The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]

FreeBSD/Linux Kernel Cross Reference
sys/sys/queue.h

Version: -  FREEBSD  -  FREEBSD-12-STABLE  -  FREEBSD-12-0  -  FREEBSD-11-STABLE  -  FREEBSD-11-2  -  FREEBSD-11-1  -  FREEBSD-11-0  -  FREEBSD-10-STABLE  -  FREEBSD-10-4  -  FREEBSD-10-3  -  FREEBSD-10-2  -  FREEBSD-10-1  -  FREEBSD-10-0  -  FREEBSD-9-STABLE  -  FREEBSD-9-3  -  FREEBSD-9-2  -  FREEBSD-9-1  -  FREEBSD-9-0  -  FREEBSD-8-STABLE  -  FREEBSD-8-4  -  FREEBSD-8-3  -  FREEBSD-8-2  -  FREEBSD-8-1  -  FREEBSD-8-0  -  FREEBSD-7-STABLE  -  FREEBSD-7-4  -  FREEBSD-7-3  -  FREEBSD-7-2  -  FREEBSD-7-1  -  FREEBSD-7-0  -  FREEBSD-6-STABLE  -  FREEBSD-6-4  -  FREEBSD-6-3  -  FREEBSD-6-2  -  FREEBSD-6-1  -  FREEBSD-6-0  -  FREEBSD-5-STABLE  -  FREEBSD-5-5  -  FREEBSD-5-4  -  FREEBSD-5-3  -  FREEBSD-5-2  -  FREEBSD-5-1  -  FREEBSD-5-0  -  FREEBSD-4-STABLE  -  FREEBSD-3-STABLE  -  FREEBSD22  -  linux-2.6  -  linux-2.4.22  -  MK83  -  MK84  -  PLAN9  -  DFBSD  -  NETBSD  -  NETBSD5  -  NETBSD4  -  NETBSD3  -  NETBSD20  -  OPENBSD  -  xnu-517  -  xnu-792  -  xnu-792.6.70  -  xnu-1228  -  xnu-1456.1.26  -  xnu-1699.24.8  -  xnu-2050.18.24  -  OPENSOLARIS  -  minix-3-1-1 
SearchContext: -  none  -  3  -  10 

    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  * 3. All advertising materials mentioning features or use of this software
   14  *    must display the following acknowledgement:
   15  *      This product includes software developed by the University of
   16  *      California, Berkeley and its contributors.
   17  * 4. Neither the name of the University nor the names of its contributors
   18  *    may be used to endorse or promote products derived from this software
   19  *    without specific prior written permission.
   20  *
   21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   31  * SUCH DAMAGE.
   32  *
   33  *      @(#)queue.h     8.5 (Berkeley) 8/20/94
   34  * $FreeBSD: releng/5.0/sys/sys/queue.h 101351 2002-08-05 05:18:43Z alfred $
   35  */
   36 
   37 #ifndef _SYS_QUEUE_H_
   38 #define _SYS_QUEUE_H_
   39 
   40 #include <sys/cdefs.h>
   41 
   42 /*
   43  * This file defines four types of data structures: singly-linked lists,
   44  * singly-linked tail queues, lists and tail queues.
   45  *
   46  * A singly-linked list is headed by a single forward pointer. The elements
   47  * are singly linked for minimum space and pointer manipulation overhead at
   48  * the expense of O(n) removal for arbitrary elements. New elements can be
   49  * added to the list after an existing element or at the head of the list.
   50  * Elements being removed from the head of the list should use the explicit
   51  * macro for this purpose for optimum efficiency. A singly-linked list may
   52  * only be traversed in the forward direction.  Singly-linked lists are ideal
   53  * for applications with large datasets and few or no removals or for
   54  * implementing a LIFO queue.
   55  *
   56  * A singly-linked tail queue is headed by a pair of pointers, one to the
   57  * head of the list and the other to the tail of the list. The elements are
   58  * singly linked for minimum space and pointer manipulation overhead at the
   59  * expense of O(n) removal for arbitrary elements. New elements can be added
   60  * to the list after an existing element, at the head of the list, or at the
   61  * end of the list. Elements being removed from the head of the tail queue
   62  * should use the explicit macro for this purpose for optimum efficiency.
   63  * A singly-linked tail queue may only be traversed in the forward direction.
