packetqueue.c

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/**
 * \addtogroup packetqueue
 * @{
 */
/*
 * Copyright (c) 2009, Swedish Institute of Computer Science.
 * 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 Institute 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 INSTITUTE 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 INSTITUTE 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.
 *
 * This file is part of the Contiki operating system.
 *
 * $Id: packetqueue.c,v 1.1 2010/06/14 19:19:16 adamdunkels Exp $
 */

/**
 * \file
 *         Packet queue management
 * \author
 *         Adam Dunkels <adam@sics.se>
 */

#include "sys/ctimer.h"
#include "net/packetqueue.h"

/*---------------------------------------------------------------------------*/
void
packetqueue_init(struct packetqueue *q)
{
  list_init(*q->list);
  memb_init(q->memb);
}
/*---------------------------------------------------------------------------*/
static void
remove_queued_packet(void *item)
{
  struct packetqueue_item *i = item;
  struct packetqueue *q = i->queue;

  list_remove(*q->list, i);
  queuebuf_free(i->buf);
  ctimer_stop(&i->lifetimer);
  memb_free(q->memb, i);
  /*  printf("removing queued packet due to timeout\n");*/
}
/*---------------------------------------------------------------------------*/
int
packetqueue_enqueue_packetbuf(struct packetqueue *q, clock_time_t lifetime,
                              void *ptr)
{
  struct packetqueue_item *i;

  /* Allocate a memory block to hold the packet queue item. */
  i = memb_alloc(q->memb);

  if(i == NULL) {
    return 0;
  }

  /* Allocate a queuebuf and copy the contents of the packetbuf into it. */
  i->buf = queuebuf_new_from_packetbuf();

  if(i->buf == NULL) {
    memb_free(q->memb, i);
    return 0;
  }

  i->queue = q;
  i->ptr = ptr;

  /* Setup a ctimer that removes the packet from the queue when its
     lifetime expires. If the lifetime is zero, we do not set a
     lifetimer. */
  if(lifetime > 0) {
    ctimer_set(&i->lifetimer, lifetime, remove_queued_packet, i);
  }

  /* Add the item to the queue. */
  list_add(*q->list, i);

  return 1;
}
/*---------------------------------------------------------------------------*/
struct packetqueue_item *
packetqueue_first(struct packetqueue *q)
{
  return list_head(*q->list);
}
/*---------------------------------------------------------------------------*/
void
packetqueue_dequeue(struct packetqueue *q)
{
  struct packetqueue_item *i;
  
  i = list_head(*q->list);
  if(i != NULL) {
    list_remove(*q->list, i);
    queuebuf_free(i->buf);
    ctimer_stop(&i->lifetimer);
    memb_free(q->memb, i);
  }
}
/*---------------------------------------------------------------------------*/
int
packetqueue_len(struct packetqueue *q)
{
  return list_length(*q->list);
}
/*---------------------------------------------------------------------------*/
struct queuebuf *
packetqueue_queuebuf(struct packetqueue_item *i)
{
  if(i != NULL) {
    return i->buf;
  } else {
    return NULL;
  }
}
/*---------------------------------------------------------------------------*/
void *
packetqueue_ptr(struct packetqueue_item *i)
{
  if(i != NULL) {
    return i->ptr;
  } else {
    return NULL;
  }
}
/*---------------------------------------------------------------------------*/
/** @} */