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  -  FREEBSD11  -  FREEBSD10  -  FREEBSD9  -  FREEBSD92  -  FREEBSD91  -  FREEBSD90  -  FREEBSD8  -  FREEBSD82  -  FREEBSD81  -  FREEBSD80  -  FREEBSD7  -  FREEBSD74  -  FREEBSD73  -  FREEBSD72  -  FREEBSD71  -  FREEBSD70  -  FREEBSD6  -  FREEBSD64  -  FREEBSD63  -  FREEBSD62  -  FREEBSD61  -  FREEBSD60  -  FREEBSD5  -  FREEBSD55  -  FREEBSD54  -  FREEBSD53  -  FREEBSD52  -  FREEBSD51  -  FREEBSD50  -  FREEBSD4  -  FREEBSD3  -  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  * SPDX-License-Identifier: BSD-3-Clause
    3  *
    4  * Copyright (c) 1991, 1993
    5  *      The Regents of the University of California.  All rights reserved.
    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  * 3. 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: head/sys/sys/queue.h 339969 2018-10-31 19:37:11Z glebius $
   33  */
   34 
   35 #ifndef _SYS_QUEUE_H_
   36 #define _SYS_QUEUE_H_
   37 
   38 #include <sys/cdefs.h>
   39 
   40 /*
   41  * This file defines four types of data structures: singly-linked lists,
   42  * singly-linked tail queues, lists and tail queues.
   43  *
   44  * A singly-linked list is headed by a single forward pointer. The elements
   45  * are singly linked for minimum space and pointer manipulation overhead at
   46  * the expense of O(n) removal for arbitrary elements. New elements can be
   47  * added to the list after an existing element or at the head of the list.
   48  * Elements being removed from the head of the list should use the explicit
   49  * macro for this purpose for optimum efficiency. A singly-linked list may
   50  * only be traversed in the forward direction.  Singly-linked lists are ideal
   51  * for applications with large datasets and few or no removals or for
   52  * implementing a LIFO queue.
   53  *
   54  * A singly-linked tail queue is headed by a pair of pointers, one to the
   55  * head of the list and the other to the tail of the list. The elements are
   56  * singly linked for minimum space and pointer manipulation overhead at the
   57  * expense of O(n) removal for arbitrary elements. New elements can be added
   58  * to the list after an existing element, at the head of the list, or at the
   59  * end of the list. Elements being removed from the head of the tail queue
   60  * should use the explicit macro for this purpose for optimum efficiency.
   61  * A singly-linked tail queue may only be traversed in the forward direction.
   62  * Singly-linked tail queues are ideal for applications with large datasets
   63  * and few or no removals or for implementing a FIFO queue.
   64  *
   65  * A list is headed by a single forward pointer (or an array of forward
   66  * pointers for a hash table header). The elements are doubly linked
   67  * so that an arbitrary element can be removed without a need to
   68  * traverse the list. New elements can be added to the list before
   69  * or after an existing element or at the head of the list. A list
   70  * may be traversed in either direction.
   71  *
   72  * A tail queue is headed by a pair of pointers, one to the head of the
   73  * list and the other to the tail of the list. The elements are doubly
   74  * linked so that an arbitrary element can be removed without a need to
   75  * traverse the list. New elements can be added to the list before or
   76  * after an existing element, at the head of the list, or at the end of
   77  * the list. A tail queue may be traversed in either direction.
   78  *
   79  * For details on the use of these macros, see the queue(3) manual page.
   80  *
   81  * Below is a summary of implemented functions where:
   82  *  +  means the macro is available
   83  *  -  means the macro is not available
   84  *  s  means the macro is available but is slow (runs in O(n) time)
   85  *
   86  *                              SLIST   LIST    STAILQ  TAILQ
   87  * _HEAD                        +       +       +       +
   88  * _CLASS_HEAD                  +       +       +       +
   89  * _HEAD_INITIALIZER            +       +       +       +
   90  * _ENTRY                       +       +       +       +
   91  * _CLASS_ENTRY                 +       +       +       +
   92  * _INIT                        +       +       +       +
   93  * _EMPTY                       +       +       +       +
   94  * _FIRST                       +       +       +       +
   95  * _NEXT                        +       +       +       +
   96  * _PREV                        -       +       -       +
   97  * _LAST                        -       -       +       +
   98  * _LAST_FAST                   -       -       -       +
   99  * _FOREACH                     +       +       +       +
  100  * _FOREACH_FROM                +       +       +       +
  101  * _FOREACH_SAFE                +       +       +       +
  102  * _FOREACH_FROM_SAFE           +       +       +       +
  103  * _FOREACH_REVERSE             -       -       -       +
  104  * _FOREACH_REVERSE_FROM        -       -       -       +
  105  * _FOREACH_REVERSE_SAFE        -       -       -       +
  106  * _FOREACH_REVERSE_FROM_SAFE   -       -       -       +
  107  * _INSERT_HEAD                 +       +       +       +
  108  * _INSERT_BEFORE               -       +       -       +
  109  * _INSERT_AFTER                +       +       +       +
  110  * _INSERT_TAIL                 -       -       +       +
  111  * _CONCAT                      s       s       +       +
  112  * _REMOVE_AFTER                +       -       +       -
