/*
 * 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: head/sys/sys/queue.h 251887 2013-06-18 02:57:56Z lstewart $
 */

#ifndef _BSD_LIST_H_
#define _BSD_LIST_H_

#include <assert.h>

#ifdef QUEUE_MACRO_DEBUG
/* Store the last 2 places the queue element or head was altered */
struct qm_trace {
	unsigned long	 lastline;
	unsigned long	 prevline;
	const char	*lastfile;
	const char	*prevfile;
};

#define	TRACEBUF	struct qm_trace trace;
#define	TRACEBUF_INITIALIZER	{ __FILE__, __LINE__, NULL, 0 } ,
#define	TRASHIT(x)	do {(x) = (void *)-1;} while (0)
#define	QMD_SAVELINK(name, link)	void **name = (void *)&(link)

#define	QMD_TRACE_HEAD(head) do {					\
	(head)->trace.prevline = (head)->trace.lastline;		\
	(head)->trace.prevfile = (head)->trace.lastfile;		\
	(head)->trace.lastline = __LINE__;				\
	(head)->trace.lastfile = __FILE__;				\
} while (0)

#define	QMD_TRACE_ELEM(elem) do {					\
	(elem)->trace.prevline = (elem)->trace.lastline;		\
	(elem)->trace.prevfile = (elem)->trace.lastfile;		\
	(elem)->trace.lastline = __LINE__;				\
	(elem)->trace.lastfile = __FILE__;				\
} while (0)

#else
#define	QMD_TRACE_ELEM(elem)
#define	QMD_TRACE_HEAD(head)
#define	QMD_SAVELINK(name, link)
#define	TRACEBUF
#define	TRACEBUF_INITIALIZER
#define	TRASHIT(x)
#endif	/* QUEUE_MACRO_DEBUG */

/*
 * 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 */         \
    TRACEBUF                            \
}

#define TAILQ_NEW(name, type)                                  \
    TAILQ_HEAD(name, type) name = TAILQ_HEAD_INITIALIZER(name);


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

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

/*
 * Tail queue functions.
 */
#if (defined(_KERNEL) && defined(INVARIANTS))
#define     QMD_TAILQ_CHECK_HEAD(head, field) do {              \
    if (!TAILQ_EMPTY(head) &&                   \
        TAILQ_FIRST((head))->field.tqe_prev !=          \
         &TAILQ_FIRST((head)))                  \
        panic("Bad tailq head %p first->prev != head", (head));     \
} while (0)

#define     QMD_TAILQ_CHECK_TAIL(head, field) do {              \
    if (*(head)->tqh_last != NULL)                  \
            panic("Bad tailq NEXT(%p->tqh_last) != NULL", (head));      \
} while (0)

#define     QMD_TAILQ_CHECK_NEXT(elm, field) do {               \
    if (TAILQ_NEXT((elm), field) != NULL &&                 \
        TAILQ_NEXT((elm), field)->field.tqe_prev !=             \
         &((elm)->field.tqe_next))                  \
        panic("Bad link elm %p next->prev != elm", (elm));  \
} while (0)

#define     QMD_TAILQ_CHECK_PREV(elm, field) do {               \
    if (*(elm)->field.tqe_prev != (elm))                \
        panic("Bad link elm %p prev->next != elm", (elm));  \
} while (0)
#else
#define     QMD_TAILQ_CHECK_HEAD(head, field)
#define     QMD_TAILQ_CHECK_TAIL(head, headname)
#define     QMD_TAILQ_CHECK_NEXT(elm, field)
#define     QMD_TAILQ_CHECK_PREV(elm, field)
#endif /* (_KERNEL && INVARIANTS) */

#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_FROM(var, head, field)                \
    for ((var) = ((var) ? (var) : TAILQ_FIRST((head)));         \
        (var);                          \
        (var) = TAILQ_NEXT((var), field))

#define     TAILQ_FOREACH_SAFE(var, head, field, tvar)          \
    for ((var) = TAILQ_FIRST((head));               \
        (var) && ((tvar) = TAILQ_NEXT((var), field), 1);        \
        (var) = (tvar))

