ext/libelf/elf_queue.h

   1 /*-
   2  * Copyright (c) 1991, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 4. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  *      @(#)queue.h     8.5 (Berkeley) 8/20/94
  30  * $FreeBSD: src/sys/sys/queue.h,v 1.68 2006/10/24 11:20:29 ru Exp $
  31  */
  32
  33 #ifndef _SYS_QUEUE_H_
  34 #define _SYS_QUEUE_H_
  35
  36 /*
  37  * This file defines four types of data structures: singly-linked lists,
  38  * singly-linked tail queues, lists and tail queues.
  39  *
  40  * A singly-linked list is headed by a single forward pointer. The elements
  41  * are singly linked for minimum space and pointer manipulation overhead at
  42  * the expense of O(n) removal for arbitrary elements. New elements can be
  43  * added to the list after an existing element or at the head of the list.
  44  * Elements being removed from the head of the list should use the explicit
  45  * macro for this purpose for optimum efficiency. A singly-linked list may
  46  * only be traversed in the forward direction.  Singly-linked lists are ideal
  47  * for applications with large datasets and few or no removals or for
  48  * implementing a LIFO queue.
  49  *
  50  * A singly-linked tail queue is headed by a pair of pointers, one to the
  51  * head of the list and the other to the tail of the list. The elements are
  52  * singly linked for minimum space and pointer manipulation overhead at the
  53  * expense of O(n) removal for arbitrary elements. New elements can be added
  54  * to the list after an existing element, at the head of the list, or at the
  55  * end of the list. Elements being removed from the head of the tail queue
  56  * should use the explicit macro for this purpose for optimum efficiency.
  57  * A singly-linked tail queue may only be traversed in the forward direction.
  58  * Singly-linked tail queues are ideal for applications with large datasets
  59  * and few or no removals or for implementing a FIFO queue.
  60  *
  61  * A list is headed by a single forward pointer (or an array of forward
  62  * pointers for a hash table header). The elements are doubly linked
  63  * so that an arbitrary element can be removed without a need to
  64  * traverse the list. New elements can be added to the list before
  65  * or after an existing element or at the head of the list. A list
  66  * may only be traversed in the forward direction.
  67  *
  68  * A tail queue is headed by a pair of pointers, one to the head of the
  69  * list and the other to the tail of the list. The elements are doubly
  70  * linked so that an arbitrary element can be removed without a need to
  71  * traverse the list. New elements can be added to the list before or
  72  * after an existing element, at the head of the list, or at the end of
  73  * the list. A tail queue may be traversed in either direction.
  74  *
  75  * For details on the use of these macros, see the queue(3) manual page.
  76  *
  77  *
  78  *                              SLIST   LIST    STAILQ  TAILQ
  79  * _HEAD                        +       +       +       +
  80  * _HEAD_INITIALIZER            +       +       +       +
  81  * _ENTRY                       +       +       +       +
  82  * _INIT                        +       +       +       +
  83  * _EMPTY                       +       +       +       +
  84  * _FIRST                       +       +       +       +
  85  * _NEXT                        +       +       +       +
  86  * _PREV                        -       -       -       +
  87  * _LAST                        -       -       +       +
  88  * _FOREACH                     +       +       +       +
  89  * _FOREACH_SAFE                +       +       +       +
  90  * _FOREACH_REVERSE             -       -       -       +
  91  * _FOREACH_REVERSE_SAFE        -       -       -       +
  92  * _INSERT_HEAD                 +       +       +       +
  93  * _INSERT_BEFORE               -       +       -       +
  94  * _INSERT_AFTER                +       +       +       +
  95  * _INSERT_TAIL                 -       -       +       +
  96  * _CONCAT                      -       -       +       +
  97  * _REMOVE_HEAD                 +       -       +       -
  98  * _REMOVE                      +       +       +       +
  99  *
 100  */
 101 #ifdef QUEUE_MACRO_DEBUG
 102 /* Store the last 2 places the queue element or head was altered */
 103 struct qm_trace {
 104         char * lastfile;
 105         int lastline;
 106         char * prevfile;
 107         int prevline;
 108 };
 109
 110 #define TRACEBUF        struct qm_trace trace;
 111 #define TRASHIT(x)      do {(x) = (void *)-1;} while (0)
 112
 113 #define QMD_TRACE_HEAD(head) do {                                       \
 114         (head)->trace.prevline = (head)->trace.lastline;                \
 115         (head)->trace.prevfile = (head)->trace.lastfile;                \
 116         (head)->trace.lastline = __LINE__;                              \
 117         (head)->trace.lastfile = __FILE__;                              \
 118 } while (0)
 119
 120 #define QMD_TRACE_ELEM(elem) do {                                       \
 121         (elem)->trace.prevline = (elem)->trace.lastline;                \
 122         (elem)->trace.prevfile = (elem)->trace.lastfile;                \
 123         (elem)->trace.lastline = __LINE__;                              \
 124         (elem)->trace.lastfile = __FILE__;                              \
 125 } while (0)
 126
 127 #else
 128 #define QMD_TRACE_ELEM(elem)
 129 #define QMD_TRACE_HEAD(head)
 130 #define TRACEBUF
 131 #define TRASHIT(x)
 132 #endif  /* QUEUE_MACRO_DEBUG */
 133
 134 /*
 135  * Singly-linked List declarations.