  113  * _REMOVE_HEAD                 +       -       +       -
  114  * _REMOVE                      s       +       s       +
  115  * _SWAP                        +       +       +       +
  116  *
  117  */
  118 #ifdef QUEUE_MACRO_DEBUG
  119 #warn Use QUEUE_MACRO_DEBUG_TRACE and/or QUEUE_MACRO_DEBUG_TRASH
  120 #define QUEUE_MACRO_DEBUG_TRACE
  121 #define QUEUE_MACRO_DEBUG_TRASH
  122 #endif
  123 
  124 #ifdef QUEUE_MACRO_DEBUG_TRACE
  125 /* Store the last 2 places the queue element or head was altered */
  126 struct qm_trace {
  127         unsigned long    lastline;
  128         unsigned long    prevline;
  129         const char      *lastfile;
  130         const char      *prevfile;
  131 };
  132 
  133 #define TRACEBUF        struct qm_trace trace;
  134 #define TRACEBUF_INITIALIZER    { __LINE__, 0, __FILE__, NULL } ,
  135 
  136 #define QMD_TRACE_HEAD(head) do {                                       \
  137         (head)->trace.prevline = (head)->trace.lastline;                \
  138         (head)->trace.prevfile = (head)->trace.lastfile;                \
  139         (head)->trace.lastline = __LINE__;                              \
  140         (head)->trace.lastfile = __FILE__;                              \
  141 } while (0)
  142 
  143 #define QMD_TRACE_ELEM(elem) do {                                       \
  144         (elem)->trace.prevline = (elem)->trace.lastline;                \
  145         (elem)->trace.prevfile = (elem)->trace.lastfile;                \
  146         (elem)->trace.lastline = __LINE__;                              \
  147         (elem)->trace.lastfile = __FILE__;                              \
  148 } while (0)
  149 
  150 #else   /* !QUEUE_MACRO_DEBUG_TRACE */
  151 #define QMD_TRACE_ELEM(elem)
  152 #define QMD_TRACE_HEAD(head)
  153 #define TRACEBUF
  154 #define TRACEBUF_INITIALIZER
  155 #endif  /* QUEUE_MACRO_DEBUG_TRACE */
  156 
  157 #ifdef QUEUE_MACRO_DEBUG_TRASH
  158 #define QMD_SAVELINK(name, link)        void **name = (void *)&(link)
  159 #define TRASHIT(x)              do {(x) = (void *)-1;} while (0)
  160 #define QMD_IS_TRASHED(x)       ((x) == (void *)(intptr_t)-1)
  161 #else   /* !QUEUE_MACRO_DEBUG_TRASH */
  162 #define QMD_SAVELINK(name, link)
  163 #define TRASHIT(x)
  164 #define QMD_IS_TRASHED(x)       0
  165 #endif  /* QUEUE_MACRO_DEBUG_TRASH */
  166 
  167 #ifdef __cplusplus
  168 /*
  169  * In C++ there can be structure lists and class lists:
  170  */
  171 #define QUEUE_TYPEOF(type) type
  172 #else
  173 #define QUEUE_TYPEOF(type) struct type
  174 #endif
  175 
  176 /*
  177  * Singly-linked List declarations.
  178  */
  179 #define SLIST_HEAD(name, type)                                          \
  180 struct name {                                                           \
  181         struct type *slh_first; /* first element */                     \
  182 }
  183 
  184 #define SLIST_CLASS_HEAD(name, type)                                    \
  185 struct name {                                                           \
  186         class type *slh_first;  /* first element */                     \
  187 }
  188 
  189 #define SLIST_HEAD_INITIALIZER(head)                                    \
  190         { NULL }
  191 
  192 #define SLIST_ENTRY(type)                                               \
  193 struct {                                                                \
  194         struct type *sle_next;  /* next element */                      \
  195 }
  196 
  197 #define SLIST_CLASS_ENTRY(type)                                         \
  198 struct {                                                                \
  199         class type *sle_next;           /* next element */              \
  200 }
  201 
  202 /*
  203  * Singly-linked List functions.
  204  */
  205 #if (defined(_KERNEL) && defined(INVARIANTS))
  206 #define QMD_SLIST_CHECK_PREVPTR(prevp, elm) do {                        \
  207         if (*(prevp) != (elm))                                          \
  208                 panic("Bad prevptr *(%p) == %p != %p",                  \
  209                     (prevp), *(prevp), (elm));                          \
  210 } while (0)
  211 #else
  212 #define QMD_SLIST_CHECK_PREVPTR(prevp, elm)
  213 #endif
  214 
  215 #define SLIST_CONCAT(head1, head2, type, field) do {                    \
  216         QUEUE_TYPEOF(type) *curelm = SLIST_FIRST(head1);                \
  217         if (curelm == NULL) {                                           \
  218                 if ((SLIST_FIRST(head1) = SLIST_FIRST(head2)) != NULL)  \
  219                         SLIST_INIT(head2);                              \
  220         } else if (SLIST_FIRST(head2) != NULL) {                        \
  221                 while (SLIST_NEXT(curelm, field) != NULL)               \
  222                         curelm = SLIST_NEXT(curelm, field);             \
  223                 SLIST_NEXT(curelm, field) = SLIST_FIRST(head2);         \
  224                 SLIST_INIT(head2);                                      \
  225         }                                                               \
  226 } while (0)
  227 
  228 #define SLIST_EMPTY(head)       ((head)->slh_first == NULL)
  229 
  230 #define SLIST_FIRST(head)       ((head)->slh_first)
  231 
  232 #define SLIST_FOREACH(var, head, field)                                 \
  233         for ((var) = SLIST_FIRST((head));                               \
  234             (var);                                                      \
