cogl/cogl-queue.h

   1 /*-
   2  * Copyright (c) 1991, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Copyright (C) 2011 Intel Corporation.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 4. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  *
  31  *      @(#)queue.h     8.5 (Berkeley) 8/20/94
  32  * $FreeBSD$
  33  */
  34
  35 #ifndef _COGL_QUEUE_H_
  36 #define _COGL_QUEUE_H_
  37
  38 /*
  39  * This file defines four types of data structures: singly-linked lists,
  40  * singly-linked tail queues, lists and tail queues.
  41  *
  42  * A singly-linked list is headed by a single forward pointer. The elements
  43  * are singly linked for minimum space and pointer manipulation overhead at
  44  * the expense of O(n) removal for arbitrary elements. New elements can be
  45  * added to the list after an existing element or at the head of the list.
  46  * Elements being removed from the head of the list should use the explicit
  47  * macro for this purpose for optimum efficiency. A singly-linked list may
  48  * only be traversed in the forward direction.  Singly-linked lists are ideal
  49  * for applications with large datasets and few or no removals or for
  50  * implementing a LIFO queue.
  51  *
  52  * A singly-linked tail queue is headed by a pair of pointers, one to the
  53  * head of the list and the other to the tail of the list. The elements are
  54  * singly linked for minimum space and pointer manipulation overhead at the
  55  * expense of O(n) removal for arbitrary elements. New elements can be added
  56  * to the list after an existing element, at the head of the list, or at the
  57  * end of the list. Elements being removed from the head of the tail queue
  58  * should use the explicit macro for this purpose for optimum efficiency.
  59  * A singly-linked tail queue may only be traversed in the forward direction.
  60  * Singly-linked tail queues are ideal for applications with large datasets
  61  * and few or no removals or for implementing a FIFO queue.
  62  *
  63  * A list is headed by a single forward pointer (or an array of forward
  64  * pointers for a hash table header). The elements are doubly linked
  65  * so that an arbitrary element can be removed without a need to
  66  * traverse the list. New elements can be added to the list before
  67  * or after an existing element or at the head of the list. A list
  68  * may only be traversed in the forward direction.
  69  *
  70  * A tail queue is headed by a pair of pointers, one to the head of the
  71  * list and the other to the tail of the list. The elements are doubly
  72  * linked so that an arbitrary element can be removed without a need to
  73  * traverse the list. New elements can be added to the list before or
  74  * after an existing element, at the head of the list, or at the end of
  75  * the list. A tail queue may be traversed in either direction.
  76  *
  77  * For details on the use of these macros, see the queue(3) manual page.
  78  *
  79  *
  80  *                              SLIST   LIST    STAILQ  TAILQ
  81  * _HEAD                        +       +       +       +
  82  * _HEAD_INITIALIZER            +       +       +       +
  83  * _ENTRY                       +       +       +       +
  84  * _INIT                        +       +       +       +
  85  * _EMPTY                       +       +       +       +
  86  * _FIRST                       +       +       +       +
  87  * _NEXT                        +       +       +       +
  88  * _PREV                        -       -       -       +
  89  * _LAST                        -       -       +       +
  90  * _FOREACH                     +       +       +       +
  91  * _FOREACH_SAFE                +       +       +       +
  92  * _FOREACH_REVERSE             -       -       -       +
  93  * _FOREACH_REVERSE_SAFE        -       -       -       +
  94  * _INSERT_HEAD                 +       +       +       +
  95  * _INSERT_BEFORE               -       +       -       +
  96  * _INSERT_AFTER                +       +       +       +
  97  * _INSERT_TAIL                 -       -       +       +
  98  * _CONCAT                      -       -       +       +
  99  * _REMOVE_AFTER                +       -       +       -
 100  * _REMOVE_HEAD                 +       -       +       -
 101  * _REMOVE                      +       +       +       +
