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Sourcecode: ipsec-tools version File versions

queue.h

/*
 * Copyright (c) 1991, 1993
 *    The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *    @(#)queue.h 8.5 (Berkeley) 8/20/94
 * $FreeBSD: src/sys/sys/queue.h,v 1.58 2004/04/07 04:19:49 imp Exp $
 *
 * 04/24/2004    Backport to v1.45 functionality for ipsec-tools
 *               Heiko Hund <heiko@ist.eigentlich.net>
 */

#ifndef _SYS_QUEUE_H_
#define _SYS_QUEUE_H_

//#include <sys/cdefs.h>

/*
 * This file defines four types of data structures: singly-linked lists,
 * singly-linked tail queues, lists and tail queues.
 *
 * A singly-linked list is headed by a single forward pointer. The elements
 * are singly linked for minimum space and pointer manipulation overhead at
 * the expense of O(n) removal for arbitrary elements. New elements can be
 * added to the list after an existing element or at the head of the list.
 * Elements being removed from the head of the list should use the explicit
 * macro for this purpose for optimum efficiency. A singly-linked list may
 * only be traversed in the forward direction.  Singly-linked lists are ideal
 * for applications with large datasets and few or no removals or for
 * implementing a LIFO queue.
 *
 * A singly-linked tail queue is headed by a pair of pointers, one to the
 * head of the list and the other to the tail of the list. The elements are
 * singly linked for minimum space and pointer manipulation overhead at the
 * expense of O(n) removal for arbitrary elements. New elements can be added
 * to the list after an existing element, at the head of the list, or at the
 * end of the list. Elements being removed from the head of the tail queue
 * should use the explicit macro for this purpose for optimum efficiency.
 * A singly-linked tail queue may only be traversed in the forward direction.
 * Singly-linked tail queues are ideal for applications with large datasets
 * and few or no removals or for implementing a FIFO queue.
 *
 * A list is headed by a single forward pointer (or an array of forward
 * pointers for a hash table header). The elements are doubly linked
 * so that an arbitrary element can be removed without a need to
 * traverse the list. New elements can be added to the list before
 * or after an existing element or at the head of the list. A list
 * may only be traversed in the forward direction.
 *
 * A tail queue is headed by a pair of pointers, one to the head of the
 * list and the other to the tail of the list. The elements are doubly
 * linked so that an arbitrary element can be removed without a need to
 * traverse the list. New elements can be added to the list before or
 * after an existing element, at the head of the list, or at the end of
 * the list. A tail queue may be traversed in either direction.
 *
 * For details on the use of these macros, see the queue(3) manual page.
 *
 *
 *                SLIST LIST  STAILQ      TAILQ
 * _HEAD          +     +     +     +
 * _HEAD_INITIALIZER    +     +     +     +
 * _ENTRY         +     +     +     +
 * _INIT          +     +     +     +
 * _EMPTY         +     +     +     +
 * _FIRST         +     +     +     +
 * _NEXT          +     +     +     +
 * _PREV          -     -     -     +
 * _LAST          -     -     +     +
 * _FOREACH       +     +     +     +
 * _FOREACH_REVERSE     -     -     -     +
 * _INSERT_HEAD         +     +     +     +
 * _INSERT_BEFORE -     +     -     +
 * _INSERT_AFTER  +     +     +     +
 * _INSERT_TAIL         -     -     +     +
 * _REMOVE_HEAD         +     -     +     -
 * _REMOVE        +     +     +     +
 *
 */

/*
 * Singly-linked List declarations.
 */
#define     SLIST_HEAD(name, type)                                \
struct name {                                               \
      struct type *slh_first; /* first element */                 \
}

#define     SLIST_HEAD_INITIALIZER(head)                          \
      { NULL }
 
#define     SLIST_ENTRY(type)                               \
struct {                                              \
      struct type *sle_next;  /* next element */                  \
}
 
/*
 * Singly-linked List functions.
 */
#define     SLIST_EMPTY(head) ((head)->slh_first == NULL)

#define     SLIST_FIRST(head) ((head)->slh_first)

#define     SLIST_FOREACH(var, head, field)                             \
      for ((var) = SLIST_FIRST((head));                     \
          (var);                                      \
          (var) = SLIST_NEXT((var), field))

