-22 op *
67 805e39bf 2021-07-22 op * A tail queue is headed by a pair of pointers, one to the head of the
68 805e39bf 2021-07-22 op * list and the other to the tail of the list. The elements are doubly
69 805e39bf 2021-07-22 op * linked so that an arbitrary element can be removed without a need to
70 805e39bf 2021-07-22 op * traverse the list. New elements can be added to the list before or
71 805e39bf 2021-07-22 op * after an existing element, at the head of the list, or at the end of
72 805e39bf 2021-07-22 op * the list. A tail queue may be traversed in either direction.
73 805e39bf 2021-07-22 op *
74 805e39bf 2021-07-22 op * An XOR simple queue is used in the same way as a regular simple queue.
75 805e39bf 2021-07-22 op * The difference is that the head structure also includes a "cookie" that
76 805e39bf 2021-07-22 op * is XOR'd with the queue pointer (first, last or next) to generate the
77 805e39bf 2021-07-22 op * real pointer value.
78 805e39bf 2021-07-22 op *
79 805e39bf 2021-07-22 op * For details on the use of these macros, see the queue(3) manual page.
80 805e39bf 2021-07-22 op */
81 805e39bf 2021-07-22 op
82 805e39bf 2021-07-22 op #if defined(QUEUE_MACRO_DEBUG) || (defined(_KERNEL) && defined(DIAGNOSTIC))
83 805e39bf 2021-07-22 op #define _Q_INVALID ((void *)-1)
84 805e39bf 2021-07-22 op #define _Q_INVALIDATE(a) (a) = _Q_INVALID
85 805e39bf 2021-07-22 op #else
86 805e39bf 2021-07-22 op #define _Q_INVALIDATE(a)
87 805e39bf 2021-07-22 op #endif
88 805e39bf 2021-07-22 op
89 805e39bf 2021-07-22 op /*
90 805e39bf 2021-07-22 op * Singly-linked List definitions.
91 805e39bf 2021-07-22 op */
92 805e39bf 2021-07-22 op #define SLIST_HEAD(name, type) \
93 805e39bf 2021-07-22 op struct name { \
94 805e39bf 2021-07-22 op struct type *slh_first; /* first element */ \
95 805e39bf 2021-07-22 op }
96 805e39bf 2021-07-22 op
97 805e39bf 2021-07-22 op #define SLIST_HEAD_INITIALIZER(head) \
98 805e39bf 2021-07-22 op { NULL }
99 805e39bf 2021-07-22 op
100 805e39bf 2021-07-22 op #define SLIST_ENTRY(type) \
101 805e39bf 2021-07-22 op struct { \
102 805e39bf 2021-07-22 op struct type *sle_next; /* next element */ \
103 805e39bf 2021-07-22 op }
104 805e39bf 2021-07-22 op
105 805e39bf 2021-07-22 op /*
106 805e39bf 2021-07-22 op * Singly-linked List access methods.
107 805e39bf 2021-07-22 op */
108 805e39bf 2021-07-22 op #define SLIST_FIRST(head) ((head)->slh_first)
109 805e39bf 2021-07-22 op #define SLIST_END(head) NULL
110 805e39bf 2021-07-22 op #define SLIST_EMPTY(head) (SLIST_FIRST(head) == SLIST_END(head))
111 805e39bf 2021-07-22 op #define SLIST_NEXT(elm, field) ((elm)->field.sle_next)
112 805e39bf 2021-07-22 op
113 805e39bf 2021-07-22 op #define SLIST_FOREACH(var, head, field) \
114 805e39bf 2021-07-22 op for((var) = SLIST_FIRST(head); \
115 805e39bf 2021-07-22 op (var) != SLIST_END(head); \
116 805e39bf 2021-07-22 op (var) = SLIST_NEXT(var, field))
117 805e39bf 2021-07-22 op
118 805e39bf 2021-07-22 op #define SLIST_FOREACH_SAFE(var, head, field, tvar) \
119 805e39bf 2021-07-22 op for ((var) = SLIST_FIRST(head); \
120 805e39bf 2021-07-22 op (var) && ((tvar) = SLIST_NEXT(var, field), 1); \
121 805e39bf 2021-07-22 op (var) = (tvar))
122 805e39bf 2021-07-22 op
123 805e39bf 2021-07-22 op /*
124 805e39bf 2021-07-22 op * Singly-linked List functions.