 102  * _SWAP                        +       +       +       +
 103  *
 104  */
 105 #ifdef COGL_QUEUE_MACRO_DEBUG
 106 /* Store the last 2 places the queue element or head was altered */
 107 struct cogl_qm_trace {
 108         char * lastfile;
 109         int lastline;
 110         char * prevfile;
 111         int prevline;
 112 };
 113
 114 #define COGL_TRACEBUF struct cogl_qm_trace trace;
 115 #define COGL_TRASHIT(x) do {(x) = (void *)-1;} while (0)
 116 #define COGL_QMD_SAVELINK(name, link) void **name = (void *)&(link)
 117
 118 #define COGL_QMD_TRACE_HEAD(head) do {                                  \
 119         (head)->trace.prevline = (head)->trace.lastline;                \
 120         (head)->trace.prevfile = (head)->trace.lastfile;                \
 121         (head)->trace.lastline = __LINE__;                              \
 122         (head)->trace.lastfile = __FILE__;                              \
 123 } while (0)
 124
 125 #define COGL_QMD_TRACE_ELEM(elem) do {                                  \
 126         (elem)->trace.prevline = (elem)->trace.lastline;                \
 127         (elem)->trace.prevfile = (elem)->trace.lastfile;                \
 128         (elem)->trace.lastline = __LINE__;                              \
 129         (elem)->trace.lastfile = __FILE__;                              \
 130 } while (0)
 131
 132 #else
 133 #define COGL_QMD_TRACE_ELEM(elem)
 134 #define COGL_QMD_TRACE_HEAD(head)
 135 #define COGL_QMD_SAVELINK(name, link)
 136 #define COGL_TRACEBUF
 137 #define COGL_TRASHIT(x)
 138 #endif  /* COGL_QUEUE_MACRO_DEBUG */
 139
 140 /*
 141  * Singly-linked List declarations.
 142  */
 143 #define COGL_SLIST_HEAD(name, type)                                     \
 144 typedef struct _ ## name {                                              \
 145   type *slh_first; /* first element */                                  \
 146 } name
 147
 148 #define COGL_SLIST_HEAD_INITIALIZER(head)                               \
 149         { NULL }
 150
 151 #define COGL_SLIST_ENTRY(type)                                          \
 152 struct {                                                                \
 153   type *sle_next;  /* next element */                                   \
 154 }
 155
 156 /*
 157  * Singly-linked List functions.
 158  */
 159 #define COGL_SLIST_EMPTY(head)  ((head)->slh_first == NULL)
 160
 161 #define COGL_SLIST_FIRST(head)  ((head)->slh_first)
 162
 163 #define COGL_SLIST_FOREACH(var, head, field)                            \
 164         for ((var) = COGL_SLIST_FIRST((head));                          \
 165             (var);                                                      \
 166             (var) = COGL_SLIST_NEXT((var), field))
 167
 168 #define COGL_SLIST_FOREACH_SAFE(var, head, field, tvar)                 \
 169         for ((var) = COGL_SLIST_FIRST((head));                          \
 170             (var) && ((tvar) = COGL_SLIST_NEXT((var), field), 1);       \
 171             (var) = (tvar))
 172
 173 #define COGL_SLIST_FOREACH_PREVPTR(var, varp, head, field)              \
 174         for ((varp) = &COGL_SLIST_FIRST((head));                        \
 175             ((var) = *(varp)) != NULL;                                  \
 176             (varp) = &COGL_SLIST_NEXT((var), field))
 177
 178 #define COGL_SLIST_INIT(head) do {                                      \
 179         COGL_SLIST_FIRST((head)) = NULL;                                \
 180 } while (0)
 181
 182 #define COGL_SLIST_INSERT_AFTER(slistelm, elm, field) do {              \
 183         COGL_SLIST_NEXT((elm), field) = COGL_SLIST_NEXT((slistelm), field);  \
 184         COGL_SLIST_NEXT((slistelm), field) = (elm);                     \
 185 } while (0)
 186
 187 #define COGL_SLIST_INSERT_HEAD(head, elm, field) do {                   \
 188         COGL_SLIST_NEXT((elm), field) = COGL_SLIST_FIRST((head));       \
 189         COGL_SLIST_FIRST((head)) = (elm);                               \
 190 } while (0)
 191
 192 #define COGL_SLIST_NEXT(elm, field)  ((elm)->field.sle_next)
 193
 194 #define COGL_SLIST_REMOVE(head, elm, type, field) do {                  \
 195         COGL_QMD_SAVELINK(oldnext, (elm)->field.sle_next);              \
 196         if (COGL_SLIST_FIRST((head)) == (elm)) {                        \
 197                 COGL_SLIST_REMOVE_HEAD((head), field);                  \