 136  */
 137 #define SLIST_HEAD(name, type)                                          \
 138 struct name {                                                           \
 139         struct type *slh_first; /* first element */                     \
 140 }
 141
 142 #define SLIST_HEAD_INITIALIZER(head)                                    \
 143         { NULL }
 144
 145 #define SLIST_ENTRY(type)                                               \
 146 struct {                                                                \
 147         struct type *sle_next;  /* next element */                      \
 148 }
 149
 150 /*
 151  * Singly-linked List functions.
 152  */
 153 #define SLIST_EMPTY(head)       ((head)->slh_first == NULL)
 154
 155 #define SLIST_FIRST(head)       ((head)->slh_first)
 156
 157 #define SLIST_FOREACH(var, head, field)                                 \
 158         for ((var) = SLIST_FIRST((head));                               \
 159             (var);                                                      \
 160             (var) = SLIST_NEXT((var), field))
 161
 162 #define SLIST_FOREACH_SAFE(var, head, field, tvar)                      \
 163         for ((var) = SLIST_FIRST((head));                               \
 164             (var) && ((tvar) = SLIST_NEXT((var), field), 1);            \
 165             (var) = (tvar))
 166
 167 #define SLIST_FOREACH_PREVPTR(var, varp, head, field)                   \
 168         for ((varp) = &SLIST_FIRST((head));                             \
 169             ((var) = *(varp)) != NULL;                                  \
 170             (varp) = &SLIST_NEXT((var), field))
 171
 172 #define SLIST_INIT(head) do {                                           \
 173         SLIST_FIRST((head)) = NULL;                                     \
 174 } while (0)
 175
 176 #define SLIST_INSERT_AFTER(slistelm, elm, field) do {                   \
 177         SLIST_NEXT((elm), field) = SLIST_NEXT((slistelm), field);       \
 178         SLIST_NEXT((slistelm), field) = (elm);                          \
 179 } while (0)
 180
 181 #define SLIST_INSERT_HEAD(head, elm, field) do {                        \
 182         SLIST_NEXT((elm), field) = SLIST_FIRST((head));                 \
 183         SLIST_FIRST((head)) = (elm);                                    \
 184 } while (0)
 185
 186 #define SLIST_NEXT(elm, field)  ((elm)->field.sle_next)
 187
 188 #define SLIST_REMOVE(head, elm, type, field) do {                       \
 189         if (SLIST_FIRST((head)) == (elm)) {                             \
 190                 SLIST_REMOVE_HEAD((head), field);                       \
 191         }                                                               \
 192         else {                                                          \
 193                 struct type *curelm = SLIST_FIRST((head));              \
 194                 while (SLIST_NEXT(curelm, field) != (elm))              \
 195                         curelm = SLIST_NEXT(curelm, field);             \
 196                 SLIST_NEXT(curelm, field) =                             \
 197                     SLIST_NEXT(SLIST_NEXT(curelm, field), field);       \
 198         }                                                               \
 199         TRASHIT((elm)->field.sle_next);                                 \
 200 } while (0)
 201
 202 #define SLIST_REMOVE_HEAD(head, field) do {                             \
 203         SLIST_FIRST((head)) = SLIST_NEXT(SLIST_FIRST((head)), field);   \
 204 } while (0)
 205
 206 /*
 207  * Singly-linked Tail queue declarations.
