sctp_bufq.h

No7信令,我需要交换类似的代码, 请店长审核,谢谢了,急着交换,谢谢

/*****************************************************************************

 @(#) sctp_bufq.h,v 0.7.8.1 2001/12/11 13:26:32 brian Exp

 -----------------------------------------------------------------------------

 Copyright (C) 2001  OpenSS7 Corporation <http://www.openss7.com>

 All Rights Reserved.

 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free Software
 Foundation; either version 2 of the License, or (at your option) any later
 version.

 This program is distributed in the hope that it will be useful, but WITHOUT
 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
 details.

 You should have received a copy of the GNU General Public License along with
 this program; if not, write to the Free Software Foundation, Inc., 675 Mass
 Ave, Cambridge, MA 02139, USA.

 -----------------------------------------------------------------------------

 U.S. GOVERNMENT RESTRICTED RIGHTS.  If you are licensing this Software on
 behalf of the U.S. Government ("Government"), the following provisions apply
 to you.  If the Software is supplied by the Department of Defense ("DoD"), it
 is classified as "Commercial Computer Software" under paragraph 252.227-7014
 of the DoD Supplement to the Federal Acquisition Regulations ("DFARS") (or any
 successor regulations) and the Government is acquiring only the license rights
 granted herein (the license rights customarily provided to non-Government
 users).  If the Software is supplied to any unit or agency of the Government
 other than DoD, it is classified as "Restricted Computer Software" and the
 Government's rights in the Software are defined in paragraph 52.227-19 of the
 Federal Acquisition Regulations ("FAR") (or any success regulations) or, in
 the cases of NASA, in paragraph 18.52.227-86 of the NASA Supplement to the FAR
 (or any successor regulations).

 -----------------------------------------------------------------------------

 Last Modified 2001/12/11 13:26:32 by brian

 *****************************************************************************/

#ifndef __SCTP_BUFQ_H__
#define __SCTP_BUFQ_H__

typedef struct bufq {
    spinlock_t  q_lock;
    mblk_t      *q_head;
    mblk_t	*q_tail;
    size_t      q_msgs;
    size_t      q_count;
} bufq_t;

static inline void bufq_init(bufq_t *q)
{
    spin_lock_init(&q->q_lock);
    q->q_head  = NULL;
    q->q_tail  = NULL;
    q->q_msgs  = 0;
    q->q_count = 0;
}

static inline size_t bufq_length(bufq_t *q)
{
    return q->q_msgs;
}

static inline size_t bufq_size(bufq_t *q)
{
    return q->q_count;
}

static inline mblk_t *bufq_head(bufq_t *q)
{
    return q->q_head;
}

static inline mblk_t *bufq_tail(bufq_t *q)
{
    return q->q_tail;
}

static inline void __bufq_add(bufq_t *q, mblk_t *mp)
{
    mblk_t *md = mp;
    q->q_msgs++;
    while ( md )
    {
	if ( md->b_wptr > md->b_rptr )
	    q->q_count += md->b_wptr - md->b_rptr;
	md = md->b_cont;
    }
    assure( q->q_head );
    assure( q->q_tail );
    assure( q->q_msgs != 1 || !q->q_head->b_next );
    assure( q->q_msgs != 1 || !q->q_tail->b_prev );
}

static inline void __bufq_sub(bufq_t *q, mblk_t *mp)
{
    mblk_t *md = mp;
    while ( md )
    {
	if ( md->b_wptr > md->b_rptr )
	    q->q_count -= md->b_wptr - md->b_rptr;
	md = md->b_cont;
    }
    q->q_msgs--;
    assure( q->q_msgs || !q->q_head );
    assure( q->q_msgs || !q->q_tail );
}

static inline void bufq_queue(bufq_t *q, mblk_t *mp)
{
    ensure( q && mp, return );
    if ( (mp->b_prev = q->q_tail) )
	mp->b_prev->b_next = mp;
    else
	q->q_head = mp;
    mp->b_next = NULL;
    q->q_tail = mp;
    __bufq_add(q, mp);
}

static inline void bufq_queue_head(bufq_t *q, mblk_t *mp)
{
    ensure( q && mp, return );
    if ( (mp->b_next = q->q_head) )
	mp->b_next->b_prev = mp;
    else
	q->q_tail = mp;
    mp->b_prev = NULL;
    q->q_head = mp;
    __bufq_add(q, mp);
}

static inline void bufq_insert(bufq_t *q, mblk_t *mp, mblk_t *np)
{
    ensure( q && mp && np, return );
    if ( (np->b_prev = mp->b_prev) )
	np->b_prev->b_next = np;
    else
	q->q_head = np;
    mp->b_prev = np;
    np->b_next = mp;
    __bufq_add(q, np);
}

static inline void bufq_append(bufq_t *q, mblk_t *mp, mblk_t *np)
{
    ensure( q && mp && np, return );
    if ( (np->b_next = mp->b_next) )
	np->b_next->b_prev = np;
    else
	q->q_tail = np;
    mp->b_next = np;
    np->b_prev = mp;
    __bufq_add(q, np);
}

static inline mblk_t *bufq_dequeue(bufq_t *q)
{
    mblk_t *mp;
    ensure( q, return(NULL) );
    if ( (mp = q->q_head) )
    {
	if ( (q->q_head = mp->b_next) )
	    mp->b_next->b_prev = NULL;
	else
	    q->q_tail  = NULL;
	mp->b_next = NULL;
	mp->b_prev = NULL;
	__bufq_sub(q, mp);
    }
    return mp;
}

static inline mblk_t *bufq_unlink(bufq_t *q, mblk_t *mp)
{
    ensure( q && mp, return(NULL) );
    if ( mp->b_next )
	mp->b_next->b_prev = mp->b_prev;
    else
	q->q_tail = mp->b_prev;
    if ( mp->b_prev )
	mp->b_prev->b_next = mp->b_next;
    else
	q->q_head = mp->b_next;
    mp->b_next = NULL;
    mp->b_prev = NULL;
    __bufq_sub(q, mp);
    return(mp);
}

static inline void bufq_freehead(bufq_t *q)
{
    if ( q->q_head )
	freemsg(bufq_dequeue(q));
}

static inline void bufq_purge(bufq_t *q)
{
    while ( q->q_head )
	freemsg(bufq_dequeue(q));
}

static inline void bufq_supply(bufq_t *q, mblk_t *mp)
{
    mblk_t *md = mp;
    while ( md )
    {
	md->b_datap->db_type = M_DATA;
	md->b_rptr = md->b_wptr = md->b_datap->db_base;
	bufq_queue(q, md);
	md = unlinkb(md);
    }
}

static inline mblk_t *bufq_resupply(bufq_t *q, mblk_t *mp, int maxsize, int maxcount)
{
    if ( bufq_length(q) > maxcount || bufq_size(q) > maxsize )
	return mp;
    bufq_supply(q, mp);
    return NULL;
}

static inline void freechunks(mblk_t *mp)
{
	mblk_t *dp, *dp_next;
	for ( dp = mp; dp; dp_next = dp->b_next, freemsg(dp), dp = dp_next );
}

#endif  __SCTP_BUFQ_H__