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improvements to lpp based on code from Adam and discussions with Thiemo.

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* queue multiple packets
* send a strobe back immediately after receiving a data packet
* double the packet lifetime to allow for a missed probe
This commit is contained in:
nvt-se 2009-03-31 12:47:00 +00:00
parent e90149b7b4
commit dd082f7fcf
1 changed files with 94 additions and 79 deletions
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173
core/net/mac/lpp.c
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@ -28,7 +28,7 @@
*
* This file is part of the Contiki operating system.
*
* $Id: lpp.c,v 1.11 2009/03/26 12:50:57 nvt-se Exp $
* $Id: lpp.c,v 1.12 2009/03/31 12:47:00 nvt-se Exp $
*/
/**
@ -51,6 +51,8 @@
*/
#include "dev/leds.h"
#include "lib/list.h"
#include "lib/memb.h"
#include "lib/random.h"
#include "net/rime.h"
#include "net/mac/mac.h"
@ -94,28 +96,27 @@ static const struct radio_driver *radio;
static void (* receiver_callback)(const struct mac_driver *);
static struct pt pt;
static struct ctimer timer;
static struct timer packet_lifetime_timer;
static struct queuebuf *queued_packet;
static uint8_t is_listening = 0;
#ifdef LPP_CONF_LISTEN_TIME
#define LPP_LISTEN_TIME LPP_CONF_LISTEN_TIME
#else
#define LPP_LISTEN_TIME CLOCK_SECOND / 64
#endif /* LPP_CONF_LISTEN_TIME */
#define LISTEN_TIME CLOCK_SECOND / 32
#define OFF_TIME CLOCK_SECOND * 1
#define PACKET_LIFETIME 2 * (LISTEN_TIME + OFF_TIME)
#ifdef LPP_CONF_OFF_TIME
#define LPP_OFF_TIME LPP_CONF_OFF_TIME
#else
#define LPP_OFF_TIME CLOCK_SECOND * 1
#endif /* LPP_CONF_OFF_TIME */
struct queue_list_item {
struct queue_list_item *next;
struct queuebuf *packet;
struct ctimer timer;
};
#define PACKET_LIFETIME LPP_LISTEN_TIME + LPP_OFF_TIME
#define DUMP_QUEUED_PACKET 0
#ifdef QUEUEBUF_CONF_NUM
#define MAX_QUEUED_PACKETS QUEUEBUF_CONF_NUM / 2
#else /* QUEUEBUF_CONF_NUM */
#define MAX_QUEUED_PACKETS 4
#endif /* QUEUEBUF_CONF_NUM */
LIST(queued_packets_list);
MEMB(queued_packets_memb, struct queue_list_item, MAX_QUEUED_PACKETS);
/*---------------------------------------------------------------------------*/
static void
@ -133,10 +134,18 @@ turn_radio_off(void)
}
/*---------------------------------------------------------------------------*/
static void
remove_queued_packet(void)
remove_queued_packet(void *item)
{
queuebuf_free(queued_packet);
queued_packet = NULL;
struct queue_list_item *i = item;
queuebuf_free(i->packet);
list_remove(queued_packets_list, i);
memb_free(&queued_packets_memb, i);
/* XXX potential optimization */
if(list_length(queued_packets_list) == 0 && is_listening == 0) {
turn_radio_off();
}
}
/*---------------------------------------------------------------------------*/
static void
@ -197,31 +206,25 @@ dutycycle(void *ptr)
while(1) {
turn_radio_on();
send_probe();
ctimer_set(t, LPP_LISTEN_TIME, (void (*)(void *))dutycycle, t);
ctimer_set(t, LISTEN_TIME, (void (*)(void *))dutycycle, t);
PT_YIELD(&pt);
if(queued_packet == NULL) {
/* if(queued_packet == NULL) {*/
if(list_length(queued_packets_list) == 0) {
if(is_listening == 0) {
turn_radio_off();
/* There is a bit of randomness here right now to avoid collisions
due to synchronization effects. Not sure how needed it is
though. XXX */
ctimer_set(t, LPP_OFF_TIME / 2 + (random_rand() % (LPP_OFF_TIME / 2)),
ctimer_set(t, OFF_TIME / 2 + (random_rand() % (OFF_TIME / 2)),
(void (*)(void *))dutycycle, t);
PT_YIELD(&pt);
} else {
is_listening--;
ctimer_set(t, LPP_OFF_TIME,
ctimer_set(t, OFF_TIME,
(void (*)(void *))dutycycle, t);
PT_YIELD(&pt);
}
} else {
/* We are currently sending a packet so we should keep the radio
turned on and not send any probes at this point. */
ctimer_set(t, PACKET_LIFETIME, (void (*)(void *))dutycycle, t);
PT_YIELD(&pt);
remove_queued_packet();
PRINTF("Removing old packet\n");
}
}
@ -266,25 +269,21 @@ send_packet(void)
/* printf("Immediately sending ACK\n");*/
return radio->send(packetbuf_hdrptr(), packetbuf_totlen());
} else {
struct queue_list_item *i;
i = memb_alloc(&queued_packets_memb);
if(i != NULL) {
i->packet = queuebuf_new_from_packetbuf();
if(i->packet == NULL) {
memb_free(&queued_packets_memb, i);