 208  */
 209 #define STAILQ_HEAD(name, type)                                         \
 210 struct name {                                                           \
 211         struct type *stqh_first;/* first element */                     \
 212         struct type **stqh_last;/* addr of last next element */         \
 213 }
 214
 215 #define STAILQ_HEAD_INITIALIZER(head)                                   \
 216         { NULL, &(head).stqh_first }
 217
 218 #define STAILQ_ENTRY(type)                                              \
 219 struct {                                                                \
 220         struct type *stqe_next; /* next element */                      \
 221 }
 222
 223 /*
 224  * Singly-linked Tail queue functions.
 225  */
 226 #define STAILQ_CONCAT(head1, head2) do {                                \
 227         if (!STAILQ_EMPTY((head2))) {                                   \
 228                 *(head1)->stqh_last = (head2)->stqh_first;              \
 229                 (head1)->stqh_last = (head2)->stqh_last;                \
 230                 STAILQ_INIT((head2));                                   \
 231         }                                                               \
 232 } while (0)
 233
 234 #define STAILQ_EMPTY(head)      ((head)->stqh_first == NULL)
 235
 236 #define STAILQ_FIRST(head)      ((head)->stqh_first)
 237
 238 #define STAILQ_FOREACH(var, head, field)                                \
 239         for((var) = STAILQ_FIRST((head));                               \
 240            (var);                                                       \
 241            (var) = STAILQ_NEXT((var), field))
 242
 243
 244 #define STAILQ_FOREACH_SAFE(var, head, field, tvar)                     \
 245         for ((var) = STAILQ_FIRST((head));                              \
 246             (var) && ((tvar) = STAILQ_NEXT((var), field), 1);           \
 247             (var) = (tvar))
 248
 249 #define STAILQ_INIT(head) do {                                          \
 250         STAILQ_FIRST((head)) = NULL;                                    \
 251         (head)->stqh_last = &STAILQ_FIRST((head));                      \
 252 } while (0)
 253
 254 #define STAILQ_INSERT_AFTER(head, tqelm, elm, field) do {               \
 255         if ((STAILQ_NEXT((elm), field) = STAILQ_NEXT((tqelm), field)) == NULL)\
 256                 (head)->stqh_last = &STAILQ_NEXT((elm), field);         \
 257         STAILQ_NEXT((tqelm), field) = (elm);                            \
 258 } while (0)
 259
 260 #define STAILQ_INSERT_HEAD(head, elm, field) do {                       \
 261         if ((STAILQ_NEXT((elm), field) = STAILQ_FIRST((head))) == NULL) \
 262                 (head)->stqh_last = &STAILQ_NEXT((elm), field);         \
 263         STAILQ_FIRST((head)) = (elm);                                   \
 264 } while (0)
 265
 266 #define STAILQ_INSERT_TAIL(head, elm, field) do {                       \
 267         STAILQ_NEXT((elm), field) = NULL;                               \
 268         *(head)->stqh_last = (elm);                                     \
 269         (head)->stqh_last = &STAILQ_NEXT((elm), field);                 \
 270 } while (0)
 271
 272 #define STAILQ_LAST(head, type, field)                                  \
 273         (STAILQ_EMPTY((head)) ?                                         \
 274                 NULL :                                                  \
 275                 ((struct type *)(void *)                                \
 276                 ((char *)((head)->stqh_last) - offsetof(struct type, field))))
 277
 278 #define STAILQ_NEXT(elm, field) ((elm)->field.stqe_next)
 279
 280 #define STAILQ_REMOVE(head, elm, type, field) do {                      \
 281         if (STAILQ_FIRST((head)) == (elm)) {                            \
 282                 STAILQ_REMOVE_HEAD((head), field);                      \
 283         }                                                               \
 284         else {                                                          \
 285                 struct type *curelm = STAILQ_FIRST((head));             \
 286                 while (STAILQ_NEXT(curelm, field) != (elm))             \
 287                         curelm = STAILQ_NEXT(curelm, field);            \
 288                 if ((STAILQ_NEXT(curelm, field) =                       \
 289                      STAILQ_NEXT(STAILQ_NEXT(curelm, field), field)) == NULL)\
 290                         (head)->stqh_last = &STAILQ_NEXT((curelm), field);\
 291         }                                                               \
 292         TRASHIT((elm)->field.stqe_next);                                \
 293 } while (0)
 294
 295 #define STAILQ_REMOVE_HEAD(head, field) do {                            \
 296         if ((STAILQ_FIRST((head)) =                                     \
 297              STAILQ_NEXT(STAILQ_FIRST((head)), field)) == NULL)         \
 298                 (head)->stqh_last = &STAILQ_FIRST((head));              \
 299 } while (0)
 300
 301 /*
 302  * List declarations.