   64  * Singly-linked tail queues are ideal for applications with large datasets
   65  * and few or no removals or for implementing a FIFO queue.
   66  *
   67  * A list is headed by a single forward pointer (or an array of forward
   68  * pointers for a hash table header). The elements are doubly linked
   69  * so that an arbitrary element can be removed without a need to
   70  * traverse the list. New elements can be added to the list before
   71  * or after an existing element or at the head of the list. A list
   72  * may only be traversed in the forward direction.
   73  *
   74  * A tail queue is headed by a pair of pointers, one to the head of the
   75  * list and the other to the tail of the list. The elements are doubly
   76  * linked so that an arbitrary element can be removed without a need to
   77  * traverse the list. New elements can be added to the list before or
   78  * after an existing element, at the head of the list, or at the end of
   79  * the list. A tail queue may be traversed in either direction.
   80  *
   81  * For details on the use of these macros, see the queue(3) manual page.
   82  *
   83  *
   84  *                      SLIST   LIST    STAILQ  TAILQ
   85  * _HEAD                +       +       +       +
   86  * _HEAD_INITIALIZER    +       +       +       +
   87  * _ENTRY               +       +       +       +
   88  * _INIT                +       +       +       +
   89  * _EMPTY               +       +       +       +
   90  * _FIRST               +       +       +       +
   91  * _NEXT                +       +       +       +
   92  * _PREV                -       -       -       +
   93  * _LAST                -       -       +       +
   94  * _FOREACH             +       +       +       +
   95  * _FOREACH_REVERSE     -       -       -       +
   96  * _INSERT_HEAD         +       +       +       +
   97  * _INSERT_BEFORE       -       +       -       +
   98  * _INSERT_AFTER        +       +       +       +
   99  * _INSERT_TAIL         -       -       +       +
  100  * _CONCAT              -       -       +       +
  101  * _REMOVE_HEAD         +       -       +       -
  102  * _REMOVE              +       +       +       +
  103  *
  104  */
  105 #define QUEUE_MACRO_DEBUG 0
  106 #if QUEUE_MACRO_DEBUG
  107 /* Store the last 2 places the queue element or head was altered */
  108 struct qm_trace {
  109         char * lastfile;
  110         int lastline;
  111         char * prevfile;
  112         int prevline;
  113 };
  114 
  115 #define TRACEBUF        struct qm_trace trace;
  116 #define TRASHIT(x)      do {(x) = (void *)-1;} while (0)
  117 
  118 #define 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 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 QMD_TRACE_ELEM(elem)
  134 #define QMD_TRACE_HEAD(head)
  135 #define TRACEBUF
  136 #define TRASHIT(x)
  137 #endif  /* QUEUE_MACRO_DEBUG */
  138 
  139 /*
  140  * Singly-linked List declarations.
  141  */
  142 #define SLIST_HEAD(name, type)                                          \
  143 struct name {                                                           \
  144         struct type *slh_first; /* first element */                     \
  145 }
  146 
  147 #define SLIST_HEAD_INITIALIZER(head)                                    \
  148         { NULL }
  149  
  150 #define SLIST_ENTRY(type)                                               \
  151 struct {                                                                \
  152         struct type *sle_next;  /* next element */                      \
  153 }
  154  
  155 /*
  156  * Singly-linked List functions.
