/*
* Copyright (c) 2010, 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.
*
*/
/**
* \file
* Common functionality for phase optimization in duty cycling radio protocols
* \author
* Adam Dunkels <adam@sics.se>
*/
#include "net/mac/phase.h"
#include "net/packetbuf.h"
#include "sys/clock.h"
#include "sys/ctimer.h"
#include "net/queuebuf.h"
#include "net/nbr-table.h"
#if PHASE_CONF_DRIFT_CORRECT
#define PHASE_DRIFT_CORRECT PHASE_CONF_DRIFT_CORRECT
#else
#define PHASE_DRIFT_CORRECT 0
#endif
struct phase {
rtimer_clock_t time;
#if PHASE_DRIFT_CORRECT
rtimer_clock_t drift;
#endif
uint8_t noacks;
struct timer noacks_timer;
};
struct phase_queueitem {
struct ctimer timer;
mac_callback_t mac_callback;
void *mac_callback_ptr;
struct queuebuf *q;
struct rdc_buf_list *buf_list;
};
#define PHASE_DEFER_THRESHOLD 1
#define PHASE_QUEUESIZE 8
#define MAX_NOACKS 16
#define MAX_NOACKS_TIME CLOCK_SECOND * 30
MEMB(queued_packets_memb, struct phase_queueitem, PHASE_QUEUESIZE);
NBR_TABLE(struct phase, nbr_phase);
#define DEBUG 0
#if DEBUG
#include <stdio.h>
#define PRINTF(...) printf(__VA_ARGS__)
#define PRINTDEBUG(...) printf(__VA_ARGS__)
#else
#define PRINTF(...)
#define PRINTDEBUG(...)
#endif
/*---------------------------------------------------------------------------*/
void
phase_update(const linkaddr_t *neighbor, rtimer_clock_t time,
int mac_status)
{
struct phase *e;
/* If we have an entry for this neighbor already, we renew it. */
e = nbr_table_get_from_lladdr(nbr_phase, neighbor);
if(e != NULL) {
if(mac_status == MAC_TX_OK) {
#if PHASE_DRIFT_CORRECT
e->drift = time-e->time;
#endif
e->time = time;
}
/* If the neighbor didn't reply to us, it may have switched
phase (rebooted). We try a number of transmissions to it
before we drop it from the phase list. */
if(mac_status == MAC_TX_NOACK) {
PRINTF("phase noacks %d to %d.%d\n", e->noacks, neighbor->u8[0], neighbor->u8[1]);
e->noacks++;
if(e->noacks == 1) {
timer_set(&e->noacks_timer, MAX_NOACKS_TIME);
}
if(e->noacks >= MAX_NOACKS || timer_expired(&e->noacks_timer)) {
PRINTF("drop %d\n", neighbor->u8[0]);
nbr_table_remove(nbr_phase, e);
return;
}
} else if(mac_status == MAC_TX_OK) {
e->noacks = 0;
}
} else {
/* No matching phase was found, so we allocate a new one. */
if(mac_status == MAC_TX_OK && e == NULL) {
e = nbr_table_add_lladdr(nbr_phase, neighbor);
if(e) {
e->time = time;
#if PHASE_DRIFT_CORRECT
e->drift = 0;
#endif
e->noacks = 0;
}
}
}
}
/*---------------------------------------------------------------------------*/
static void
send_packet(void *ptr)
{
struct phase_queueitem *p = ptr;
if(p->buf_list == NULL) {
queuebuf_to_packetbuf(p->q);
queuebuf_free(p->q);
NETSTACK_RDC.send(p->mac_callback, p->mac_callback_ptr);
} else {
NETSTACK_RDC.send_list(p->mac_callback, p->mac_callback_ptr, p->buf_list);
}
memb_free(&queued_packets_memb, p);
}
/*---------------------------------------------------------------------------*/
phase_status_t
phase_wait(const linkaddr_t *neighbor, rtimer_clock_t cycle_time,
rtimer_clock_t guard_time,
mac_callback_t mac_callback, void *mac_callback_ptr,
struct rdc_buf_list *buf_list)
{
struct phase *e;
// const linkaddr_t *neighbor = packetbuf_addr(PACKETBUF_ADDR_RECEIVER);
/* We go through the list of phases to find if we have recorded a
phase for this particular neighbor. If so, we can compute the
time for the next expected phase and setup a ctimer to switch on
the radio just before the phase. */
e = nbr_table_get_from_lladdr(nbr_phase, neighbor);
if(e != NULL) {
rtimer_clock_t wait, now, expected, sync;
clock_time_t ctimewait;
/* We expect phases to happen every CYCLE_TIME time
units. The next expected phase is at time e->time +
CYCLE_TIME. To compute a relative offset, we subtract
with clock_time(). Because we are only interested in turning
on the radio within the CYCLE_TIME period, we compute the
waiting time with modulo CYCLE_TIME. */
/* printf("neighbor phase 0x%02x (cycle 0x%02x)\n", e->time & (cycle_time - 1),
cycle_time);*/
/* if(e->noacks > 0) {
printf("additional wait %d\n", additional_wait);
}*/
now = RTIMER_NOW();
sync = (e == NULL) ? now : e->time;
#if PHASE_DRIFT_CORRECT
{
int32_t s;
if(e->drift > cycle_time) {
s = e->drift % cycle_time / (e->drift / cycle_time); /* drift per cycle */
s = s * (now - sync) / cycle_time; /* estimated drift to now */
sync += s; /* add it in */
}
}
#endif
/* Check if cycle_time is a power of two */
if(!(cycle_time & (cycle_time - 1))) {
/* Faster if cycle_time is a power of two */
wait = (rtimer_clock_t)((sync - now) & (cycle_time - 1));
} else {
/* Works generally */
wait = cycle_time - (rtimer_clock_t)((now - sync) % cycle_time);
}
if(wait < guard_time) {
wait += cycle_time;
}
ctimewait = (CLOCK_SECOND * (wait - guard_time)) / RTIMER_ARCH_SECOND;
if(ctimewait > PHASE_DEFER_THRESHOLD) {
struct phase_queueitem *p;
p = memb_alloc(&queued_packets_memb);
if(p != NULL) {
if(buf_list == NULL) {
packetbuf_set_attr(PACKETBUF_ATTR_IS_CREATED_AND_SECURED, 1);
p->q = queuebuf_new_from_packetbuf();
}
p->mac_callback = mac_callback;
p->mac_callback_ptr = mac_callback_ptr;
p->buf_list = buf_list;
ctimer_set(&p->timer, ctimewait, send_packet, p);
return PHASE_DEFERRED;
}
}
expected = now + wait - guard_time;
if(!RTIMER_CLOCK_LT(expected, now)) {
/* Wait until the receiver is expected to be awake */
while(RTIMER_CLOCK_LT(RTIMER_NOW(), expected));
}
return PHASE_SEND_NOW;
}
return PHASE_UNKNOWN;
}
/*---------------------------------------------------------------------------*/
void
phase_init(void)
{
memb_init(&queued_packets_memb);
nbr_table_register(nbr_phase, NULL);
}
/*---------------------------------------------------------------------------*/