 303  */
 304 #define LIST_HEAD(name, type)                                           \
 305 struct name {                                                           \
 306         struct type *lh_first;  /* first element */                     \
 307 }
 308
 309 #define LIST_HEAD_INITIALIZER(head)                                     \
 310         { NULL }
 311
 312 #define LIST_ENTRY(type)                                                \
 313 struct {                                                                \
 314         struct type *le_next;   /* next element */                      \
 315         struct type **le_prev;  /* address of previous next element */  \
 316 }
 317
 318 /*
 319  * List functions.
 320  */
 321
 322 #if (defined(_KERNEL) && defined(INVARIANTS))
 323 #define QMD_LIST_CHECK_HEAD(head, field) do {                           \
 324         if (LIST_FIRST((head)) != NULL &&                               \
 325             LIST_FIRST((head))->field.le_prev !=                        \
 326              &LIST_FIRST((head)))                                       \
 327                 panic("Bad list head %p first->prev != head", (head));  \
 328 } while (0)
 329
 330 #define QMD_LIST_CHECK_NEXT(elm, field) do {                            \
 331         if (LIST_NEXT((elm), field) != NULL &&                          \
 332             LIST_NEXT((elm), field)->field.le_prev !=                   \
 333              &((elm)->field.le_next))                                   \
 334                 panic("Bad link elm %p next->prev != elm", (elm));      \
 335 } while (0)
 336
 337 #define QMD_LIST_CHECK_PREV(elm, field) do {                            \
 338         if (*(elm)->field.le_prev != (elm))                             \
 339                 panic("Bad link elm %p prev->next != elm", (elm));      \
 340 } while (0)
 341 #else
 342 #define QMD_LIST_CHECK_HEAD(head, field)
 343 #define QMD_LIST_CHECK_NEXT(elm, field)
 344 #define QMD_LIST_CHECK_PREV(elm, field)
 345 #endif /* (_KERNEL && INVARIANTS) */
 346
 347 #define LIST_EMPTY(head)        ((head)->lh_first == NULL)
 348
 349 #define LIST_FIRST(head)        ((head)->lh_first)
 350
 351 #define LIST_FOREACH(var, head, field)                                  \
 352         for ((var) = LIST_FIRST((head));                                \
 353             (var);                                                      \
 354             (var) = LIST_NEXT((var), field))
 355
 356 #define LIST_FOREACH_SAFE(var, head, field, tvar)                       \
 357         for ((var) = LIST_FIRST((head));                                \
 358             (var) && ((tvar) = LIST_NEXT((var), field), 1);             \
 359             (var) = (tvar))
 360
 361 #define LIST_INIT(head) do {                                            \
 362         LIST_FIRST((head)) = NULL;                                      \
 363 } while (0)
 364
 365 #define LIST_INSERT_AFTER(listelm, elm, field) do {                     \
 366         QMD_LIST_CHECK_NEXT(listelm, field);                            \
 367         if ((LIST_NEXT((elm), field) = LIST_NEXT((listelm), field)) != NULL)\
 368                 LIST_NEXT((listelm), field)->field.le_prev =            \
 369                     &LIST_NEXT((elm), field);                           \
 370         LIST_NEXT((listelm), field) = (elm);                            \
 371         (elm)->field.le_prev = &LIST_NEXT((listelm), field);            \
 372 } while (0)
 373
 374 #define LIST_INSERT_BEFORE(listelm, elm, field) do {                    \
 375         QMD_LIST_CHECK_PREV(listelm, field);                            \
 376         (elm)->field.le_prev = (listelm)->field.le_prev;                \
 377         LIST_NEXT((elm), field) = (listelm);                            \
 378         *(listelm)->field.le_prev = (elm);                              \
 379         (listelm)->field.le_prev = &LIST_NEXT((elm), field);            \
 380 } while (0)
 381
 382 #define LIST_INSERT_HEAD(head, elm, field) do {                         \
