File:  [Qemu by Fabrice Bellard] / qemu / qemu-queue.h
Revision 1.1.1.3 (vendor branch): download - view: text, annotated - select for diffs
Tue Apr 24 19:34:34 2018 UTC (2 years, 3 months ago) by root
Branches: qemu, MAIN
CVS tags: qemu1101, HEAD
qemu 1.1.1

    1: /*      $NetBSD: queue.h,v 1.52 2009/04/20 09:56:08 mschuett Exp $ */
    2: 
    3: /*
    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.
    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: /*
   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.
   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: 
   81: #include "qemu-barrier.h" /* for smp_wmb() */
   82: 
   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: 
  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: 
  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: /*
  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: /*
  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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