/*      $NetBSD: queue.h,v 1.38 2004/04/18 14:12:05 lukem Exp $ */
/*      $Id$ */

/*
 * 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.
 * 3. 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
 */

#ifndef _ASN1_QUEUE_H_
#define _ASN1_QUEUE_H_

/*
 * Tail queue definitions.
 */
#define ASN1_TAILQ_HEAD(name, type)                                     \
struct name {                                                           \
        struct type *tqh_first; /* first element */                     \
        struct type **tqh_last; /* addr of last next element */         \
}

#define ASN1_TAILQ_HEAD_INITIALIZER(head)                               \
        { NULL, &(head).tqh_first }
#define ASN1_TAILQ_ENTRY(type)                                          \
struct {                                                                \
        struct type *tqe_next;  /* next element */                      \
        struct type **tqe_prev; /* address of previous next element */  \
}

/*
 * Tail queue functions.
 */
#if defined(_KERNEL) && defined(QUEUEDEBUG)
#define QUEUEDEBUG_ASN1_TAILQ_INSERT_HEAD(head, elm, field)             \
        if ((head)->tqh_first &&                                        \
            (head)->tqh_first->field.tqe_prev != &(head)->tqh_first)    \
                panic("ASN1_TAILQ_INSERT_HEAD %p %s:%d", (head), __FILE__, __LINE__);
#define QUEUEDEBUG_ASN1_TAILQ_INSERT_TAIL(head, elm, field)             \
        if (*(head)->tqh_last != NULL)                                  \
                panic("ASN1_TAILQ_INSERT_TAIL %p %s:%d", (head), __FILE__, __LINE__);
#define QUEUEDEBUG_ASN1_TAILQ_OP(elm, field)                            \
        if ((elm)->field.tqe_next &&                                    \
            (elm)->field.tqe_next->field.tqe_prev !=                    \
            &(elm)->field.tqe_next)                                     \
                panic("ASN1_TAILQ_* forw %p %s:%d", (elm), __FILE__, __LINE__);\
        if (*(elm)->field.tqe_prev != (elm))                            \
                panic("ASN1_TAILQ_* back %p %s:%d", (elm), __FILE__, __LINE__);
#define QUEUEDEBUG_ASN1_TAILQ_PREREMOVE(head, elm, field)               \
        if ((elm)->field.tqe_next == NULL &&                            \
            (head)->tqh_last != &(elm)->field.tqe_next)                 \
                panic("ASN1_TAILQ_PREREMOVE head %p elm %p %s:%d",      \
                      (head), (elm), __FILE__, __LINE__);
#define QUEUEDEBUG_ASN1_TAILQ_POSTREMOVE(elm, field)                    \
        (elm)->field.tqe_next = (void *)1L;                             \
        (elm)->field.tqe_prev = (void *)1L;
#else
#define QUEUEDEBUG_ASN1_TAILQ_INSERT_HEAD(head, elm, field)
#define QUEUEDEBUG_ASN1_TAILQ_INSERT_TAIL(head, elm, field)
#define QUEUEDEBUG_ASN1_TAILQ_OP(elm, field)
#define QUEUEDEBUG_ASN1_TAILQ_PREREMOVE(head, elm, field)
#define QUEUEDEBUG_ASN1_TAILQ_POSTREMOVE(elm, field)
#endif

#define ASN1_TAILQ_INIT(head) do {                                      \
        (head)->tqh_first = NULL;                                       \
        (head)->tqh_last = &(head)->tqh_first;                          \
} while (/*CONSTCOND*/0)

#define ASN1_TAILQ_INSERT_HEAD(head, elm, field) do {                   \
        QUEUEDEBUG_ASN1_TAILQ_INSERT_HEAD((head), (elm), field)         \
        if (((elm)->field.tqe_next = (head)->tqh_first) != NULL)        \
                (head)->tqh_first->field.tqe_prev =                     \
                    &(elm)->field.tqe_next;                             \
        else                                                            \
                (head)->tqh_last = &(elm)->field.tqe_next;              \
        (head)->tqh_first = (elm);                                      \
        (elm)->field.tqe_prev = &(head)->tqh_first;                     \
} while (/*CONSTCOND*/0)