 383         QMD_LIST_CHECK_HEAD((head), field);                             \
 384         if ((LIST_NEXT((elm), field) = LIST_FIRST((head))) != NULL)     \
 385                 LIST_FIRST((head))->field.le_prev = &LIST_NEXT((elm), field);\
 386         LIST_FIRST((head)) = (elm);                                     \
 387         (elm)->field.le_prev = &LIST_FIRST((head));                     \
 388 } while (0)
 389
 390 #define LIST_NEXT(elm, field)   ((elm)->field.le_next)
 391
 392 #define LIST_REMOVE(elm, field) do {                                    \
 393         QMD_LIST_CHECK_NEXT(elm, field);                                \
 394         QMD_LIST_CHECK_PREV(elm, field);                                \
 395         if (LIST_NEXT((elm), field) != NULL)                            \
 396                 LIST_NEXT((elm), field)->field.le_prev =                \
 397                     (elm)->field.le_prev;                               \
 398         *(elm)->field.le_prev = LIST_NEXT((elm), field);                \
 399         TRASHIT((elm)->field.le_next);                                  \
 400         TRASHIT((elm)->field.le_prev);                                  \
 401 } while (0)
 402
 403 /*
 404  * Tail queue declarations.
 405  */
 406 #define TAILQ_HEAD(name, type)                                          \
 407 struct name {                                                           \
 408         struct type *tqh_first; /* first element */                     \
 409         struct type **tqh_last; /* addr of last next element */         \
 410         TRACEBUF                                                        \
 411 }
 412
 413 #define TAILQ_HEAD_INITIALIZER(head)                                    \
 414         { NULL, &(head).tqh_first }
 415
 416 #define TAILQ_ENTRY(type)                                               \
 417 struct {                                                                \
 418         struct type *tqe_next;  /* next element */                      \
 419         struct type **tqe_prev; /* address of previous next element */  \
 420         TRACEBUF                                                        \
 421 }
 422
 423 /*
 424  * Tail queue functions.
 425  */
 426 #if (defined(_KERNEL) && defined(INVARIANTS))
 427 #define QMD_TAILQ_CHECK_HEAD(head, field) do {                          \
 428         if (!TAILQ_EMPTY(head) &&                                       \
 429             TAILQ_FIRST((head))->field.tqe_prev !=                      \
 430              &TAILQ_FIRST((head)))                                      \
 431                 panic("Bad tailq head %p first->prev != head", (head)); \
 432 } while (0)
 433
 434 #define QMD_TAILQ_CHECK_TAIL(head, field) do {                          \
 435         if (*(head)->tqh_last != NULL)                                  \
 436                 panic("Bad tailq NEXT(%p->tqh_last) != NULL", (head));  \
 437 } while (0)
 438
 439 #define QMD_TAILQ_CHECK_NEXT(elm, field) do {                           \
 440         if (TAILQ_NEXT((elm), field) != NULL &&                         \
 441             TAILQ_NEXT((elm), field)->field.tqe_prev !=                 \
 442              &((elm)->field.tqe_next))                                  \
 443                 panic("Bad link elm %p next->prev != elm", (elm));      \
 444 } while (0)
 445
 446 #define QMD_TAILQ_CHECK_PREV(elm, field) do {                           \
 447         if (*(elm)->field.tqe_prev != (elm))                            \
 448                 panic("Bad link elm %p prev->next != elm", (elm));      \
 449 } while (0)
 450 #else
 451 #define QMD_TAILQ_CHECK_HEAD(head, field)
 452 #define QMD_TAILQ_CHECK_TAIL(head, headname)
 453 #define QMD_TAILQ_CHECK_NEXT(elm, field)
 454 #define QMD_TAILQ_CHECK_PREV(elm, field)
 455 #endif /* (_KERNEL && INVARIANTS) */
 456
 457 #define TAILQ_CONCAT(head1, head2, field) do {                          \
 458         if (!TAILQ_EMPTY(head2)) {                                      \
