Annotation of qemu/qemu-queue.h, revision 1.1.1.3

1.1       root        1: /*      $NetBSD: queue.h,v 1.52 2009/04/20 09:56:08 mschuett Exp $ */
                      2: 
                      3: /*
1.1.1.3 ! root        4:  * QEMU version: Copy from netbsd, removed debug code, removed some of
        !             5:  * the implementations.  Left in singly-linked lists, lists, simple
        !             6:  * queues, and tail queues.
1.1       root        7:  */
                      8: 
                      9: /*
                     10:  * Copyright (c) 1991, 1993
                     11:  *      The Regents of the University of California.  All rights reserved.
                     12:  *
                     13:  * Redistribution and use in source and binary forms, with or without
                     14:  * modification, are permitted provided that the following conditions
                     15:  * are met:
                     16:  * 1. Redistributions of source code must retain the above copyright
                     17:  *    notice, this list of conditions and the following disclaimer.
                     18:  * 2. Redistributions in binary form must reproduce the above copyright
                     19:  *    notice, this list of conditions and the following disclaimer in the
                     20:  *    documentation and/or other materials provided with the distribution.
                     21:  * 3. Neither the name of the University nor the names of its contributors
                     22:  *    may be used to endorse or promote products derived from this software
                     23:  *    without specific prior written permission.
                     24:  *
                     25:  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
                     26:  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
                     27:  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
                     28:  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
                     29:  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
                     30:  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
                     31:  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
                     32:  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
                     33:  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
                     34:  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
                     35:  * SUCH DAMAGE.
                     36:  *
                     37:  *      @(#)queue.h     8.5 (Berkeley) 8/20/94
                     38:  */
                     39: 
                     40: #ifndef QEMU_SYS_QUEUE_H_
                     41: #define QEMU_SYS_QUEUE_H_
                     42: 
                     43: /*
1.1.1.3 ! root       44:  * This file defines four types of data structures: singly-linked lists,
        !            45:  * lists, simple queues, and tail queues.
        !            46:  *
        !            47:  * A singly-linked list is headed by a single forward pointer. The
        !            48:  * elements are singly linked for minimum space and pointer manipulation
        !            49:  * overhead at the expense of O(n) removal for arbitrary elements. New
        !            50:  * elements can be added to the list after an existing element or at the
        !            51:  * head of the list.  Elements being removed from the head of the list
        !            52:  * should use the explicit macro for this purpose for optimum
        !            53:  * efficiency. A singly-linked list may only be traversed in the forward
        !            54:  * direction.  Singly-linked lists are ideal for applications with large
        !            55:  * datasets and few or no removals or for implementing a LIFO queue.
1.1       root       56:  *
                     57:  * A list is headed by a single forward pointer (or an array of forward
                     58:  * pointers for a hash table header). The elements are doubly linked
                     59:  * so that an arbitrary element can be removed without a need to
                     60:  * traverse the list. New elements can be added to the list before
                     61:  * or after an existing element or at the head of the list. A list
                     62:  * may only be traversed in the forward direction.
                     63:  *
                     64:  * A simple queue is headed by a pair of pointers, one the head of the
                     65:  * list and the other to the tail of the list. The elements are singly
                     66:  * linked to save space, so elements can only be removed from the
                     67:  * head of the list. New elements can be added to the list after
                     68:  * an existing element, at the head of the list, or at the end of the
                     69:  * list. A simple queue may only be traversed in the forward direction.
                     70:  *
                     71:  * A tail queue is headed by a pair of pointers, one to the head of the
                     72:  * list and the other to the tail of the list. The elements are doubly
                     73:  * linked so that an arbitrary element can be removed without a need to
                     74:  * traverse the list. New elements can be added to the list before or
                     75:  * after an existing element, at the head of the list, or at the end of
                     76:  * the list. A tail queue may be traversed in either direction.
                     77:  *
                     78:  * For details on the use of these macros, see the queue(3) manual page.
                     79:  */
                     80: 
1.1.1.2   root       81: #include "qemu-barrier.h" /* for smp_wmb() */
                     82: 
1.1       root       83: /*
                     84:  * List definitions.
                     85:  */
                     86: #define QLIST_HEAD(name, type)                                          \
                     87: struct name {                                                           \
                     88:         struct type *lh_first;  /* first element */                     \
                     89: }
                     90: 
                     91: #define QLIST_HEAD_INITIALIZER(head)                                    \
                     92:         { NULL }
                     93: 
                     94: #define QLIST_ENTRY(type)                                               \
                     95: struct {                                                                \
                     96:         struct type *le_next;   /* next element */                      \
                     97:         struct type **le_prev;  /* address of previous next element */  \
                     98: }
                     99: 
                    100: /*
                    101:  * List functions.