 198         }                                                               \
 199         else {                                                          \
 200                 type *curelm = COGL_SLIST_FIRST((head));                \
 201                 while (COGL_SLIST_NEXT(curelm, field) != (elm))         \
 202                         curelm = COGL_SLIST_NEXT(curelm, field);        \
 203                 COGL_SLIST_REMOVE_AFTER(curelm, field);                 \
 204         }                                                               \
 205         COGL_TRASHIT(*oldnext);                                         \
 206 } while (0)
 207
 208 #define COGL_SLIST_REMOVE_AFTER(elm, field) do {                        \
 209         COGL_SLIST_NEXT(elm, field) =                                   \
 210             COGL_SLIST_NEXT(COGL_SLIST_NEXT(elm, field), field);        \
 211 } while (0)
 212
 213 #define COGL_SLIST_REMOVE_HEAD(head, field) do {                        \
 214     COGL_SLIST_FIRST((head)) =                                          \
 215       COGL_SLIST_NEXT(COGL_SLIST_FIRST((head)), field);                 \
 216 } while (0)
 217
 218 #define COGL_SLIST_SWAP(head1, head2, type) do {                        \
 219         type *swap_first = COGL_SLIST_FIRST(head1);                     \
 220         COGL_SLIST_FIRST(head1) = COGL_SLIST_FIRST(head2);              \
 221         COGL_SLIST_FIRST(head2) = swap_first;                           \
 222 } while (0)
 223
 224 /*
 225  * Singly-linked Tail queue declarations.
 226  */
 227 #define COGL_STAILQ_HEAD(name, type)                                    \
 228 typedef struct _ ## name {                                              \
 229         type *stqh_first;/* first element */                            \
 230         type **stqh_last;/* addr of last next element */                \
 231 } name
 232
 233 #define COGL_STAILQ_HEAD_INITIALIZER(head)                              \
 234         { NULL, &(head).stqh_first }
 235
 236 #define COGL_STAILQ_ENTRY(type)                                         \
 237 struct {                                                                \
 238         type *stqe_next; /* next element */                             \
 239 }
 240
 241 /*
 242  * Singly-linked Tail queue functions.
 243  */
 244 #define COGL_STAILQ_CONCAT(head1, head2) do {                           \
 245         if (!COGL_STAILQ_EMPTY((head2))) {                              \
 246                 *(head1)->stqh_last = (head2)->stqh_first;              \
 247                 (head1)->stqh_last = (head2)->stqh_last;                \
 248                 COGL_STAILQ_INIT((head2));                              \
 249         }                                                               \
 250 } while (0)
 251
 252 #define COGL_STAILQ_EMPTY(head) ((head)->stqh_first == NULL)
 253
 254 #define COGL_STAILQ_FIRST(head) ((head)->stqh_first)
 255
 256 #define COGL_STAILQ_FOREACH(var, head, field)                           \
 257         for((var) = COGL_STAILQ_FIRST((head));                          \
 258            (var);                                                       \
 259            (var) = COGL_STAILQ_NEXT((var), field))
 260
 261
 262 #define COGL_STAILQ_FOREACH_SAFE(var, head, field, tvar)                \
 263         for ((var) = COGL_STAILQ_FIRST((head));                         \
 264             (var) && ((tvar) = COGL_STAILQ_NEXT((var), field), 1);      \
 265             (var) = (tvar))
 266
 267 #define COGL_STAILQ_INIT(head) do {                                     \
 268         COGL_STAILQ_FIRST((head)) = NULL;                               \
 269         (head)->stqh_last = &COGL_STAILQ_FIRST((head));                 \
 270 } while (0)
 271
 272 #define COGL_STAILQ_INSERT_AFTER(head, tqelm, elm, field) do {          \
 273     if ((COGL_STAILQ_NEXT((elm), field) =                               \
 274          COGL_STAILQ_NEXT((tqelm), field)) == NULL)                     \
 275       (head)->stqh_last = &COGL_STAILQ_NEXT((elm), field);              \
 276     COGL_STAILQ_NEXT((tqelm), field) = (elm);                           \
 277 } while (0)
 278
 279 #define COGL_STAILQ_INSERT_HEAD(head, elm, field) do {                  \
 280     if ((COGL_STAILQ_NEXT((elm), field) =                               \
 281          COGL_STAILQ_FIRST((head))) == NULL)                            \