125 805e39bf 2021-07-22 op */
126 805e39bf 2021-07-22 op #define SLIST_INIT(head) { \
127 805e39bf 2021-07-22 op SLIST_FIRST(head) = SLIST_END(head); \
128 805e39bf 2021-07-22 op }
129 805e39bf 2021-07-22 op
130 805e39bf 2021-07-22 op #define SLIST_INSERT_AFTER(slistelm, elm, field) do { \
131 805e39bf 2021-07-22 op (elm)->field.sle_next = (slistelm)->field.sle_next; \
132 805e39bf 2021-07-22 op (slistelm)->field.sle_next = (elm); \
133 805e39bf 2021-07-22 op } while (0)
134 805e39bf 2021-07-22 op
135 805e39bf 2021-07-22 op #define SLIST_INSERT_HEAD(head, elm, field) do { \
136 805e39bf 2021-07-22 op (elm)->field.sle_next = (head)->slh_first; \
137 805e39bf 2021-07-22 op (head)->slh_first = (elm); \
138 805e39bf 2021-07-22 op } while (0)
139 805e39bf 2021-07-22 op
140 805e39bf 2021-07-22 op #define SLIST_REMOVE_AFTER(elm, field) do { \
141 805e39bf 2021-07-22 op (elm)->field.sle_next = (elm)->field.sle_next->field.sle_next; \
142 805e39bf 2021-07-22 op } while (0)
143 805e39bf 2021-07-22 op
144 805e39bf 2021-07-22 op #define SLIST_REMOVE_HEAD(head, field) do { \
145 805e39bf 2021-07-22 op (head)->slh_first = (head)->slh_first->field.sle_next; \
146 805e39bf 2021-07-22 op } while (0)
147 805e39bf 2021-07-22 op
148 805e39bf 2021-07-22 op #define SLIST_REMOVE(head, elm, type, field) do { \
149 805e39bf 2021-07-22 op if ((head)->slh_first == (elm)) { \
150 805e39bf 2021-07-22 op SLIST_REMOVE_HEAD((head), field); \
151 805e39bf 2021-07-22 op } else { \
152 805e39bf 2021-07-22 op struct type *curelm = (head)->slh_first; \
153 805e39bf 2021-07-22 op \
154 805e39bf 2021-07-22 op while (curelm->field.sle_next != (elm)) \
155 805e39bf 2021-07-22 op curelm = curelm->field.sle_next; \
156 805e39bf 2021-07-22 op curelm->field.sle_next = \
157 805e39bf 2021-07-22 op curelm->field.sle_next->field.sle_next; \
158 805e39bf 2021-07-22 op } \
159 805e39bf 2021-07-22 op _Q_INVALIDATE((elm)->field.sle_next); \
160 805e39bf 2021-07-22 op } while (0)
161 805e39bf 2021-07-22 op
162 805e39bf 2021-07-22 op /*
163 805e39bf 2021-07-22 op * List definitions.
164 805e39bf 2021-07-22 op */
165 805e39bf 2021-07-22 op #define LIST_HEAD(name, type) \
166 805e39bf 2021-07-22 op struct name { \
167 805e39bf 2021-07-22 op struct type *lh_first; /* first element */ \
168 805e39bf 2021-07-22 op }
169 805e39bf 2021-07-22 op
170 805e39bf 2021-07-22 op #define LIST_HEAD_INITIALIZER(head) \
171 805e39bf 2021-07-22 op { NULL }
172 805e39bf 2021-07-22 op
173 805e39bf 2021-07-22 op #define LIST_ENTRY(type) \
174 805e39bf 2021-07-22 op struct { \
175 805e39bf 2021-07-22 op struct type *le_next; /* next element */ \
176 805e39bf 2021-07-22 op struct type **le_prev; /* address of previous next element */ \
177 805e39bf 2021-07-22 op }
178 805e39bf 2021-07-22 op
179 805e39bf 2021-07-22 op /*
180 805e39bf 2021-07-22 op * List access methods.
181 805e39bf 2021-07-22 op */
182 805e39bf 2021-07-22 op #define LIST_FIRST(head) ((head)->lh_first)
183 805e39bf 2021-07-22 op #define LIST_END(head) NULL
184 805e39bf 2021-07-22 op #define LIST_EMPTY(head) (LIST_FIRST(head) == LIST_END(head))
185 805e39bf 2021-07-22 op #define LIST_NEXT(elm, field) ((elm)->field.le_next)
186 805e39bf 2021-07-22 op
187 805e39bf 2021-07-22 op #define LIST_FOREACH(var, head, field) \
188 805e39bf 2021-07-22 op for((var) = LIST_FIRST(head); \
189 805e39bf 2021-07-22 op (var)!= LIST_END(head); \
190 805e39bf 2021-07-22 op (var) = LIST_NEXT(var, field))
191 805e39bf 2021-07-22 op
192 805e39bf 2021-07-22 op #define LIST_FOREACH_SAFE(var, head, field, tvar) \
193 805e39bf 2021-07-22 op for ((var) = LIST_FIRST(head); \
194 805e39bf 2021-07-22 op (var) && ((tvar) = LIST_NEXT(var, field), 1); \
195 805e39bf 2021-07-22 op (var) = (tvar))
196 805e39bf 2021-07-22 op
197 805e39bf 2021-07-22 op /*
198 805e39bf 2021-07-22 op * List functions.
