openssh/openbsd-compat/sys-queue.h

   1 /*      $OpenBSD: queue.h,v 1.23 2003/06/02 23:28:21 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 _FAKE_QUEUE_H_
  36 #define _FAKE_QUEUE_H_
  37
  38 /*
  39  * Ignore all <sys/queue.h> since older platforms have broken/incomplete
  40  * <sys/queue.h> that are too hard to work around.
  41  */
  42 #undef SLIST_HEAD
  43 #undef SLIST_HEAD_INITIALIZER
  44 #undef SLIST_ENTRY
  45 #undef SLIST_FIRST
  46 #undef SLIST_END
  47 #undef SLIST_EMPTY
  48 #undef SLIST_NEXT
  49 #undef SLIST_FOREACH
  50 #undef SLIST_INIT
  51 #undef SLIST_INSERT_AFTER
  52 #undef SLIST_INSERT_HEAD
  53 #undef SLIST_REMOVE_HEAD
  54 #undef SLIST_REMOVE
  55 #undef LIST_HEAD
  56 #undef LIST_HEAD_INITIALIZER
  57 #undef LIST_ENTRY
  58 #undef LIST_FIRST
  59 #undef LIST_END
  60 #undef LIST_EMPTY
  61 #undef LIST_NEXT
  62 #undef LIST_FOREACH
  63 #undef LIST_INIT
  64 #undef LIST_INSERT_AFTER
  65 #undef LIST_INSERT_BEFORE
  66 #undef LIST_INSERT_HEAD
  67 #undef LIST_REMOVE
  68 #undef LIST_REPLACE
  69 #undef SIMPLEQ_HEAD
  70 #undef SIMPLEQ_HEAD_INITIALIZER
  71 #undef SIMPLEQ_ENTRY
  72 #undef SIMPLEQ_FIRST
  73 #undef SIMPLEQ_END
  74 #undef SIMPLEQ_EMPTY
  75 #undef SIMPLEQ_NEXT
  76 #undef SIMPLEQ_FOREACH
  77 #undef SIMPLEQ_INIT
  78 #undef SIMPLEQ_INSERT_HEAD
  79 #undef SIMPLEQ_INSERT_TAIL
  80 #undef SIMPLEQ_INSERT_AFTER
  81 #undef SIMPLEQ_REMOVE_HEAD
  82 #undef TAILQ_HEAD
  83 #undef TAILQ_HEAD_INITIALIZER
  84 #undef TAILQ_ENTRY
  85 #undef TAILQ_FIRST
  86 #undef TAILQ_END
  87 #undef TAILQ_NEXT
  88 #undef TAILQ_LAST
  89 #undef TAILQ_PREV
  90 #undef TAILQ_EMPTY
  91 #undef TAILQ_FOREACH
  92 #undef TAILQ_FOREACH_REVERSE
  93 #undef TAILQ_INIT
  94 #undef TAILQ_INSERT_HEAD
  95 #undef TAILQ_INSERT_TAIL
  96 #undef TAILQ_INSERT_AFTER
  97 #undef TAILQ_INSERT_BEFORE
  98 #undef TAILQ_REMOVE
  99 #undef TAILQ_REPLACE
 100 #undef CIRCLEQ_HEAD
 101 #undef CIRCLEQ_HEAD_INITIALIZER
 102 #undef CIRCLEQ_ENTRY
 103 #undef CIRCLEQ_FIRST
 104 #undef CIRCLEQ_LAST
 105 #undef CIRCLEQ_END
 106 #undef CIRCLEQ_NEXT
 107 #undef CIRCLEQ_PREV
 108 #undef CIRCLEQ_EMPTY
 109 #undef CIRCLEQ_FOREACH
 110 #undef CIRCLEQ_FOREACH_REVERSE
 111 #undef CIRCLEQ_INIT
 112 #undef CIRCLEQ_INSERT_AFTER
 113 #undef CIRCLEQ_INSERT_BEFORE
 114 #undef CIRCLEQ_INSERT_HEAD
 115 #undef CIRCLEQ_INSERT_TAIL
 116 #undef CIRCLEQ_REMOVE
 117 #undef CIRCLEQ_REPLACE
 118
 119 /*
 120  * This file defines five types of data structures: singly-linked lists,
 121  * lists, simple queues, tail queues, and circular queues.
 122  *
 123  *
 124  * A singly-linked list is headed by a single forward pointer. The elements
 125  * are singly linked for minimum space and pointer manipulation overhead at
 126  * the expense of O(n) removal for arbitrary elements. New elements can be
 127  * added to the list after an existing element or at the head of the list.