 282       (head)->stqh_last = &COGL_STAILQ_NEXT((elm), field);              \
 283     COGL_STAILQ_FIRST((head)) = (elm);                                  \
 284   } while (0)
 285
 286 #define COGL_STAILQ_INSERT_TAIL(head, elm, field) do {                  \
 287         COGL_STAILQ_NEXT((elm), field) = NULL;                          \
 288         *(head)->stqh_last = (elm);                                     \
 289         (head)->stqh_last = &COGL_STAILQ_NEXT((elm), field);            \
 290 } while (0)
 291
 292 #define COGL_STAILQ_LAST(head, type, field)                             \
 293         (COGL_STAILQ_EMPTY((head)) ?                                    \
 294                 NULL :                                                  \
 295                 ((type *)(void *)                                       \
 296                  ((char *)((head)->stqh_last) -                         \
 297                   __offsetof(struct type, field))))
 298
 299 #define COGL_STAILQ_NEXT(elm, field) ((elm)->field.stqe_next)
 300
 301 #define COGL_STAILQ_REMOVE(head, elm, type, field) do {                 \
 302         COGL_QMD_SAVELINK(oldnext, (elm)->field.stqe_next);             \
 303         if (COGL_STAILQ_FIRST((head)) == (elm)) {                       \
 304                 COGL_STAILQ_REMOVE_HEAD((head), field);                 \
 305         }                                                               \
 306         else {                                                          \
 307                 type *curelm = COGL_STAILQ_FIRST((head));               \
 308                 while (COGL_STAILQ_NEXT(curelm, field) != (elm))        \
 309                         curelm = COGL_STAILQ_NEXT(curelm, field);       \
 310                 COGL_STAILQ_REMOVE_AFTER(head, curelm, field);          \
 311         }                                                               \
 312         COGL_TRASHIT(*oldnext);                                         \
 313 } while (0)
 314
 315 #define COGL_STAILQ_REMOVE_AFTER(head, elm, field) do {                 \
 316         if ((COGL_STAILQ_NEXT(elm, field) =                             \
 317              COGL_STAILQ_NEXT(COGL_STAILQ_NEXT(elm, field),             \
 318                               field)) == NULL)                          \
 319                 (head)->stqh_last = &COGL_STAILQ_NEXT((elm), field);    \
 320 } while (0)
 321
 322 #define COGL_STAILQ_REMOVE_HEAD(head, field) do {                       \
 323         if ((COGL_STAILQ_FIRST((head)) =                                \
 324              COGL_STAILQ_NEXT(COGL_STAILQ_FIRST((head)), field)) == NULL) \
 325                 (head)->stqh_last = &COGL_STAILQ_FIRST((head));         \
 326 } while (0)
 327
 328 #define COGL_STAILQ_SWAP(head1, head2, type) do {                       \
 329         type *swap_first = COGL_STAILQ_FIRST(head1);                    \
 330         type **swap_last = (head1)->stqh_last;                          \
 331         COGL_STAILQ_FIRST(head1) = COGL_STAILQ_FIRST(head2);            \
 332         (head1)->stqh_last = (head2)->stqh_last;                        \
 333         COGL_STAILQ_FIRST(head2) = swap_first;                          \
 334         (head2)->stqh_last = swap_last;                                 \
 335         if (COGL_STAILQ_EMPTY(head1))                                   \
 336                 (head1)->stqh_last = &COGL_STAILQ_FIRST(head1);         \
 337         if (COGL_STAILQ_EMPTY(head2))                                   \
 338                 (head2)->stqh_last = &COGL_STAILQ_FIRST(head2);         \
 339 } while (0)
 340
 341
 342 /*
 343  * List declarations.
 344  */
 345 #define COGL_LIST_HEAD(name, type)                                      \
 346 typedef struct _ ## name {                                              \
 347         type *lh_first;  /* first element */                            \
 348 } name
 349
 350 #define COGL_LIST_HEAD_INITIALIZER(head)                                \
 351         { NULL }
 352
 353 #define COGL_LIST_ENTRY(type)                                           \
 354 struct {                                                                \
 355         type *le_next;   /* next element */                             \
 356         type **le_prev;  /* address of previous next element */         \
 357 }
 358
 359 /*
 360  * List functions.