#define ASN1_TAILQ_INSERT_TAIL(head, elm, field) do {                   \
        QUEUEDEBUG_ASN1_TAILQ_INSERT_TAIL((head), (elm), field)         \
        (elm)->field.tqe_next = NULL;                                   \
        (elm)->field.tqe_prev = (head)->tqh_last;                       \
        *(head)->tqh_last = (elm);                                      \
        (head)->tqh_last = &(elm)->field.tqe_next;                      \
} while (/*CONSTCOND*/0)

#define ASN1_TAILQ_INSERT_AFTER(head, listelm, elm, field) do {         \
        QUEUEDEBUG_ASN1_TAILQ_OP((listelm), field)                      \
        if (((elm)->field.tqe_next = (listelm)->field.tqe_next) != NULL)\
                (elm)->field.tqe_next->field.tqe_prev =                 \
                    &(elm)->field.tqe_next;                             \
        else                                                            \
                (head)->tqh_last = &(elm)->field.tqe_next;              \
        (listelm)->field.tqe_next = (elm);                              \
        (elm)->field.tqe_prev = &(listelm)->field.tqe_next;             \
} while (/*CONSTCOND*/0)

#define ASN1_TAILQ_INSERT_BEFORE(listelm, elm, field) do {              \
        QUEUEDEBUG_ASN1_TAILQ_OP((listelm), field)                      \
        (elm)->field.tqe_prev = (listelm)->field.tqe_prev;              \
        (elm)->field.tqe_next = (listelm);                              \
        *(listelm)->field.tqe_prev = (elm);                             \
        (listelm)->field.tqe_prev = &(elm)->field.tqe_next;             \
} while (/*CONSTCOND*/0)

#define ASN1_TAILQ_REMOVE(head, elm, field) do {                        \
        QUEUEDEBUG_ASN1_TAILQ_PREREMOVE((head), (elm), field)           \
        QUEUEDEBUG_ASN1_TAILQ_OP((elm), field)                          \
        if (((elm)->field.tqe_next) != NULL)                            \
                (elm)->field.tqe_next->field.tqe_prev =                 \
                    (elm)->field.tqe_prev;                              \
        else                                                            \
                (head)->tqh_last = (elm)->field.tqe_prev;               \
        *(elm)->field.tqe_prev = (elm)->field.tqe_next;                 \
        QUEUEDEBUG_ASN1_TAILQ_POSTREMOVE((elm), field);                 \
} while (/*CONSTCOND*/0)

#define ASN1_TAILQ_FOREACH(var, head, field)                            \
        for ((var) = ((head)->tqh_first);                               \
                (var);                                                  \
                (var) = ((var)->field.tqe_next))

#define ASN1_TAILQ_FOREACH_REVERSE(var, head, headname, field)          \
        for ((var) = (*(((struct headname *)((head)->tqh_last))->tqh_last)); \
                (var);                                                  \
                (var) = (*(((struct headname *)((var)->field.tqe_prev))->tqh_last)))

/*
 * Tail queue access methods.
 */
#define ASN1_TAILQ_EMPTY(head)          ((head)->tqh_first == NULL)
#define ASN1_TAILQ_FIRST(head)          ((head)->tqh_first)
#define ASN1_TAILQ_NEXT(elm, field)             ((elm)->field.tqe_next)

#define ASN1_TAILQ_LAST(head, headname) \
        (*(((struct headname *)((head)->tqh_last))->tqh_last))
#define ASN1_TAILQ_PREV(elm, headname, field) \
        (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last))


#endif  /* !_ASN1_QUEUE_H_ */