 128  * Elements being removed from the head of the list should use the explicit
 129  * macro for this purpose for optimum efficiency. A singly-linked list may
 130  * only be traversed in the forward direction.  Singly-linked lists are ideal
 131  * for applications with large datasets and few or no removals or for
 132  * implementing a LIFO queue.
 133  *
 134  * A list is headed by a single forward pointer (or an array of forward
 135  * pointers for a hash table header). The elements are doubly linked
 136  * so that an arbitrary element can be removed without a need to
 137  * traverse the list. New elements can be added to the list before
 138  * or after an existing element or at the head of the list. A list
 139  * may only be traversed in the forward direction.
 140  *
 141  * A simple queue is headed by a pair of pointers, one the head of the
 142  * list and the other to the tail of the list. The elements are singly
 143  * linked to save space, so elements can only be removed from the
 144  * head of the list. New elements can be added to the list before or after
 145  * an existing element, at the head of the list, or at the end of the
 146  * list. A simple queue may only be traversed in the forward direction.
 147  *
 148  * A tail queue is headed by a pair of pointers, one to the head of the
 149  * list and the other to the tail of the list. The elements are doubly
 150  * linked so that an arbitrary element can be removed without a need to
 151  * traverse the list. New elements can be added to the list before or
 152  * after an existing element, at the head of the list, or at the end of
 153  * the list. A tail queue may be traversed in either direction.
 154  *
 155  * A circle queue is headed by a pair of pointers, one to the head of the
 156  * list and the other to the tail of the list. The elements are doubly
 157  * linked so that an arbitrary element can be removed without a need to
 158  * traverse the list. New elements can be added to the list before or after
 159  * an existing element, at the head of the list, or at the end of the list.
 160  * A circle queue may be traversed in either direction, but has a more
 161  * complex end of list detection.
 162  *
 163  * For details on the use of these macros, see the queue(3) manual page.
 164  */
 165
 166 /*
 167  * Singly-linked List definitions.
 168  */
 169 #define SLIST_HEAD(name, type)                                          \
 170 struct name {                                                           \
 171         struct type *slh_first; /* first element */                     \
 172 }
 173
 174 #define SLIST_HEAD_INITIALIZER(head)                                    \
 175         { NULL }
 176
 177 #define SLIST_ENTRY(type)                                               \
 178 struct {                                                                \
 179         struct type *sle_next;  /* next element */                      \
 180 }
 181
 182 /*
 183  * Singly-linked List access methods.
 184  */
 185 #define SLIST_FIRST(head)       ((head)->slh_first)
 186 #define SLIST_END(head)         NULL
 187 #define SLIST_EMPTY(head)       (SLIST_FIRST(head) == SLIST_END(head))
 188 #define SLIST_NEXT(elm, field)  ((elm)->field.sle_next)
 189
 190 #define SLIST_FOREACH(var, head, field)                                 \
 191         for((var) = SLIST_FIRST(head);                                  \
 192             (var) != SLIST_END(head);                                   \
 193             (var) = SLIST_NEXT(var, field))
 194
 195 /*
 196  * Singly-linked List functions.
 197  */
 198 #define SLIST_INIT(head) {                                              \
 199         SLIST_FIRST(head) = SLIST_END(head);                            \
 200 }
 201
 202 #define SLIST_INSERT_AFTER(slistelm, elm, field) do {                   \
 203         (elm)->field.sle_next = (slistelm)->field.sle_next;             \
 204         (slistelm)->field.sle_next = (elm);                             \
 205 } while (0)
 206
 207 #define SLIST_INSERT_HEAD(head, elm, field) do {                        \
 208         (elm)->field.sle_next = (head)->slh_first;                      \
 209         (head)->slh_first = (elm);                                      \
 210 } while (0)
 211
 212 #define SLIST_REMOVE_HEAD(head, field) do {                             \
 213         (head)->slh_first = (head)->slh_first->field.sle_next;          \
 214 } while (0)
 215
 216 #define SLIST_REMOVE(head, elm, type, field) do {                       \
 217         if ((head)->slh_first == (elm)) {                               \
 218                 SLIST_REMOVE_HEAD((head), field);                       \
 219         }                                                               \
 220         else {                                                          \
 221                 struct type *curelm = (head)->slh_first;                \
 222                 while( curelm->field.sle_next != (elm) )                \
 223                         curelm = curelm->field.sle_next;                \
 224                 curelm->field.sle_next =                                \
 225                     curelm->field.sle_next->field.sle_next;             \
 226         }                                                               \
 227 } while (0)
 228
 229 /*
 230  * List definitions.
