pthread_workqueue-0.8.2/src/windows/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 1.72.2.1.2.1 2009/10/25 01:10:29 kensmith 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_AFTER                +       -       +       -
  98  * _REMOVE_HEAD                 +       -       +       -
  99  * _REMOVE                      +       +       +       +
 100  *
 101  */
 102 #ifdef QUEUE_MACRO_DEBUG
 103 /* Store the last 2 places the queue element or head was altered */
 104 struct qm_trace {
 105         char * lastfile;
 106         int lastline;
 107         char * prevfile;
 108         int prevline;
 109 };
 110
 111 #define TRACEBUF        struct qm_trace trace;
 112 #define TRASHIT(x)      do {(x) = (void *)-1;} while (0)
 113
 114 #define QMD_TRACE_HEAD(head) do {                                       \
 115         (head)->trace.prevline = (head)->trace.lastline;                \
 116         (head)->trace.prevfile = (head)->trace.lastfile;                \
 117         (head)->trace.lastline = __LINE__;                              \
 118         (head)->trace.lastfile = __FILE__;                              \
 119 } while (0)
 120
 121 #define QMD_TRACE_ELEM(elem) do {                                       \
 122         (elem)->trace.prevline = (elem)->trace.lastline;                \
 123         (elem)->trace.prevfile = (elem)->trace.lastfile;                \
 124         (elem)->trace.lastline = __LINE__;                              \
 125         (elem)->trace.lastfile = __FILE__;                              \
 126 } while (0)
 127
 128 #else
 129 #define QMD_TRACE_ELEM(elem)
 130 #define QMD_TRACE_HEAD(head)
 131 #define TRACEBUF
 132 #define TRASHIT(x)
 133 #endif  /* QUEUE_MACRO_DEBUG */
 134
 135 #ifndef _WIN32
 136 /*
 137  * Singly-linked List declarations.
 138  */
 139 #define SLIST_HEAD(name, type)                                          \
 140 struct name {                                                           \
 141         struct type *slh_first; /* first element */                     \
 142 }
 143
 144 #define SLIST_HEAD_INITIALIZER(head)                                    \
 145         { NULL }
 146
 147 #define SLIST_ENTRY(type)                                               \
 148 struct {                                                                \
 149         struct type *sle_next;  /* next element */                      \
 150 }
 151
 152 /*
 153  * Singly-linked List functions.
 154  */
 155 #define SLIST_EMPTY(head)       ((head)->slh_first == NULL)
 156
 157 #define SLIST_FIRST(head)       ((head)->slh_first)
 158
 159 #define SLIST_FOREACH(var, head, field)                                 \
 160         for ((var) = SLIST_FIRST((head));                               \
 161             (var);                                                      \
 162             (var) = SLIST_NEXT((var), field))
 163
 164 #define SLIST_FOREACH_SAFE(var, head, field, tvar)                      \
 165         for ((var) = SLIST_FIRST((head));                               \
 166             (var) && ((tvar) = SLIST_NEXT((var), field), 1);            \
 167             (var) = (tvar))
 168
 169 #define SLIST_FOREACH_PREVPTR(var, varp, head, field)                   \
 170         for ((varp) = &SLIST_FIRST((head));                             \
 171             ((var) = *(varp)) != NULL;                                  \
 172             (varp) = &SLIST_NEXT((var), field))
 173
 174 #define SLIST_INIT(head) do {                                           \
 175         SLIST_FIRST((head)) = NULL;                                     \
 176 } while (0)
 177
 178 #define SLIST_INSERT_AFTER(slistelm, elm, field) do {                   \
 179         SLIST_NEXT((elm), field) = SLIST_NEXT((slistelm), field);       \
 180         SLIST_NEXT((slistelm), field) = (elm);                          \
 181 } while (0)
 182
 183 #define SLIST_INSERT_HEAD(head, elm, field) do {                        \
 184         SLIST_NEXT((elm), field) = SLIST_FIRST((head));                 \
 185         SLIST_FIRST((head)) = (elm);                                    \
 186 } while (0)
 187
 188 #define SLIST_NEXT(elm, field)  ((elm)->field.sle_next)
