crypto/openssh/openbsd-compat/fake-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. All advertising materials mentioning features or use of this software
  17  *    must display the following acknowledgement:
  18  *      This product includes software developed by the University of
  19  *      California, Berkeley and its contributors.
  20  * 4. Neither the name of the University nor the names of its contributors
  21  *    may be used to endorse or promote products derived from this software
  22  *    without specific prior written permission.
  23  *
  24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  34  * SUCH DAMAGE.
  35  *
  36  *      @(#)queue.h     8.5 (Berkeley) 8/20/94
  37  */
  38
  39 #ifndef _FAKE_QUEUE_H_
  40 #define _FAKE_QUEUE_H_
  41
  42 /*
  43  * Ignore all <sys/queue.h> since older platforms have broken/incomplete
  44  * <sys/queue.h> that are too hard to work around.
  45  */
  46 #undef SLIST_HEAD
  47 #undef SLIST_HEAD_INITIALIZER
  48 #undef SLIST_ENTRY
  49 #undef SLIST_FIRST
  50 #undef SLIST_END
  51 #undef SLIST_EMPTY
  52 #undef SLIST_NEXT
  53 #undef SLIST_FOREACH
  54 #undef SLIST_INIT
  55 #undef SLIST_INSERT_AFTER
  56 #undef SLIST_INSERT_HEAD
  57 #undef SLIST_REMOVE_HEAD
  58 #undef SLIST_REMOVE
  59 #undef LIST_HEAD
  60 #undef LIST_HEAD_INITIALIZER
  61 #undef LIST_ENTRY
  62 #undef LIST_FIRST
  63 #undef LIST_END
  64 #undef LIST_EMPTY
  65 #undef LIST_NEXT
  66 #undef LIST_FOREACH
  67 #undef LIST_INIT
  68 #undef LIST_INSERT_AFTER
  69 #undef LIST_INSERT_BEFORE
  70 #undef LIST_INSERT_HEAD
  71 #undef LIST_REMOVE
  72 #undef LIST_REPLACE
  73 #undef SIMPLEQ_HEAD
  74 #undef SIMPLEQ_HEAD_INITIALIZER
  75 #undef SIMPLEQ_ENTRY
  76 #undef SIMPLEQ_FIRST
  77 #undef SIMPLEQ_END
  78 #undef SIMPLEQ_EMPTY
  79 #undef SIMPLEQ_NEXT
  80 #undef SIMPLEQ_FOREACH
  81 #undef SIMPLEQ_INIT
  82 #undef SIMPLEQ_INSERT_HEAD
  83 #undef SIMPLEQ_INSERT_TAIL
  84 #undef SIMPLEQ_INSERT_AFTER
  85 #undef SIMPLEQ_REMOVE_HEAD
  86 #undef TAILQ_HEAD
  87 #undef TAILQ_HEAD_INITIALIZER
  88 #undef TAILQ_ENTRY
  89 #undef TAILQ_FIRST
  90 #undef TAILQ_END
  91 #undef TAILQ_NEXT
  92 #undef TAILQ_LAST
  93 #undef TAILQ_PREV
  94 #undef TAILQ_EMPTY
  95 #undef TAILQ_FOREACH
  96 #undef TAILQ_FOREACH_REVERSE
  97 #undef TAILQ_INIT
  98 #undef TAILQ_INSERT_HEAD
  99 #undef TAILQ_INSERT_TAIL
 100 #undef TAILQ_INSERT_AFTER
 101 #undef TAILQ_INSERT_BEFORE
 102 #undef TAILQ_REMOVE
 103 #undef TAILQ_REPLACE
 104 #undef CIRCLEQ_HEAD
 105 #undef CIRCLEQ_HEAD_INITIALIZER
 106 #undef CIRCLEQ_ENTRY
 107 #undef CIRCLEQ_FIRST
 108 #undef CIRCLEQ_LAST
 109 #undef CIRCLEQ_END
 110 #undef CIRCLEQ_NEXT
 111 #undef CIRCLEQ_PREV
 112 #undef CIRCLEQ_EMPTY
 113 #undef CIRCLEQ_FOREACH
 114 #undef CIRCLEQ_FOREACH_REVERSE
 115 #undef CIRCLEQ_INIT
 116 #undef CIRCLEQ_INSERT_AFTER
 117 #undef CIRCLEQ_INSERT_BEFORE
 118 #undef CIRCLEQ_INSERT_HEAD
 119 #undef CIRCLEQ_INSERT_TAIL
 120 #undef CIRCLEQ_REMOVE
 121 #undef CIRCLEQ_REPLACE
 122
 123 /*
 124  * This file defines five types of data structures: singly-linked lists,
 125  * lists, simple queues, tail queues, and circular queues.