199 805e39bf 2021-07-22 op */
200 805e39bf 2021-07-22 op #define LIST_INIT(head) do { \
201 805e39bf 2021-07-22 op LIST_FIRST(head) = LIST_END(head); \
202 805e39bf 2021-07-22 op } while (0)
203 805e39bf 2021-07-22 op
204 805e39bf 2021-07-22 op #define LIST_INSERT_AFTER(listelm, elm, field) do { \
205 805e39bf 2021-07-22 op if (((elm)->field.le_next = (listelm)->field.le_next) != NULL) \
206 805e39bf 2021-07-22 op (listelm)->field.le_next->field.le_prev = \
207 805e39bf 2021-07-22 op &(elm)->field.le_next; \
208 805e39bf 2021-07-22 op (listelm)->field.le_next = (elm); \
209 805e39bf 2021-07-22 op (elm)->field.le_prev = &(listelm)->field.le_next; \
210 805e39bf 2021-07-22 op } while (0)
211 805e39bf 2021-07-22 op
212 805e39bf 2021-07-22 op #define LIST_INSERT_BEFORE(listelm, elm, field) do { \
213 805e39bf 2021-07-22 op (elm)->field.le_prev = (listelm)->field.le_prev; \
214 805e39bf 2021-07-22 op (elm)->field.le_next = (listelm); \
215 805e39bf 2021-07-22 op *(listelm)->field.le_prev = (elm); \
216 805e39bf 2021-07-22 op (listelm)->field.le_prev = &(elm)->field.le_next; \
217 805e39bf 2021-07-22 op } while (0)
218 805e39bf 2021-07-22 op
219 805e39bf 2021-07-22 op #define LIST_INSERT_HEAD(head, elm, field) do { \
220 805e39bf 2021-07-22 op if (((elm)->field.le_next = (head)->lh_first) != NULL) \
221 805e39bf 2021-07-22 op (head)->lh_first->field.le_prev = &(elm)->field.le_next;\
222 805e39bf 2021-07-22 op (head)->lh_first = (elm); \
223 805e39bf 2021-07-22 op (elm)->field.le_prev = &(head)->lh_first; \
224 805e39bf 2021-07-22 op } while (0)
225 805e39bf 2021-07-22 op
226 805e39bf 2021-07-22 op #define LIST_REMOVE(elm, field) do { \
227 805e39bf 2021-07-22 op if ((elm)->field.le_next != NULL) \
228 805e39bf 2021-07-22 op (elm)->field.le_next->field.le_prev = \
229 805e39bf 2021-07-22 op (elm)->field.le_prev; \
230 805e39bf 2021-07-22 op *(elm)->field.le_prev = (elm)->field.le_next; \
231 805e39bf 2021-07-22 op _Q_INVALIDATE((elm)->field.le_prev); \
232 805e39bf 2021-07-22 op _Q_INVALIDATE((elm)->field.le_next); \
233 805e39bf 2021-07-22 op } while (0)
234 805e39bf 2021-07-22 op
235 805e39bf 2021-07-22 op #define LIST_REPLACE(elm, elm2, field) do { \
236 805e39bf 2021-07-22 op if (((elm2)->field.le_next = (elm)->field.le_next) != NULL) \
237 805e39bf 2021-07-22 op (elm2)->field.le_next->field.le_prev = \
238 805e39bf 2021-07-22 op &(elm2)->field.le_next; \
239 805e39bf 2021-07-22 op (elm2)->field.le_prev = (elm)->field.le_prev; \
240 805e39bf 2021-07-22 op *(elm2)->field.le_prev = (elm2); \
241 805e39bf 2021-07-22 op _Q_INVALIDATE((elm)->field.le_prev); \
242 805e39bf 2021-07-22 op _Q_INVALIDATE((elm)->field.le_next); \
243 805e39bf 2021-07-22 op } while (0)
244 805e39bf 2021-07-22 op
245 805e39bf 2021-07-22 op /*
246 805e39bf 2021-07-22 op * Simple queue definitions.
247 805e39bf 2021-07-22 op */
248 805e39bf 2021-07-22 op #define SIMPLEQ_HEAD(name, type) \
249 805e39bf 2021-07-22 op struct name { \
250 805e39bf 2021-07-22 op struct type *sqh_first; /* first element */ \
251 805e39bf 2021-07-22 op struct type **sqh_last; /* addr of last next element */ \
252 805e39bf 2021-07-22 op }
253 805e39bf 2021-07-22 op
254 805e39bf 2021-07-22 op #define SIMPLEQ_HEAD_INITIALIZER(head) \
255 805e39bf 2021-07-22 op { NULL, &(head).sqh_first }
256 805e39bf 2021-07-22 op
257 805e39bf 2021-07-22 op #define SIMPLEQ_ENTRY(type) \
258 805e39bf 2021-07-22 op struct { \
259 805e39bf 2021-07-22 op struct type *sqe_next; /* next element */ \
260 805e39bf 2021-07-22 op }
261 805e39bf 2021-07-22 op
262 805e39bf 2021-07-22 op /*
263 805e39bf 2021-07-22 op * Simple queue access methods.
264 805e39bf 2021-07-22 op */
265 805e39bf 2021-07-22 op #define SIMPLEQ_FIRST(head) ((head)->sqh_first)
266 805e39bf 2021-07-22 op #define SIMPLEQ_END(head) NULL
267 805e39bf 2021-07-22 op #define SIMPLEQ_EMPTY(head) (SIMPLEQ_FIRST(head) == SIMPLEQ_END(head))
268 805e39bf 2021-07-22 op #define SIMPLEQ_NEXT(elm, field) ((elm)->field.sqe_next)
269 805e39bf 2021-07-22 op
270 805e39bf 2021-07-22 op #define SIMPLEQ_FOREACH(var, head, field) \
271 805e39bf 2021-07-22 op for((var) = SIMPLEQ_FIRST(head); \
272 805e39bf 2021-07-22 op (var) != SIMPLEQ_END(head); \
273 805e39bf 2021-07-22 op (var) = SIMPLEQ_NEXT(var, field))
274 805e39bf 2021-07-22 op
275 805e39bf 2021-07-22 op #define SIMPLEQ_FOREACH_SAFE(var, head, field, tvar) \
276 805e39bf 2021-07-22 op for ((var) = SIMPLEQ_FIRST(head); \
277 805e39bf 2021-07-22 op (var) && ((tvar) = SIMPLEQ_NEXT(var, field), 1); \
278 805e39bf 2021-07-22 op (var) = (tvar))
279 805e39bf 2021-07-22 op
280 805e39bf 2021-07-22 op /*
281 805e39bf 2021-07-22 op * Simple queue functions.