 361  */
 362
 363 #if (defined(_KERNEL) && defined(INVARIANTS))
 364 #define COGL_QMD_LIST_CHECK_HEAD(head, field) do {                      \
 365         if (COGL_LIST_FIRST((head)) != NULL &&                          \
 366             COGL_LIST_FIRST((head))->field.le_prev !=                   \
 367              &COGL_LIST_FIRST((head)))                                  \
 368                 panic("Bad list head %p first->prev != head", (head));  \
 369 } while (0)
 370
 371 #define COGL_QMD_LIST_CHECK_NEXT(elm, field) do {                       \
 372         if (COGL_LIST_NEXT((elm), field) != NULL &&                     \
 373             COGL_LIST_NEXT((elm), field)->field.le_prev !=              \
 374              &((elm)->field.le_next))                                   \
 375                 panic("Bad link elm %p next->prev != elm", (elm));      \
 376 } while (0)
 377
 378 #define COGL_QMD_LIST_CHECK_PREV(elm, field) do {                       \
 379         if (*(elm)->field.le_prev != (elm))                             \
 380                 panic("Bad link elm %p prev->next != elm", (elm));      \
 381 } while (0)
 382 #else
 383 #define COGL_QMD_LIST_CHECK_HEAD(head, field)
 384 #define COGL_QMD_LIST_CHECK_NEXT(elm, field)
 385 #define COGL_QMD_LIST_CHECK_PREV(elm, field)
 386 #endif /* (_KERNEL && INVARIANTS) */
 387
 388 #define COGL_LIST_EMPTY(head)   ((head)->lh_first == NULL)
 389
 390 #define COGL_LIST_FIRST(head)   ((head)->lh_first)
 391
 392 #define COGL_LIST_FOREACH(var, head, field)                             \
 393         for ((var) = COGL_LIST_FIRST((head));                           \
 394             (var);                                                      \
 395             (var) = COGL_LIST_NEXT((var), field))
 396
 397 #define COGL_LIST_FOREACH_SAFE(var, head, field, tvar)                  \
 398         for ((var) = COGL_LIST_FIRST((head));                           \
 399             (var) && ((tvar) = COGL_LIST_NEXT((var), field), 1);        \
 400             (var) = (tvar))
 401
 402 #define COGL_LIST_INIT(head) do {                                       \
 403         COGL_LIST_FIRST((head)) = NULL;                                 \
 404 } while (0)
 405
 406 #define COGL_LIST_INSERT_AFTER(listelm, elm, field) do {                \
 407         COGL_QMD_LIST_CHECK_NEXT(listelm, field);                       \
 408         if ((COGL_LIST_NEXT((elm), field) =                             \
 409              COGL_LIST_NEXT((listelm), field)) != NULL)                 \
 410                 COGL_LIST_NEXT((listelm), field)->field.le_prev =       \
 411                     &COGL_LIST_NEXT((elm), field);                      \
 412         COGL_LIST_NEXT((listelm), field) = (elm);                       \
 413         (elm)->field.le_prev = &COGL_LIST_NEXT((listelm), field);       \
 414 } while (0)
 415
 416 #define COGL_LIST_INSERT_BEFORE(listelm, elm, field) do {               \
 417         COGL_QMD_LIST_CHECK_PREV(listelm, field);                       \
 418         (elm)->field.le_prev = (listelm)->field.le_prev;                \
 419         COGL_LIST_NEXT((elm), field) = (listelm);                       \
 420         *(listelm)->field.le_prev = (elm);                              \
 421         (listelm)->field.le_prev = &COGL_LIST_NEXT((elm), field);       \
 422 } while (0)
 423
 424 #define COGL_LIST_INSERT_HEAD(head, elm, field) do {                    \
 425         COGL_QMD_LIST_CHECK_HEAD((head), field);                        \
 426         if ((COGL_LIST_NEXT((elm), field) =                             \
 427              COGL_LIST_FIRST((head))) != NULL)                          \
 428           COGL_LIST_FIRST((head))->field.le_prev =                      \
 429             &COGL_LIST_NEXT((elm), field);                              \
 430         COGL_LIST_FIRST((head)) = (elm);                                \
 431         (elm)->field.le_prev = &COGL_LIST_FIRST((head));                \
 432 } while (0)
 433
 434 #define COGL_LIST_NEXT(elm, field)   ((elm)->field.le_next)
 435
 436 #define COGL_LIST_REMOVE(elm, field) do {                               \
 437         COGL_QMD_SAVELINK(oldnext, (elm)->field.le_next);               \