 126  *
 127  *
 128  * A singly-linked list is headed by a single forward pointer. The elements
 129  * are singly linked for minimum space and pointer manipulation overhead at
 130  * the expense of O(n) removal for arbitrary elements. New elements can be
 131  * added to the list after an existing element or at the head of the list.
 132  * Elements being removed from the head of the list should use the explicit
 133  * macro for this purpose for optimum efficiency. A singly-linked list may
 134  * only be traversed in the forward direction.  Singly-linked lists are ideal
 135  * for applications with large datasets and few or no removals or for
 136  * implementing a LIFO queue.
 137  *
 138  * A list is headed by a single forward pointer (or an array of forward
 139  * pointers for a hash table header). The elements are doubly linked
 140  * so that an arbitrary element can be removed without a need to
 141  * traverse the list. New elements can be added to the list before
 142  * or after an existing element or at the head of the list. A list
 143  * may only be traversed in the forward direction.
 144  *
 145  * A simple queue is headed by a pair of pointers, one the head of the
 146  * list and the other to the tail of the list. The elements are singly
 147  * linked to save space, so elements can only be removed from the
 148  * head of the list. New elements can be added to the list before or after
 149  * an existing element, at the head of the list, or at the end of the
 150  * list. A simple queue may only be traversed in the forward direction.
 151  *
 152  * A tail queue is headed by a pair of pointers, one to the head of the
 153  * list and the other to the tail of the list. The elements are doubly
 154  * linked so that an arbitrary element can be removed without a need to
 155  * traverse the list. New elements can be added to the list before or
 156  * after an existing element, at the head of the list, or at the end of
 157  * the list. A tail queue may be traversed in either direction.
 158  *
 159  * A circle queue is headed by a pair of pointers, one to the head of the
 160  * list and the other to the tail of the list. The elements are doubly
 161  * linked so that an arbitrary element can be removed without a need to
 162  * traverse the list. New elements can be added to the list before or after
 163  * an existing element, at the head of the list, or at the end of the list.
 164  * A circle queue may be traversed in either direction, but has a more
 165  * complex end of list detection.
 166  *
 167  * For details on the use of these macros, see the queue(3) manual page.
 168  */
 169
 170 /*
 171  * Singly-linked List definitions.
 172  */
 173 #define SLIST_HEAD(name, type)                                          \
 174 struct name {                                                           \
 175         struct type *slh_first; /* first element */                     \
 176 }
 177
 178 #define SLIST_HEAD_INITIALIZER(head)                                    \
 179         { NULL }
 180
 181 #define SLIST_ENTRY(type)                                               \
 182 struct {                                                                \
 183         struct type *sle_next;  /* next element */                      \
 184 }
 185
 186 /*
 187  * Singly-linked List access methods.
 188  */
 189 #define SLIST_FIRST(head)       ((head)->slh_first)
 190 #define SLIST_END(head)         NULL
 191 #define SLIST_EMPTY(head)       (SLIST_FIRST(head) == SLIST_END(head))
 192 #define SLIST_NEXT(elm, field)  ((elm)->field.sle_next)
 193
 194 #define SLIST_FOREACH(var, head, field)                                 \
 195         for((var) = SLIST_FIRST(head);                                  \
 196             (var) != SLIST_END(head);                                   \
 197             (var) = SLIST_NEXT(var, field))
 198
 199 /*
 200  * Singly-linked List functions.