 189
 190 #define SLIST_REMOVE(head, elm, type, field) do {                       \
 191         if (SLIST_FIRST((head)) == (elm)) {                             \
 192                 SLIST_REMOVE_HEAD((head), field);                       \
 193         }                                                               \
 194         else {                                                          \
 195                 struct type *curelm = SLIST_FIRST((head));              \
 196                 while (SLIST_NEXT(curelm, field) != (elm))              \
 197                         curelm = SLIST_NEXT(curelm, field);             \
 198                 SLIST_REMOVE_AFTER(curelm, field);                      \
 199         }                                                               \
 200         TRASHIT((elm)->field.sle_next);                                 \
 201 } while (0)
 202
 203 #define SLIST_REMOVE_AFTER(elm, field) do {                             \
 204         SLIST_NEXT(elm, field) =                                        \
 205             SLIST_NEXT(SLIST_NEXT(elm, field), field);                  \
 206 } while (0)
 207
 208 #define SLIST_REMOVE_HEAD(head, field) do {                             \
 209         SLIST_FIRST((head)) = SLIST_NEXT(SLIST_FIRST((head)), field);   \
 210 } while (0)
 211
 212 #endif /* defined(_WIN32) */
 213
 214 /*
 215  * Singly-linked Tail queue declarations.
 216  */
 217 #define STAILQ_HEAD(name, type)                                         \
 218 struct name {                                                           \
 219         struct type *stqh_first;/* first element */                     \
 220         struct type **stqh_last;/* addr of last next element */         \
 221 }
 222
 223 #define STAILQ_HEAD_INITIALIZER(head)                                   \
 224         { NULL, &(head).stqh_first }
 225
 226 #define STAILQ_ENTRY(type)                                              \
 227 struct {                                                                \
 228         struct type *stqe_next; /* next element */                      \
 229 }
 230
 231 /*
 232  * Singly-linked Tail queue functions.
 233  */
 234 #define STAILQ_CONCAT(head1, head2) do {                                \
 235         if (!STAILQ_EMPTY((head2))) {                                   \
 236                 *(head1)->stqh_last = (head2)->stqh_first;              \
 237                 (head1)->stqh_last = (head2)->stqh_last;                \
 238                 STAILQ_INIT((head2));                                   \
 239         }                                                               \
 240 } while (0)
 241
 242 #define STAILQ_EMPTY(head)      ((head)->stqh_first == NULL)
 243
 244 #define STAILQ_FIRST(head)      ((head)->stqh_first)
 245
 246 #define STAILQ_FOREACH(var, head, field)                                \
 247         for((var) = STAILQ_FIRST((head));                               \
 248            (var);                                                       \
 249            (var) = STAILQ_NEXT((var), field))
 250
 251
 252 #define STAILQ_FOREACH_SAFE(var, head, field, tvar)                     \
 253         for ((var) = STAILQ_FIRST((head));                              \
 254             (var) && ((tvar) = STAILQ_NEXT((var), field), 1);           \
 255             (var) = (tvar))
 256
 257 #define STAILQ_INIT(head) do {                                          \
 258         STAILQ_FIRST((head)) = NULL;                                    \
 259         (head)->stqh_last = &STAILQ_FIRST((head));                      \
 260 } while (0)
 261
 262 #define STAILQ_INSERT_AFTER(head, tqelm, elm, field) do {               \
 263         if ((STAILQ_NEXT((elm), field) = STAILQ_NEXT((tqelm), field)) == NULL)\
 264                 (head)->stqh_last = &STAILQ_NEXT((elm), field);         \
 265         STAILQ_NEXT((tqelm), field) = (elm);                            \
 266 } while (0)
 267
 268 #define STAILQ_INSERT_HEAD(head, elm, field) do {                       \
 269         if ((STAILQ_NEXT((elm), field) = STAILQ_FIRST((head))) == NULL) \
 270                 (head)->stqh_last = &STAILQ_NEXT((elm), field);         \