  157  */
  158 #define SLIST_EMPTY(head)       ((head)->slh_first == NULL)
  159 
  160 #define SLIST_FIRST(head)       ((head)->slh_first)
  161 
  162 #define SLIST_FOREACH(var, head, field)                                 \
  163         for ((var) = SLIST_FIRST((head));                               \
  164             (var);                                                      \
  165             (var) = SLIST_NEXT((var), field))
  166 
  167 #define SLIST_FOREACH_PREVPTR(var, varp, head, field)                   \
  168         for ((varp) = &SLIST_FIRST((head));                             \
  169             ((var) = *(varp)) != NULL;                                  \
  170             (varp) = &SLIST_NEXT((var), field))
  171 
  172 #define SLIST_INIT(head) do {                                           \
  173         SLIST_FIRST((head)) = NULL;                                     \
  174 } while (0)
  175 
  176 #define SLIST_INSERT_AFTER(slistelm, elm, field) do {                   \
  177         SLIST_NEXT((elm), field) = SLIST_NEXT((slistelm), field);       \
  178         SLIST_NEXT((slistelm), field) = (elm);                          \
  179 } while (0)
  180 
  181 #define SLIST_INSERT_HEAD(head, elm, field) do {                        \
  182         SLIST_NEXT((elm), field) = SLIST_FIRST((head));                 \
  183         SLIST_FIRST((head)) = (elm);                                    \
  184 } while (0)
  185 
  186 #define SLIST_NEXT(elm, field)  ((elm)->field.sle_next)
  187 
  188 #define SLIST_REMOVE(head, elm, type, field) do {                       \
  189         if (SLIST_FIRST((head)) == (elm)) {                             \
  190                 SLIST_REMOVE_HEAD((head), field);                       \
  191         }                                                               \
  192         else {                                                          \
  193                 struct type *curelm = SLIST_FIRST((head));              \
  194                 while (SLIST_NEXT(curelm, field) != (elm))              \
  195                         curelm = SLIST_NEXT(curelm, field);             \
  196                 SLIST_NEXT(curelm, field) =                             \
  197                     SLIST_NEXT(SLIST_NEXT(curelm, field), field);       \
  198         }                                                               \
  199 } while (0)
  200 
  201 #define SLIST_REMOVE_HEAD(head, field) do {                             \
  202         SLIST_FIRST((head)) = SLIST_NEXT(SLIST_FIRST((head)), field);   \
  203 } while (0)
  204 
  205 /*
  206  * Singly-linked Tail queue declarations.
  207  */
  208 #define STAILQ_HEAD(name, type)                                         \
  209 struct name {                                                           \
  210         struct type *stqh_first;/* first element */                     \
  211         struct type **stqh_last;/* addr of last next element */         \
  212 }
  213 
  214 #define STAILQ_HEAD_INITIALIZER(head)                                   \
  215         { NULL, &(head).stqh_first }
  216 
  217 #define STAILQ_ENTRY(type)                                              \
  218 struct {                                                                \
  219         struct type *stqe_next; /* next element */                      \
  220 }
  221 
  222 /*
  223  * Singly-linked Tail queue functions.
  224  */
  225 #define STAILQ_CONCAT(head1, head2) do {                                \
  226         if (!STAILQ_EMPTY((head2))) {                                   \
  227                 *(head1)->stqh_last = (head2)->stqh_first;              \
  228                 (head1)->stqh_last = (head2)->stqh_last;                \
  229                 STAILQ_INIT((head2));                                   \
  230         }                                                               \
  231 } while (0)
  232 
  233 #define STAILQ_EMPTY(head)      ((head)->stqh_first == NULL)
  234 
  235 #define STAILQ_FIRST(head)      ((head)->stqh_first)
  236 
  237 #define STAILQ_FOREACH(var, head, field)                                \
  238         for((var) = STAILQ_FIRST((head));                               \
  239            (var);                                                       \
  240            (var) = STAILQ_NEXT((var), field))
  241 
  242 #define STAILQ_INIT(head) do {                                          \
  243         STAILQ_FIRST((head)) = NULL;                                    \
  244         (head)->stqh_last = &STAILQ_FIRST((head));                      \
  245 } while (0)
  246 
  247 #define STAILQ_INSERT_AFTER(head, tqelm, elm, field) do {               \
  248         if ((STAILQ_NEXT((elm), field) = STAILQ_NEXT((tqelm), field)) == NULL)\
  249                 (head)->stqh_last = &STAILQ_NEXT((elm), field);         \
  250         STAILQ_NEXT((tqelm), field) = (elm);                            \
  251 } while (0)
  252 
  253 #define STAILQ_INSERT_HEAD(head, elm, field) do {                       \
  254         if ((STAILQ_NEXT((elm), field) = STAILQ_FIRST((head))) == NULL) \
  255                 (head)->stqh_last = &STAILQ_NEXT((elm), field);         \
  256         STAILQ_FIRST((head)) = (elm);                                   \
  257 } while (0)
  258 
  259 #define STAILQ_INSERT_TAIL(head, elm, field) do {                       \
  260         STAILQ_NEXT((elm), field) = NULL;                               \