 201  */
 202 #define SLIST_INIT(head) {                                              \
 203         SLIST_FIRST(head) = SLIST_END(head);                            \
 204 }
 205
 206 #define SLIST_INSERT_AFTER(slistelm, elm, field) do {                   \
 207         (elm)->field.sle_next = (slistelm)->field.sle_next;             \
 208         (slistelm)->field.sle_next = (elm);                             \
 209 } while (0)
 210
 211 #define SLIST_INSERT_HEAD(head, elm, field) do {                        \
 212         (elm)->field.sle_next = (head)->slh_first;                      \
 213         (head)->slh_first = (elm);                                      \
 214 } while (0)
 215
 216 #define SLIST_REMOVE_HEAD(head, field) do {                             \
 217         (head)->slh_first = (head)->slh_first->field.sle_next;          \
 218 } while (0)
 219
 220 #define SLIST_REMOVE(head, elm, type, field) do {                       \
 221         if ((head)->slh_first == (elm)) {                               \
 222                 SLIST_REMOVE_HEAD((head), field);                       \
 223         }                                                               \
 224         else {                                                          \
 225                 struct type *curelm = (head)->slh_first;                \
 226                 while( curelm->field.sle_next != (elm) )                \
 227                         curelm = curelm->field.sle_next;                \
 228                 curelm->field.sle_next =                                \
 229                     curelm->field.sle_next->field.sle_next;             \
 230         }                                                               \
 231 } while (0)
 232
 233 /*
 234  * List definitions.
 235  */
 236 #define LIST_HEAD(name, type)                                           \
 237 struct name {                                                           \
 238         struct type *lh_first;  /* first element */                     \
 239 }
 240
 241 #define LIST_HEAD_INITIALIZER(head)                                     \
 242         { NULL }
 243
 244 #define LIST_ENTRY(type)                                                \
 245 struct {                                                                \
 246         struct type *le_next;   /* next element */                      \
 247         struct type **le_prev;  /* address of previous next element */  \
 248 }
 249
 250 /*
 251  * List access methods
 252  */
 253 #define LIST_FIRST(head)                ((head)->lh_first)
 254 #define LIST_END(head)                  NULL
 255 #define LIST_EMPTY(head)                (LIST_FIRST(head) == LIST_END(head))
 256 #define LIST_NEXT(elm, field)           ((elm)->field.le_next)
 257
 258 #define LIST_FOREACH(var, head, field)                                  \
 259         for((var) = LIST_FIRST(head);                                   \
 260             (var)!= LIST_END(head);                                     \
 261             (var) = LIST_NEXT(var, field))
 262
 263 /*
 264  * List functions.