 231  */
 232 #define LIST_HEAD(name, type)                                           \
 233 struct name {                                                           \
 234         struct type *lh_first;  /* first element */                     \
 235 }
 236
 237 #define LIST_HEAD_INITIALIZER(head)                                     \
 238         { NULL }
 239
 240 #define LIST_ENTRY(type)                                                \
 241 struct {                                                                \
 242         struct type *le_next;   /* next element */                      \
 243         struct type **le_prev;  /* address of previous next element */  \
 244 }
 245
 246 /*
 247  * List access methods
 248  */
 249 #define LIST_FIRST(head)                ((head)->lh_first)
 250 #define LIST_END(head)                  NULL
 251 #define LIST_EMPTY(head)                (LIST_FIRST(head) == LIST_END(head))
 252 #define LIST_NEXT(elm, field)           ((elm)->field.le_next)
 253
 254 #define LIST_FOREACH(var, head, field)                                  \
 255         for((var) = LIST_FIRST(head);                                   \
 256             (var)!= LIST_END(head);                                     \
 257             (var) = LIST_NEXT(var, field))
 258
 259 /*
 260  * List functions.
 261  */
 262 #define LIST_INIT(head) do {                                            \
 263         LIST_FIRST(head) = LIST_END(head);                              \
 264 } while (0)
 265
 266 #define LIST_INSERT_AFTER(listelm, elm, field) do {                     \
 267         if (((elm)->field.le_next = (listelm)->field.le_next) != NULL)  \
 268                 (listelm)->field.le_next->field.le_prev =               \
 269                     &(elm)->field.le_next;                              \
 270         (listelm)->field.le_next = (elm);                               \
 271         (elm)->field.le_prev = &(listelm)->field.le_next;               \
 272 } while (0)
 273
 274 #define LIST_INSERT_BEFORE(listelm, elm, field) do {                    \
 275         (elm)->field.le_prev = (listelm)->field.le_prev;                \
 276         (elm)->field.le_next = (listelm);                               \
 277         *(listelm)->field.le_prev = (elm);                              \
 278         (listelm)->field.le_prev = &(elm)->field.le_next;               \
 279 } while (0)
 280
 281 #define LIST_INSERT_HEAD(head, elm, field) do {                         \
 282         if (((elm)->field.le_next = (head)->lh_first) != NULL)          \
 283                 (head)->lh_first->field.le_prev = &(elm)->field.le_next;\
 284         (head)->lh_first = (elm);                                       \
 285         (elm)->field.le_prev = &(head)->lh_first;                       \
 286 } while (0)
 287
 288 #define LIST_REMOVE(elm, field) do {                                    \
 289         if ((elm)->field.le_next != NULL)                               \
 290                 (elm)->field.le_next->field.le_prev =                   \
 291                     (elm)->field.le_prev;                               \
 292         *(elm)->field.le_prev = (elm)->field.le_next;                   \
 293 } while (0)
 294
 295 #define LIST_REPLACE(elm, elm2, field) do {                             \
 296         if (((elm2)->field.le_next = (elm)->field.le_next) != NULL)     \
 297                 (elm2)->field.le_next->field.le_prev =                  \
 298                     &(elm2)->field.le_next;                             \
 299         (elm2)->field.le_prev = (elm)->field.le_prev;                   \
 300         *(elm2)->field.le_prev = (elm2);                                \
 301 } while (0)
 302
 303 /*
 304  * Simple queue definitions.
 305  */
 306 #define SIMPLEQ_HEAD(name, type)                                        \
 307 struct name {                                                           \
 308         struct type *sqh_first; /* first element */                     \
 309         struct type **sqh_last; /* addr of last next element */         \
 310 }
 311
 312 #define SIMPLEQ_HEAD_INITIALIZER(head)                                  \
 313         { NULL, &(head).sqh_first }
 314
 315 #define SIMPLEQ_ENTRY(type)                                             \
 316 struct {                                                                \
 317         struct type *sqe_next;  /* next element */                      \
 318 }
 319
 320 /*
 321  * Simple queue access methods.