 438         COGL_QMD_SAVELINK(oldprev, (elm)->field.le_prev);               \
 439         COGL_QMD_LIST_CHECK_NEXT(elm, field);                           \
 440         COGL_QMD_LIST_CHECK_PREV(elm, field);                           \
 441         if (COGL_LIST_NEXT((elm), field) != NULL)                       \
 442                 COGL_LIST_NEXT((elm), field)->field.le_prev =           \
 443                     (elm)->field.le_prev;                               \
 444         *(elm)->field.le_prev = COGL_LIST_NEXT((elm), field);           \
 445         COGL_TRASHIT(*oldnext);                                         \
 446         COGL_TRASHIT(*oldprev);                                         \
 447 } while (0)
 448
 449 #define COGL_LIST_SWAP(head1, head2, type, field) do {                  \
 450         type *swap_tmp = COGL_LIST_FIRST((head1));                      \
 451         COGL_LIST_FIRST((head1)) = COGL_LIST_FIRST((head2));            \
 452         COGL_LIST_FIRST((head2)) = swap_tmp;                            \
 453         if ((swap_tmp = COGL_LIST_FIRST((head1))) != NULL)              \
 454                 swap_tmp->field.le_prev = &COGL_LIST_FIRST((head1));    \
 455         if ((swap_tmp = COGL_LIST_FIRST((head2))) != NULL)              \
 456                 swap_tmp->field.le_prev = &COGL_LIST_FIRST((head2));    \
 457 } while (0)
 458
 459 /*
 460  * Tail queue declarations.
 461  */
 462 #define COGL_TAILQ_HEAD(name, type)                                     \
 463 typedef struct _ ## name {                                              \
 464         type *tqh_first; /* first element */                            \
 465         type **tqh_last; /* addr of last next element */                \
 466         COGL_TRACEBUF                                                   \
 467 } name
 468
 469 #define COGL_TAILQ_HEAD_INITIALIZER(head)                               \
 470         { NULL, &(head).tqh_first }
 471
 472 #define COGL_TAILQ_ENTRY(type)                                          \
 473 struct {                                                                \
 474         type *tqe_next;  /* next element */                             \
 475         type **tqe_prev; /* address of previous next element */         \
 476         COGL_TRACEBUF                                                   \
 477 }
 478
 479 /*
 480  * Tail queue functions.
 481  */
 482 #if (defined(_KERNEL) && defined(INVARIANTS))
 483 #define COGL_QMD_TAILQ_CHECK_HEAD(head, field) do {                     \
 484         if (!COGL_TAILQ_EMPTY(head) &&                                  \
 485             COGL_TAILQ_FIRST((head))->field.tqe_prev !=                 \
 486              &COGL_TAILQ_FIRST((head)))                                 \
 487                 panic("Bad tailq head %p first->prev != head", (head)); \
 488 } while (0)
 489
 490 #define COGL_QMD_TAILQ_CHECK_TAIL(head, field) do {                     \
 491         if (*(head)->tqh_last != NULL)                                  \
 492                 panic("Bad tailq NEXT(%p->tqh_last) != NULL", (head));  \
 493 } while (0)
 494
 495 #define COGL_QMD_TAILQ_CHECK_NEXT(elm, field) do {                      \
 496         if (COGL_TAILQ_NEXT((elm), field) != NULL &&                    \
 497             COGL_TAILQ_NEXT((elm), field)->field.tqe_prev !=            \
 498              &((elm)->field.tqe_next))                                  \
 499                 panic("Bad link elm %p next->prev != elm", (elm));      \
 500 } while (0)
 501
 502 #define COGL_QMD_TAILQ_CHECK_PREV(elm, field) do {                      \
 503         if (*(elm)->field.tqe_prev != (elm))                            \
 504                 panic("Bad link elm %p prev->next != elm", (elm));      \
 505 } while (0)
 506 #else
 507 #define COGL_QMD_TAILQ_CHECK_HEAD(head, field)
 508 #define COGL_QMD_TAILQ_CHECK_TAIL(head, headname)
 509 #define COGL_QMD_TAILQ_CHECK_NEXT(elm, field)
 510 #define COGL_QMD_TAILQ_CHECK_PREV(elm, field)
 511 #endif /* (_KERNEL && INVARIANTS) */
 512
 513 #define COGL_TAILQ_CONCAT(head1, head2, field) do {                     \
 514         if (!COGL_TAILQ_EMPTY(head2)) {                                 \