                    102:  */
                    103: #define QLIST_INIT(head) do {                                           \
                    104:         (head)->lh_first = NULL;                                        \
                    105: } while (/*CONSTCOND*/0)
                    106: 
                    107: #define QLIST_INSERT_AFTER(listelm, elm, field) do {                    \
                    108:         if (((elm)->field.le_next = (listelm)->field.le_next) != NULL)  \
                    109:                 (listelm)->field.le_next->field.le_prev =               \
                    110:                     &(elm)->field.le_next;                              \
                    111:         (listelm)->field.le_next = (elm);                               \
                    112:         (elm)->field.le_prev = &(listelm)->field.le_next;               \
                    113: } while (/*CONSTCOND*/0)
                    114: 
                    115: #define QLIST_INSERT_BEFORE(listelm, elm, field) do {                   \
                    116:         (elm)->field.le_prev = (listelm)->field.le_prev;                \
                    117:         (elm)->field.le_next = (listelm);                               \
                    118:         *(listelm)->field.le_prev = (elm);                              \
                    119:         (listelm)->field.le_prev = &(elm)->field.le_next;               \
                    120: } while (/*CONSTCOND*/0)
                    121: 
                    122: #define QLIST_INSERT_HEAD(head, elm, field) do {                        \
                    123:         if (((elm)->field.le_next = (head)->lh_first) != NULL)          \
                    124:                 (head)->lh_first->field.le_prev = &(elm)->field.le_next;\
                    125:         (head)->lh_first = (elm);                                       \
                    126:         (elm)->field.le_prev = &(head)->lh_first;                       \
                    127: } while (/*CONSTCOND*/0)
                    128: 
1.1.1.2   root      129: #define QLIST_INSERT_HEAD_RCU(head, elm, field) do {                    \
                    130:         (elm)->field.le_prev = &(head)->lh_first;                       \
                    131:         (elm)->field.le_next = (head)->lh_first;                        \
                    132:         smp_wmb(); /* fill elm before linking it */                     \
                    133:         if ((head)->lh_first != NULL)  {                                \
                    134:             (head)->lh_first->field.le_prev = &(elm)->field.le_next;    \
                    135:         }                                                               \
                    136:         (head)->lh_first = (elm);                                       \
                    137:         smp_wmb();                                                      \
                    138: } while (/* CONSTCOND*/0)
                    139: 
1.1       root      140: #define QLIST_REMOVE(elm, field) do {                                   \
                    141:         if ((elm)->field.le_next != NULL)                               \
                    142:                 (elm)->field.le_next->field.le_prev =                   \
                    143:                     (elm)->field.le_prev;                               \
                    144:         *(elm)->field.le_prev = (elm)->field.le_next;                   \
                    145: } while (/*CONSTCOND*/0)
                    146: 
                    147: #define QLIST_FOREACH(var, head, field)                                 \
                    148:         for ((var) = ((head)->lh_first);                                \
                    149:                 (var);                                                  \
                    150:                 (var) = ((var)->field.le_next))
                    151: 
                    152: #define QLIST_FOREACH_SAFE(var, head, field, next_var)                  \
                    153:         for ((var) = ((head)->lh_first);                                \
                    154:                 (var) && ((next_var) = ((var)->field.le_next), 1);      \
                    155:                 (var) = (next_var))
                    156: 
                    157: /*
                    158:  * List access methods.
                    159:  */
                    160: #define QLIST_EMPTY(head)                ((head)->lh_first == NULL)
                    161: #define QLIST_FIRST(head)                ((head)->lh_first)
                    162: #define QLIST_NEXT(elm, field)           ((elm)->field.le_next)
                    163: 
                    164: 
                    165: /*
1.1.1.3 ! root      166:  * Singly-linked List definitions.
        !           167:  */
        !           168: #define QSLIST_HEAD(name, type)                                          \
        !           169: struct name {                                                           \
        !           170:         struct type *slh_first; /* first element */                     \
        !           171: }
        !           172: 
        !           173: #define QSLIST_HEAD_INITIALIZER(head)                                    \
        !           174:         { NULL }
        !           175: 
        !           176: #define QSLIST_ENTRY(type)                                               \
        !           177: struct {                                                                \
        !           178:         struct type *sle_next;  /* next element */                      \
        !           179: }
        !           180: 
        !           181: /*
        !           182:  * Singly-linked List functions.