  261         *(head)->stqh_last = (elm);                                     \
  262         (head)->stqh_last = &STAILQ_NEXT((elm), field);                 \
  263 } while (0)
  264 
  265 #define STAILQ_LAST(head, type, field)                                  \
  266         (STAILQ_EMPTY((head)) ?                                         \
  267                 NULL :                                                  \
  268                 ((struct type *)                                        \
  269                 ((char *)((head)->stqh_last) - __offsetof(struct type, field))))
  270 
  271 #define STAILQ_NEXT(elm, field) ((elm)->field.stqe_next)
  272 
  273 #define STAILQ_REMOVE(head, elm, type, field) do {                      \
  274         if (STAILQ_FIRST((head)) == (elm)) {                            \
  275                 STAILQ_REMOVE_HEAD((head), field);                      \
  276         }                                                               \
  277         else {                                                          \
  278                 struct type *curelm = STAILQ_FIRST((head));             \
  279                 while (STAILQ_NEXT(curelm, field) != (elm))             \
  280                         curelm = STAILQ_NEXT(curelm, field);            \
  281                 if ((STAILQ_NEXT(curelm, field) =                       \
  282                      STAILQ_NEXT(STAILQ_NEXT(curelm, field), field)) == NULL)\
  283                         (head)->stqh_last = &STAILQ_NEXT((curelm), field);\
  284         }                                                               \
  285 } while (0)
  286 
  287 #define STAILQ_REMOVE_HEAD(head, field) do {                            \
  288         if ((STAILQ_FIRST((head)) =                                     \
  289              STAILQ_NEXT(STAILQ_FIRST((head)), field)) == NULL)         \
  290                 (head)->stqh_last = &STAILQ_FIRST((head));              \
  291 } while (0)
  292 
  293 #define STAILQ_REMOVE_HEAD_UNTIL(head, elm, field) do {                 \
  294         if ((STAILQ_FIRST((head)) = STAILQ_NEXT((elm), field)) == NULL) \
  295                 (head)->stqh_last = &STAILQ_FIRST((head));              \
  296 } while (0)
  297 
  298 /*
  299  * List declarations.
  300  */
  301 #define LIST_HEAD(name, type)                                           \
  302 struct name {                                                           \
  303         struct type *lh_first;  /* first element */                     \
  304 }
  305 
  306 #define LIST_HEAD_INITIALIZER(head)                                     \
  307         { NULL }
  308 
  309 #define LIST_ENTRY(type)                                                \
  310 struct {                                                                \
  311         struct type *le_next;   /* next element */                      \
  312         struct type **le_prev;  /* address of previous next element */  \
  313 }
  314 
  315 /*
  316  * List functions.
  317  */
  318 
  319 #define LIST_EMPTY(head)        ((head)->lh_first == NULL)
  320 
  321 #define LIST_FIRST(head)        ((head)->lh_first)
  322 
  323 #define LIST_FOREACH(var, head, field)                                  \
  324         for ((var) = LIST_FIRST((head));                                \
  325             (var);                                                      \
  326             (var) = LIST_NEXT((var), field))
  327 
  328 #define LIST_INIT(head) do {                                            \
  329         LIST_FIRST((head)) = NULL;                                      \
  330 } while (0)
  331 
  332 #define LIST_INSERT_AFTER(listelm, elm, field) do {                     \
  333         if ((LIST_NEXT((elm), field) = LIST_NEXT((listelm), field)) != NULL)\
  334                 LIST_NEXT((listelm), field)->field.le_prev =            \
  335                     &LIST_NEXT((elm), field);                           \
  336         LIST_NEXT((listelm), field) = (elm);                            \
  337         (elm)->field.le_prev = &LIST_NEXT((listelm), field);            \
  338 } while (0)
  339 
  340 #define LIST_INSERT_BEFORE(listelm, elm, field) do {                    \
  341         (elm)->field.le_prev = (listelm)->field.le_prev;                \
  342         LIST_NEXT((elm), field) = (listelm);                            \
  343         *(listelm)->field.le_prev = (elm);                              \
  344         (listelm)->field.le_prev = &LIST_NEXT((elm), field);            \
  345 } while (0)
  346 
  347 #define LIST_INSERT_HEAD(head, elm, field) do {                         \
  348         if ((LIST_NEXT((elm), field) = LIST_FIRST((head))) != NULL)     \
  349                 LIST_FIRST((head))->field.le_prev = &LIST_NEXT((elm), field);\
  350         LIST_FIRST((head)) = (elm);                                     \
  351         (elm)->field.le_prev = &LIST_FIRST((head));                     \
  352 } while (0)
  353 
  354 #define LIST_NEXT(elm, field)   ((elm)->field.le_next)
  355 
  356 #define LIST_REMOVE(elm, field) do {                                    \
  357         if (LIST_NEXT((elm), field) != NULL)                            \
  358                 LIST_NEXT((elm), field)->field.le_prev =                \
  359                     (elm)->field.le_prev;                               \
  360         *(elm)->field.le_prev = LIST_NEXT((elm), field);                \
  361 } while (0)
  362 
  363 /*
  364  * Tail queue declarations.