 271         STAILQ_FIRST((head)) = (elm);                                   \
 272 } while (0)
 273
 274 #define STAILQ_INSERT_TAIL(head, elm, field) do {                       \
 275         STAILQ_NEXT((elm), field) = NULL;                               \
 276         *(head)->stqh_last = (elm);                                     \
 277         (head)->stqh_last = &STAILQ_NEXT((elm), field);                 \
 278 } while (0)
 279
 280 #define STAILQ_LAST(head, type, field)                                  \
 281         (STAILQ_EMPTY((head)) ?                                         \
 282                 NULL :                                                  \
 283                 ((struct type *)(void *)                                \
 284                 ((char *)((head)->stqh_last) - __offsetof(struct type, field))))
 285
 286 #define STAILQ_NEXT(elm, field) ((elm)->field.stqe_next)
 287
 288 #define STAILQ_REMOVE(head, elm, type, field) do {                      \
 289         if (STAILQ_FIRST((head)) == (elm)) {                            \
 290                 STAILQ_REMOVE_HEAD((head), field);                      \
 291         }                                                               \
 292         else {                                                          \
 293                 struct type *curelm = STAILQ_FIRST((head));             \
 294                 while (STAILQ_NEXT(curelm, field) != (elm))             \
 295                         curelm = STAILQ_NEXT(curelm, field);            \
 296                 STAILQ_REMOVE_AFTER(head, curelm, field);               \
 297         }                                                               \
 298         TRASHIT((elm)->field.stqe_next);                                \
 299 } while (0)
 300
 301 #define STAILQ_REMOVE_HEAD(head, field) do {                            \
 302         if ((STAILQ_FIRST((head)) =                                     \
 303              STAILQ_NEXT(STAILQ_FIRST((head)), field)) == NULL)         \
 304                 (head)->stqh_last = &STAILQ_FIRST((head));              \
 305 } while (0)
 306
 307 #define STAILQ_REMOVE_AFTER(head, elm, field) do {                      \
 308         if ((STAILQ_NEXT(elm, field) =                                  \
 309              STAILQ_NEXT(STAILQ_NEXT(elm, field), field)) == NULL)      \
 310                 (head)->stqh_last = &STAILQ_NEXT((elm), field);         \
 311 } while (0)
 312
 313 #define STAILQ_SWAP(head1, head2, type) do {                            \
 314         struct type *swap_first = STAILQ_FIRST(head1);                  \
 315         struct type **swap_last = (head1)->stqh_last;                   \
 316         STAILQ_FIRST(head1) = STAILQ_FIRST(head2);                      \
 317         (head1)->stqh_last = (head2)->stqh_last;                        \
 318         STAILQ_FIRST(head2) = swap_first;                               \
 319         (head2)->stqh_last = swap_last;                                 \
 320         if (STAILQ_EMPTY(head1))                                        \
 321                 (head1)->stqh_last = &STAILQ_FIRST(head1);              \
 322         if (STAILQ_EMPTY(head2))                                        \
 323                 (head2)->stqh_last = &STAILQ_FIRST(head2);              \
 324 } while (0)
 325
 326
 327 /*
 328  * List declarations.
 329  * NOTE: LIST_HEAD conflicts with a Linux macro.
 330  */
 331 #define LIST_HEAD(name, type)                                           \
 332 struct name {                                                           \
 333         struct type *lh_first;  /* first element */                     \
 334 }
 335
 336 #define LIST_HEAD_INITIALIZER(head)                                     \
 337         { NULL }
 338
 339 #define LIST_ENTRY(type)                                                \
 340 struct {                                                                \
 341         struct type *le_next;   /* next element */                      \
 342         struct type **le_prev;  /* address of previous next element */  \
 343 }
 344
 345 /*
 346  * List functions.