  235             (var) = SLIST_NEXT((var), field))
  236 
  237 #define SLIST_FOREACH_FROM(var, head, field)                            \
  238         for ((var) = ((var) ? (var) : SLIST_FIRST((head)));             \
  239             (var);                                                      \
  240             (var) = SLIST_NEXT((var), field))
  241 
  242 #define SLIST_FOREACH_SAFE(var, head, field, tvar)                      \
  243         for ((var) = SLIST_FIRST((head));                               \
  244             (var) && ((tvar) = SLIST_NEXT((var), field), 1);            \
  245             (var) = (tvar))
  246 
  247 #define SLIST_FOREACH_FROM_SAFE(var, head, field, tvar)                 \
  248         for ((var) = ((var) ? (var) : SLIST_FIRST((head)));             \
  249             (var) && ((tvar) = SLIST_NEXT((var), field), 1);            \
  250             (var) = (tvar))
  251 
  252 #define SLIST_FOREACH_PREVPTR(var, varp, head, field)                   \
  253         for ((varp) = &SLIST_FIRST((head));                             \
  254             ((var) = *(varp)) != NULL;                                  \
  255             (varp) = &SLIST_NEXT((var), field))
  256 
  257 #define SLIST_INIT(head) do {                                           \
  258         SLIST_FIRST((head)) = NULL;                                     \
  259 } while (0)
  260 
  261 #define SLIST_INSERT_AFTER(slistelm, elm, field) do {                   \
  262         SLIST_NEXT((elm), field) = SLIST_NEXT((slistelm), field);       \
  263         SLIST_NEXT((slistelm), field) = (elm);                          \
  264 } while (0)
  265 
  266 #define SLIST_INSERT_HEAD(head, elm, field) do {                        \
  267         SLIST_NEXT((elm), field) = SLIST_FIRST((head));                 \
  268         SLIST_FIRST((head)) = (elm);                                    \
  269 } while (0)
  270 
  271 #define SLIST_NEXT(elm, field)  ((elm)->field.sle_next)
  272 
  273 #define SLIST_REMOVE(head, elm, type, field) do {                       \
  274         QMD_SAVELINK(oldnext, (elm)->field.sle_next);                   \
  275         if (SLIST_FIRST((head)) == (elm)) {                             \
  276                 SLIST_REMOVE_HEAD((head), field);                       \
  277         }                                                               \
  278         else {                                                          \
  279                 QUEUE_TYPEOF(type) *curelm = SLIST_FIRST(head);         \
  280                 while (SLIST_NEXT(curelm, field) != (elm))              \
  281                         curelm = SLIST_NEXT(curelm, field);             \
  282                 SLIST_REMOVE_AFTER(curelm, field);                      \
  283         }                                                               \
  284         TRASHIT(*oldnext);                                              \
  285 } while (0)
  286 
  287 #define SLIST_REMOVE_AFTER(elm, field) do {                             \
  288         SLIST_NEXT(elm, field) =                                        \
  289             SLIST_NEXT(SLIST_NEXT(elm, field), field);                  \
  290 } while (0)
  291 
  292 #define SLIST_REMOVE_HEAD(head, field) do {                             \
  293         SLIST_FIRST((head)) = SLIST_NEXT(SLIST_FIRST((head)), field);   \
  294 } while (0)
  295 
  296 #define SLIST_REMOVE_PREVPTR(prevp, elm, field) do {                    \
  297         QMD_SLIST_CHECK_PREVPTR(prevp, elm);                            \
  298         *(prevp) = SLIST_NEXT(elm, field);                              \
  299         TRASHIT((elm)->field.sle_next);                                 \
  300 } while (0)
  301 
  302 #define SLIST_SWAP(head1, head2, type) do {                             \
  303         QUEUE_TYPEOF(type) *swap_first = SLIST_FIRST(head1);            \
  304         SLIST_FIRST(head1) = SLIST_FIRST(head2);                        \
  305         SLIST_FIRST(head2) = swap_first;                                \
  306 } while (0)
  307 
  308 /*
  309  * Singly-linked Tail queue declarations.
  310  */
  311 #define STAILQ_HEAD(name, type)                                         \
  312 struct name {                                                           \
  313         struct type *stqh_first;/* first element */                     \
  314         struct type **stqh_last;/* addr of last next element */         \
  315 }
  316 
  317 #define STAILQ_CLASS_HEAD(name, type)                                   \
  318 struct name {                                                           \
  319         class type *stqh_first; /* first element */                     \
  320         class type **stqh_last; /* addr of last next element */         \
  321 }
  322 
  323 #define STAILQ_HEAD_INITIALIZER(head)                                   \
  324         { NULL, &(head).stqh_first }
  325 
  326 #define STAILQ_ENTRY(type)                                              \
  327 struct {                                                                \
  328         struct type *stqe_next; /* next element */                      \
  329 }
  330 
  331 #define STAILQ_CLASS_ENTRY(type)                                        \
  332 struct {                                                                \
  333         class type *stqe_next;  /* next element */                      \
  334 }
  335 
  336 /*
  337  * Singly-linked Tail queue functions.