return 0;
} else {
list_add(queued_packets_list, i);
ctimer_set(&i->timer, PACKET_LIFETIME, remove_queued_packet, i);
/* If a packet is already queued, the DUMP_QUEUED_PACKET option
determines if the queued packet should be replaced with the new
packet, or if the new packet should be dropped. XXX haven't
measured the effect of this option */
#if DUMP_QUEUED_PACKET
if(queued_packet != NULL) {
remove_queued_packet();
/* Wait for a probe packet from a neighbor */
turn_radio_on();
}
}
queued_packet = queuebuf_new_from_packetbuf();
#else /* DUMP_QUEUED_PACKET */
if(queued_packet == NULL) {
queued_packet = queuebuf_new_from_packetbuf();
}
#endif /* DUMP_QUEUED_PACKET */
timer_set(&packet_lifetime_timer, PACKET_LIFETIME);
/* Wait for a probe packet from a neighbor */
turn_radio_on();
}
return 1;
}
@ -299,7 +298,7 @@ static int
read_packet(void)
{
int len;
struct lpp_hdr *hdr, *qhdr;
struct lpp_hdr *hdr;
packetbuf_clear();
len = radio->read(packetbuf_dataptr(), PACKETBUF_SIZE);
@ -327,43 +326,57 @@ read_packet(void)
adata->data[i].id,
adata->data[i].value);
}
/* Check if the outbound packet has been waiting too long in the
queue. If so, we remove the packet from the queue. */
if(queued_packet != NULL && timer_expired(&packet_lifetime_timer)) {
remove_queued_packet();
}
if(queued_packet != NULL) {
qhdr = queuebuf_dataptr(queued_packet);
if(rimeaddr_cmp(&qhdr->receiver, &hdr->sender) ||
rimeaddr_cmp(&qhdr->receiver, &rimeaddr_null)) {
PRINTF("%d.%d: got a probe from %d.%d, sending packet to %d.%d\n",
rimeaddr_node_addr.u8[0], rimeaddr_node_addr.u8[1],
hdr->sender.u8[0], hdr->sender.u8[1],
qhdr->receiver.u8[0], qhdr->receiver.u8[1]);
if(list_length(queued_packets_list) > 0) {
struct queue_list_item *i;
for(i = list_head(queued_packets_list); i != NULL; i = i->next) {
struct lpp_hdr *qhdr;
qhdr = queuebuf_dataptr(i->packet);
if(rimeaddr_cmp(&qhdr->receiver, &hdr->sender) ||
rimeaddr_cmp(&qhdr->receiver, &rimeaddr_null)) {
PRINTF("%d.%d: got a probe from %d.%d, sending packet to %d.%d\n",
rimeaddr_node_addr.u8[0], rimeaddr_node_addr.u8[1],
hdr->sender.u8[0], hdr->sender.u8[1],
qhdr->receiver.u8[0], qhdr->receiver.u8[1]);
radio->send(queuebuf_dataptr(queued_packet),
queuebuf_datalen(queued_packet));
radio->send(queuebuf_dataptr(i->packet),
queuebuf_datalen(i->packet));
/* If the packet was not a broadcast packet, we dequeue it
now. Broadcast packets should be transmitted to all
neighbors, and are dequeued by the dutycycling function
instead, after the appropriate time. */
if(!rimeaddr_cmp(&qhdr->receiver, &rimeaddr_null)) {
remove_queued_packet(i);
}
turn_radio_on(); /* XXX Awaiting an ACK: we should check the
packet type of the queued packet to see
if it is a data packet. If not, we
should not turn the radio on. */
/* If the packet was not a broadcast packet, we dequeue it
now. Broadcast packets should be transmitted to all
neighbors, and are dequeued by the dutycycling function
instead, after the appropriate time. */
if(!rimeaddr_cmp(&qhdr->receiver, &rimeaddr_null)) {
remove_queued_packet();
}
turn_radio_on(); /* XXX Awaiting an ACK: we should check the
packet type of the queued packet to see
if it is a data packet. If not, we
should not turn the radio on. */
}
}
} else if(hdr->type == TYPE_DATA) {
PRINTF("%d.%d: got data from %d.%d\n",
rimeaddr_node_addr.u8[0], rimeaddr_node_addr.u8[1],
hdr->sender.u8[0], hdr->sender.u8[1]);
/* XXX send probe after receiving a packet to facilitate data
streaming. We must first copy the contents of the packetbuf into
a queuebuf to avoid overwriting the data with the probe packet. */
struct queuebuf *q;
q = queuebuf_new_from_packetbuf();
if(q != NULL) {
send_probe();
queuebuf_to_packetbuf(q);
queuebuf_free(q);
}
}
len = packetbuf_datalen();
}
@ -416,10 +429,12 @@ lpp_init(const struct radio_driver *d)
{
radio = d;
radio->set_receive_function(input_packet);
ctimer_set(&timer, LPP_LISTEN_TIME, (void (*)(void *))dutycycle, &timer);
ctimer_set(&timer, LISTEN_TIME, (void (*)(void *))dutycycle, &timer);
announcement_register_listen_callback(listen_callback);
memb_init(&queued_packets_memb);
list_init(queued_packets_list);
return &lpp_driver;
}
/*---------------------------------------------------------------------------*/