 347  */
 348
 349 #if (defined(_KERNEL) && defined(INVARIANTS))
 350 #define QMD_LIST_CHECK_HEAD(head, field) do {                           \
 351         if (LIST_FIRST((head)) != NULL &&                               \
 352             LIST_FIRST((head))->field.le_prev !=                        \
 353              &LIST_FIRST((head)))                                       \
 354                 panic("Bad list head %p first->prev != head", (head));  \
 355 } while (0)
 356
 357 #define QMD_LIST_CHECK_NEXT(elm, field) do {                            \
 358         if (LIST_NEXT((elm), field) != NULL &&                          \
 359             LIST_NEXT((elm), field)->field.le_prev !=                   \
 360              &((elm)->field.le_next))                                   \
 361                 panic("Bad link elm %p next->prev != elm", (elm));      \
 362 } while (0)
 363
 364 #define QMD_LIST_CHECK_PREV(elm, field) do {                            \
 365         if (*(elm)->field.le_prev != (elm))                             \
 366                 panic("Bad link elm %p prev->next != elm", (elm));      \
 367 } while (0)
 368 #else
 369 #define QMD_LIST_CHECK_HEAD(head, field)
 370 #define QMD_LIST_CHECK_NEXT(elm, field)
 371 #define QMD_LIST_CHECK_PREV(elm, field)
 372 #endif /* (_KERNEL && INVARIANTS) */
 373
 374 #define LIST_EMPTY(head)        ((head)->lh_first == NULL)
 375
 376 #define LIST_FIRST(head)        ((head)->lh_first)
 377
 378 #define LIST_FOREACH(var, head, field)                                  \
 379         for ((var) = LIST_FIRST((head));                                \
 380             (var);                                                      \
 381             (var) = LIST_NEXT((var), field))
 382
 383 #define LIST_FOREACH_SAFE(var, head, field, tvar)                       \
 384         for ((var) = LIST_FIRST((head));                                \
 385             (var) && ((tvar) = LIST_NEXT((var), field), 1);             \
 386             (var) = (tvar))
 387
 388 #define LIST_INIT(head) do {                                            \
 389         LIST_FIRST((head)) = NULL;                                      \
 390 } while (0)
 391
 392 #define LIST_INSERT_AFTER(listelm, elm, field) do {                     \
 393         QMD_LIST_CHECK_NEXT(listelm, field);                            \
 394         if ((LIST_NEXT((elm), field) = LIST_NEXT((listelm), field)) != NULL)\
 395                 LIST_NEXT((listelm), field)->field.le_prev =            \
 396                     &LIST_NEXT((elm), field);                           \
 397         LIST_NEXT((listelm), field) = (elm);                            \
 398         (elm)->field.le_prev = &LIST_NEXT((listelm), field);            \
 399 } while (0)
 400
 401 #define LIST_INSERT_BEFORE(listelm, elm, field) do {                    \
 402         QMD_LIST_CHECK_PREV(listelm, field);                            \
 403         (elm)->field.le_prev = (listelm)->field.le_prev;                \
 404         LIST_NEXT((elm), field) = (listelm);                            \
 405         *(listelm)->field.le_prev = (elm);                              \
 406         (listelm)->field.le_prev = &LIST_NEXT((elm), field);            \
 407 } while (0)
 408
 409 #define LIST_INSERT_HEAD(head, elm, field) do {                         \
 410         QMD_LIST_CHECK_HEAD((head), field);                             \
 411         if ((LIST_NEXT((elm), field) = LIST_FIRST((head))) != NULL)     \
 412                 LIST_FIRST((head))->field.le_prev = &LIST_NEXT((elm), field);\
 413         LIST_FIRST((head)) = (elm);                                     \
 414         (elm)->field.le_prev = &LIST_FIRST((head));                     \
 415 } while (0)
 416
 417 #define LIST_NEXT(elm, field)   ((elm)->field.le_next)
 418
 419 #define LIST_REMOVE(elm, field) do {                                    \
 420         QMD_LIST_CHECK_NEXT(elm, field);                                \
 421         QMD_LIST_CHECK_PREV(elm, field);                                \