  338  */
  339 #define STAILQ_CONCAT(head1, head2) do {                                \
  340         if (!STAILQ_EMPTY((head2))) {                                   \
  341                 *(head1)->stqh_last = (head2)->stqh_first;              \
  342                 (head1)->stqh_last = (head2)->stqh_last;                \
  343                 STAILQ_INIT((head2));                                   \
  344         }                                                               \
  345 } while (0)
  346 
  347 #define STAILQ_EMPTY(head)      ((head)->stqh_first == NULL)
  348 
  349 #define STAILQ_FIRST(head)      ((head)->stqh_first)
  350 
  351 #define STAILQ_FOREACH(var, head, field)                                \
  352         for((var) = STAILQ_FIRST((head));                               \
  353            (var);                                                       \
  354            (var) = STAILQ_NEXT((var), field))
  355 
  356 #define STAILQ_FOREACH_FROM(var, head, field)                           \
  357         for ((var) = ((var) ? (var) : STAILQ_FIRST((head)));            \
  358            (var);                                                       \
  359            (var) = STAILQ_NEXT((var), field))
  360 
  361 #define STAILQ_FOREACH_SAFE(var, head, field, tvar)                     \
  362         for ((var) = STAILQ_FIRST((head));                              \
  363             (var) && ((tvar) = STAILQ_NEXT((var), field), 1);           \
  364             (var) = (tvar))
  365 
  366 #define STAILQ_FOREACH_FROM_SAFE(var, head, field, tvar)                \
  367         for ((var) = ((var) ? (var) : STAILQ_FIRST((head)));            \
  368             (var) && ((tvar) = STAILQ_NEXT((var), field), 1);           \
  369             (var) = (tvar))
  370 
  371 #define STAILQ_INIT(head) do {                                          \
  372         STAILQ_FIRST((head)) = NULL;                                    \
  373         (head)->stqh_last = &STAILQ_FIRST((head));                      \
  374 } while (0)
  375 
  376 #define STAILQ_INSERT_AFTER(head, tqelm, elm, field) do {               \
  377         if ((STAILQ_NEXT((elm), field) = STAILQ_NEXT((tqelm), field)) == NULL)\
  378                 (head)->stqh_last = &STAILQ_NEXT((elm), field);         \
  379         STAILQ_NEXT((tqelm), field) = (elm);                            \
  380 } while (0)
  381 
  382 #define STAILQ_INSERT_HEAD(head, elm, field) do {                       \
  383         if ((STAILQ_NEXT((elm), field) = STAILQ_FIRST((head))) == NULL) \
  384                 (head)->stqh_last = &STAILQ_NEXT((elm), field);         \
  385         STAILQ_FIRST((head)) = (elm);                                   \
  386 } while (0)
  387 
  388 #define STAILQ_INSERT_TAIL(head, elm, field) do {                       \
  389         STAILQ_NEXT((elm), field) = NULL;                               \
  390         *(head)->stqh_last = (elm);                                     \
  391         (head)->stqh_last = &STAILQ_NEXT((elm), field);                 \
  392 } while (0)
  393 
  394 #define STAILQ_LAST(head, type, field)                          \
  395         (STAILQ_EMPTY((head)) ? NULL :                          \
  396             __containerof((head)->stqh_last,                    \
  397             QUEUE_TYPEOF(type), field.stqe_next))
  398 
  399 #define STAILQ_NEXT(elm, field) ((elm)->field.stqe_next)
  400 
  401 #define STAILQ_REMOVE(head, elm, type, field) do {                      \
  402         QMD_SAVELINK(oldnext, (elm)->field.stqe_next);                  \
  403         if (STAILQ_FIRST((head)) == (elm)) {                            \
  404                 STAILQ_REMOVE_HEAD((head), field);                      \
  405         }                                                               \
  406         else {                                                          \
  407                 QUEUE_TYPEOF(type) *curelm = STAILQ_FIRST(head);        \
  408                 while (STAILQ_NEXT(curelm, field) != (elm))             \
  409                         curelm = STAILQ_NEXT(curelm, field);            \
  410                 STAILQ_REMOVE_AFTER(head, curelm, field);               \
  411         }                                                               \
  412         TRASHIT(*oldnext);                                              \
  413 } while (0)
  414 
  415 #define STAILQ_REMOVE_AFTER(head, elm, field) do {                      \
  416         if ((STAILQ_NEXT(elm, field) =                                  \
  417              STAILQ_NEXT(STAILQ_NEXT(elm, field), field)) == NULL)      \
  418                 (head)->stqh_last = &STAILQ_NEXT((elm), field);         \
  419 } while (0)
  420 
  421 #define STAILQ_REMOVE_HEAD(head, field) do {                            \
  422         if ((STAILQ_FIRST((head)) =                                     \
  423              STAILQ_NEXT(STAILQ_FIRST((head)), field)) == NULL)         \
  424                 (head)->stqh_last = &STAILQ_FIRST((head));              \
  425 } while (0)
  426 
  427 #define STAILQ_SWAP(head1, head2, type) do {                            \
  428         QUEUE_TYPEOF(type) *swap_first = STAILQ_FIRST(head1);           \
  429         QUEUE_TYPEOF(type) **swap_last = (head1)->stqh_last;            \
  430         STAILQ_FIRST(head1) = STAILQ_FIRST(head2);                      \
  431         (head1)->stqh_last = (head2)->stqh_last;                        \
  432         STAILQ_FIRST(head2) = swap_first;                               \
  433         (head2)->stqh_last = swap_last;                                 \
  434         if (STAILQ_EMPTY(head1))                                        \
  435                 (head1)->stqh_last = &STAILQ_FIRST(head1);              \
  436         if (STAILQ_EMPTY(head2))                                        \
  437                 (head2)->stqh_last = &STAILQ_FIRST(head2);              \
  438 } while (0)
  439 
  440 
  441 /*
  442  * List declarations.
  443  */
  444 #define LIST_HEAD(name, type)                                           \
  445 struct name {                                                           \
  446         struct type *lh_first;  /* first element */                     \
  447 }
  448 
  449 #define LIST_CLASS_HEAD(name, type)                                     \
  450 struct name {                                                           \
  451         class type *lh_first;   /* first element */                     \
  452 }
  453 
  454 #define LIST_HEAD_INITIALIZER(head)                                     \
  455         { NULL }
  456 
  457 #define LIST_ENTRY(type)                                                \
  458 struct {                                                                \
  459         struct type *le_next;   /* next element */                      \
  460         struct type **le_prev;  /* address of previous next element */  \
  461 }
  462 
  463 #define LIST_CLASS_ENTRY(type)                                          \
  464 struct {                                                                \
  465         class type *le_next;    /* next element */                      \
  466         class type **le_prev;   /* address of previous next element */  \
  467 }
  468 
  469 /*
  470  * List functions.
