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Merge pull request #1579 from bkozak-scanimetrics/fix_csma_backoff

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Use collisions for csma backoff and retry
This commit is contained in:
Antonio Lignan 2016-04-28 10:24:55 +02:00
commit 4251539237
10 changed files with 169 additions and 164 deletions
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8
core/contiki-default-conf.h
View File

@ -220,14 +220,6 @@
* on the target platform, and are therefore platform-specific.
*/
/* SICSLOWPAN_CONF_MAX_MAC_TRANSMISSIONS specifies how many times the
MAC layer should resend packets if no link-layer ACK was
received. This only makes sense with the csma_driver
NETSTACK_CONF_MAC. */
#ifndef SICSLOWPAN_CONF_MAX_MAC_TRANSMISSIONS
#define SICSLOWPAN_CONF_MAX_MAC_TRANSMISSIONS 4
#endif /* SICSLOWPAN_CONF_MAX_MAC_TRANSMISSIONS */
/* SICSLOWPAN_CONF_FRAG specifies if 6lowpan fragmentation should be
used or not. Fragmentation is on by default. */
#ifndef SICSLOWPAN_CONF_FRAG

9
core/net/ipv6/sicslowpan.c
View File

@ -92,12 +92,6 @@ void uip_log(char *msg);
#define UIP_LOG(m)
#endif /* UIP_LOGGING == 1 */
#ifdef SICSLOWPAN_CONF_MAX_MAC_TRANSMISSIONS
#define SICSLOWPAN_MAX_MAC_TRANSMISSIONS SICSLOWPAN_CONF_MAX_MAC_TRANSMISSIONS
#else
#define SICSLOWPAN_MAX_MAC_TRANSMISSIONS 4
#endif
#ifndef SICSLOWPAN_COMPRESSION
#ifdef SICSLOWPAN_CONF_COMPRESSION
#define SICSLOWPAN_COMPRESSION SICSLOWPAN_CONF_COMPRESSION
@ -1290,9 +1284,6 @@ output(const uip_lladdr_t *localdest)
packetbuf_clear();
packetbuf_ptr = packetbuf_dataptr();
packetbuf_set_attr(PACKETBUF_ATTR_MAX_MAC_TRANSMISSIONS,
SICSLOWPAN_MAX_MAC_TRANSMISSIONS);
if(callback) {
/* call the attribution when the callback comes, but set attributes
here ! */

