contiki/core/net/mac/tdma_mac.c

256 lines
7.2 KiB
C

/*
* 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.
*
*/
#include "contiki.h"
#include "net/mac/tdma_mac.h"
#include "net/packetbuf.h"
#include "net/uip-fw.h"
#include "sys/rtimer.h"
#include "net/rime.h"
#include "lib/memb.h"
#include "lib/list.h"
#include "dev/leds.h"
#include "node-id.h"
#include <string.h>
#include <stdio.h>
#define DEBUG 1
#if DEBUG
#define DLEDS_ON(x) leds_on(x)
#define DLEDS_OFF(x) leds_off(x)
#define DLEDS_TOGGLE(x) leds_toggle(x)
#define PRINTF(...) printf(__VA_ARGS__)
#else
#define DLEDS_ON(x)
#define DLEDS_OFF(x)
#define DLEDS_TOGGLE(x)
#define PRINTF(...)
#endif
/* TDMA configuration */
#define NR_SLOTS 3
#define SLOT_LENGTH (RTIMER_SECOND/3)
#define GUARD_PERIOD (RTIMER_SECOND/12)
#define MY_SLOT (node_id % NR_SLOTS)
#define PERIOD_LENGTH RTIMER_SECOND
/* Buffers */
#define NUM_PACKETS 8
uint8_t lastqueued = 0;
uint8_t nextsend = 0;
uint8_t freeslot = 0;
struct queuebuf* data[NUM_PACKETS];
int id[NUM_PACKETS];
static struct rtimer rtimer;
uint8_t timer_on = 0;
static const struct radio_driver *radio;
static void (* receiver_callback)(const struct mac_driver *);
static int id_counter = 0;
static int sent_counter = 0;
/*---------------------------------------------------------------------------*/
static char
transmitter(struct rtimer *t, void *ptr)
{
int r;
rtimer_clock_t now, rest, period_start, slot_start;
/* Calculate slot start time */
now = RTIMER_NOW();
rest = now % PERIOD_LENGTH;
period_start = now - rest;
slot_start = period_start + MY_SLOT*SLOT_LENGTH;
/* Check if we are inside our slot */
if(now < slot_start ||
now > slot_start + SLOT_LENGTH - GUARD_PERIOD) {
PRINTF("TIMER We are outside our slot: %u != [%u,%u]\n", now, slot_start, slot_start + SLOT_LENGTH);
while(now > slot_start + SLOT_LENGTH - GUARD_PERIOD) {
slot_start += PERIOD_LENGTH;
}
PRINTF("TIMER Rescheduling until %u\n", slot_start);
r = rtimer_set(&rtimer, slot_start, 1,
(void (*)(struct rtimer *, void *))transmitter, NULL);
if(r) {
PRINTF("TIMER Error #1: %d\n", r);
}
return 1;
}
/* Transmit queued packets */
while(nextsend != freeslot) {
PRINTF("RADIO Transmitting packet #%i\n", id[nextsend]);
if(!radio->send(queuebuf_dataptr(data[nextsend]),
queuebuf_datalen(data[nextsend]))) {
sent_counter++;
PRINTF("RADIO Transmit OK for #%i, total=%i\n", id[nextsend], sent_counter);
DLEDS_TOGGLE(LEDS_GREEN);
} else {
PRINTF("RADIO Transmit failed for #%i, total=%i\n", id[nextsend], sent_counter);
DLEDS_TOGGLE(LEDS_RED);
}
nextsend = (nextsend + 1) % NUM_PACKETS;
/* Recalculate new slot */
if(RTIMER_NOW() > slot_start + SLOT_LENGTH - GUARD_PERIOD) {
PRINTF("TIMER No more time to transmit\n");
break;
}
}
/* Calculate time of our next slot */
slot_start += PERIOD_LENGTH;
PRINTF("TIMER Rescheduling until %u\n", slot_start);
r = rtimer_set(&rtimer, slot_start, 1,
(void (*)(struct rtimer *, void *))transmitter, NULL);
if(r) {
PRINTF("TIMER Error #2: %d\n", r);
}
return 0;
}
/*---------------------------------------------------------------------------*/
static int
send(void)
{
int r;
id_counter++;
/* Clean up already sent packets */
while(lastqueued != nextsend) {
PRINTF("BUFFER Cleaning up packet #%i\n", id[lastqueued]);
queuebuf_free(data[lastqueued]);
data[lastqueued] = NULL;
lastqueued = (lastqueued + 1) % NUM_PACKETS;
}
if((freeslot + 1) % NUM_PACKETS == lastqueued) {
PRINTF("BUFFER Buffer full, dropping packet #%i\n", (id_counter+1));
return UIP_FW_DROPPED;
}
/* Allocate queue buf for packet */
data[freeslot] = queuebuf_new_from_packetbuf();
id[freeslot] = id_counter;
if(data[freeslot] == NULL) {
PRINTF("BUFFER Queuebuffer full, dropping packet #%i\n", id[freeslot]);
return UIP_FW_DROPPED;
}
PRINTF("BUFFER Wrote packet #%i to buffer \n", id[freeslot]);
freeslot = (freeslot + 1) % NUM_PACKETS;
if(!timer_on) {
PRINTF("TIMER Starting timer\n");
r = rtimer_set(&rtimer, RTIMER_NOW() + RTIMER_SECOND, 1,
(void (*)(struct rtimer *, void *))transmitter, NULL);
if(r) {
PRINTF("TIMER Error #3: %d\n", r);
} else {
timer_on = 1;
}
}
return UIP_FW_OK; /* TODO Return what? */
}
/*---------------------------------------------------------------------------*/
static void
input(const struct radio_driver *d)
{
receiver_callback(&tdma_mac_driver);
}
/*---------------------------------------------------------------------------*/
static int
read(void)
{
int len;
packetbuf_clear();
len = radio->read(packetbuf_dataptr(), PACKETBUF_SIZE);
packetbuf_set_datalen(len);
return len;
}
/*---------------------------------------------------------------------------*/
static void
set_receive_function(void (* recv)(const struct mac_driver *))
{
receiver_callback = recv;
}
/*---------------------------------------------------------------------------*/
static int
on(void)
{
return radio->on();
}
/*---------------------------------------------------------------------------*/
static int
off(int keep_radio_on)
{
if(keep_radio_on) {
return radio->on();
} else {
return radio->off();
}
}
/*---------------------------------------------------------------------------*/
const struct mac_driver *
tdma_mac_init(const struct radio_driver *d)
{
int i;
for(i = 0; i < NUM_PACKETS; i++) {
data[i] = NULL;
}
radio = d;
radio->set_receive_function(input);
radio->on();
return &tdma_mac_driver;
}
/*---------------------------------------------------------------------------*/
const struct mac_driver tdma_mac_driver = {
"TDMA MAC",
tdma_mac_init,
send,
read,
set_receive_function,
on,
off,
};