  471  */
  472 
  473 #if (defined(_KERNEL) && defined(INVARIANTS))
  474 /*
  475  * QMD_LIST_CHECK_HEAD(LIST_HEAD *head, LIST_ENTRY NAME)
  476  *
  477  * If the list is non-empty, validates that the first element of the list
  478  * points back at 'head.'
  479  */
  480 #define QMD_LIST_CHECK_HEAD(head, field) do {                           \
  481         if (LIST_FIRST((head)) != NULL &&                               \
  482             LIST_FIRST((head))->field.le_prev !=                        \
  483              &LIST_FIRST((head)))                                       \
  484                 panic("Bad list head %p first->prev != head", (head));  \
  485 } while (0)
  486 
  487 /*
  488  * QMD_LIST_CHECK_NEXT(TYPE *elm, LIST_ENTRY NAME)
  489  *
  490  * If an element follows 'elm' in the list, validates that the next element
  491  * points back at 'elm.'
  492  */
  493 #define QMD_LIST_CHECK_NEXT(elm, field) do {                            \
  494         if (LIST_NEXT((elm), field) != NULL &&                          \
  495             LIST_NEXT((elm), field)->field.le_prev !=                   \
  496              &((elm)->field.le_next))                                   \
  497                 panic("Bad link elm %p next->prev != elm", (elm));      \
  498 } while (0)
  499 
  500 /*
  501  * QMD_LIST_CHECK_PREV(TYPE *elm, LIST_ENTRY NAME)
  502  *
  503  * Validates that the previous element (or head of the list) points to 'elm.'
  504  */
  505 #define QMD_LIST_CHECK_PREV(elm, field) do {                            \
  506         if (*(elm)->field.le_prev != (elm))                             \
  507                 panic("Bad link elm %p prev->next != elm", (elm));      \
  508 } while (0)
  509 #else
  510 #define QMD_LIST_CHECK_HEAD(head, field)
  511 #define QMD_LIST_CHECK_NEXT(elm, field)
  512 #define QMD_LIST_CHECK_PREV(elm, field)
  513 #endif /* (_KERNEL && INVARIANTS) */
  514 
  515 #define LIST_CONCAT(head1, head2, type, field) do {                           \
  516         QUEUE_TYPEOF(type) *curelm = LIST_FIRST(head1);                       \
  517         if (curelm == NULL) {                                                 \
  518                 if ((LIST_FIRST(head1) = LIST_FIRST(head2)) != NULL) {        \
  519                         LIST_FIRST(head2)->field.le_prev =                    \
  520                             &LIST_FIRST((head1));                             \
  521                         LIST_INIT(head2);                                     \
  522                 }                                                             \
  523         } else if (LIST_FIRST(head2) != NULL) {                               \
  524                 while (LIST_NEXT(curelm, field) != NULL)                      \
  525                         curelm = LIST_NEXT(curelm, field);                    \
  526                 LIST_NEXT(curelm, field) = LIST_FIRST(head2);                 \
  527                 LIST_FIRST(head2)->field.le_prev = &LIST_NEXT(curelm, field); \
  528                 LIST_INIT(head2);                                             \
  529         }                                                                     \
  530 } while (0)
  531 
  532 #define LIST_EMPTY(head)        ((head)->lh_first == NULL)
  533 
  534 #define LIST_FIRST(head)        ((head)->lh_first)
  535 
  536 #define LIST_FOREACH(var, head, field)                                  \
  537         for ((var) = LIST_FIRST((head));                                \
  538             (var);                                                      \
  539             (var) = LIST_NEXT((var), field))
  540 
  541 #define LIST_FOREACH_FROM(var, head, field)                             \
  542         for ((var) = ((var) ? (var) : LIST_FIRST((head)));              \
  543             (var);                                                      \
  544             (var) = LIST_NEXT((var), field))
  545 
  546 #define LIST_FOREACH_SAFE(var, head, field, tvar)                       \
  547         for ((var) = LIST_FIRST((head));                                \
  548             (var) && ((tvar) = LIST_NEXT((var), field), 1);             \
  549             (var) = (tvar))
  550 
  551 #define LIST_FOREACH_FROM_SAFE(var, head, field, tvar)                  \
  552         for ((var) = ((var) ? (var) : LIST_FIRST((head)));              \
  553             (var) && ((tvar) = LIST_NEXT((var), field), 1);             \
  554             (var) = (tvar))
  555 
  556 #define LIST_INIT(head) do {                                            \
  557         LIST_FIRST((head)) = NULL;                                      \
  558 } while (0)
  559 
  560 #define LIST_INSERT_AFTER(listelm, elm, field) do {                     \
  561         QMD_LIST_CHECK_NEXT(listelm, field);                            \
  562         if ((LIST_NEXT((elm), field) = LIST_NEXT((listelm), field)) != NULL)\
  563                 LIST_NEXT((listelm), field)->field.le_prev =            \
  564                     &LIST_NEXT((elm), field);                           \
  565         LIST_NEXT((listelm), field) = (elm);                            \
  566         (elm)->field.le_prev = &LIST_NEXT((listelm), field);            \
  567 } while (0)
  568 
  569 #define LIST_INSERT_BEFORE(listelm, elm, field) do {                    \
  570         QMD_LIST_CHECK_PREV(listelm, field);                            \
  571         (elm)->field.le_prev = (listelm)->field.le_prev;                \
  572         LIST_NEXT((elm), field) = (listelm);                            \
  573         *(listelm)->field.le_prev = (elm);                              \