 422         if (LIST_NEXT((elm), field) != NULL)                            \
 423                 LIST_NEXT((elm), field)->field.le_prev =                \
 424                     (elm)->field.le_prev;                               \
 425         *(elm)->field.le_prev = LIST_NEXT((elm), field);                \
 426         TRASHIT((elm)->field.le_next);                                  \
 427         TRASHIT((elm)->field.le_prev);                                  \
 428 } while (0)
 429
 430 #define LIST_SWAP(head1, head2, type, field) do {                       \
 431         struct type *swap_tmp = LIST_FIRST((head1));                    \
 432         LIST_FIRST((head1)) = LIST_FIRST((head2));                      \
 433         LIST_FIRST((head2)) = swap_tmp;                                 \
 434         if ((swap_tmp = LIST_FIRST((head1))) != NULL)                   \
 435                 swap_tmp->field.le_prev = &LIST_FIRST((head1));         \
 436         if ((swap_tmp = LIST_FIRST((head2))) != NULL)                   \
 437                 swap_tmp->field.le_prev = &LIST_FIRST((head2));         \
 438 } while (0)
 439
 440 /*
 441  * Tail queue declarations.
 442  */
 443 #define TAILQ_HEAD(name, type)                                          \
 444 struct name {                                                           \
 445         struct type *tqh_first; /* first element */                     \
 446         struct type **tqh_last; /* addr of last next element */         \
 447         TRACEBUF                                                        \
 448 }
 449
 450 #define TAILQ_HEAD_INITIALIZER(head)                                    \
 451         { NULL, &(head).tqh_first }
 452
 453 #define TAILQ_ENTRY(type)                                               \
 454 struct {                                                                \
 455         struct type *tqe_next;  /* next element */                      \
 456         struct type **tqe_prev; /* address of previous next element */  \
 457         TRACEBUF                                                        \
 458 }
 459
 460 /*
 461  * Tail queue functions.
 462  */
 463 #if (defined(_KERNEL) && defined(INVARIANTS))
 464 #define QMD_TAILQ_CHECK_HEAD(head, field) do {                          \
 465         if (!TAILQ_EMPTY(head) &&                                       \
 466             TAILQ_FIRST((head))->field.tqe_prev !=                      \
 467              &TAILQ_FIRST((head)))                                      \
 468                 panic("Bad tailq head %p first->prev != head", (head)); \
 469 } while (0)
 470
 471 #define QMD_TAILQ_CHECK_TAIL(head, field) do {                          \
 472         if (*(head)->tqh_last != NULL)                                  \
 473                 panic("Bad tailq NEXT(%p->tqh_last) != NULL", (head));  \
 474 } while (0)
 475
 476 #define QMD_TAILQ_CHECK_NEXT(elm, field) do {                           \
 477         if (TAILQ_NEXT((elm), field) != NULL &&                         \
 478             TAILQ_NEXT((elm), field)->field.tqe_prev !=                 \
 479              &((elm)->field.tqe_next))                                  \
 480                 panic("Bad link elm %p next->prev != elm", (elm));      \
 481 } while (0)
 482
 483 #define QMD_TAILQ_CHECK_PREV(elm, field) do {                           \
 484         if (*(elm)->field.tqe_prev != (elm))                            \
 485                 panic("Bad link elm %p prev->next != elm", (elm));      \
 486 } while (0)
 487 #else
 488 #define QMD_TAILQ_CHECK_HEAD(head, field)
 489 #define QMD_TAILQ_CHECK_TAIL(head, headname)
 490 #define QMD_TAILQ_CHECK_NEXT(elm, field)
 491 #define QMD_TAILQ_CHECK_PREV(elm, field)
 492 #endif /* (_KERNEL && INVARIANTS) */
 493
 494 #define TAILQ_CONCAT(head1, head2, field) do {                          \
 495         if (!TAILQ_EMPTY(head2)) {                                      \
 496                 *(head1)->tqh_last = (head2)->tqh_first;                \