#define     SLIST_INIT(head) do {                                 \
      SLIST_FIRST((head)) = NULL;                           \
} while (0)

#define     SLIST_INSERT_AFTER(slistelm, elm, field) do {               \
      SLIST_NEXT((elm), field) = SLIST_NEXT((slistelm), field);   \
      SLIST_NEXT((slistelm), field) = (elm);                      \
} while (0)

#define     SLIST_INSERT_HEAD(head, elm, field) do {              \
      SLIST_NEXT((elm), field) = SLIST_FIRST((head));             \
      SLIST_FIRST((head)) = (elm);                          \
} while (0)

#define     SLIST_NEXT(elm, field)  ((elm)->field.sle_next)

#define     SLIST_REMOVE(head, elm, type, field) do {             \
      if (SLIST_FIRST((head)) == (elm)) {                   \
            SLIST_REMOVE_HEAD((head), field);               \
      }                                               \
      else {                                                \
            struct type *curelm = SLIST_FIRST((head));            \
            while (SLIST_NEXT(curelm, field) != (elm))            \
                  curelm = SLIST_NEXT(curelm, field);       \
            SLIST_NEXT(curelm, field) =                     \
                SLIST_NEXT(SLIST_NEXT(curelm, field), field);     \
      }                                               \
} while (0)

#define     SLIST_REMOVE_HEAD(head, field) do {                   \
      SLIST_FIRST((head)) = SLIST_NEXT(SLIST_FIRST((head)), field);     \
} while (0)

/*
 * Singly-linked Tail queue declarations.
 */
#define     STAILQ_HEAD(name, type)                               \
struct name {                                               \
      struct type *stqh_first;/* first element */                 \
      struct type **stqh_last;/* addr of last next element */           \
}

#define     STAILQ_HEAD_INITIALIZER(head)                         \
      { NULL, &(head).stqh_first }

#define     STAILQ_ENTRY(type)                                    \
struct {                                              \
      struct type *stqe_next; /* next element */                  \
}

/*
 * Singly-linked Tail queue functions.
 */
#define     STAILQ_EMPTY(head)      ((head)->stqh_first == NULL)

#define     STAILQ_FIRST(head)      ((head)->stqh_first)

#define     STAILQ_FOREACH(var, head, field)                      \
      for((var) = STAILQ_FIRST((head));                     \
         (var);                                       \
         (var) = STAILQ_NEXT((var), field))

#define     STAILQ_INIT(head) do {                                \
      STAILQ_FIRST((head)) = NULL;                          \
      (head)->stqh_last = &STAILQ_FIRST((head));                  \
} while (0)

#define     STAILQ_INSERT_AFTER(head, tqelm, elm, field) do {           \
      if ((STAILQ_NEXT((elm), field) = STAILQ_NEXT((tqelm), field)) == NULL)\
            (head)->stqh_last = &STAILQ_NEXT((elm), field);       \
      STAILQ_NEXT((tqelm), field) = (elm);                        \
} while (0)

#define     STAILQ_INSERT_HEAD(head, elm, field) do {             \
      if ((STAILQ_NEXT((elm), field) = STAILQ_FIRST((head))) == NULL)   \
            (head)->stqh_last = &STAILQ_NEXT((elm), field);       \
      STAILQ_FIRST((head)) = (elm);                         \
} while (0)

#define     STAILQ_INSERT_TAIL(head, elm, field) do {             \
      STAILQ_NEXT((elm), field) = NULL;                     \
      *(head)->stqh_last = (elm);                           \
      (head)->stqh_last = &STAILQ_NEXT((elm), field);             \
} while (0)

#define     STAILQ_LAST(head, type, field)                              \
      (STAILQ_EMPTY(head) ?                                 \
            NULL :                                          \
              ((struct type *)                              \
            ((char *)((head)->stqh_last) - __offsetof(struct type, field))))

#define     STAILQ_NEXT(elm, field) ((elm)->field.stqe_next)

#define     STAILQ_REMOVE(head, elm, type, field) do {                  \
      if (STAILQ_FIRST((head)) == (elm)) {                        \
            STAILQ_REMOVE_HEAD(head, field);                \
      }                                               \
      else {                                                \
            struct type *curelm = STAILQ_FIRST((head));           \
            while (STAILQ_NEXT(curelm, field) != (elm))           \
                  curelm = STAILQ_NEXT(curelm, field);            \
            if ((STAILQ_NEXT(curelm, field) =               \
                 STAILQ_NEXT(STAILQ_NEXT(curelm, field), field)) == NULL)\
                  (head)->stqh_last = &STAILQ_NEXT((curelm), field);\
      }                                               \
} while (0)