 459                 *(head1)->tqh_last = (head2)->tqh_first;                \
 460                 (head2)->tqh_first->field.tqe_prev = (head1)->tqh_last; \
 461                 (head1)->tqh_last = (head2)->tqh_last;                  \
 462                 TAILQ_INIT((head2));                                    \
 463                 QMD_TRACE_HEAD(head1);                                  \
 464                 QMD_TRACE_HEAD(head2);                                  \
 465         }                                                               \
 466 } while (0)
 467
 468 #define TAILQ_EMPTY(head)       ((head)->tqh_first == NULL)
 469
 470 #define TAILQ_FIRST(head)       ((head)->tqh_first)
 471
 472 #define TAILQ_FOREACH(var, head, field)                                 \
 473         for ((var) = TAILQ_FIRST((head));                               \
 474             (var);                                                      \
 475             (var) = TAILQ_NEXT((var), field))
 476
 477 #define TAILQ_FOREACH_SAFE(var, head, field, tvar)                      \
 478         for ((var) = TAILQ_FIRST((head));                               \
 479             (var) && ((tvar) = TAILQ_NEXT((var), field), 1);            \
 480             (var) = (tvar))
 481
 482 #define TAILQ_FOREACH_REVERSE(var, head, headname, field)               \
 483         for ((var) = TAILQ_LAST((head), headname);                      \
 484             (var);                                                      \
 485             (var) = TAILQ_PREV((var), headname, field))
 486
 487 #define TAILQ_FOREACH_REVERSE_SAFE(var, head, headname, field, tvar)    \
 488         for ((var) = TAILQ_LAST((head), headname);                      \
 489             (var) && ((tvar) = TAILQ_PREV((var), headname, field), 1);  \
 490             (var) = (tvar))
 491
 492 #define TAILQ_INIT(head) do {                                           \
 493         TAILQ_FIRST((head)) = NULL;                                     \
 494         (head)->tqh_last = &TAILQ_FIRST((head));                        \
 495         QMD_TRACE_HEAD(head);                                           \
 496 } while (0)
 497
 498 #define TAILQ_INSERT_AFTER(head, listelm, elm, field) do {              \
 499         QMD_TAILQ_CHECK_NEXT(listelm, field);                           \
 500         if ((TAILQ_NEXT((elm), field) = TAILQ_NEXT((listelm), field)) != NULL)\
 501                 TAILQ_NEXT((elm), field)->field.tqe_prev =              \
 502                     &TAILQ_NEXT((elm), field);                          \
 503         else {                                                          \
 504                 (head)->tqh_last = &TAILQ_NEXT((elm), field);           \
 505                 QMD_TRACE_HEAD(head);                                   \
 506         }                                                               \
 507         TAILQ_NEXT((listelm), field) = (elm);                           \
 508         (elm)->field.tqe_prev = &TAILQ_NEXT((listelm), field);          \
 509         QMD_TRACE_ELEM(&(elm)->field);                                  \
 510         QMD_TRACE_ELEM(&listelm->field);                                \
 511 } while (0)
 512
 513 #define TAILQ_INSERT_BEFORE(listelm, elm, field) do {                   \
 514         QMD_TAILQ_CHECK_PREV(listelm, field);                           \
 515         (elm)->field.tqe_prev = (listelm)->field.tqe_prev;              \
 516         TAILQ_NEXT((elm), field) = (listelm);                           \
 517         *(listelm)->field.tqe_prev = (elm);                             \
 518         (listelm)->field.tqe_prev = &TAILQ_NEXT((elm), field);          \
 519         QMD_TRACE_ELEM(&(elm)->field);                                  \
 520         QMD_TRACE_ELEM(&listelm->field);                                \
 521 } while (0)
 522
 523 #define TAILQ_INSERT_HEAD(head, elm, field) do {                        \
 524         QMD_TAILQ_CHECK_HEAD(head, field);                              \
 525         if ((TAILQ_NEXT((elm), field) = TAILQ_FIRST((head))) != NULL)   \
