osd-contiki/core/net/mac/xmac.c

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/* XXX: TODO: turn radio off when a packet not destined for us is heard. */
/*
* 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: xmac.c,v 1.2 2007/05/15 08:07:07 adamdunkels Exp $
*/
/**
* \file
* A simple power saving MAC protocol based on X-MAC [SenSys 2006]
* \author
* Adam Dunkels <adam@sics.se>
*/
#include "sys/pt.h"
#include "net/mac/xmac.h"
#include "sys/rtimer.h"
#include "dev/leds.h"
#include "net/rime.h"
#include "dev/radio.h"
#ifdef CHAMELEON
#include "net/chameleon/packattr.h"
#endif
extern rimeaddr_t uc_receiver;
struct powercycle {
struct pt pt;
struct rtimer rt;
rtimer_clock_t ontime, offtime;
int num_strobes;
};
struct xmac_hdr {
rimeaddr_t sender;
rimeaddr_t receiver;
};
static struct rtimer rt;
static struct pt pt;
#ifdef XMAC_CONF_BASE_TIME
#define BASE_TIME XMAC_CONF_BASE_TIME
#else
#define BASE_TIME (RTIMER_ARCH_SECOND / 100)
#endif
#ifdef XMAC_CONF_DUTYCYCLE
#define DUTYCYCLE XMAC_CONF_DUTYCYCLE
#else
#define DUTYCYCLE 10
#endif
#define OFF_TIME BASE_TIME * (DUTYCYCLE)
#define ON_TIME BASE_TIME
#define STROBE_WAIT_TIME ON_TIME / 2
static volatile unsigned char should_be_awake = 0;
static volatile unsigned char someone_is_sending = 0;
static volatile unsigned char we_are_sending = 0;
static volatile unsigned char radio_is_on = 0;
static volatile unsigned char long_off = 0;
static const struct radio_driver *radio;
#undef LEDS_ON
#undef LEDS_OFF
#undef LEDS_TOGGLE
#include <stdio.h>
#define DEBUG 0
#if DEBUG
#define LEDS_ON(x) leds_on(x)
#define LEDS_OFF(x) leds_off(x)
#define LEDS_TOGGLE(x) leds_toggle(x)
#include <stdio.h>
#define PRINTF(...) printf(__VA_ARGS__)
#else
#define LEDS_ON(x)
#define LEDS_OFF(x)
#define LEDS_TOGGLE(x)
#define PRINTF(...)
#endif
/*---------------------------------------------------------------------------*/
static void
powercycle(struct rtimer *t, void *ptr)
{
PT_BEGIN(&pt);
while(1) {
rtimer_clock_t t1, t2;
t1 = rtimer_arch_now();
if(should_be_awake == 0) {
radio->off();
radio_is_on = 0;
LEDS_OFF(LEDS_RED);
} else {
should_be_awake++;
if(should_be_awake > 2) {
should_be_awake = 0;
}
}
if(rtimer_set(t, RTIMER_TIME(t) + OFF_TIME, 1, powercycle, ptr)) {
PRINTF("xmac: could not set rtimer\n");
}
t2 = rtimer_arch_now();
/* printf("xmac 1 %d\n", t2 - t1); */
PT_YIELD(&pt);
if(we_are_sending) {
PRINTF("xmac: we are sending 1, stopping timer\n");
PT_YIELD(&pt);
}
t1 = rtimer_arch_now();
if(radio_is_on == 0) {
radio->on();
radio_is_on = 1;
LEDS_ON(LEDS_RED);
}
if(rtimer_set(t, RTIMER_TIME(t) + ON_TIME, 1, powercycle, ptr)) {
PRINTF("xmac: could not set rtimer\n");
}
t2 = rtimer_arch_now();
/* printf("xmac 2 %d\n", t2 - t1); */
PT_YIELD(&pt);
if(we_are_sending) {
PRINTF("xmac: we are sending 2, stopping timer\n");
PT_YIELD(&pt);
}
if(long_off) {
/* XXX should wait for a complete packet that is not destined to
us to swisch past us. */
long_off = 0;
}
}
PT_END(&pt);
}
/*---------------------------------------------------------------------------*/
static void
send(void)
{
rtimer_clock_t t0, t1;
int strobes;
struct xmac_hdr *hdr;
int got_ack = 0;
we_are_sending = 1;
radio->on();
/* printf("xmac_send\n");*/
PRINTF("xmac: send() len %d\n", rimebuf_totlen());
rimebuf_hdralloc(sizeof(struct xmac_hdr));
hdr = rimebuf_hdrptr();
rimeaddr_copy(&hdr->sender, &rimeaddr_node_addr);
#if CHAMELEON
rimeaddr_copy(&hdr->receiver, packattr_aget(PACKATTR_RECEIVER));
#else
rimeaddr_copy(&hdr->receiver, &uc_receiver);
#endif
rimebuf_compact();
/* should_be_awake = 1;
while(!radio_is_on) {}*/
t0 = RTIMER_NOW();
strobes = 0;
do {
struct xmac_hdr msg;
rtimer_clock_t t;
int len;
t = RTIMER_NOW();
LEDS_TOGGLE(LEDS_GREEN);
rimeaddr_copy(&msg.sender, &rimeaddr_node_addr);
#if CHAMELEON
rimeaddr_copy(&msg.receiver, packattr_aget(PACKATTR_RECEIVER));
#else