 322  */
 323 #define SIMPLEQ_FIRST(head)         ((head)->sqh_first)
 324 #define SIMPLEQ_END(head)           NULL
 325 #define SIMPLEQ_EMPTY(head)         (SIMPLEQ_FIRST(head) == SIMPLEQ_END(head))
 326 #define SIMPLEQ_NEXT(elm, field)    ((elm)->field.sqe_next)
 327
 328 #define SIMPLEQ_FOREACH(var, head, field)                               \
 329         for((var) = SIMPLEQ_FIRST(head);                                \
 330             (var) != SIMPLEQ_END(head);                                 \
 331             (var) = SIMPLEQ_NEXT(var, field))
 332
 333 /*
 334  * Simple queue functions.
 335  */
 336 #define SIMPLEQ_INIT(head) do {                                         \
 337         (head)->sqh_first = NULL;                                       \
 338         (head)->sqh_last = &(head)->sqh_first;                          \
 339 } while (0)
 340
 341 #define SIMPLEQ_INSERT_HEAD(head, elm, field) do {                      \
 342         if (((elm)->field.sqe_next = (head)->sqh_first) == NULL)        \
 343                 (head)->sqh_last = &(elm)->field.sqe_next;              \
 344         (head)->sqh_first = (elm);                                      \
 345 } while (0)
 346
 347 #define SIMPLEQ_INSERT_TAIL(head, elm, field) do {                      \
 348         (elm)->field.sqe_next = NULL;                                   \
 349         *(head)->sqh_last = (elm);                                      \
 350         (head)->sqh_last = &(elm)->field.sqe_next;                      \
 351 } while (0)
 352
 353 #define SIMPLEQ_INSERT_AFTER(head, listelm, elm, field) do {            \
 354         if (((elm)->field.sqe_next = (listelm)->field.sqe_next) == NULL)\
 355                 (head)->sqh_last = &(elm)->field.sqe_next;              \
 356         (listelm)->field.sqe_next = (elm);                              \
 357 } while (0)
 358
 359 #define SIMPLEQ_REMOVE_HEAD(head, elm, field) do {                      \
 360         if (((head)->sqh_first = (elm)->field.sqe_next) == NULL)        \
 361                 (head)->sqh_last = &(head)->sqh_first;                  \
 362 } while (0)
 363
 364 /*
 365  * Tail queue definitions.
 366  */
 367 #define TAILQ_HEAD(name, type)                                          \
 368 struct name {                                                           \
 369         struct type *tqh_first; /* first element */                     \
 370         struct type **tqh_last; /* addr of last next element */         \
 371 }
 372
 373 #define TAILQ_HEAD_INITIALIZER(head)                                    \
 374         { NULL, &(head).tqh_first }
 375
 376 #define TAILQ_ENTRY(type)                                               \
 377 struct {                                                                \
 378         struct type *tqe_next;  /* next element */                      \
 379         struct type **tqe_prev; /* address of previous next element */  \
 380 }
 381
 382 /*
 383  * tail queue access methods
 384  */
 385 #define TAILQ_FIRST(head)               ((head)->tqh_first)
 386 #define TAILQ_END(head)                 NULL
 387 #define TAILQ_NEXT(elm, field)          ((elm)->field.tqe_next)
 388 #define TAILQ_LAST(head, headname)                                      \
 389         (*(((struct headname *)((head)->tqh_last))->tqh_last))
 390 /* XXX */
 391 #define TAILQ_PREV(elm, headname, field)                                \
 392         (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last))
 393 #define TAILQ_EMPTY(head)                                               \
 394         (TAILQ_FIRST(head) == TAILQ_END(head))
 395
 396 #define TAILQ_FOREACH(var, head, field)                                 \
 397         for((var) = TAILQ_FIRST(head);                                  \
 398             (var) != TAILQ_END(head);                                   \
 399             (var) = TAILQ_NEXT(var, field))
 400
 401 #define TAILQ_FOREACH_REVERSE(var, head, field, headname)               \
 402         for((var) = TAILQ_LAST(head, headname);                         \
 403             (var) != TAILQ_END(head);                                   \
 404             (var) = TAILQ_PREV(var, headname, field))
 405
 406 /*
 407  * Tail queue functions.