 526                 TAILQ_FIRST((head))->field.tqe_prev =                   \
 527                     &TAILQ_NEXT((elm), field);                          \
 528         else                                                            \
 529                 (head)->tqh_last = &TAILQ_NEXT((elm), field);           \
 530         TAILQ_FIRST((head)) = (elm);                                    \
 531         (elm)->field.tqe_prev = &TAILQ_FIRST((head));                   \
 532         QMD_TRACE_HEAD(head);                                           \
 533         QMD_TRACE_ELEM(&(elm)->field);                                  \
 534 } while (0)
 535
 536 #define TAILQ_INSERT_TAIL(head, elm, field) do {                        \
 537         QMD_TAILQ_CHECK_TAIL(head, field);                              \
 538         TAILQ_NEXT((elm), field) = NULL;                                \
 539         (elm)->field.tqe_prev = (head)->tqh_last;                       \
 540         *(head)->tqh_last = (elm);                                      \
 541         (head)->tqh_last = &TAILQ_NEXT((elm), field);                   \
 542         QMD_TRACE_HEAD(head);                                           \
 543         QMD_TRACE_ELEM(&(elm)->field);                                  \
 544 } while (0)
 545
 546 #define TAILQ_LAST(head, headname)                                      \
 547         (*(((struct headname *)((head)->tqh_last))->tqh_last))
 548
 549 #define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next)
 550
 551 #define TAILQ_PREV(elm, headname, field)                                \
 552         (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last))
 553
 554 #define TAILQ_REMOVE(head, elm, field) do {                             \
 555         QMD_TAILQ_CHECK_NEXT(elm, field);                               \
 556         QMD_TAILQ_CHECK_PREV(elm, field);                               \
 557         if ((TAILQ_NEXT((elm), field)) != NULL)                         \
 558                 TAILQ_NEXT((elm), field)->field.tqe_prev =              \
 559                     (elm)->field.tqe_prev;                              \
 560         else {                                                          \
 561                 (head)->tqh_last = (elm)->field.tqe_prev;               \
 562                 QMD_TRACE_HEAD(head);                                   \
 563         }                                                               \
 564         *(elm)->field.tqe_prev = TAILQ_NEXT((elm), field);              \
 565         TRASHIT((elm)->field.tqe_next);                                 \
 566         TRASHIT((elm)->field.tqe_prev);                                 \
 567         QMD_TRACE_ELEM(&(elm)->field);                                  \
 568 } while (0)
 569
 570
 571 #ifdef _KERNEL
 572
 573 /*
 574  * XXX insque() and remque() are an old way of handling certain queues.
 575  * They bogusly assumes that all queue heads look alike.
 576  */
 577
 578 struct quehead {
 579         struct quehead *qh_link;
 580         struct quehead *qh_rlink;
 581 };
 582
 583 #ifdef __CC_SUPPORTS___INLINE
 584
 585 static __inline void
 586 insque(void *a, void *b)
 587 {
 588         struct quehead *element = (struct quehead *)a,
 589                  *head = (struct quehead *)b;
 590
 591         element->qh_link = head->qh_link;
 592         element->qh_rlink = head;
 593         head->qh_link = element;
 594         element->qh_link->qh_rlink = element;
 595 }
 596
 597 static __inline void
 598 remque(void *a)
 599 {
 600         struct quehead *element = (struct quehead *)a;
 601
 602         element->qh_link->qh_rlink = element->qh_rlink;
 603         element->qh_rlink->qh_link = element->qh_link;
 604         element->qh_rlink = 0;
 605 }
 606
 607 #else /* !__CC_SUPPORTS___INLINE */
 608
 609 void    insque(void *a, void *b);
 610 void    remque(void *a);
 611
 612 #endif /* __CC_SUPPORTS___INLINE */
 613
 614 #endif /* _KERNEL */
 615
 616 #endif /* !_SYS_QUEUE_H_ */