  574         (listelm)->field.le_prev = &LIST_NEXT((elm), field);            \
  575 } while (0)
  576 
  577 #define LIST_INSERT_HEAD(head, elm, field) do {                         \
  578         QMD_LIST_CHECK_HEAD((head), field);                             \
  579         if ((LIST_NEXT((elm), field) = LIST_FIRST((head))) != NULL)     \
  580                 LIST_FIRST((head))->field.le_prev = &LIST_NEXT((elm), field);\
  581         LIST_FIRST((head)) = (elm);                                     \
  582         (elm)->field.le_prev = &LIST_FIRST((head));                     \
  583 } while (0)
  584 
  585 #define LIST_NEXT(elm, field)   ((elm)->field.le_next)
  586 
  587 #define LIST_PREV(elm, head, type, field)                       \
  588         ((elm)->field.le_prev == &LIST_FIRST((head)) ? NULL :   \
  589             __containerof((elm)->field.le_prev,                 \
  590             QUEUE_TYPEOF(type), field.le_next))
  591 
  592 #define LIST_REMOVE(elm, field) do {                                    \
  593         QMD_SAVELINK(oldnext, (elm)->field.le_next);                    \
  594         QMD_SAVELINK(oldprev, (elm)->field.le_prev);                    \
  595         QMD_LIST_CHECK_NEXT(elm, field);                                \
  596         QMD_LIST_CHECK_PREV(elm, field);                                \
  597         if (LIST_NEXT((elm), field) != NULL)                            \
  598                 LIST_NEXT((elm), field)->field.le_prev =                \
  599                     (elm)->field.le_prev;                               \
  600         *(elm)->field.le_prev = LIST_NEXT((elm), field);                \
  601         TRASHIT(*oldnext);                                              \
  602         TRASHIT(*oldprev);                                              \
  603 } while (0)
  604 
  605 #define LIST_SWAP(head1, head2, type, field) do {                       \
  606         QUEUE_TYPEOF(type) *swap_tmp = LIST_FIRST(head1);               \
  607         LIST_FIRST((head1)) = LIST_FIRST((head2));                      \
  608         LIST_FIRST((head2)) = swap_tmp;                                 \
  609         if ((swap_tmp = LIST_FIRST((head1))) != NULL)                   \
  610                 swap_tmp->field.le_prev = &LIST_FIRST((head1));         \
  611         if ((swap_tmp = LIST_FIRST((head2))) != NULL)                   \
  612                 swap_tmp->field.le_prev = &LIST_FIRST((head2));         \
  613 } while (0)
  614 
  615 /*
  616  * Tail queue declarations.
  617  */
  618 #define TAILQ_HEAD(name, type)                                          \
  619 struct name {                                                           \
  620         struct type *tqh_first; /* first element */                     \
  621         struct type **tqh_last; /* addr of last next element */         \
  622         TRACEBUF                                                        \
  623 }
  624 
  625 #define TAILQ_CLASS_HEAD(name, type)                                    \
  626 struct name {                                                           \
  627         class type *tqh_first;  /* first element */                     \
  628         class type **tqh_last;  /* addr of last next element */         \
  629         TRACEBUF                                                        \
  630 }
  631 
  632 #define TAILQ_HEAD_INITIALIZER(head)                                    \
  633         { NULL, &(head).tqh_first, TRACEBUF_INITIALIZER }
  634 
  635 #define TAILQ_ENTRY(type)                                               \
  636 struct {                                                                \
  637         struct type *tqe_next;  /* next element */                      \
  638         struct type **tqe_prev; /* address of previous next element */  \
  639         TRACEBUF                                                        \
  640 }
  641 
  642 #define TAILQ_CLASS_ENTRY(type)                                         \
  643 struct {                                                                \
  644         class type *tqe_next;   /* next element */                      \
  645         class type **tqe_prev;  /* address of previous next element */  \
  646         TRACEBUF                                                        \
  647 }
  648 
  649 /*
  650  * Tail queue functions.
  651  */
  652 #if (defined(_KERNEL) && defined(INVARIANTS))
  653 /*
  654  * QMD_TAILQ_CHECK_HEAD(TAILQ_HEAD *head, TAILQ_ENTRY NAME)
  655  *
  656  * If the tailq is non-empty, validates that the first element of the tailq
  657  * points back at 'head.'
  658  */
  659 #define QMD_TAILQ_CHECK_HEAD(head, field) do {                          \
  660         if (!TAILQ_EMPTY(head) &&                                       \
  661             TAILQ_FIRST((head))->field.tqe_prev !=                      \
  662              &TAILQ_FIRST((head)))                                      \
  663                 panic("Bad tailq head %p first->prev != head", (head)); \
  664 } while (0)
  665 
  666 /*
  667  * QMD_TAILQ_CHECK_TAIL(TAILQ_HEAD *head, TAILQ_ENTRY NAME)
  668  *
  669  * Validates that the tail of the tailq is a pointer to pointer to NULL.
  670  */
  671 #define QMD_TAILQ_CHECK_TAIL(head, field) do {                          \
  672         if (*(head)->tqh_last != NULL)                                  \
  673                 panic("Bad tailq NEXT(%p->tqh_last) != NULL", (head));  \
  674 } while (0)
  675 
  676 /*
  677  * QMD_TAILQ_CHECK_NEXT(TYPE *elm, TAILQ_ENTRY NAME)
  678  *
  679  * If an element follows 'elm' in the tailq, validates that the next element
  680  * points back at 'elm.'