        !           183:  */
        !           184: #define QSLIST_INIT(head) do {                                           \
        !           185:         (head)->slh_first = NULL;                                       \
        !           186: } while (/*CONSTCOND*/0)
        !           187: 
        !           188: #define QSLIST_INSERT_AFTER(slistelm, elm, field) do {                   \
        !           189:         (elm)->field.sle_next = (slistelm)->field.sle_next;             \
        !           190:         (slistelm)->field.sle_next = (elm);                             \
        !           191: } while (/*CONSTCOND*/0)
        !           192: 
        !           193: #define QSLIST_INSERT_HEAD(head, elm, field) do {                        \
        !           194:         (elm)->field.sle_next = (head)->slh_first;                      \
        !           195:         (head)->slh_first = (elm);                                      \
        !           196: } while (/*CONSTCOND*/0)
        !           197: 
        !           198: #define QSLIST_REMOVE_HEAD(head, field) do {                             \
        !           199:         (head)->slh_first = (head)->slh_first->field.sle_next;          \
        !           200: } while (/*CONSTCOND*/0)
        !           201: 
        !           202: #define QSLIST_REMOVE_AFTER(slistelm, field) do {                        \
        !           203:         (slistelm)->field.sle_next =                                    \
        !           204:             QSLIST_NEXT(QSLIST_NEXT((slistelm), field), field);           \
        !           205: } while (/*CONSTCOND*/0)
        !           206: 
        !           207: #define QSLIST_FOREACH(var, head, field)                                 \
        !           208:         for((var) = (head)->slh_first; (var); (var) = (var)->field.sle_next)
        !           209: 
        !           210: #define QSLIST_FOREACH_SAFE(var, head, field, tvar)                      \
        !           211:         for ((var) = QSLIST_FIRST((head));                               \
        !           212:             (var) && ((tvar) = QSLIST_NEXT((var), field), 1);            \
        !           213:             (var) = (tvar))
        !           214: 
        !           215: /*
        !           216:  * Singly-linked List access methods.
        !           217:  */
        !           218: #define QSLIST_EMPTY(head)       ((head)->slh_first == NULL)
        !           219: #define QSLIST_FIRST(head)       ((head)->slh_first)
        !           220: #define QSLIST_NEXT(elm, field)  ((elm)->field.sle_next)
        !           221: 
        !           222: 
        !           223: /*
1.1       root      224:  * Simple queue definitions.
                    225:  */
                    226: #define QSIMPLEQ_HEAD(name, type)                                       \
                    227: struct name {                                                           \
                    228:     struct type *sqh_first;    /* first element */                      \
                    229:     struct type **sqh_last;    /* addr of last next element */          \
                    230: }
                    231: 
                    232: #define QSIMPLEQ_HEAD_INITIALIZER(head)                                 \
                    233:     { NULL, &(head).sqh_first }
                    234: 
                    235: #define QSIMPLEQ_ENTRY(type)                                            \
                    236: struct {                                                                \
                    237:     struct type *sqe_next;    /* next element */                        \
                    238: }
                    239: 
                    240: /*
                    241:  * Simple queue functions.