#define     STAILQ_REMOVE_HEAD(head, field) do {                        \
      if ((STAILQ_FIRST((head)) =                           \
           STAILQ_NEXT(STAILQ_FIRST((head)), field)) == NULL)           \
            (head)->stqh_last = &STAILQ_FIRST((head));            \
} while (0)

#define     STAILQ_REMOVE_HEAD_UNTIL(head, elm, field) do {             \
      if ((STAILQ_FIRST((head)) = STAILQ_NEXT((elm), field)) == NULL)   \
            (head)->stqh_last = &STAILQ_FIRST((head));            \
} while (0)

/*
 * List declarations.
 */
#define     LIST_HEAD(name, type)                                 \
struct name {                                               \
      struct type *lh_first;  /* first element */                 \
}

#define     LIST_HEAD_INITIALIZER(head)                           \
      { NULL }

#define     LIST_ENTRY(type)                                \
struct {                                              \
      struct type *le_next;   /* next element */                  \
      struct type **le_prev;  /* address of previous next element */    \
}

/*
 * List functions.
 */

#define     LIST_EMPTY(head)  ((head)->lh_first == NULL)

#define     LIST_FIRST(head)  ((head)->lh_first)

#define     LIST_FOREACH(var, head, field)                              \
      for ((var) = LIST_FIRST((head));                      \
          (var);                                      \
          (var) = LIST_NEXT((var), field))

#define     LIST_INIT(head) do {                                  \
      LIST_FIRST((head)) = NULL;                            \
} while (0)

#define     LIST_INSERT_AFTER(listelm, elm, field) do {                 \
      if ((LIST_NEXT((elm), field) = LIST_NEXT((listelm), field)) != NULL)\
            LIST_NEXT((listelm), field)->field.le_prev =          \
                &LIST_NEXT((elm), field);                   \
      LIST_NEXT((listelm), field) = (elm);                        \
      (elm)->field.le_prev = &LIST_NEXT((listelm), field);        \
} while (0)

#define     LIST_INSERT_BEFORE(listelm, elm, field) do {                \
      (elm)->field.le_prev = (listelm)->field.le_prev;            \
      LIST_NEXT((elm), field) = (listelm);                        \
      *(listelm)->field.le_prev = (elm);                    \
      (listelm)->field.le_prev = &LIST_NEXT((elm), field);        \
} while (0)

#define     LIST_INSERT_HEAD(head, elm, field) do {                     \
      if ((LIST_NEXT((elm), field) = LIST_FIRST((head))) != NULL) \
            LIST_FIRST((head))->field.le_prev = &LIST_NEXT((elm), field);\
      LIST_FIRST((head)) = (elm);                           \
      (elm)->field.le_prev = &LIST_FIRST((head));                 \
} while (0)

#define     LIST_NEXT(elm, field)   ((elm)->field.le_next)

#define     LIST_REMOVE(elm, field) do {                          \
      if (LIST_NEXT((elm), field) != NULL)                        \
            LIST_NEXT((elm), field)->field.le_prev =        \
                (elm)->field.le_prev;                       \
      *(elm)->field.le_prev = LIST_NEXT((elm), field);            \
} while (0)

/*
 * Tail queue declarations.
 */
#define     TAILQ_HEAD(name, type)                                \
struct name {                                               \
      struct type *tqh_first; /* first element */                 \
      struct type **tqh_last; /* addr of last next element */           \
}

#define     TAILQ_HEAD_INITIALIZER(head)                          \
      { NULL, &(head).tqh_first }

#define     TAILQ_ENTRY(type)                               \
struct {                                              \
      struct type *tqe_next;  /* next element */                  \
      struct type **tqe_prev; /* address of previous next element */    \
}

/*
 * Tail queue functions.
 */
#define     TAILQ_EMPTY(head) ((head)->tqh_first == NULL)

#define     TAILQ_FIRST(head) ((head)->tqh_first)