284
core/net/mac/csma.c
View File

@ -63,26 +63,35 @@
#define PRINTF(...)
#endif /* DEBUG */
#ifndef CSMA_MAX_BACKOFF_EXPONENT
#ifdef CSMA_CONF_MAX_BACKOFF_EXPONENT
#define CSMA_MAX_BACKOFF_EXPONENT CSMA_CONF_MAX_BACKOFF_EXPONENT
#else
#define CSMA_MAX_BACKOFF_EXPONENT 3
#endif /* CSMA_CONF_MAX_BACKOFF_EXPONENT */
#endif /* CSMA_MAX_BACKOFF_EXPONENT */
/* Constants of the IEEE 802.15.4 standard */
#ifndef CSMA_MAX_MAC_TRANSMISSIONS
#ifdef CSMA_CONF_MAX_MAC_TRANSMISSIONS
#define CSMA_MAX_MAC_TRANSMISSIONS CSMA_CONF_MAX_MAC_TRANSMISSIONS
/* macMinBE: Initial backoff exponent. Range 0--CSMA_MAX_BE */
#ifdef CSMA_CONF_MIN_BE
#define CSMA_MIN_BE CSMA_CONF_MIN_BE
#else
#define CSMA_MAX_MAC_TRANSMISSIONS 3
#endif /* CSMA_CONF_MAX_MAC_TRANSMISSIONS */
#endif /* CSMA_MAX_MAC_TRANSMISSIONS */
#define CSMA_MIN_BE 0
#endif
#if CSMA_MAX_MAC_TRANSMISSIONS < 1
#error CSMA_CONF_MAX_MAC_TRANSMISSIONS must be at least 1.
#error Change CSMA_CONF_MAX_MAC_TRANSMISSIONS in contiki-conf.h or in your Makefile.
#endif /* CSMA_CONF_MAX_MAC_TRANSMISSIONS < 1 */
/* macMaxBE: Maximum backoff exponent. Range 3--8 */
#ifdef CSMA_CONF_MAX_BE
#define CSMA_MAX_BE CSMA_CONF_MAX_BE
#else
#define CSMA_MAX_BE 4
#endif
/* macMaxCSMABackoffs: Maximum number of backoffs in case of channel busy/collision. Range 0--5 */
#ifdef CSMA_CONF_MAX_BACKOFF
#define CSMA_MAX_BACKOFF CSMA_CONF_MAX_BACKOFF
#else
#define CSMA_MAX_BACKOFF 5
#endif
/* macMaxFrameRetries: Maximum number of re-transmissions attampts. Range 0--7 */
#ifdef CSMA_CONF_MAX_FRAME_RETRIES
#define CSMA_MAX_MAX_FRAME_RETRIES CSMA_CONF_MAX_FRAME_RETRIES
#else
#define CSMA_MAX_MAX_FRAME_RETRIES 7
#endif
/* Packet metadata */
struct qbuf_metadata {
@ -97,7 +106,7 @@ struct neighbor_queue {
linkaddr_t addr;
struct ctimer transmit_timer;
uint8_t transmissions;
uint8_t collisions, deferrals;
uint8_t collisions;
LIST_STRUCT(queued_packet_list);
};
@ -123,7 +132,6 @@ LIST(neighbor_list);
static void packet_sent(void *ptr, int status, int num_transmissions);
static void transmit_packet_list(void *ptr);
/*---------------------------------------------------------------------------*/
static struct neighbor_queue *
neighbor_queue_from_addr(const linkaddr_t *addr)
@ -139,18 +147,18 @@ neighbor_queue_from_addr(const linkaddr_t *addr)
}
/*---------------------------------------------------------------------------*/
static clock_time_t
default_timebase(void)
backoff_period(void)
{
clock_time_t time;
/* The retransmission time must be proportional to the channel
check interval of the underlying radio duty cycling layer. */
time = NETSTACK_RDC.channel_check_interval();
/* If the radio duty cycle has no channel check interval (i.e., it
does not turn the radio off), we make the retransmission time
proportional to the configured MAC channel check rate. */
/* If the radio duty cycle has no channel check interval, we use
* the default in IEEE 802.15.4: aUnitBackoffPeriod which is
* 20 symbols i.e. 320 usec. That is, 1/3125 second. */
if(time == 0) {
time = CLOCK_SECOND / NETSTACK_RDC_CHANNEL_CHECK_RATE;
time = MAX(CLOCK_SECOND / 3125, 1);
}
return time;
}
@ -171,10 +179,28 @@ transmit_packet_list(void *ptr)
}
/*---------------------------------------------------------------------------*/
static void
schedule_transmission(struct neighbor_queue *n)
{
clock_time_t delay;
int backoff_exponent; /* BE in IEEE 802.15.4 */
backoff_exponent = MIN(n->collisions, CSMA_MAX_BE);
/* Compute max delay as per IEEE 802.15.4: 2^BE-1 backoff periods */
delay = ((1 << backoff_exponent) - 1) * backoff_period();
if(delay > 0) {
/* Pick a time for next transmission */
delay = random_rand() % delay;
}
PRINTF("csma: scheduling transmission in %u ticks, NB=%u, BE=%u\n",
(unsigned)delay, n->collisions, backoff_exponent);
ctimer_set(&n->transmit_timer, delay, transmit_packet_list, n);
}
/*---------------------------------------------------------------------------*/
static void
free_packet(struct neighbor_queue *n, struct rdc_buf_list *p, int status)
{
clock_time_t tx_delay;
if(p != NULL) {
/* Remove packet from list and deallocate */
list_remove(n->queued_packet_list, p);
@ -187,11 +213,9 @@ free_packet(struct neighbor_queue *n, struct rdc_buf_list *p, int status)
if(list_head(n->queued_packet_list) != NULL) {
/* There is a next packet. We reset current tx information */
n->transmissions = 0;
n->collisions = 0;
n->deferrals = 0;
/* Set a timer for next transmissions */
tx_delay = (status == MAC_TX_OK) ? 0 : default_timebase();
ctimer_set(&n->transmit_timer, tx_delay, transmit_packet_list, n);
n->collisions = CSMA_MIN_BE;
/* Schedule next transmissions */
schedule_transmission(n);
} else {
/* This was the last packet in the queue, we free the neighbor */
ctimer_stop(&n->transmit_timer);