282 805e39bf 2021-07-22 op */
283 805e39bf 2021-07-22 op #define SIMPLEQ_INIT(head) do { \
284 805e39bf 2021-07-22 op (head)->sqh_first = NULL; \
285 805e39bf 2021-07-22 op (head)->sqh_last = &(head)->sqh_first; \
286 805e39bf 2021-07-22 op } while (0)
287 805e39bf 2021-07-22 op
288 805e39bf 2021-07-22 op #define SIMPLEQ_INSERT_HEAD(head, elm, field) do { \
289 805e39bf 2021-07-22 op if (((elm)->field.sqe_next = (head)->sqh_first) == NULL) \
290 805e39bf 2021-07-22 op (head)->sqh_last = &(elm)->field.sqe_next; \
291 805e39bf 2021-07-22 op (head)->sqh_first = (elm); \
292 805e39bf 2021-07-22 op } while (0)
293 805e39bf 2021-07-22 op
294 805e39bf 2021-07-22 op #define SIMPLEQ_INSERT_TAIL(head, elm, field) do { \
295 805e39bf 2021-07-22 op (elm)->field.sqe_next = NULL; \
296 805e39bf 2021-07-22 op *(head)->sqh_last = (elm); \
297 805e39bf 2021-07-22 op (head)->sqh_last = &(elm)->field.sqe_next; \
298 805e39bf 2021-07-22 op } while (0)
299 805e39bf 2021-07-22 op
300 805e39bf 2021-07-22 op #define SIMPLEQ_INSERT_AFTER(head, listelm, elm, field) do { \
301 805e39bf 2021-07-22 op if (((elm)->field.sqe_next = (listelm)->field.sqe_next) == NULL)\
302 805e39bf 2021-07-22 op (head)->sqh_last = &(elm)->field.sqe_next; \
303 805e39bf 2021-07-22 op (listelm)->field.sqe_next = (elm); \
304 805e39bf 2021-07-22 op } while (0)
305 805e39bf 2021-07-22 op
306 805e39bf 2021-07-22 op #define SIMPLEQ_REMOVE_HEAD(head, field) do { \
307 805e39bf 2021-07-22 op if (((head)->sqh_first = (head)->sqh_first->field.sqe_next) == NULL) \
308 805e39bf 2021-07-22 op (head)->sqh_last = &(head)->sqh_first; \
309 805e39bf 2021-07-22 op } while (0)
310 805e39bf 2021-07-22 op
311 805e39bf 2021-07-22 op #define SIMPLEQ_REMOVE_AFTER(head, elm, field) do { \
312 805e39bf 2021-07-22 op if (((elm)->field.sqe_next = (elm)->field.sqe_next->field.sqe_next) \
313 805e39bf 2021-07-22 op == NULL) \
314 805e39bf 2021-07-22 op (head)->sqh_last = &(elm)->field.sqe_next; \
315 805e39bf 2021-07-22 op } while (0)
316 805e39bf 2021-07-22 op
317 805e39bf 2021-07-22 op #define SIMPLEQ_CONCAT(head1, head2) do { \
318 805e39bf 2021-07-22 op if (!SIMPLEQ_EMPTY((head2))) { \
319 805e39bf 2021-07-22 op *(head1)->sqh_last = (head2)->sqh_first; \
320 805e39bf 2021-07-22 op (head1)->sqh_last = (head2)->sqh_last; \
321 805e39bf 2021-07-22 op SIMPLEQ_INIT((head2)); \
322 805e39bf 2021-07-22 op } \
323 805e39bf 2021-07-22 op } while (0)
324 805e39bf 2021-07-22 op
325 805e39bf 2021-07-22 op /*
326 805e39bf 2021-07-22 op * XOR Simple queue definitions.
327 805e39bf 2021-07-22 op */
328 805e39bf 2021-07-22 op #define XSIMPLEQ_HEAD(name, type) \
329 805e39bf 2021-07-22 op struct name { \
330 805e39bf 2021-07-22 op struct type *sqx_first; /* first element */ \
331 805e39bf 2021-07-22 op struct type **sqx_last; /* addr of last next element */ \
332 805e39bf 2021-07-22 op unsigned long sqx_cookie; \
333 805e39bf 2021-07-22 op }
334 805e39bf 2021-07-22 op
335 805e39bf 2021-07-22 op #define XSIMPLEQ_ENTRY(type) \
336 805e39bf 2021-07-22 op struct { \
337 805e39bf 2021-07-22 op struct type *sqx_next; /* next element */ \
338 805e39bf 2021-07-22 op }
339 805e39bf 2021-07-22 op
340 805e39bf 2021-07-22 op /*
341 805e39bf 2021-07-22 op * XOR Simple queue access methods.
342 805e39bf 2021-07-22 op */
343 805e39bf 2021-07-22 op #define XSIMPLEQ_XOR(head, ptr) ((__typeof(ptr))((head)->sqx_cookie ^ \
344 805e39bf 2021-07-22 op (unsigned long)(ptr)))
345 805e39bf 2021-07-22 op #define XSIMPLEQ_FIRST(head) XSIMPLEQ_XOR(head, ((head)->sqx_first))
346 805e39bf 2021-07-22 op #define XSIMPLEQ_END(head) NULL
347 805e39bf 2021-07-22 op #define XSIMPLEQ_EMPTY(head) (XSIMPLEQ_FIRST(head) == XSIMPLEQ_END(head))
348 805e39bf 2021-07-22 op #define XSIMPLEQ_NEXT(head, elm, field) XSIMPLEQ_XOR(head, ((elm)->field.sqx_next))
349 805e39bf 2021-07-22 op
350 805e39bf 2021-07-22 op
351 805e39bf 2021-07-22 op #define XSIMPLEQ_FOREACH(var, head, field) \
352 805e39bf 2021-07-22 op for ((var) = XSIMPLEQ_FIRST(head); \
353 805e39bf 2021-07-22 op (var) != XSIMPLEQ_END(head); \
354 805e39bf 2021-07-22 op (var) = XSIMPLEQ_NEXT(head, var, field))
355 805e39bf 2021-07-22 op
356 805e39bf 2021-07-22 op #define XSIMPLEQ_FOREACH_SAFE(var, head, field, tvar) \
357 805e39bf 2021-07-22 op for ((var) = XSIMPLEQ_FIRST(head); \
358 805e39bf 2021-07-22 op (var) && ((tvar) = XSIMPLEQ_NEXT(head, var, field), 1); \
359 805e39bf 2021-07-22 op (var) = (tvar))
360 805e39bf 2021-07-22 op
361 805e39bf 2021-07-22 op /*
362 805e39bf 2021-07-22 op * XOR Simple queue functions.