 408  */
 409 #define TAILQ_INIT(head) do {                                           \
 410         (head)->tqh_first = NULL;                                       \
 411         (head)->tqh_last = &(head)->tqh_first;                          \
 412 } while (0)
 413
 414 #define TAILQ_INSERT_HEAD(head, elm, field) do {                        \
 415         if (((elm)->field.tqe_next = (head)->tqh_first) != NULL)        \
 416                 (head)->tqh_first->field.tqe_prev =                     \
 417                     &(elm)->field.tqe_next;                             \
 418         else                                                            \
 419                 (head)->tqh_last = &(elm)->field.tqe_next;              \
 420         (head)->tqh_first = (elm);                                      \
 421         (elm)->field.tqe_prev = &(head)->tqh_first;                     \
 422 } while (0)
 423
 424 #define TAILQ_INSERT_TAIL(head, elm, field) do {                        \
 425         (elm)->field.tqe_next = NULL;                                   \
 426         (elm)->field.tqe_prev = (head)->tqh_last;                       \
 427         *(head)->tqh_last = (elm);                                      \
 428         (head)->tqh_last = &(elm)->field.tqe_next;                      \
 429 } while (0)
 430
 431 #define TAILQ_INSERT_AFTER(head, listelm, elm, field) do {              \
 432         if (((elm)->field.tqe_next = (listelm)->field.tqe_next) != NULL)\
 433                 (elm)->field.tqe_next->field.tqe_prev =                 \
 434                     &(elm)->field.tqe_next;                             \
 435         else                                                            \
 436                 (head)->tqh_last = &(elm)->field.tqe_next;              \
 437         (listelm)->field.tqe_next = (elm);                              \
 438         (elm)->field.tqe_prev = &(listelm)->field.tqe_next;             \
 439 } while (0)
 440
 441 #define TAILQ_INSERT_BEFORE(listelm, elm, field) do {                   \
 442         (elm)->field.tqe_prev = (listelm)->field.tqe_prev;              \
 443         (elm)->field.tqe_next = (listelm);                              \
 444         *(listelm)->field.tqe_prev = (elm);                             \
 445         (listelm)->field.tqe_prev = &(elm)->field.tqe_next;             \
 446 } while (0)
 447
 448 #define TAILQ_REMOVE(head, elm, field) do {                             \
 449         if (((elm)->field.tqe_next) != NULL)                            \
 450                 (elm)->field.tqe_next->field.tqe_prev =                 \
 451                     (elm)->field.tqe_prev;                              \
 452         else                                                            \
 453                 (head)->tqh_last = (elm)->field.tqe_prev;               \
 454         *(elm)->field.tqe_prev = (elm)->field.tqe_next;                 \
 455 } while (0)
 456
 457 #define TAILQ_REPLACE(head, elm, elm2, field) do {                      \
 458         if (((elm2)->field.tqe_next = (elm)->field.tqe_next) != NULL)   \
 459                 (elm2)->field.tqe_next->field.tqe_prev =                \
 460                     &(elm2)->field.tqe_next;                            \
 461         else                                                            \
 462                 (head)->tqh_last = &(elm2)->field.tqe_next;             \
 463         (elm2)->field.tqe_prev = (elm)->field.tqe_prev;                 \
 464         *(elm2)->field.tqe_prev = (elm2);                               \
 465 } while (0)
 466
 467 /*
 468  * Circular queue definitions.
 469  */
 470 #define CIRCLEQ_HEAD(name, type)                                        \
 471 struct name {                                                           \
 472         struct type *cqh_first;         /* first element */             \
 473         struct type *cqh_last;          /* last element */              \
 474 }
 475
 476 #define CIRCLEQ_HEAD_INITIALIZER(head)                                  \
 477         { CIRCLEQ_END(&head), CIRCLEQ_END(&head) }
 478
 479 #define CIRCLEQ_ENTRY(type)                                             \
 480 struct {                                                                \
 481         struct type *cqe_next;          /* next element */              \
 482         struct type *cqe_prev;          /* previous element */          \
 483 }
 484
 485 /*
 486  * Circular queue access methods
 487  */
 488 #define CIRCLEQ_FIRST(head)             ((head)->cqh_first)
 489 #define CIRCLEQ_LAST(head)              ((head)->cqh_last)
 490 #define CIRCLEQ_END(head)               ((void *)(head))
 491 #define CIRCLEQ_NEXT(elm, field)        ((elm)->field.cqe_next)
 492 #define CIRCLEQ_PREV(elm, field)        ((elm)->field.cqe_prev)
 493 #define CIRCLEQ_EMPTY(head)                                             \
 494         (CIRCLEQ_FIRST(head) == CIRCLEQ_END(head))
 495
 496 #define CIRCLEQ_FOREACH(var, head, field)                               \
 497         for((var) = CIRCLEQ_FIRST(head);                                \
 498             (var) != CIRCLEQ_END(head);                                 \
 499             (var) = CIRCLEQ_NEXT(var, field))
 500
 501 #define CIRCLEQ_FOREACH_REVERSE(var, head, field)                       \
 502         for((var) = CIRCLEQ_LAST(head);                                 \
 503             (var) != CIRCLEQ_END(head);                                 \
 504             (var) = CIRCLEQ_PREV(var, field))
 505
 506 /*
 507  * Circular queue functions.