 515                 *(head1)->tqh_last = (head2)->tqh_first;                \
 516                 (head2)->tqh_first->field.tqe_prev = (head1)->tqh_last; \
 517                 (head1)->tqh_last = (head2)->tqh_last;                  \
 518                 COGL_TAILQ_INIT((head2));                               \
 519                 COGL_QMD_TRACE_HEAD(head1);                             \
 520                 COGL_QMD_TRACE_HEAD(head2);                             \
 521         }                                                               \
 522 } while (0)
 523
 524 #define COGL_TAILQ_EMPTY(head)  ((head)->tqh_first == NULL)
 525
 526 #define COGL_TAILQ_FIRST(head)  ((head)->tqh_first)
 527
 528 #define COGL_TAILQ_FOREACH(var, head, field)                            \
 529         for ((var) = COGL_TAILQ_FIRST((head));                          \
 530             (var);                                                      \
 531             (var) = COGL_TAILQ_NEXT((var), field))
 532
 533 #define COGL_TAILQ_FOREACH_SAFE(var, head, field, tvar)                 \
 534         for ((var) = COGL_TAILQ_FIRST((head));                          \
 535             (var) && ((tvar) = COGL_TAILQ_NEXT((var), field), 1);       \
 536             (var) = (tvar))
 537
 538 #define COGL_TAILQ_FOREACH_REVERSE(var, head, headname, field)          \
 539         for ((var) = COGL_TAILQ_LAST((head), headname);                 \
 540             (var);                                                      \
 541             (var) = COGL_TAILQ_PREV((var), headname, field))
 542
 543 #define COGL_TAILQ_FOREACH_REVERSE_SAFE(var, head, headname, field, tvar) \
 544         for ((var) = COGL_TAILQ_LAST((head), headname);                 \
 545             (var) && ((tvar) = COGL_TAILQ_PREV((var), headname, field), 1); \
 546             (var) = (tvar))
 547
 548 #define COGL_TAILQ_INIT(head) do {                                      \
 549         COGL_TAILQ_FIRST((head)) = NULL;                                \
 550         (head)->tqh_last = &COGL_TAILQ_FIRST((head));                   \
 551         COGL_QMD_TRACE_HEAD(head);                                      \
 552 } while (0)
 553
 554 #define COGL_TAILQ_INSERT_AFTER(head, listelm, elm, field) do {         \
 555         COGL_QMD_TAILQ_CHECK_NEXT(listelm, field);                      \
 556         if ((COGL_TAILQ_NEXT((elm), field) =                            \
 557              COGL_TAILQ_NEXT((listelm), field)) != NULL)                \
 558                 COGL_TAILQ_NEXT((elm), field)->field.tqe_prev =         \
 559                     &COGL_TAILQ_NEXT((elm), field);                     \
 560         else {                                                          \
 561                 (head)->tqh_last = &COGL_TAILQ_NEXT((elm), field);      \
 562                 COGL_QMD_TRACE_HEAD(head);                              \
 563         }                                                               \
 564         COGL_TAILQ_NEXT((listelm), field) = (elm);                      \
 565         (elm)->field.tqe_prev = &COGL_TAILQ_NEXT((listelm), field);     \
 566         COGL_QMD_TRACE_ELEM(&(elm)->field);                             \
 567         COGL_QMD_TRACE_ELEM(&listelm->field);                           \
 568 } while (0)
 569
 570 #define COGL_TAILQ_INSERT_BEFORE(listelm, elm, field) do {              \
 571         COGL_QMD_TAILQ_CHECK_PREV(listelm, field);                      \
 572         (elm)->field.tqe_prev = (listelm)->field.tqe_prev;              \
 573         COGL_TAILQ_NEXT((elm), field) = (listelm);                      \
 574         *(listelm)->field.tqe_prev = (elm);                             \
 575         (listelm)->field.tqe_prev = &COGL_TAILQ_NEXT((elm), field);     \
 576         COGL_QMD_TRACE_ELEM(&(elm)->field);                             \
 577         COGL_QMD_TRACE_ELEM(&listelm->field);                           \
 578 } while (0)
 579
 580 #define COGL_TAILQ_INSERT_HEAD(head, elm, field) do {                   \
 581         COGL_QMD_TAILQ_CHECK_HEAD(head, field);                         \
 582         if ((COGL_TAILQ_NEXT((elm), field) =                            \