363 805e39bf 2021-07-22 op */
364 805e39bf 2021-07-22 op #define XSIMPLEQ_INIT(head) do { \
365 805e39bf 2021-07-22 op arc4random_buf(&(head)->sqx_cookie, sizeof((head)->sqx_cookie)); \
366 805e39bf 2021-07-22 op (head)->sqx_first = XSIMPLEQ_XOR(head, NULL); \
367 805e39bf 2021-07-22 op (head)->sqx_last = XSIMPLEQ_XOR(head, &(head)->sqx_first); \
368 805e39bf 2021-07-22 op } while (0)
369 805e39bf 2021-07-22 op
370 805e39bf 2021-07-22 op #define XSIMPLEQ_INSERT_HEAD(head, elm, field) do { \
371 805e39bf 2021-07-22 op if (((elm)->field.sqx_next = (head)->sqx_first) == \
372 805e39bf 2021-07-22 op XSIMPLEQ_XOR(head, NULL)) \
373 805e39bf 2021-07-22 op (head)->sqx_last = XSIMPLEQ_XOR(head, &(elm)->field.sqx_next); \
374 805e39bf 2021-07-22 op (head)->sqx_first = XSIMPLEQ_XOR(head, (elm)); \
375 805e39bf 2021-07-22 op } while (0)
376 805e39bf 2021-07-22 op
377 805e39bf 2021-07-22 op #define XSIMPLEQ_INSERT_TAIL(head, elm, field) do { \
378 805e39bf 2021-07-22 op (elm)->field.sqx_next = XSIMPLEQ_XOR(head, NULL); \
379 805e39bf 2021-07-22 op *(XSIMPLEQ_XOR(head, (head)->sqx_last)) = XSIMPLEQ_XOR(head, (elm)); \
380 805e39bf 2021-07-22 op (head)->sqx_last = XSIMPLEQ_XOR(head, &(elm)->field.sqx_next); \
381 805e39bf 2021-07-22 op } while (0)
382 805e39bf 2021-07-22 op
383 805e39bf 2021-07-22 op #define XSIMPLEQ_INSERT_AFTER(head, listelm, elm, field) do { \
384 805e39bf 2021-07-22 op if (((elm)->field.sqx_next = (listelm)->field.sqx_next) == \
385 805e39bf 2021-07-22 op XSIMPLEQ_XOR(head, NULL)) \
386 805e39bf 2021-07-22 op (head)->sqx_last = XSIMPLEQ_XOR(head, &(elm)->field.sqx_next); \
387 805e39bf 2021-07-22 op (listelm)->field.sqx_next = XSIMPLEQ_XOR(head, (elm)); \
388 805e39bf 2021-07-22 op } while (0)
389 805e39bf 2021-07-22 op
390 805e39bf 2021-07-22 op #define XSIMPLEQ_REMOVE_HEAD(head, field) do { \
391 805e39bf 2021-07-22 op if (((head)->sqx_first = XSIMPLEQ_XOR(head, \
392 805e39bf 2021-07-22 op (head)->sqx_first)->field.sqx_next) == XSIMPLEQ_XOR(head, NULL)) \
393 805e39bf 2021-07-22 op (head)->sqx_last = XSIMPLEQ_XOR(head, &(head)->sqx_first); \
394 805e39bf 2021-07-22 op } while (0)
395 805e39bf 2021-07-22 op
396 805e39bf 2021-07-22 op #define XSIMPLEQ_REMOVE_AFTER(head, elm, field) do { \
397 805e39bf 2021-07-22 op if (((elm)->field.sqx_next = XSIMPLEQ_XOR(head, \
398 805e39bf 2021-07-22 op (elm)->field.sqx_next)->field.sqx_next) \
399 805e39bf 2021-07-22 op == XSIMPLEQ_XOR(head, NULL)) \
400 805e39bf 2021-07-22 op (head)->sqx_last = \
401 805e39bf 2021-07-22 op XSIMPLEQ_XOR(head, &(elm)->field.sqx_next); \
402 805e39bf 2021-07-22 op } while (0)
403 805e39bf 2021-07-22 op
404 805e39bf 2021-07-22 op
405 805e39bf 2021-07-22 op /*
406 805e39bf 2021-07-22 op * Tail queue definitions.
407 805e39bf 2021-07-22 op */
408 805e39bf 2021-07-22 op #define TAILQ_HEAD(name, type) \
409 805e39bf 2021-07-22 op struct name { \
410 805e39bf 2021-07-22 op struct type *tqh_first; /* first element */ \
411 805e39bf 2021-07-22 op struct type **tqh_last; /* addr of last next element */ \
412 805e39bf 2021-07-22 op }
413 805e39bf 2021-07-22 op
414 805e39bf 2021-07-22 op #define TAILQ_HEAD_INITIALIZER(head) \
415 805e39bf 2021-07-22 op { NULL, &(head).tqh_first }
416 805e39bf 2021-07-22 op
417 805e39bf 2021-07-22 op #define TAILQ_ENTRY(type) \
418 805e39bf 2021-07-22 op struct { \
419 805e39bf 2021-07-22 op struct type *tqe_next; /* next element */ \
420 805e39bf 2021-07-22 op struct type **tqe_prev; /* address of previous next element */ \
421 805e39bf 2021-07-22 op }
422 805e39bf 2021-07-22 op
423 805e39bf 2021-07-22 op /*
424 805e39bf 2021-07-22 op * Tail queue access methods.