  365  */
  366 #define TAILQ_HEAD(name, type)                                          \
  367 struct name {                                                           \
  368         struct type *tqh_first; /* first element */                     \
  369         struct type **tqh_last; /* addr of last next element */         \
  370         TRACEBUF                                                        \
  371 }
  372 
  373 #define TAILQ_HEAD_INITIALIZER(head)                                    \
  374         { NULL, &(head).tqh_first }
  375 
  376 #define TAILQ_ENTRY(type)                                               \
  377 struct {                                                                \
  378         struct type *tqe_next;  /* next element */                      \
  379         struct type **tqe_prev; /* address of previous next element */  \
  380         TRACEBUF                                                        \
  381 }
  382 
  383 /*
  384  * Tail queue functions.
  385  */
  386 #define TAILQ_CONCAT(head1, head2, field) do {                          \
  387         if (!TAILQ_EMPTY(head2)) {                                      \
  388                 *(head1)->tqh_last = (head2)->tqh_first;                \
  389                 (head2)->tqh_first->field.tqe_prev = (head1)->tqh_last; \
  390                 (head1)->tqh_last = (head2)->tqh_last;                  \
  391                 TAILQ_INIT((head2));                                    \
  392                 QMD_TRACE_HEAD(head);                                   \
  393                 QMD_TRACE_HEAD(head2);                                  \
  394         }                                                               \
  395 } while (0)
  396 
  397 #define TAILQ_EMPTY(head)       ((head)->tqh_first == NULL)
  398 
  399 #define TAILQ_FIRST(head)       ((head)->tqh_first)
  400 
  401 #define TAILQ_FOREACH(var, head, field)                                 \
  402         for ((var) = TAILQ_FIRST((head));                               \
  403             (var);                                                      \
  404             (var) = TAILQ_NEXT((var), field))
  405 
  406 #define TAILQ_FOREACH_REVERSE(var, head, headname, field)               \
  407         for ((var) = TAILQ_LAST((head), headname);                      \
  408             (var);                                                      \
  409             (var) = TAILQ_PREV((var), headname, field))
  410 
  411 #define TAILQ_INIT(head) do {                                           \
  412         TAILQ_FIRST((head)) = NULL;                                     \
  413         (head)->tqh_last = &TAILQ_FIRST((head));                        \
  414         QMD_TRACE_HEAD(head);                                           \
  415 } while (0)
  416 
  417 #define TAILQ_INSERT_AFTER(head, listelm, elm, field) do {              \
  418         if ((TAILQ_NEXT((elm), field) = TAILQ_NEXT((listelm), field)) != NULL)\
  419                 TAILQ_NEXT((elm), field)->field.tqe_prev =              \
  420                     &TAILQ_NEXT((elm), field);                          \
  421         else {                                                          \
  422                 (head)->tqh_last = &TAILQ_NEXT((elm), field);           \
  423                 QMD_TRACE_HEAD(head);                                   \
  424         }                                                               \
  425         TAILQ_NEXT((listelm), field) = (elm);                           \
  426         (elm)->field.tqe_prev = &TAILQ_NEXT((listelm), field);          \
  427         QMD_TRACE_ELEM(&(elm)->field);                                  \
  428         QMD_TRACE_ELEM(&listelm->field);                                \
  429 } while (0)
  430 
  431 #define TAILQ_INSERT_BEFORE(listelm, elm, field) do {                   \
  432         (elm)->field.tqe_prev = (listelm)->field.tqe_prev;              \
  433         TAILQ_NEXT((elm), field) = (listelm);                           \
  434         *(listelm)->field.tqe_prev = (elm);                             \
  435         (listelm)->field.tqe_prev = &TAILQ_NEXT((elm), field);          \
  436         QMD_TRACE_ELEM(&(elm)->field);                                  \