 265  */
 266 #define LIST_INIT(head) do {                                            \
 267         LIST_FIRST(head) = LIST_END(head);                              \
 268 } while (0)
 269
 270 #define LIST_INSERT_AFTER(listelm, elm, field) do {                     \
 271         if (((elm)->field.le_next = (listelm)->field.le_next) != NULL)  \
 272                 (listelm)->field.le_next->field.le_prev =               \
 273                     &(elm)->field.le_next;                              \
 274         (listelm)->field.le_next = (elm);                               \
 275         (elm)->field.le_prev = &(listelm)->field.le_next;               \
 276 } while (0)
 277
 278 #define LIST_INSERT_BEFORE(listelm, elm, field) do {                    \
 279         (elm)->field.le_prev = (listelm)->field.le_prev;                \
 280         (elm)->field.le_next = (listelm);                               \
 281         *(listelm)->field.le_prev = (elm);                              \
 282         (listelm)->field.le_prev = &(elm)->field.le_next;               \
 283 } while (0)
 284
 285 #define LIST_INSERT_HEAD(head, elm, field) do {                         \
 286         if (((elm)->field.le_next = (head)->lh_first) != NULL)          \
 287                 (head)->lh_first->field.le_prev = &(elm)->field.le_next;\
 288         (head)->lh_first = (elm);                                       \
 289         (elm)->field.le_prev = &(head)->lh_first;                       \
 290 } while (0)
 291
 292 #define LIST_REMOVE(elm, field) do {                                    \
 293         if ((elm)->field.le_next != NULL)                               \
 294                 (elm)->field.le_next->field.le_prev =                   \
 295                     (elm)->field.le_prev;                               \
 296         *(elm)->field.le_prev = (elm)->field.le_next;                   \
 297 } while (0)
 298
 299 #define LIST_REPLACE(elm, elm2, field) do {                             \
 300         if (((elm2)->field.le_next = (elm)->field.le_next) != NULL)     \
 301                 (elm2)->field.le_next->field.le_prev =                  \
 302                     &(elm2)->field.le_next;                             \
 303         (elm2)->field.le_prev = (elm)->field.le_prev;                   \
 304         *(elm2)->field.le_prev = (elm2);                                \
 305 } while (0)
 306
 307 /*
 308  * Simple queue definitions.
 309  */
 310 #define SIMPLEQ_HEAD(name, type)                                        \
 311 struct name {                                                           \
 312         struct type *sqh_first; /* first element */                     \
 313         struct type **sqh_last; /* addr of last next element */         \
 314 }
 315
 316 #define SIMPLEQ_HEAD_INITIALIZER(head)                                  \
 317         { NULL, &(head).sqh_first }
 318
 319 #define SIMPLEQ_ENTRY(type)                                             \
 320 struct {                                                                \
 321         struct type *sqe_next;  /* next element */                      \
 322 }
 323
 324 /*
 325  * Simple queue access methods.
 326  */
 327 #define SIMPLEQ_FIRST(head)         ((head)->sqh_first)
 328 #define SIMPLEQ_END(head)           NULL
 329 #define SIMPLEQ_EMPTY(head)         (SIMPLEQ_FIRST(head) == SIMPLEQ_END(head))
 330 #define SIMPLEQ_NEXT(elm, field)    ((elm)->field.sqe_next)
 331
 332 #define SIMPLEQ_FOREACH(var, head, field)                               \
 333         for((var) = SIMPLEQ_FIRST(head);                                \
 334             (var) != SIMPLEQ_END(head);                                 \
 335             (var) = SIMPLEQ_NEXT(var, field))
 336
 337 /*
 338  * Simple queue functions.
 339  */
 340 #define SIMPLEQ_INIT(head) do {                                         \
 341         (head)->sqh_first = NULL;                                       \
 342         (head)->sqh_last = &(head)->sqh_first;                          \
 343 } while (0)
 344
 345 #define SIMPLEQ_INSERT_HEAD(head, elm, field) do {                      \
 346         if (((elm)->field.sqe_next = (head)->sqh_first) == NULL)        \
 347                 (head)->sqh_last = &(elm)->field.sqe_next;              \
 348         (head)->sqh_first = (elm);                                      \
 349 } while (0)
 350
 351 #define SIMPLEQ_INSERT_TAIL(head, elm, field) do {                      \
 352         (elm)->field.sqe_next = NULL;                                   \
 353         *(head)->sqh_last = (elm);                                      \
 354         (head)->sqh_last = &(elm)->field.sqe_next;                      \
 355 } while (0)
 356
 357 #define SIMPLEQ_INSERT_AFTER(head, listelm, elm, field) do {            \
 358         if (((elm)->field.sqe_next = (listelm)->field.sqe_next) == NULL)\
 359                 (head)->sqh_last = &(elm)->field.sqe_next;              \
 360         (listelm)->field.sqe_next = (elm);                              \
 361 } while (0)
 362
 363 #define SIMPLEQ_REMOVE_HEAD(head, elm, field) do {                      \
 364         if (((head)->sqh_first = (elm)->field.sqe_next) == NULL)        \
 365                 (head)->sqh_last = &(head)->sqh_first;                  \
 366 } while (0)
 367
 368 /*
 369  * Tail queue definitions.