425 805e39bf 2021-07-22 op */
426 805e39bf 2021-07-22 op #define TAILQ_FIRST(head) ((head)->tqh_first)
427 805e39bf 2021-07-22 op #define TAILQ_END(head) NULL
428 805e39bf 2021-07-22 op #define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next)
429 805e39bf 2021-07-22 op #define TAILQ_LAST(head, headname) \
430 805e39bf 2021-07-22 op (*(((struct headname *)((head)->tqh_last))->tqh_last))
431 805e39bf 2021-07-22 op /* XXX */
432 805e39bf 2021-07-22 op #define TAILQ_PREV(elm, headname, field) \
433 805e39bf 2021-07-22 op (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last))
434 805e39bf 2021-07-22 op #define TAILQ_EMPTY(head) \
435 805e39bf 2021-07-22 op (TAILQ_FIRST(head) == TAILQ_END(head))
436 805e39bf 2021-07-22 op
437 805e39bf 2021-07-22 op #define TAILQ_FOREACH(var, head, field) \
438 805e39bf 2021-07-22 op for((var) = TAILQ_FIRST(head); \
439 805e39bf 2021-07-22 op (var) != TAILQ_END(head); \
440 805e39bf 2021-07-22 op (var) = TAILQ_NEXT(var, field))
441 805e39bf 2021-07-22 op
442 805e39bf 2021-07-22 op #define TAILQ_FOREACH_SAFE(var, head, field, tvar) \
443 805e39bf 2021-07-22 op for ((var) = TAILQ_FIRST(head); \
444 805e39bf 2021-07-22 op (var) != TAILQ_END(head) && \
445 805e39bf 2021-07-22 op ((tvar) = TAILQ_NEXT(var, field), 1); \
446 805e39bf 2021-07-22 op (var) = (tvar))
447 805e39bf 2021-07-22 op
448 805e39bf 2021-07-22 op
449 805e39bf 2021-07-22 op #define TAILQ_FOREACH_REVERSE(var, head, headname, field) \
450 805e39bf 2021-07-22 op for((var) = TAILQ_LAST(head, headname); \
451 805e39bf 2021-07-22 op (var) != TAILQ_END(head); \
452 805e39bf 2021-07-22 op (var) = TAILQ_PREV(var, headname, field))
453 805e39bf 2021-07-22 op
454 805e39bf 2021-07-22 op #define TAILQ_FOREACH_REVERSE_SAFE(var, head, headname, field, tvar) \
455 805e39bf 2021-07-22 op for ((var) = TAILQ_LAST(head, headname); \
456 805e39bf 2021-07-22 op (var) != TAILQ_END(head) && \
457 805e39bf 2021-07-22 op ((tvar) = TAILQ_PREV(var, headname, field), 1); \
458 805e39bf 2021-07-22 op (var) = (tvar))
459 805e39bf 2021-07-22 op
460 805e39bf 2021-07-22 op /*
461 805e39bf 2021-07-22 op * Tail queue functions.
462 805e39bf 2021-07-22 op */
463 805e39bf 2021-07-22 op #define TAILQ_INIT(head) do { \
464 805e39bf 2021-07-22 op (head)->tqh_first = NULL; \
465 805e39bf 2021-07-22 op (head)->tqh_last = &(head)->tqh_first; \
466 805e39bf 2021-07-22 op } while (0)
467 805e39bf 2021-07-22 op
468 805e39bf 2021-07-22 op #define TAILQ_INSERT_HEAD(head, elm, field) do { \
469 805e39bf 2021-07-22 op if (((elm)->field.tqe_next = (head)->tqh_first) != NULL) \
470 805e39bf 2021-07-22 op (head)->tqh_first->field.tqe_prev = \
471 805e39bf 2021-07-22 op &(elm)->field.tqe_next; \
472 805e39bf 2021-07-22 op else \
473 805e39bf 2021-07-22 op (head)->tqh_last = &(elm)->field.tqe_next; \
474 805e39bf 2021-07-22 op (head)->tqh_first = (elm); \
475 805e39bf 2021-07-22 op (elm)->field.tqe_prev = &(head)->tqh_first; \
476 805e39bf 2021-07-22 op } while (0)
477 805e39bf 2021-07-22 op
478 805e39bf 2021-07-22 op #define TAILQ_INSERT_TAIL(head, elm, field) do { \
479 805e39bf 2021-07-22 op (elm)->field.tqe_next = NULL; \
480 805e39bf 2021-07-22 op (elm)->field.tqe_prev = (head)->tqh_last; \
481 805e39bf 2021-07-22 op *(head)->tqh_last = (elm); \
482 805e39bf 2021-07-22 op (head)->tqh_last = &(elm)->field.tqe_next; \
483 805e39bf 2021-07-22 op } while (0)
484 805e39bf 2021-07-22 op
485 805e39bf 2021-07-22 op #define TAILQ_INSERT_AFTER(head, listelm, elm, field) do { \
486 805e39bf 2021-07-22 op if (((elm)->field.tqe_next = (listelm)->field.tqe_next) != NULL)\
487 805e39bf 2021-07-22 op (elm)->field.tqe_next->field.tqe_prev = \
488 805e39bf 2021-07-22 op &(elm)->field.tqe_next; \
489 805e39bf 2021-07-22 op else \
490 805e39bf 2021-07-22 op (head)->tqh_last = &(elm)->field.tqe_next; \
491 805e39bf 2021-07-22 op (listelm)->field.tqe_next = (elm); \
492 805e39bf 2021-07-22 op (elm)->field.tqe_prev = &(listelm)->field.tqe_next; \
493 805e39bf 2021-07-22 op } while (0)
494 805e39bf 2021-07-22 op
495 805e39bf 2021-07-22 op #define TAILQ_INSERT_BEFORE(listelm, elm, field) do { \
496 805e39bf 2021-07-22 op (elm)->field.tqe_prev = (listelm)->field.tqe_prev; \