 497                 (head2)->tqh_first->field.tqe_prev = (head1)->tqh_last; \
 498                 (head1)->tqh_last = (head2)->tqh_last;                  \
 499                 TAILQ_INIT((head2));                                    \
 500                 QMD_TRACE_HEAD(head1);                                  \
 501                 QMD_TRACE_HEAD(head2);                                  \
 502         }                                                               \
 503 } while (0)
 504
 505 #define TAILQ_EMPTY(head)       ((head)->tqh_first == NULL)
 506
 507 #define TAILQ_FIRST(head)       ((head)->tqh_first)
 508
 509 #define TAILQ_FOREACH(var, head, field)                                 \
 510         for ((var) = TAILQ_FIRST((head));                               \
 511             (var);                                                      \
 512             (var) = TAILQ_NEXT((var), field))
 513
 514 #define TAILQ_FOREACH_SAFE(var, head, field, tvar)                      \
 515         for ((var) = TAILQ_FIRST((head));                               \
 516             (var) && ((tvar) = TAILQ_NEXT((var), field), 1);            \
 517             (var) = (tvar))
 518
 519 #define TAILQ_FOREACH_REVERSE(var, head, headname, field)               \
 520         for ((var) = TAILQ_LAST((head), headname);                      \
 521             (var);                                                      \
 522             (var) = TAILQ_PREV((var), headname, field))
 523
 524 #define TAILQ_FOREACH_REVERSE_SAFE(var, head, headname, field, tvar)    \
 525         for ((var) = TAILQ_LAST((head), headname);                      \
 526             (var) && ((tvar) = TAILQ_PREV((var), headname, field), 1);  \
 527             (var) = (tvar))
 528
 529 #define TAILQ_INIT(head) do {                                           \
 530         TAILQ_FIRST((head)) = NULL;                                     \
 531         (head)->tqh_last = &TAILQ_FIRST((head));                        \
 532         QMD_TRACE_HEAD(head);                                           \
 533 } while (0)
 534
 535 #define TAILQ_INSERT_AFTER(head, listelm, elm, field) do {              \
 536         QMD_TAILQ_CHECK_NEXT(listelm, field);                           \
 537         if ((TAILQ_NEXT((elm), field) = TAILQ_NEXT((listelm), field)) != NULL)\
 538                 TAILQ_NEXT((elm), field)->field.tqe_prev =              \
 539                     &TAILQ_NEXT((elm), field);                          \
 540         else {                                                          \
 541                 (head)->tqh_last = &TAILQ_NEXT((elm), field);           \
 542                 QMD_TRACE_HEAD(head);                                   \
 543         }                                                               \
 544         TAILQ_NEXT((listelm), field) = (elm);                           \
 545         (elm)->field.tqe_prev = &TAILQ_NEXT((listelm), field);          \
 546         QMD_TRACE_ELEM(&(elm)->field);                                  \
 547         QMD_TRACE_ELEM(&listelm->field);                                \
 548 } while (0)
 549
 550 #define TAILQ_INSERT_BEFORE(listelm, elm, field) do {                   \
 551         QMD_TAILQ_CHECK_PREV(listelm, field);                           \
 552         (elm)->field.tqe_prev = (listelm)->field.tqe_prev;              \
 553         TAILQ_NEXT((elm), field) = (listelm);                           \
 554         *(listelm)->field.tqe_prev = (elm);                             \
 555         (listelm)->field.tqe_prev = &TAILQ_NEXT((elm), field);          \
 556         QMD_TRACE_ELEM(&(elm)->field);                                  \
 557         QMD_TRACE_ELEM(&listelm->field);                                \
 558 } while (0)
 559
 560 #define TAILQ_INSERT_HEAD(head, elm, field) do {                        \
 561         QMD_TAILQ_CHECK_HEAD(head, field);                              \
 562         if ((TAILQ_NEXT((elm), field) = TAILQ_FIRST((head))) != NULL)   \