#define     TAILQ_FOREACH_FROM_SAFE(var, head, field, tvar)             \
    for ((var) = ((var) ? (var) : TAILQ_FIRST((head)));         \
        (var) && ((tvar) = TAILQ_NEXT((var), field), 1);        \
        (var) = (tvar))

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

#define     TAILQ_FOREACH_REVERSE_FROM(var, head, headname, field)      \
    for ((var) = ((var) ? (var) : TAILQ_LAST((head), headname));    \
        (var);                          \
        (var) = TAILQ_PREV((var), headname, field))

#define     TAILQ_FOREACH_REVERSE_SAFE(var, head, headname, field, tvar)    \
    for ((var) = TAILQ_LAST((head), headname);          \
        (var) && ((tvar) = TAILQ_PREV((var), headname, field), 1);  \
        (var) = (tvar))

#define     TAILQ_FOREACH_REVERSE_FROM_SAFE(var, head, headname, field, tvar) \
    for ((var) = ((var) ? (var) : TAILQ_LAST((head), headname));    \
        (var) && ((tvar) = TAILQ_PREV((var), headname, field), 1);  \
        (var) = (tvar))

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

#define     TAILQ_INSERT_AFTER(head, listelm, elm, field) do {      \
    QMD_TAILQ_CHECK_NEXT(listelm, field);               \
    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);       \
        QMD_TRACE_HEAD(head);                   \
    }                               \
    TAILQ_NEXT((listelm), field) = (elm);               \
    (elm)->field.tqe_prev = &TAILQ_NEXT((listelm), field);      \
    QMD_TRACE_ELEM(&(elm)->field);                  \
    QMD_TRACE_ELEM(&listelm->field);                \
} while (0)

#define     TAILQ_INSERT_BEFORE(listelm, elm, field) do {           \
    QMD_TAILQ_CHECK_PREV(listelm, field);               \
    (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);      \
    QMD_TRACE_ELEM(&(elm)->field);                  \
    QMD_TRACE_ELEM(&listelm->field);                \
} while (0)

#define     TAILQ_INSERT_HEAD(head, elm, field) do {            \
    QMD_TAILQ_CHECK_HEAD(head, field);              \
    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));           \
    QMD_TRACE_HEAD(head);                       \
    QMD_TRACE_ELEM(&(elm)->field);                  \
} while (0)

#define     TAILQ_INSERT_TAIL(head, elm, field) do {            \
    QMD_TAILQ_CHECK_TAIL(head, field);              \
    TAILQ_NEXT((elm), field) = NULL;                \
    (elm)->field.tqe_prev = (head)->tqh_last;           \
    *(head)->tqh_last = (elm);                  \
    (head)->tqh_last = &TAILQ_NEXT((elm), field);           \
    QMD_TRACE_HEAD(head);                       \
    QMD_TRACE_ELEM(&(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 {                 \
    QMD_SAVELINK(oldnext, (elm)->field.tqe_next);           \
    QMD_SAVELINK(oldprev, (elm)->field.tqe_prev);           \
    QMD_TAILQ_CHECK_NEXT(elm, field);               \
    QMD_TAILQ_CHECK_PREV(elm, field);               \
    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;       \
        QMD_TRACE_HEAD(head);                   \
    }                               \
    *(elm)->field.tqe_prev = TAILQ_NEXT((elm), field);      \
    TRASHIT(*oldnext);                      \
    TRASHIT(*oldprev);                      \
    QMD_TRACE_ELEM(&(elm)->field);                  \
} while (0)

#define TAILQ_FOREACH_MATCHING_SAFE(var, head, field, tvar, search_expr) \
    for ((var) = TAILQ_FIRST((head));                                   \
         (var) && ((tvar) = TAILQ_NEXT((var), field), 1);               \
         (var) = (tvar))                                                \
        if (search_expr)
#endif //_BSD_LIST_H_