                    242:  */
                    243: #define QSIMPLEQ_INIT(head) do {                                        \
                    244:     (head)->sqh_first = NULL;                                           \
                    245:     (head)->sqh_last = &(head)->sqh_first;                              \
                    246: } while (/*CONSTCOND*/0)
                    247: 
                    248: #define QSIMPLEQ_INSERT_HEAD(head, elm, field) do {                     \
                    249:     if (((elm)->field.sqe_next = (head)->sqh_first) == NULL)            \
                    250:         (head)->sqh_last = &(elm)->field.sqe_next;                      \
                    251:     (head)->sqh_first = (elm);                                          \
                    252: } while (/*CONSTCOND*/0)
                    253: 
                    254: #define QSIMPLEQ_INSERT_TAIL(head, elm, field) do {                     \
                    255:     (elm)->field.sqe_next = NULL;                                       \
                    256:     *(head)->sqh_last = (elm);                                          \
                    257:     (head)->sqh_last = &(elm)->field.sqe_next;                          \
                    258: } while (/*CONSTCOND*/0)
                    259: 
                    260: #define QSIMPLEQ_INSERT_AFTER(head, listelm, elm, field) do {           \
                    261:     if (((elm)->field.sqe_next = (listelm)->field.sqe_next) == NULL)    \
                    262:         (head)->sqh_last = &(elm)->field.sqe_next;                      \
                    263:     (listelm)->field.sqe_next = (elm);                                  \
                    264: } while (/*CONSTCOND*/0)
                    265: 
                    266: #define QSIMPLEQ_REMOVE_HEAD(head, field) do {                          \
                    267:     if (((head)->sqh_first = (head)->sqh_first->field.sqe_next) == NULL)\
                    268:         (head)->sqh_last = &(head)->sqh_first;                          \
                    269: } while (/*CONSTCOND*/0)
                    270: 
                    271: #define QSIMPLEQ_REMOVE(head, elm, type, field) do {                    \
                    272:     if ((head)->sqh_first == (elm)) {                                   \
                    273:         QSIMPLEQ_REMOVE_HEAD((head), field);                            \
                    274:     } else {                                                            \
                    275:         struct type *curelm = (head)->sqh_first;                        \
                    276:         while (curelm->field.sqe_next != (elm))                         \
                    277:             curelm = curelm->field.sqe_next;                            \
                    278:         if ((curelm->field.sqe_next =                                   \
                    279:             curelm->field.sqe_next->field.sqe_next) == NULL)            \
                    280:                 (head)->sqh_last = &(curelm)->field.sqe_next;           \
                    281:     }                                                                   \
                    282: } while (/*CONSTCOND*/0)
                    283: 
                    284: #define QSIMPLEQ_FOREACH(var, head, field)                              \
                    285:     for ((var) = ((head)->sqh_first);                                   \
                    286:         (var);                                                          \
                    287:         (var) = ((var)->field.sqe_next))
                    288: 
                    289: #define QSIMPLEQ_FOREACH_SAFE(var, head, field, next)                   \
                    290:     for ((var) = ((head)->sqh_first);                                   \
                    291:         (var) && ((next = ((var)->field.sqe_next)), 1);                 \
                    292:         (var) = (next))
                    293: 
                    294: #define QSIMPLEQ_CONCAT(head1, head2) do {                              \
                    295:     if (!QSIMPLEQ_EMPTY((head2))) {                                     \
                    296:         *(head1)->sqh_last = (head2)->sqh_first;                        \
                    297:         (head1)->sqh_last = (head2)->sqh_last;                          \
                    298:         QSIMPLEQ_INIT((head2));                                         \
                    299:     }                                                                   \
                    300: } while (/*CONSTCOND*/0)
                    301: 
                    302: #define QSIMPLEQ_LAST(head, type, field)                                \
                    303:     (QSIMPLEQ_EMPTY((head)) ?                                           \
                    304:         NULL :                                                          \
                    305:             ((struct type *)(void *)                                    \
                    306:         ((char *)((head)->sqh_last) - offsetof(struct type, field))))
                    307: 
                    308: /*
                    309:  * Simple queue access methods.
                    310:  */
                    311: #define QSIMPLEQ_EMPTY(head)        ((head)->sqh_first == NULL)
                    312: #define QSIMPLEQ_FIRST(head)        ((head)->sqh_first)
                    313: #define QSIMPLEQ_NEXT(elm, field)   ((elm)->field.sqe_next)
                    314: 
                    315: 
                    316: /*
                    317:  * Tail queue definitions.
                    318:  */
                    319: #define Q_TAILQ_HEAD(name, type, qual)                                  \
                    320: struct name {                                                           \
                    321:         qual type *tqh_first;           /* first element */             \
                    322:         qual type *qual *tqh_last;      /* addr of last next element */ \
                    323: }
                    324: #define QTAILQ_HEAD(name, type)  Q_TAILQ_HEAD(name, struct type,)
                    325: 
                    326: #define QTAILQ_HEAD_INITIALIZER(head)                                   \
                    327:         { NULL, &(head).tqh_first }
                    328: 
                    329: #define Q_TAILQ_ENTRY(type, qual)                                       \
                    330: struct {                                                                \
                    331:         qual type *tqe_next;            /* next element */              \
                    332:         qual type *qual *tqe_prev;      /* address of previous next element */\
                    333: }
                    334: #define QTAILQ_ENTRY(type)       Q_TAILQ_ENTRY(struct type,)
                    335: 
                    336: /*
                    337:  * Tail queue functions.