 370  */
 371 #define TAILQ_HEAD(name, type)                                          \
 372 struct name {                                                           \
 373         struct type *tqh_first; /* first element */                     \
 374         struct type **tqh_last; /* addr of last next element */         \
 375 }
 376
 377 #define TAILQ_HEAD_INITIALIZER(head)                                    \
 378         { NULL, &(head).tqh_first }
 379
 380 #define TAILQ_ENTRY(type)                                               \
 381 struct {                                                                \
 382         struct type *tqe_next;  /* next element */                      \
 383         struct type **tqe_prev; /* address of previous next element */  \
 384 }
 385
 386 /*
 387  * tail queue access methods
 388  */
 389 #define TAILQ_FIRST(head)               ((head)->tqh_first)
 390 #define TAILQ_END(head)                 NULL
 391 #define TAILQ_NEXT(elm, field)          ((elm)->field.tqe_next)
 392 #define TAILQ_LAST(head, headname)                                      \
 393         (*(((struct headname *)((head)->tqh_last))->tqh_last))
 394 /* XXX */
 395 #define TAILQ_PREV(elm, headname, field)                                \
 396         (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last))
 397 #define TAILQ_EMPTY(head)                                               \
 398         (TAILQ_FIRST(head) == TAILQ_END(head))
 399
 400 #define TAILQ_FOREACH(var, head, field)                                 \
 401         for((var) = TAILQ_FIRST(head);                                  \
 402             (var) != TAILQ_END(head);                                   \
 403             (var) = TAILQ_NEXT(var, field))
 404
 405 #define TAILQ_FOREACH_REVERSE(var, head, field, headname)               \
 406         for((var) = TAILQ_LAST(head, headname);                         \
 407             (var) != TAILQ_END(head);                                   \
 408             (var) = TAILQ_PREV(var, headname, field))
 409
 410 /*
 411  * Tail queue functions.
 412  */
 413 #define TAILQ_INIT(head) do {                                           \
 414         (head)->tqh_first = NULL;                                       \
 415         (head)->tqh_last = &(head)->tqh_first;                          \
 416 } while (0)
 417
 418 #define TAILQ_INSERT_HEAD(head, elm, field) do {                        \
 419         if (((elm)->field.tqe_next = (head)->tqh_first) != NULL)        \
 420                 (head)->tqh_first->field.tqe_prev =                     \
 421                     &(elm)->field.tqe_next;                             \
 422         else                                                            \
 423                 (head)->tqh_last = &(elm)->field.tqe_next;              \
 424         (head)->tqh_first = (elm);                                      \
 425         (elm)->field.tqe_prev = &(head)->tqh_first;                     \
 426 } while (0)
 427
 428 #define TAILQ_INSERT_TAIL(head, elm, field) do {                        \
 429         (elm)->field.tqe_next = NULL;                                   \
 430         (elm)->field.tqe_prev = (head)->tqh_last;                       \
 431         *(head)->tqh_last = (elm);                                      \
 432         (head)->tqh_last = &(elm)->field.tqe_next;                      \
 433 } while (0)
 434
 435 #define TAILQ_INSERT_AFTER(head, listelm, elm, field) do {              \
 436         if (((elm)->field.tqe_next = (listelm)->field.tqe_next) != NULL)\
 437                 (elm)->field.tqe_next->field.tqe_prev =                 \
 438                     &(elm)->field.tqe_next;                             \
 439         else                                                            \
