osd-contiki/core/net/rime/trickle.c
2008-07-08 10:59:31 +00:00

207 lines
6 KiB
C

/**
* \addtogroup trickle
* @{
*/
/*
* Copyright (c) 2007, 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: trickle.c,v 1.11 2008/07/08 10:59:31 adamdunkels Exp $
*/
/**
* \file
* Trickle (reliable single source flooding) for Rime
* \author
* Adam Dunkels <adam@sics.se>
*/
#include "net/rime/trickle.h"
#include "lib/random.h"
#if NETSIM
#include "ether.h"
#endif
#define INTERVAL_MIN 1
#define INTERVAL_MAX 4
#define DUPLICATE_THRESHOLD 1
#define SEQNO_LT(a, b) ((signed char)((a) - (b)) < 0)
static const struct rimebuf_attrlist attributes[] =
{
TRICKLE_ATTRIBUTES RIMEBUF_ATTR_LAST
};
#define DEBUG 0
#if DEBUG
#include <stdio.h>
#define PRINTF(...) printf(__VA_ARGS__)
#else
#define PRINTF(...)
#endif
static int run_trickle(struct trickle_conn *c);
/*---------------------------------------------------------------------------*/
static void
send(void *ptr)
{
struct trickle_conn *c = ptr;
if(c->q != NULL) {
queuebuf_to_rimebuf(c->q);
broadcast_send(&c->c);
} else {
PRINTF("%d.%d: trickle send but c->q == NULL\n",
rimeaddr_node_addr.u8[0], rimeaddr_node_addr.u8[1]);
}
}
/*---------------------------------------------------------------------------*/
static void
timer_callback(void *ptr)
{
struct trickle_conn *c = ptr;
run_trickle(c);
}
/*---------------------------------------------------------------------------*/
static void
reset_interval(struct trickle_conn *c)
{
PT_INIT(&c->pt);
run_trickle(c);
}
/*---------------------------------------------------------------------------*/
static void
set_timer(struct trickle_conn *c, struct ctimer *t, clock_time_t i)
{
ctimer_set(t, i, timer_callback, c);
}
/*---------------------------------------------------------------------------*/
static int
run_trickle(struct trickle_conn *c)
{
clock_time_t interval;
PT_BEGIN(&c->pt);
while(1) {
interval = c->interval << c->interval_scaling;
set_timer(c, &c->interval_timer, interval);
set_timer(c, &c->t, interval / 2 + (random_rand() % (interval / 2)));
c->duplicates = 0;
PT_YIELD(&c->pt); /* Wait until listen timeout */
if(c->duplicates < DUPLICATE_THRESHOLD) {
send(c);
}
PT_YIELD(&c->pt); /* Wait until interval timer expired. */
if(c->interval_scaling < INTERVAL_MAX) {
c->interval_scaling++;
}
}
PT_END(&c->pt);
}
/*---------------------------------------------------------------------------*/
static void
recv(struct broadcast_conn *bc, rimeaddr_t *from)
{
struct trickle_conn *c = (struct trickle_conn *)bc;
uint16_t seqno = rimebuf_attr(RIMEBUF_ATTR_EPACKET_ID);
PRINTF("%d.%d: trickle recv seqno %d our %d\n",
rimeaddr_node_addr.u8[0], rimeaddr_node_addr.u8[1],
seqno, c->seqno);
if(seqno == c->seqno) {
/* c->cb->recv(c);*/
++c->duplicates;
} else if(SEQNO_LT(seqno, c->seqno)) {
c->interval_scaling = 0;
send(c);
} else { /* hdr->seqno > c->seqno */
#if NETSIM
/* ether_set_line(from->u8[0], from->u8[1]);*/
#endif /* NETSIM */
c->seqno = seqno;
/* Store the incoming data in the queuebuf */
if(c->q != NULL) {
queuebuf_free(c->q);
}
c->q = queuebuf_new_from_rimebuf();
c->interval_scaling = 0;
reset_interval(c);
send(c);
c->cb->recv(c);
}
}
/*---------------------------------------------------------------------------*/
static CC_CONST_FUNCTION struct broadcast_callbacks bc = { recv };
/*---------------------------------------------------------------------------*/
void
trickle_open(struct trickle_conn *c, clock_time_t interval,
uint16_t channel, const struct trickle_callbacks *cb)
{
broadcast_open(&c->c, channel, &bc);
c->cb = cb;
c->q = NULL;
c->interval = interval;
c->interval_scaling = 0;
channel_set_attributes(channel, attributes);
}
/*---------------------------------------------------------------------------*/
void
trickle_close(struct trickle_conn *c)
{
broadcast_close(&c->c);
ctimer_stop(&c->t);
ctimer_stop(&c->interval_timer);
}
/*---------------------------------------------------------------------------*/
void
trickle_send(struct trickle_conn *c)
{
if(c->q != NULL) {
queuebuf_free(c->q);
}
c->seqno++;
rimebuf_set_attr(RIMEBUF_ATTR_EPACKET_ID, c->seqno);
c->q = queuebuf_new_from_rimebuf();
PRINTF("%d.%d: trickle send seqno %d\n",
rimeaddr_node_addr.u8[0], rimeaddr_node_addr.u8[1],
c->seqno);
reset_interval(c);
send(c);
}
/*---------------------------------------------------------------------------*/
/** @} */