 508  */
 509 #define CIRCLEQ_INIT(head) do {                                         \
 510         (head)->cqh_first = CIRCLEQ_END(head);                          \
 511         (head)->cqh_last = CIRCLEQ_END(head);                           \
 512 } while (0)
 513
 514 #define CIRCLEQ_INSERT_AFTER(head, listelm, elm, field) do {            \
 515         (elm)->field.cqe_next = (listelm)->field.cqe_next;              \
 516         (elm)->field.cqe_prev = (listelm);                              \
 517         if ((listelm)->field.cqe_next == CIRCLEQ_END(head))             \
 518                 (head)->cqh_last = (elm);                               \
 519         else                                                            \
 520                 (listelm)->field.cqe_next->field.cqe_prev = (elm);      \
 521         (listelm)->field.cqe_next = (elm);                              \
 522 } while (0)
 523
 524 #define CIRCLEQ_INSERT_BEFORE(head, listelm, elm, field) do {           \
 525         (elm)->field.cqe_next = (listelm);                              \
 526         (elm)->field.cqe_prev = (listelm)->field.cqe_prev;              \
 527         if ((listelm)->field.cqe_prev == CIRCLEQ_END(head))             \
 528                 (head)->cqh_first = (elm);                              \
 529         else                                                            \
 530                 (listelm)->field.cqe_prev->field.cqe_next = (elm);      \
 531         (listelm)->field.cqe_prev = (elm);                              \
 532 } while (0)
 533
 534 #define CIRCLEQ_INSERT_HEAD(head, elm, field) do {                      \
 535         (elm)->field.cqe_next = (head)->cqh_first;                      \
 536         (elm)->field.cqe_prev = CIRCLEQ_END(head);                      \
 537         if ((head)->cqh_last == CIRCLEQ_END(head))                      \
 538                 (head)->cqh_last = (elm);                               \
 539         else                                                            \
 540                 (head)->cqh_first->field.cqe_prev = (elm);              \
 541         (head)->cqh_first = (elm);                                      \
 542 } while (0)
 543
 544 #define CIRCLEQ_INSERT_TAIL(head, elm, field) do {                      \
 545         (elm)->field.cqe_next = CIRCLEQ_END(head);                      \
 546         (elm)->field.cqe_prev = (head)->cqh_last;                       \
 547         if ((head)->cqh_first == CIRCLEQ_END(head))                     \
 548                 (head)->cqh_first = (elm);                              \
 549         else                                                            \
 550                 (head)->cqh_last->field.cqe_next = (elm);               \
 551         (head)->cqh_last = (elm);                                       \
 552 } while (0)
 553
 554 #define CIRCLEQ_REMOVE(head, elm, field) do {                           \
 555         if ((elm)->field.cqe_next == CIRCLEQ_END(head))                 \
 556                 (head)->cqh_last = (elm)->field.cqe_prev;               \
 557         else                                                            \
 558                 (elm)->field.cqe_next->field.cqe_prev =                 \
 559                     (elm)->field.cqe_prev;                              \
 560         if ((elm)->field.cqe_prev == CIRCLEQ_END(head))                 \
 561                 (head)->cqh_first = (elm)->field.cqe_next;              \
 562         else                                                            \
 563                 (elm)->field.cqe_prev->field.cqe_next =                 \
 564                     (elm)->field.cqe_next;                              \
 565 } while (0)
 566
 567 #define CIRCLEQ_REPLACE(head, elm, elm2, field) do {                    \
 568         if (((elm2)->field.cqe_next = (elm)->field.cqe_next) ==         \
 569             CIRCLEQ_END(head))                                          \
 570                 (head).cqh_last = (elm2);                               \
 571         else                                                            \
 572                 (elm2)->field.cqe_next->field.cqe_prev = (elm2);        \
 573         if (((elm2)->field.cqe_prev = (elm)->field.cqe_prev) ==         \
 574             CIRCLEQ_END(head))                                          \
 575                 (head).cqh_first = (elm2);                              \
 576         else                                                            \
 577                 (elm2)->field.cqe_prev->field.cqe_next = (elm2);        \
 578 } while (0)
 579
 580 #endif  /* !_FAKE_QUEUE_H_ */