 440                 (head)->tqh_last = &(elm)->field.tqe_next;              \
 441         (listelm)->field.tqe_next = (elm);                              \
 442         (elm)->field.tqe_prev = &(listelm)->field.tqe_next;             \
 443 } while (0)
 444
 445 #define TAILQ_INSERT_BEFORE(listelm, elm, field) do {                   \
 446         (elm)->field.tqe_prev = (listelm)->field.tqe_prev;              \
 447         (elm)->field.tqe_next = (listelm);                              \
 448         *(listelm)->field.tqe_prev = (elm);                             \
 449         (listelm)->field.tqe_prev = &(elm)->field.tqe_next;             \
 450 } while (0)
 451
 452 #define TAILQ_REMOVE(head, elm, field) do {                             \
 453         if (((elm)->field.tqe_next) != NULL)                            \
 454                 (elm)->field.tqe_next->field.tqe_prev =                 \
 455                     (elm)->field.tqe_prev;                              \
 456         else                                                            \
 457                 (head)->tqh_last = (elm)->field.tqe_prev;               \
 458         *(elm)->field.tqe_prev = (elm)->field.tqe_next;                 \
 459 } while (0)
 460
 461 #define TAILQ_REPLACE(head, elm, elm2, field) do {                      \
 462         if (((elm2)->field.tqe_next = (elm)->field.tqe_next) != NULL)   \
 463                 (elm2)->field.tqe_next->field.tqe_prev =                \
 464                     &(elm2)->field.tqe_next;                            \
 465         else                                                            \
 466                 (head)->tqh_last = &(elm2)->field.tqe_next;             \
 467         (elm2)->field.tqe_prev = (elm)->field.tqe_prev;                 \
 468         *(elm2)->field.tqe_prev = (elm2);                               \
 469 } while (0)
 470
 471 /*
 472  * Circular queue definitions.
 473  */
 474 #define CIRCLEQ_HEAD(name, type)                                        \
 475 struct name {                                                           \
 476         struct type *cqh_first;         /* first element */             \
 477         struct type *cqh_last;          /* last element */              \
 478 }
 479
 480 #define CIRCLEQ_HEAD_INITIALIZER(head)                                  \
 481         { CIRCLEQ_END(&head), CIRCLEQ_END(&head) }
 482
 483 #define CIRCLEQ_ENTRY(type)                                             \
 484 struct {                                                                \
 485         struct type *cqe_next;          /* next element */              \
 486         struct type *cqe_prev;          /* previous element */          \
 487 }
 488
 489 /*
 490  * Circular queue access methods
 491  */
 492 #define CIRCLEQ_FIRST(head)             ((head)->cqh_first)
 493 #define CIRCLEQ_LAST(head)              ((head)->cqh_last)
 494 #define CIRCLEQ_END(head)               ((void *)(head))
 495 #define CIRCLEQ_NEXT(elm, field)        ((elm)->field.cqe_next)
 496 #define CIRCLEQ_PREV(elm, field)        ((elm)->field.cqe_prev)
 497 #define CIRCLEQ_EMPTY(head)                                             \
 498         (CIRCLEQ_FIRST(head) == CIRCLEQ_END(head))
 499
 500 #define CIRCLEQ_FOREACH(var, head, field)                               \
 501         for((var) = CIRCLEQ_FIRST(head);                                \
 502             (var) != CIRCLEQ_END(head);                                 \
 503             (var) = CIRCLEQ_NEXT(var, field))
 504
 505 #define CIRCLEQ_FOREACH_REVERSE(var, head, field)                       \
 506         for((var) = CIRCLEQ_LAST(head);                                 \
 507             (var) != CIRCLEQ_END(head);                                 \
 508             (var) = CIRCLEQ_PREV(var, field))
 509
 510 /*
 511  * Circular queue functions.