  437         QMD_TRACE_ELEM(&listelm->field);                                \
  438 } while (0)
  439 
  440 #define TAILQ_INSERT_HEAD(head, elm, field) do {                        \
  441         if ((TAILQ_NEXT((elm), field) = TAILQ_FIRST((head))) != NULL)   \
  442                 TAILQ_FIRST((head))->field.tqe_prev =                   \
  443                     &TAILQ_NEXT((elm), field);                          \
  444         else                                                            \
  445                 (head)->tqh_last = &TAILQ_NEXT((elm), field);           \
  446         TAILQ_FIRST((head)) = (elm);                                    \
  447         (elm)->field.tqe_prev = &TAILQ_FIRST((head));                   \
  448         QMD_TRACE_HEAD(head);                                           \
  449         QMD_TRACE_ELEM(&(elm)->field);                                  \
  450 } while (0)
  451 
  452 #define TAILQ_INSERT_TAIL(head, elm, field) do {                        \
  453         TAILQ_NEXT((elm), field) = NULL;                                \
  454         (elm)->field.tqe_prev = (head)->tqh_last;                       \
  455         *(head)->tqh_last = (elm);                                      \
  456         (head)->tqh_last = &TAILQ_NEXT((elm), field);                   \
  457         QMD_TRACE_HEAD(head);                                           \
  458         QMD_TRACE_ELEM(&(elm)->field);                                  \
  459 } while (0)
  460 
  461 #define TAILQ_LAST(head, headname)                                      \
  462         (*(((struct headname *)((head)->tqh_last))->tqh_last))
  463 
  464 #define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next)
  465 
  466 #define TAILQ_PREV(elm, headname, field)                                \
  467         (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last))
  468 
  469 #define TAILQ_REMOVE(head, elm, field) do {                             \
  470         if ((TAILQ_NEXT((elm), field)) != NULL)                         \
  471                 TAILQ_NEXT((elm), field)->field.tqe_prev =              \
  472                     (elm)->field.tqe_prev;                              \
  473         else {                                                          \
  474                 (head)->tqh_last = (elm)->field.tqe_prev;               \
  475                 QMD_TRACE_HEAD(head);                                   \
  476         }                                                               \
  477         *(elm)->field.tqe_prev = TAILQ_NEXT((elm), field);              \
  478         TRASHIT((elm)->field.tqe_next);                                 \
  479         TRASHIT((elm)->field.tqe_prev);                                 \
  480         QMD_TRACE_ELEM(&(elm)->field);                                  \
  481 } while (0)
  482 
  483 
  484 #ifdef _KERNEL
  485 
  486 /*
  487  * XXX insque() and remque() are an old way of handling certain queues.
  488  * They bogusly assumes that all queue heads look alike.
  489  */
  490 
  491 struct quehead {
  492         struct quehead *qh_link;
  493         struct quehead *qh_rlink;
  494 };
  495 
  496 #ifdef  __GNUC__
  497 
  498 static __inline void
  499 insque(void *a, void *b)
  500 {
  501         struct quehead *element = (struct quehead *)a,
  502                  *head = (struct quehead *)b;
  503 
  504         element->qh_link = head->qh_link;
  505         element->qh_rlink = head;
  506         head->qh_link = element;
  507         element->qh_link->qh_rlink = element;
  508 }
  509 
  510 static __inline void
  511 remque(void *a)
  512 {
  513         struct quehead *element = (struct quehead *)a;
  514 
  515         element->qh_link->qh_rlink = element->qh_rlink;
  516         element->qh_rlink->qh_link = element->qh_link;
  517         element->qh_rlink = 0;
  518 }
  519 
  520 #else /* !__GNUC__ */
  521 
  522 void    insque(void *a, void *b);
  523 void    remque(void *a);
  524 
  525 #endif /* __GNUC__ */
  526 
  527 #endif /* _KERNEL */
  528 
  529 #endif /* !_SYS_QUEUE_H_ */

Cache object: 0a4b7af35a5686ef42a0b2930074f945


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]


This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.