  681  */
  682 #define QMD_TAILQ_CHECK_NEXT(elm, field) do {                           \
  683         if (TAILQ_NEXT((elm), field) != NULL &&                         \
  684             TAILQ_NEXT((elm), field)->field.tqe_prev !=                 \
  685              &((elm)->field.tqe_next))                                  \
  686                 panic("Bad link elm %p next->prev != elm", (elm));      \
  687 } while (0)
  688 
  689 /*
  690  * QMD_TAILQ_CHECK_PREV(TYPE *elm, TAILQ_ENTRY NAME)
  691  *
  692  * Validates that the previous element (or head of the tailq) points to 'elm.'
  693  */
  694 #define QMD_TAILQ_CHECK_PREV(elm, field) do {                           \
  695         if (*(elm)->field.tqe_prev != (elm))                            \
  696                 panic("Bad link elm %p prev->next != elm", (elm));      \
  697 } while (0)
  698 #else
  699 #define QMD_TAILQ_CHECK_HEAD(head, field)
  700 #define QMD_TAILQ_CHECK_TAIL(head, headname)
  701 #define QMD_TAILQ_CHECK_NEXT(elm, field)
  702 #define QMD_TAILQ_CHECK_PREV(elm, field)
  703 #endif /* (_KERNEL && INVARIANTS) */
  704 
  705 #define TAILQ_CONCAT(head1, head2, field) do {                          \
  706         if (!TAILQ_EMPTY(head2)) {                                      \
  707                 *(head1)->tqh_last = (head2)->tqh_first;                \
  708                 (head2)->tqh_first->field.tqe_prev = (head1)->tqh_last; \
  709                 (head1)->tqh_last = (head2)->tqh_last;                  \
  710                 TAILQ_INIT((head2));                                    \
  711                 QMD_TRACE_HEAD(head1);                                  \
  712                 QMD_TRACE_HEAD(head2);                                  \
  713         }                                                               \
  714 } while (0)
  715 
  716 #define TAILQ_EMPTY(head)       ((head)->tqh_first == NULL)
  717 
  718 #define TAILQ_FIRST(head)       ((head)->tqh_first)
  719 
  720 #define TAILQ_FOREACH(var, head, field)                                 \
  721         for ((var) = TAILQ_FIRST((head));                               \
  722             (var);                                                      \
  723             (var) = TAILQ_NEXT((var), field))
  724 
  725 #define TAILQ_FOREACH_FROM(var, head, field)                            \
  726         for ((var) = ((var) ? (var) : TAILQ_FIRST((head)));             \
  727             (var);                                                      \
  728             (var) = TAILQ_NEXT((var), field))
  729 
  730 #define TAILQ_FOREACH_SAFE(var, head, field, tvar)                      \
  731         for ((var) = TAILQ_FIRST((head));                               \
  732             (var) && ((tvar) = TAILQ_NEXT((var), field), 1);            \
  733             (var) = (tvar))
  734 
  735 #define TAILQ_FOREACH_FROM_SAFE(var, head, field, tvar)                 \
  736         for ((var) = ((var) ? (var) : TAILQ_FIRST((head)));             \
  737             (var) && ((tvar) = TAILQ_NEXT((var), field), 1);            \
  738             (var) = (tvar))
  739 
  740 #define TAILQ_FOREACH_REVERSE(var, head, headname, field)               \
  741         for ((var) = TAILQ_LAST((head), headname);                      \
  742             (var);                                                      \
  743             (var) = TAILQ_PREV((var), headname, field))
  744 
  745 #define TAILQ_FOREACH_REVERSE_FROM(var, head, headname, field)          \
  746         for ((var) = ((var) ? (var) : TAILQ_LAST((head), headname));    \
  747             (var);                                                      \
  748             (var) = TAILQ_PREV((var), headname, field))
  749 
  750 #define TAILQ_FOREACH_REVERSE_SAFE(var, head, headname, field, tvar)    \
  751         for ((var) = TAILQ_LAST((head), headname);                      \
  752             (var) && ((tvar) = TAILQ_PREV((var), headname, field), 1);  \
  753             (var) = (tvar))
  754 
  755 #define TAILQ_FOREACH_REVERSE_FROM_SAFE(var, head, headname, field, tvar) \
  756         for ((var) = ((var) ? (var) : TAILQ_LAST((head), headname));    \
  757             (var) && ((tvar) = TAILQ_PREV((var), headname, field), 1);  \
  758             (var) = (tvar))
  759 
  760 #define TAILQ_INIT(head) do {                                           \
  761         TAILQ_FIRST((head)) = NULL;                                     \
  762         (head)->tqh_last = &TAILQ_FIRST((head));                        \
  763         QMD_TRACE_HEAD(head);                                           \
  764 } while (0)
  765 
  766 #define TAILQ_INSERT_AFTER(head, listelm, elm, field) do {              \
  767         QMD_TAILQ_CHECK_NEXT(listelm, field);                           \
  768         if ((TAILQ_NEXT((elm), field) = TAILQ_NEXT((listelm), field)) != NULL)\
  769                 TAILQ_NEXT((elm), field)->field.tqe_prev =              \
  770                     &TAILQ_NEXT((elm), field);                          \
  771         else {                                                          \
  772                 (head)->tqh_last = &TAILQ_NEXT((elm), field);           \
  773                 QMD_TRACE_HEAD(head);                                   \
  774         }                                                               \
  775         TAILQ_NEXT((listelm), field) = (elm);                           \
  776         (elm)->field.tqe_prev = &TAILQ_NEXT((listelm), field);          \
  777         QMD_TRACE_ELEM(&(elm)->field);                                  \
  778         QMD_TRACE_ELEM(&(listelm)->field);                              \
  779 } while (0)
  780 
  781 #define TAILQ_INSERT_BEFORE(listelm, elm, field) do {                   \