 512  */
 513 #define CIRCLEQ_INIT(head) do {                                         \
 514         (head)->cqh_first = CIRCLEQ_END(head);                          \
 515         (head)->cqh_last = CIRCLEQ_END(head);                           \
 516 } while (0)
 517
 518 #define CIRCLEQ_INSERT_AFTER(head, listelm, elm, field) do {            \
 519         (elm)->field.cqe_next = (listelm)->field.cqe_next;              \
 520         (elm)->field.cqe_prev = (listelm);                              \
 521         if ((listelm)->field.cqe_next == CIRCLEQ_END(head))             \
 522                 (head)->cqh_last = (elm);                               \
 523         else                                                            \
 524                 (listelm)->field.cqe_next->field.cqe_prev = (elm);      \
 525         (listelm)->field.cqe_next = (elm);                              \
 526 } while (0)
 527
 528 #define CIRCLEQ_INSERT_BEFORE(head, listelm, elm, field) do {           \
 529         (elm)->field.cqe_next = (listelm);                              \
 530         (elm)->field.cqe_prev = (listelm)->field.cqe_prev;              \
 531         if ((listelm)->field.cqe_prev == CIRCLEQ_END(head))             \
 532                 (head)->cqh_first = (elm);                              \
 533         else                                                            \
 534                 (listelm)->field.cqe_prev->field.cqe_next = (elm);      \
 535         (listelm)->field.cqe_prev = (elm);                              \
 536 } while (0)
 537
 538 #define CIRCLEQ_INSERT_HEAD(head, elm, field) do {                      \
 539         (elm)->field.cqe_next = (head)->cqh_first;                      \
 540         (elm)->field.cqe_prev = CIRCLEQ_END(head);                      \
 541         if ((head)->cqh_last == CIRCLEQ_END(head))                      \
 542                 (head)->cqh_last = (elm);                               \
 543         else                                                            \
 544                 (head)->cqh_first->field.cqe_prev = (elm);              \
 545         (head)->cqh_first = (elm);                                      \
 546 } while (0)
 547
 548 #define CIRCLEQ_INSERT_TAIL(head, elm, field) do {                      \
 549         (elm)->field.cqe_next = CIRCLEQ_END(head);                      \
 550         (elm)->field.cqe_prev = (head)->cqh_last;                       \
 551         if ((head)->cqh_first == CIRCLEQ_END(head))                     \
 552                 (head)->cqh_first = (elm);                              \
 553         else                                                            \
 554                 (head)->cqh_last->field.cqe_next = (elm);               \
 555         (head)->cqh_last = (elm);                                       \
 556 } while (0)
 557
 558 #define CIRCLEQ_REMOVE(head, elm, field) do {                           \
 559         if ((elm)->field.cqe_next == CIRCLEQ_END(head))                 \
 560                 (head)->cqh_last = (elm)->field.cqe_prev;               \
 561         else                                                            \
 562                 (elm)->field.cqe_next->field.cqe_prev =                 \
 563                     (elm)->field.cqe_prev;                              \
 564         if ((elm)->field.cqe_prev == CIRCLEQ_END(head))                 \
 565                 (head)->cqh_first = (elm)->field.cqe_next;              \
 566         else                                                            \
 567                 (elm)->field.cqe_prev->field.cqe_next =                 \
 568                     (elm)->field.cqe_next;                              \
 569 } while (0)
 570
 571 #define CIRCLEQ_REPLACE(head, elm, elm2, field) do {                    \
 572         if (((elm2)->field.cqe_next = (elm)->field.cqe_next) ==         \
 573             CIRCLEQ_END(head))                                          \
 574                 (head).cqh_last = (elm2);                               \
 575         else                                                            \
 576                 (elm2)->field.cqe_next->field.cqe_prev = (elm2);        \
 577         if (((elm2)->field.cqe_prev = (elm)->field.cqe_prev) ==         \
 578             CIRCLEQ_END(head))                                          \
 579                 (head).cqh_first = (elm2);                              \
 580         else                                                            \
 581                 (elm2)->field.cqe_prev->field.cqe_next = (elm2);        \
 582 } while (0)
 583
 584 #endif  /* !_FAKE_QUEUE_H_ */