 563                 TAILQ_FIRST((head))->field.tqe_prev =                   \
 564                     &TAILQ_NEXT((elm), field);                          \
 565         else                                                            \
 566                 (head)->tqh_last = &TAILQ_NEXT((elm), field);           \
 567         TAILQ_FIRST((head)) = (elm);                                    \
 568         (elm)->field.tqe_prev = &TAILQ_FIRST((head));                   \
 569         QMD_TRACE_HEAD(head);                                           \
 570         QMD_TRACE_ELEM(&(elm)->field);                                  \
 571 } while (0)
 572
 573 #define TAILQ_INSERT_TAIL(head, elm, field) do {                        \
 574         QMD_TAILQ_CHECK_TAIL(head, field);                              \
 575         TAILQ_NEXT((elm), field) = NULL;                                \
 576         (elm)->field.tqe_prev = (head)->tqh_last;                       \
 577         *(head)->tqh_last = (elm);                                      \
 578         (head)->tqh_last = &TAILQ_NEXT((elm), field);                   \
 579         QMD_TRACE_HEAD(head);                                           \
 580         QMD_TRACE_ELEM(&(elm)->field);                                  \
 581 } while (0)
 582
 583 #define TAILQ_LAST(head, headname)                                      \
 584         (*(((struct headname *)((head)->tqh_last))->tqh_last))
 585
 586 #define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next)
 587
 588 #define TAILQ_PREV(elm, headname, field)                                \
 589         (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last))
 590
 591 #define TAILQ_REMOVE(head, elm, field) do {                             \
 592         QMD_TAILQ_CHECK_NEXT(elm, field);                               \
 593         QMD_TAILQ_CHECK_PREV(elm, field);                               \
 594         if ((TAILQ_NEXT((elm), field)) != NULL)                         \
 595                 TAILQ_NEXT((elm), field)->field.tqe_prev =              \
 596                     (elm)->field.tqe_prev;                              \
 597         else {                                                          \
 598                 (head)->tqh_last = (elm)->field.tqe_prev;               \
 599                 QMD_TRACE_HEAD(head);                                   \
 600         }                                                               \
 601         *(elm)->field.tqe_prev = TAILQ_NEXT((elm), field);              \
 602         TRASHIT((elm)->field.tqe_next);                                 \
 603         TRASHIT((elm)->field.tqe_prev);                                 \
 604         QMD_TRACE_ELEM(&(elm)->field);                                  \
 605 } while (0)
 606
 607 #define TAILQ_SWAP(head1, head2, type, field) do {                      \
 608         struct type *swap_first = (head1)->tqh_first;                   \
 609         struct type **swap_last = (head1)->tqh_last;                    \
 610         (head1)->tqh_first = (head2)->tqh_first;                        \
 611         (head1)->tqh_last = (head2)->tqh_last;                          \
 612         (head2)->tqh_first = swap_first;                                \
 613         (head2)->tqh_last = swap_last;                                  \
 614         if ((swap_first = (head1)->tqh_first) != NULL)                  \
 615                 swap_first->field.tqe_prev = &(head1)->tqh_first;       \
 616         else                                                            \
 617                 (head1)->tqh_last = &(head1)->tqh_first;                \
 618         if ((swap_first = (head2)->tqh_first) != NULL)                  \
 619                 swap_first->field.tqe_prev = &(head2)->tqh_first;       \
 620         else                                                            \
 621                 (head2)->tqh_last = &(head2)->tqh_first;                \
 622 } while (0)
 623
 624 #endif /* !_SYS_QUEUE_H_ */