 583              COGL_TAILQ_FIRST((head))) != NULL)                         \
 584                 COGL_TAILQ_FIRST((head))->field.tqe_prev =              \
 585                     &COGL_TAILQ_NEXT((elm), field);                     \
 586         else                                                            \
 587                 (head)->tqh_last = &COGL_TAILQ_NEXT((elm), field);      \
 588         COGL_TAILQ_FIRST((head)) = (elm);                               \
 589         (elm)->field.tqe_prev = &COGL_TAILQ_FIRST((head));              \
 590         COGL_QMD_TRACE_HEAD(head);                                      \
 591         COGL_QMD_TRACE_ELEM(&(elm)->field);                             \
 592 } while (0)
 593
 594 #define COGL_TAILQ_INSERT_TAIL(head, elm, field) do {                   \
 595         COGL_QMD_TAILQ_CHECK_TAIL(head, field);                         \
 596         COGL_TAILQ_NEXT((elm), field) = NULL;                           \
 597         (elm)->field.tqe_prev = (head)->tqh_last;                       \
 598         *(head)->tqh_last = (elm);                                      \
 599         (head)->tqh_last = &COGL_TAILQ_NEXT((elm), field);              \
 600         COGL_QMD_TRACE_HEAD(head);                                      \
 601         COGL_QMD_TRACE_ELEM(&(elm)->field);                             \
 602 } while (0)
 603
 604 #define COGL_TAILQ_LAST(head, headname)                                 \
 605         (*(((headname *)((head)->tqh_last))->tqh_last))
 606
 607 #define COGL_TAILQ_NEXT(elm, field) ((elm)->field.tqe_next)
 608
 609 #define COGL_TAILQ_PREV(elm, headname, field)                           \
 610         (*(((headname *)((elm)->field.tqe_prev))->tqh_last))
 611
 612 #define COGL_TAILQ_REMOVE(head, elm, field) do {                        \
 613         COGL_QMD_SAVELINK(oldnext, (elm)->field.tqe_next);              \
 614         COGL_QMD_SAVELINK(oldprev, (elm)->field.tqe_prev);              \
 615         COGL_QMD_TAILQ_CHECK_NEXT(elm, field);                          \
 616         COGL_QMD_TAILQ_CHECK_PREV(elm, field);                          \
 617         if ((COGL_TAILQ_NEXT((elm), field)) != NULL)                    \
 618                 COGL_TAILQ_NEXT((elm), field)->field.tqe_prev =         \
 619                     (elm)->field.tqe_prev;                              \
 620         else {                                                          \
 621                 (head)->tqh_last = (elm)->field.tqe_prev;               \
 622                 COGL_QMD_TRACE_HEAD(head);                              \
 623         }                                                               \
 624         *(elm)->field.tqe_prev = COGL_TAILQ_NEXT((elm), field);         \
 625         COGL_TRASHIT(*oldnext);                                         \
 626         COGL_TRASHIT(*oldprev);                                         \
 627         COGL_QMD_TRACE_ELEM(&(elm)->field);                             \
 628 } while (0)
 629
 630 #define COGL_TAILQ_SWAP(head1, head2, type, field) do {                 \
 631         type *swap_first = (head1)->tqh_first;                          \
 632         type **swap_last = (head1)->tqh_last;                           \
 633         (head1)->tqh_first = (head2)->tqh_first;                        \
 634         (head1)->tqh_last = (head2)->tqh_last;                          \
 635         (head2)->tqh_first = swap_first;                                \
 636         (head2)->tqh_last = swap_last;                                  \
 637         if ((swap_first = (head1)->tqh_first) != NULL)                  \
 638                 swap_first->field.tqe_prev = &(head1)->tqh_first;       \
 639         else                                                            \
 640                 (head1)->tqh_last = &(head1)->tqh_first;                \
 641         if ((swap_first = (head2)->tqh_first) != NULL)                  \
 642                 swap_first->field.tqe_prev = &(head2)->tqh_first;       \
 643         else                                                            \
 644                 (head2)->tqh_last = &(head2)->tqh_first;                \
 645 } while (0)
 646
 647 #endif /* !_COGL_QUEUE_H_ */