  782         QMD_TAILQ_CHECK_PREV(listelm, field);                           \
  783         (elm)->field.tqe_prev = (listelm)->field.tqe_prev;              \
  784         TAILQ_NEXT((elm), field) = (listelm);                           \
  785         *(listelm)->field.tqe_prev = (elm);                             \
  786         (listelm)->field.tqe_prev = &TAILQ_NEXT((elm), field);          \
  787         QMD_TRACE_ELEM(&(elm)->field);                                  \
  788         QMD_TRACE_ELEM(&(listelm)->field);                              \
  789 } while (0)
  790 
  791 #define TAILQ_INSERT_HEAD(head, elm, field) do {                        \
  792         QMD_TAILQ_CHECK_HEAD(head, field);                              \
  793         if ((TAILQ_NEXT((elm), field) = TAILQ_FIRST((head))) != NULL)   \
  794                 TAILQ_FIRST((head))->field.tqe_prev =                   \
  795                     &TAILQ_NEXT((elm), field);                          \
  796         else                                                            \
  797                 (head)->tqh_last = &TAILQ_NEXT((elm), field);           \
  798         TAILQ_FIRST((head)) = (elm);                                    \
  799         (elm)->field.tqe_prev = &TAILQ_FIRST((head));                   \
  800         QMD_TRACE_HEAD(head);                                           \
  801         QMD_TRACE_ELEM(&(elm)->field);                                  \
  802 } while (0)
  803 
  804 #define TAILQ_INSERT_TAIL(head, elm, field) do {                        \
  805         QMD_TAILQ_CHECK_TAIL(head, field);                              \
  806         TAILQ_NEXT((elm), field) = NULL;                                \
  807         (elm)->field.tqe_prev = (head)->tqh_last;                       \
  808         *(head)->tqh_last = (elm);                                      \
  809         (head)->tqh_last = &TAILQ_NEXT((elm), field);                   \
  810         QMD_TRACE_HEAD(head);                                           \
  811         QMD_TRACE_ELEM(&(elm)->field);                                  \
  812 } while (0)
  813 
  814 #define TAILQ_LAST(head, headname)                                      \
  815         (*(((struct headname *)((head)->tqh_last))->tqh_last))
  816 
  817 /*
  818  * The FAST function is fast in that it causes no data access other
  819  * then the access to the head. The standard LAST function above
  820  * will cause a data access of both the element you want and 
  821  * the previous element. FAST is very useful for instances when
  822  * you may want to prefetch the last data element.
  823  */
  824 #define TAILQ_LAST_FAST(head, type, field)                      \
  825     (TAILQ_EMPTY(head) ? NULL : __containerof((head)->tqh_last, QUEUE_TYPEOF(type), field.tqe_next))
  826 
  827 #define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next)
  828 
  829 #define TAILQ_PREV(elm, headname, field)                                \
  830         (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last))
  831 
  832 #define TAILQ_REMOVE(head, elm, field) do {                             \
  833         QMD_SAVELINK(oldnext, (elm)->field.tqe_next);                   \
  834         QMD_SAVELINK(oldprev, (elm)->field.tqe_prev);                   \
  835         QMD_TAILQ_CHECK_NEXT(elm, field);                               \
  836         QMD_TAILQ_CHECK_PREV(elm, field);                               \
  837         if ((TAILQ_NEXT((elm), field)) != NULL)                         \
  838                 TAILQ_NEXT((elm), field)->field.tqe_prev =              \
  839                     (elm)->field.tqe_prev;                              \
  840         else {                                                          \
  841                 (head)->tqh_last = (elm)->field.tqe_prev;               \
  842                 QMD_TRACE_HEAD(head);                                   \
  843         }                                                               \
  844         *(elm)->field.tqe_prev = TAILQ_NEXT((elm), field);              \
  845         TRASHIT(*oldnext);                                              \
  846         TRASHIT(*oldprev);                                              \
  847         QMD_TRACE_ELEM(&(elm)->field);                                  \
  848 } while (0)
  849 
  850 #define TAILQ_SWAP(head1, head2, type, field) do {                      \
  851         QUEUE_TYPEOF(type) *swap_first = (head1)->tqh_first;            \
  852         QUEUE_TYPEOF(type) **swap_last = (head1)->tqh_last;             \
  853         (head1)->tqh_first = (head2)->tqh_first;                        \
  854         (head1)->tqh_last = (head2)->tqh_last;                          \
  855         (head2)->tqh_first = swap_first;                                \
  856         (head2)->tqh_last = swap_last;                                  \
  857         if ((swap_first = (head1)->tqh_first) != NULL)                  \
  858                 swap_first->field.tqe_prev = &(head1)->tqh_first;       \
  859         else                                                            \
  860                 (head1)->tqh_last = &(head1)->tqh_first;                \
  861         if ((swap_first = (head2)->tqh_first) != NULL)                  \
  862                 swap_first->field.tqe_prev = &(head2)->tqh_first;       \
  863         else                                                            \
  864                 (head2)->tqh_last = &(head2)->tqh_first;                \
  865 } while (0)
  866 
  867 #endif /* !_SYS_QUEUE_H_ */

Cache object: 64be2a1fb734d19c272b4273b28de1d2


[ 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.