497 805e39bf 2021-07-22 op (elm)->field.tqe_next = (listelm); \
498 805e39bf 2021-07-22 op *(listelm)->field.tqe_prev = (elm); \
499 805e39bf 2021-07-22 op (listelm)->field.tqe_prev = &(elm)->field.tqe_next; \
500 805e39bf 2021-07-22 op } while (0)
501 805e39bf 2021-07-22 op
502 805e39bf 2021-07-22 op #define TAILQ_REMOVE(head, elm, field) do { \
503 805e39bf 2021-07-22 op if (((elm)->field.tqe_next) != NULL) \
504 805e39bf 2021-07-22 op (elm)->field.tqe_next->field.tqe_prev = \
505 805e39bf 2021-07-22 op (elm)->field.tqe_prev; \
506 805e39bf 2021-07-22 op else \
507 805e39bf 2021-07-22 op (head)->tqh_last = (elm)->field.tqe_prev; \
508 805e39bf 2021-07-22 op *(elm)->field.tqe_prev = (elm)->field.tqe_next; \
509 805e39bf 2021-07-22 op _Q_INVALIDATE((elm)->field.tqe_prev); \
510 805e39bf 2021-07-22 op _Q_INVALIDATE((elm)->field.tqe_next); \
511 805e39bf 2021-07-22 op } while (0)
512 805e39bf 2021-07-22 op
513 805e39bf 2021-07-22 op #define TAILQ_REPLACE(head, elm, elm2, field) do { \
514 805e39bf 2021-07-22 op if (((elm2)->field.tqe_next = (elm)->field.tqe_next) != NULL) \
515 805e39bf 2021-07-22 op (elm2)->field.tqe_next->field.tqe_prev = \
516 805e39bf 2021-07-22 op &(elm2)->field.tqe_next; \
517 805e39bf 2021-07-22 op else \
518 805e39bf 2021-07-22 op (head)->tqh_last = &(elm2)->field.tqe_next; \
519 805e39bf 2021-07-22 op (elm2)->field.tqe_prev = (elm)->field.tqe_prev; \
520 805e39bf 2021-07-22 op *(elm2)->field.tqe_prev = (elm2); \
521 805e39bf 2021-07-22 op _Q_INVALIDATE((elm)->field.tqe_prev); \
522 805e39bf 2021-07-22 op _Q_INVALIDATE((elm)->field.tqe_next); \
523 805e39bf 2021-07-22 op } while (0)
524 805e39bf 2021-07-22 op
525 805e39bf 2021-07-22 op #define TAILQ_CONCAT(head1, head2, field) do { \
526 805e39bf 2021-07-22 op if (!TAILQ_EMPTY(head2)) { \
527 805e39bf 2021-07-22 op *(head1)->tqh_last = (head2)->tqh_first; \
528 805e39bf 2021-07-22 op (head2)->tqh_first->field.tqe_prev = (head1)->tqh_last; \
529 805e39bf 2021-07-22 op (head1)->tqh_last = (head2)->tqh_last; \
530 805e39bf 2021-07-22 op TAILQ_INIT((head2)); \
531 805e39bf 2021-07-22 op } \
532 805e39bf 2021-07-22 op } while (0)
533 805e39bf 2021-07-22 op
534 805e39bf 2021-07-22 op /*
535 805e39bf 2021-07-22 op * Singly-linked Tail queue declarations.
536 805e39bf 2021-07-22 op */
537 805e39bf 2021-07-22 op #define STAILQ_HEAD(name, type) \
538 805e39bf 2021-07-22 op struct name { \
539 805e39bf 2021-07-22 op struct type *stqh_first; /* first element */ \
540 805e39bf 2021-07-22 op struct type **stqh_last; /* addr of last next element */ \
541 805e39bf 2021-07-22 op }
542 805e39bf 2021-07-22 op
543 805e39bf 2021-07-22 op #define STAILQ_HEAD_INITIALIZER(head) \
544 805e39bf 2021-07-22 op { NULL, &(head).stqh_first }
545 805e39bf 2021-07-22 op
546 805e39bf 2021-07-22 op #define STAILQ_ENTRY(type) \
547 805e39bf 2021-07-22 op struct { \
548 805e39bf 2021-07-22 op struct type *stqe_next; /* next element */ \
549 805e39bf 2021-07-22 op }
550 805e39bf 2021-07-22 op
551 805e39bf 2021-07-22 op /*
552 805e39bf 2021-07-22 op * Singly-linked Tail queue access methods.
553 805e39bf 2021-07-22 op */
554 805e39bf 2021-07-22 op #define STAILQ_FIRST(head) ((head)->stqh_first)
555 805e39bf 2021-07-22 op #define STAILQ_END(head) NULL
556 805e39bf 2021-07-22 op #define STAILQ_EMPTY(head) (STAILQ_FIRST(head) == STAILQ_END(head))
557 805e39bf 2021-07-22 op #define STAILQ_NEXT(elm, field) ((elm)->field.stqe_next)
558 805e39bf 2021-07-22 op
559 805e39bf 2021-07-22 op #define STAILQ_FOREACH(var, head, field) \
560 805e39bf 2021-07-22 op for ((var) = STAILQ_FIRST(head); \
561 805e39bf 2021-07-22 op (var) != STAILQ_END(head); \
562 805e39bf 2021-07-22 op (var) = STAILQ_NEXT(var, field))
563 805e39bf 2021-07-22 op
564 805e39bf 2021-07-22 op #define STAILQ_FOREACH_SAFE(var, head, field, tvar) \
565 805e39bf 2021-07-22 op for ((var) = STAILQ_FIRST(head); \
566 805e39bf 2021-07-22 op (var) && ((tvar) = STAILQ_NEXT(var, field), 1); \
567 805e39bf 2021-07-22 op (var) = (tvar))
568 805e39bf 2021-07-22 op
569 805e39bf 2021-07-22 op /*
570 805e39bf 2021-07-22 op * Singly-linked Tail queue functions.