#define     TAILQ_FOREACH(var, head, field)                             \
      for ((var) = TAILQ_FIRST((head));                     \
          (var);                                      \
          (var) = TAILQ_NEXT((var), field))

#define     TAILQ_FOREACH_REVERSE(var, head, headname, field)           \
      for ((var) = TAILQ_LAST((head), headname);                  \
          (var);                                      \
          (var) = TAILQ_PREV((var), headname, field))

#define     TAILQ_INIT(head) do {                                 \
      TAILQ_FIRST((head)) = NULL;                           \
      (head)->tqh_last = &TAILQ_FIRST((head));              \
} while (0)

#define     TAILQ_INSERT_AFTER(head, listelm, elm, field) do {          \
      if ((TAILQ_NEXT((elm), field) = TAILQ_NEXT((listelm), field)) != NULL)\
            TAILQ_NEXT((elm), field)->field.tqe_prev =            \
                &TAILQ_NEXT((elm), field);                        \
      else                                            \
            (head)->tqh_last = &TAILQ_NEXT((elm), field);         \
      TAILQ_NEXT((listelm), field) = (elm);                       \
      (elm)->field.tqe_prev = &TAILQ_NEXT((listelm), field);            \
} while (0)

#define     TAILQ_INSERT_BEFORE(listelm, elm, field) do {               \
      (elm)->field.tqe_prev = (listelm)->field.tqe_prev;          \
      TAILQ_NEXT((elm), field) = (listelm);                       \
      *(listelm)->field.tqe_prev = (elm);                   \
      (listelm)->field.tqe_prev = &TAILQ_NEXT((elm), field);            \
} while (0)

#define     TAILQ_INSERT_HEAD(head, elm, field) do {              \
      if ((TAILQ_NEXT((elm), field) = TAILQ_FIRST((head))) != NULL)     \
            TAILQ_FIRST((head))->field.tqe_prev =                 \
                &TAILQ_NEXT((elm), field);                        \
      else                                            \
            (head)->tqh_last = &TAILQ_NEXT((elm), field);         \
      TAILQ_FIRST((head)) = (elm);                          \
      (elm)->field.tqe_prev = &TAILQ_FIRST((head));               \
} while (0)

#define     TAILQ_INSERT_TAIL(head, elm, field) do {              \
      TAILQ_NEXT((elm), field) = NULL;                      \
      (elm)->field.tqe_prev = (head)->tqh_last;             \
      *(head)->tqh_last = (elm);                            \
      (head)->tqh_last = &TAILQ_NEXT((elm), field);               \
} while (0)

#define     TAILQ_LAST(head, headname)                            \
      (*(((struct headname *)((head)->tqh_last))->tqh_last))

#define     TAILQ_NEXT(elm, field) ((elm)->field.tqe_next)

#define     TAILQ_PREV(elm, headname, field)                      \
      (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last))

#define     TAILQ_REMOVE(head, elm, field) do {                   \
      if ((TAILQ_NEXT((elm), field)) != NULL)                     \
            TAILQ_NEXT((elm), field)->field.tqe_prev =            \
                (elm)->field.tqe_prev;                      \
      else                                            \
            (head)->tqh_last = (elm)->field.tqe_prev;       \
      *(elm)->field.tqe_prev = TAILQ_NEXT((elm), field);          \
} while (0)


#ifdef _KERNEL

/*
 * XXX insque() and remque() are an old way of handling certain queues.
 * They bogusly assumes that all queue heads look alike.
 */

struct quehead {
      struct quehead *qh_link;
      struct quehead *qh_rlink;
};

#ifdef      __GNUC__

static __inline void
insque(void *a, void *b)
{
      struct quehead *element = (struct quehead *)a,
             *head = (struct quehead *)b;

      element->qh_link = head->qh_link;
      element->qh_rlink = head;
      head->qh_link = element;
      element->qh_link->qh_rlink = element;
}

static __inline void
remque(void *a)
{
      struct quehead *element = (struct quehead *)a;

      element->qh_link->qh_rlink = element->qh_rlink;
      element->qh_rlink->qh_link = element->qh_link;
      element->qh_rlink = 0;
}

#else /* !__GNUC__ */

void  insque __P((void *a, void *b));
void  remque __P((void *a));

#endif /* __GNUC__ */

#endif /* _KERNEL */

#endif /* !_SYS_QUEUE_H_ */

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