rimeaddr_copy(&msg.receiver, &uc_receiver);
#endif
/* printf("sender %d.%d receiver %d.%d node %d.%d.\n",
msg.sender.u8[0],msg.sender.u8[1],
msg.receiver.u8[0],msg.receiver.u8[1],
rimeaddr_node_addr.u8[0], rimeaddr_node_addr.u8[1]);*/
radio->send((const u8_t *)&msg, sizeof(struct xmac_hdr));
while(RTIMER_CLOCK_LT(RTIMER_NOW(), t + STROBE_WAIT_TIME)) {
/* See if we got an ACK */
/* printf("befor read\n");*/
len = radio->read((u8_t *)&msg, sizeof(struct xmac_hdr));
/* printf("after read len %d\n", len);*/
if(len > 0) {
PRINTF("xmac len %d sender %d.%d receiver %d.%d node %d.%d.\n", len,
msg.sender.u8[0],msg.sender.u8[1],
msg.receiver.u8[0],msg.receiver.u8[1],
rimeaddr_node_addr.u8[0], rimeaddr_node_addr.u8[1]);
if(rimeaddr_cmp(&msg.receiver, &rimeaddr_node_addr)) {
/* We got an ACK from the receiver, so we can immediately send
the packet. */
got_ack = 1;
break;
}
}
}
/* PRINTF("xmac Strobe %d got_ack %d\n", strobes, got_ack);*/
++strobes;
if(got_ack) {
break;
}
} while(RTIMER_CLOCK_LT(RTIMER_NOW(), t0 + OFF_TIME + ON_TIME));
radio->send(rimebuf_hdrptr(), rimebuf_totlen());
PRINTF("xmac: send, done\n");
/* printf("Strobe %d got_ack %d\n", strobes, got_ack);*/
LEDS_OFF(LEDS_GREEN);
PT_INIT(&pt);
if(rtimer_set(&rt, RTIMER_NOW() + ON_TIME, 1, powercycle, NULL)) {
PRINTF("xmac: could not set rtimer after send\n");
}
we_are_sending = 0;
}
/*---------------------------------------------------------------------------*/
static void
qsend(void)
{
if(someone_is_sending) {
PRINTF("xmac: should queue packet, now just dropping %d %d %d %d.\n",
should_be_awake, someone_is_sending, we_are_sending, radio_is_on);
} else {
PRINTF("xmac: send immediately.\n");
send();
}
}
/*---------------------------------------------------------------------------*/
static void
input(const struct radio_driver *d)
{
struct xmac_hdr *hdr;
u8_t len;
rimebuf_clear();
PRINTF("xmac: input ");
len = d->read(rimebuf_dataptr(), RIMEBUF_SIZE);
PRINTF("%d bytes\n", len);
if(len > 0) {
someone_is_sending = 1;
rimebuf_set_datalen(len);
hdr = rimebuf_dataptr();
rimebuf_hdrreduce(sizeof(struct xmac_hdr));
if(rimeaddr_cmp(&hdr->receiver, &rimeaddr_node_addr)) {
should_be_awake = 1;
PRINTF("xmac: for us\n");
if(!rimeaddr_cmp(&hdr->sender, &rimeaddr_node_addr) &&
rimebuf_totlen() == 0) {
/* XXX Send an ACK and wait for packet . */
PRINTF("xmac: got sender %d.%d receiver %d.%d\n",
hdr->sender.u8[0],hdr->sender.u8[1],
hdr->receiver.u8[0],hdr->receiver.u8[1]);
while(!radio_is_on) {}
{
struct xmac_hdr msg;
rimeaddr_copy(&msg.receiver, &hdr->sender);
rimeaddr_copy(&msg.sender, &hdr->sender);
PRINTF("xmac: sending sender %d.%d receiver %d.%d\n",
msg.sender.u8[0],msg.sender.u8[1],
msg.receiver.u8[0],msg.receiver.u8[1]);
radio->send((const u8_t *)&msg, sizeof(struct xmac_hdr));
}
}
} else if(rimeaddr_cmp(&hdr->receiver, &rimeaddr_null)) {
/* Wait for the actual packet to arrive. */
should_be_awake = 1;
/* PRINTF("xmac: broadcast\n");*/
} else {
/* Go back to sleep. XXX should not turn on the radio again
until this packet has passed. */
should_be_awake = 0;
someone_is_sending = 0;
long_off = 1;
/* XXX set timer to turn someone_is_sending off again and send queued packet. */
/* PRINTF("xmac: not for us\n");*/
}
if(rimebuf_totlen() > 0) {
/* We have received the final packet, so we can go back to being
asleep. */
someone_is_sending = 0;
should_be_awake = 0;
PRINTF("xmac: final packet received\n");
rime_input();
/* XXX send queued packet. */
}
}
}
/*---------------------------------------------------------------------------*/
void
xmac_init(const struct radio_driver *d)
{
radio_is_on = 0;
should_be_awake = 0;
PT_INIT(&pt);
rtimer_set(&rt, RTIMER_NOW() + OFF_TIME, 1, powercycle, NULL);
rime_set_output(qsend);
radio = d;
radio->set_receive_function(input);
}
/*---------------------------------------------------------------------------*/