571 805e39bf 2021-07-22 op */
572 805e39bf 2021-07-22 op #define STAILQ_INIT(head) do { \
573 805e39bf 2021-07-22 op STAILQ_FIRST((head)) = NULL; \
574 805e39bf 2021-07-22 op (head)->stqh_last = &STAILQ_FIRST((head)); \
575 805e39bf 2021-07-22 op } while (0)
576 805e39bf 2021-07-22 op
577 805e39bf 2021-07-22 op #define STAILQ_INSERT_HEAD(head, elm, field) do { \
578 805e39bf 2021-07-22 op if ((STAILQ_NEXT((elm), field) = STAILQ_FIRST((head))) == NULL) \
579 805e39bf 2021-07-22 op (head)->stqh_last = &STAILQ_NEXT((elm), field); \
580 805e39bf 2021-07-22 op STAILQ_FIRST((head)) = (elm); \
581 805e39bf 2021-07-22 op } while (0)
582 805e39bf 2021-07-22 op
583 805e39bf 2021-07-22 op #define STAILQ_INSERT_TAIL(head, elm, field) do { \
584 805e39bf 2021-07-22 op STAILQ_NEXT((elm), field) = NULL; \
585 805e39bf 2021-07-22 op *(head)->stqh_last = (elm); \
586 805e39bf 2021-07-22 op (head)->stqh_last = &STAILQ_NEXT((elm), field); \
587 805e39bf 2021-07-22 op } while (0)
588 805e39bf 2021-07-22 op
589 805e39bf 2021-07-22 op #define STAILQ_INSERT_AFTER(head, listelm, elm, field) do { \
590 805e39bf 2021-07-22 op if ((STAILQ_NEXT((elm), field) = STAILQ_NEXT((elm), field)) == NULL)\
591 805e39bf 2021-07-22 op (head)->stqh_last = &STAILQ_NEXT((elm), field); \
592 805e39bf 2021-07-22 op STAILQ_NEXT((elm), field) = (elm); \
593 805e39bf 2021-07-22 op } while (0)
594 805e39bf 2021-07-22 op
595 805e39bf 2021-07-22 op #define STAILQ_REMOVE_HEAD(head, field) do { \
596 805e39bf 2021-07-22 op if ((STAILQ_FIRST((head)) = \
597 805e39bf 2021-07-22 op STAILQ_NEXT(STAILQ_FIRST((head)), field)) == NULL) \
598 805e39bf 2021-07-22 op (head)->stqh_last = &STAILQ_FIRST((head)); \
599 805e39bf 2021-07-22 op } while (0)
600 805e39bf 2021-07-22 op
601 805e39bf 2021-07-22 op #define STAILQ_REMOVE_AFTER(head, elm, field) do { \
602 805e39bf 2021-07-22 op if ((STAILQ_NEXT(elm, field) = \
603 805e39bf 2021-07-22 op STAILQ_NEXT(STAILQ_NEXT(elm, field), field)) == NULL) \
604 805e39bf 2021-07-22 op (head)->stqh_last = &STAILQ_NEXT((elm), field); \
605 805e39bf 2021-07-22 op } while (0)
606 805e39bf 2021-07-22 op
607 805e39bf 2021-07-22 op #define STAILQ_REMOVE(head, elm, type, field) do { \
608 805e39bf 2021-07-22 op if (STAILQ_FIRST((head)) == (elm)) { \
609 805e39bf 2021-07-22 op STAILQ_REMOVE_HEAD((head), field); \
610 805e39bf 2021-07-22 op } else { \
611 805e39bf 2021-07-22 op struct type *curelm = (head)->stqh_first; \
612 805e39bf 2021-07-22 op while (STAILQ_NEXT(curelm, field) != (elm)) \
613 805e39bf 2021-07-22 op curelm = STAILQ_NEXT(curelm, field); \
614 805e39bf 2021-07-22 op STAILQ_REMOVE_AFTER(head, curelm, field); \
615 805e39bf 2021-07-22 op } \
616 805e39bf 2021-07-22 op } while (0)
617 805e39bf 2021-07-22 op
618 805e39bf 2021-07-22 op #define STAILQ_CONCAT(head1, head2) do { \
619 805e39bf 2021-07-22 op if (!STAILQ_EMPTY((head2))) { \
620 805e39bf 2021-07-22 op *(head1)->stqh_last = (head2)->stqh_first; \
621 805e39bf 2021-07-22 op (head1)->stqh_last = (head2)->stqh_last; \
622 805e39bf 2021-07-22 op STAILQ_INIT((head2)); \
623 805e39bf 2021-07-22 op } \
624 805e39bf 2021-07-22 op } while (0)
625 805e39bf 2021-07-22 op
626 805e39bf 2021-07-22 op #define STAILQ_LAST(head, type, field) \
627 805e39bf 2021-07-22 op (STAILQ_EMPTY((head)) ? NULL : \
628 805e39bf 2021-07-22 op ((struct type *)(void *) \
629 805e39bf 2021-07-22 op ((char *)((head)->stqh_last) - offsetof(struct type, field))))
630 805e39bf 2021-07-22 op
631 805e39bf 2021-07-22 op #endif /* !_SYS_QUEUE_H_ */