                    338:  */
                    339: #define QTAILQ_INIT(head) do {                                          \
                    340:         (head)->tqh_first = NULL;                                       \
                    341:         (head)->tqh_last = &(head)->tqh_first;                          \
                    342: } while (/*CONSTCOND*/0)
                    343: 
                    344: #define QTAILQ_INSERT_HEAD(head, elm, field) do {                       \
                    345:         if (((elm)->field.tqe_next = (head)->tqh_first) != NULL)        \
                    346:                 (head)->tqh_first->field.tqe_prev =                     \
                    347:                     &(elm)->field.tqe_next;                             \
                    348:         else                                                            \
                    349:                 (head)->tqh_last = &(elm)->field.tqe_next;              \
                    350:         (head)->tqh_first = (elm);                                      \
                    351:         (elm)->field.tqe_prev = &(head)->tqh_first;                     \
                    352: } while (/*CONSTCOND*/0)
                    353: 
                    354: #define QTAILQ_INSERT_TAIL(head, elm, field) do {                       \
                    355:         (elm)->field.tqe_next = NULL;                                   \
                    356:         (elm)->field.tqe_prev = (head)->tqh_last;                       \
                    357:         *(head)->tqh_last = (elm);                                      \
                    358:         (head)->tqh_last = &(elm)->field.tqe_next;                      \
                    359: } while (/*CONSTCOND*/0)
                    360: 
                    361: #define QTAILQ_INSERT_AFTER(head, listelm, elm, field) do {             \
                    362:         if (((elm)->field.tqe_next = (listelm)->field.tqe_next) != NULL)\
                    363:                 (elm)->field.tqe_next->field.tqe_prev =                 \
                    364:                     &(elm)->field.tqe_next;                             \
                    365:         else                                                            \
                    366:                 (head)->tqh_last = &(elm)->field.tqe_next;              \
                    367:         (listelm)->field.tqe_next = (elm);                              \
                    368:         (elm)->field.tqe_prev = &(listelm)->field.tqe_next;             \
                    369: } while (/*CONSTCOND*/0)
                    370: 
                    371: #define QTAILQ_INSERT_BEFORE(listelm, elm, field) do {                  \
                    372:         (elm)->field.tqe_prev = (listelm)->field.tqe_prev;              \
                    373:         (elm)->field.tqe_next = (listelm);                              \
                    374:         *(listelm)->field.tqe_prev = (elm);                             \
                    375:         (listelm)->field.tqe_prev = &(elm)->field.tqe_next;             \
                    376: } while (/*CONSTCOND*/0)
                    377: 
                    378: #define QTAILQ_REMOVE(head, elm, field) do {                            \
                    379:         if (((elm)->field.tqe_next) != NULL)                            \
                    380:                 (elm)->field.tqe_next->field.tqe_prev =                 \
                    381:                     (elm)->field.tqe_prev;                              \
                    382:         else                                                            \
                    383:                 (head)->tqh_last = (elm)->field.tqe_prev;               \
                    384:         *(elm)->field.tqe_prev = (elm)->field.tqe_next;                 \
                    385: } while (/*CONSTCOND*/0)
                    386: 
                    387: #define QTAILQ_FOREACH(var, head, field)                                \
                    388:         for ((var) = ((head)->tqh_first);                               \
                    389:                 (var);                                                  \
                    390:                 (var) = ((var)->field.tqe_next))
                    391: 
                    392: #define QTAILQ_FOREACH_SAFE(var, head, field, next_var)                 \
                    393:         for ((var) = ((head)->tqh_first);                               \
                    394:                 (var) && ((next_var) = ((var)->field.tqe_next), 1);     \
                    395:                 (var) = (next_var))
                    396: 
                    397: #define QTAILQ_FOREACH_REVERSE(var, head, headname, field)              \
                    398:         for ((var) = (*(((struct headname *)((head)->tqh_last))->tqh_last));    \
                    399:                 (var);                                                  \
                    400:                 (var) = (*(((struct headname *)((var)->field.tqe_prev))->tqh_last)))
                    401: 
                    402: /*
                    403:  * Tail queue access methods.
                    404:  */
                    405: #define QTAILQ_EMPTY(head)               ((head)->tqh_first == NULL)
                    406: #define QTAILQ_FIRST(head)               ((head)->tqh_first)
                    407: #define QTAILQ_NEXT(elm, field)          ((elm)->field.tqe_next)
                    408: 
                    409: #define QTAILQ_LAST(head, headname) \
                    410:         (*(((struct headname *)((head)->tqh_last))->tqh_last))
                    411: #define QTAILQ_PREV(elm, headname, field) \
                    412:         (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last))
                    413: 
                    414: #endif  /* !QEMU_SYS_QUEUE_H_ */

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