@ -202,34 +226,103 @@ free_packet(struct neighbor_queue *n, struct rdc_buf_list *p, int status)
}
/*---------------------------------------------------------------------------*/
static void
tx_done(int status, struct rdc_buf_list *q, struct neighbor_queue *n)
{
mac_callback_t sent;
struct qbuf_metadata *metadata;
void *cptr;
metadata = (struct qbuf_metadata *)q->ptr;
sent = metadata->sent;
cptr = metadata->cptr;
switch(status) {
case MAC_TX_OK:
PRINTF("csma: rexmit ok %d\n", n->transmissions);
break;
case MAC_TX_COLLISION:
case MAC_TX_NOACK:
PRINTF("csma: drop with status %d after %d transmissions, %d collisions\n",
status, n->transmissions, n->collisions);
break;
default:
PRINTF("csma: rexmit failed %d: %d\n", n->transmissions, status);
break;
}
free_packet(n, q, status);
mac_call_sent_callback(sent, cptr, status, n->transmissions);
}
/*---------------------------------------------------------------------------*/
static void
rexmit(struct rdc_buf_list *q, struct neighbor_queue *n)
{
schedule_transmission(n);
/* This is needed to correctly attribute energy that we spent
transmitting this packet. */
queuebuf_update_attr_from_packetbuf(q->buf);
}
/*---------------------------------------------------------------------------*/
static void
collision(struct rdc_buf_list *q, struct neighbor_queue *n,
int num_transmissions)
{
struct qbuf_metadata *metadata;
metadata = (struct qbuf_metadata *)q->ptr;
n->collisions += num_transmissions;
if(n->collisions > CSMA_MAX_BACKOFF) {
n->collisions = CSMA_MIN_BE;
/* Increment to indicate a next retry */
n->transmissions++;
}
if(n->transmissions >= metadata->max_transmissions) {
tx_done(MAC_TX_COLLISION, q, n);
} else {
PRINTF("csma: rexmit collision %d\n", n->transmissions);
rexmit(q, n);
}
}
/*---------------------------------------------------------------------------*/
static void
noack(struct rdc_buf_list *q, struct neighbor_queue *n, int num_transmissions)
{
struct qbuf_metadata *metadata;
metadata = (struct qbuf_metadata *)q->ptr;
n->collisions = CSMA_MIN_BE;
n->transmissions += num_transmissions;
if(n->transmissions >= metadata->max_transmissions) {
tx_done(MAC_TX_NOACK, q, n);
} else {
PRINTF("csma: rexmit noack %d\n", n->transmissions);
rexmit(q, n);
}
}
/*---------------------------------------------------------------------------*/
static void
tx_ok(struct rdc_buf_list *q, struct neighbor_queue *n, int num_transmissions)
{
n->collisions = CSMA_MIN_BE;
n->transmissions += num_transmissions;
tx_done(MAC_TX_OK, q, n);
}
/*---------------------------------------------------------------------------*/
static void
packet_sent(void *ptr, int status, int num_transmissions)
{
struct neighbor_queue *n;
struct rdc_buf_list *q;
struct qbuf_metadata *metadata;
clock_time_t time = 0;
mac_callback_t sent;
void *cptr;
int num_tx;
int backoff_exponent;
int backoff_transmissions;
n = ptr;
if(n == NULL) {
return;
}
switch(status) {
case MAC_TX_OK:
case MAC_TX_NOACK:
n->transmissions += num_transmissions;
break;
case MAC_TX_COLLISION:
n->collisions += num_transmissions;
break;
case MAC_TX_DEFERRED:
n->deferrals += num_transmissions;
break;
}
/* Find out what packet this callback refers to */
for(q = list_head(n->queued_packet_list);
@ -240,78 +333,30 @@ packet_sent(void *ptr, int status, int num_transmissions)
}
}
if(q != NULL) {
metadata = (struct qbuf_metadata *)q->ptr;
if(metadata != NULL) {
sent = metadata->sent;
cptr = metadata->cptr;
num_tx = n->transmissions;
if(status == MAC_TX_COLLISION ||
status == MAC_TX_NOACK) {
/* If the transmission was not performed because of a
collision or noack, we must retransmit the packet. */
if(q == NULL) {
PRINTF("csma: seqno %d not found\n",
packetbuf_attr(PACKETBUF_ATTR_MAC_SEQNO));
return;
} else if(q->ptr == NULL) {
PRINTF("csma: no metadata\n");
return;
}
switch(status) {
case MAC_TX_COLLISION:
PRINTF("csma: rexmit collision %d\n", n->transmissions);
case MAC_TX_OK:
tx_ok(q, n, num_transmissions);
break;
case MAC_TX_NOACK:
PRINTF("csma: rexmit noack %d\n", n->transmissions);
noack(q, n, num_transmissions);
break;
case MAC_TX_COLLISION:
collision(q, n, num_transmissions);
break;
case MAC_TX_DEFERRED:
break;
default:
PRINTF("csma: rexmit err %d, %d\n", status, n->transmissions);
}
/* The retransmission time must be proportional to the channel
check interval of the underlying radio duty cycling layer. */
time = default_timebase();
/* The retransmission time uses a truncated exponential backoff
* so that the interval between the transmissions increase with
* each retransmit. */
backoff_exponent = num_tx;
/* Truncate the exponent if needed. */
if(backoff_exponent > CSMA_MAX_BACKOFF_EXPONENT) {
backoff_exponent = CSMA_MAX_BACKOFF_EXPONENT;
}
/* Proceed to exponentiation. */
backoff_transmissions = 1 << backoff_exponent;
/* Pick a time for next transmission, within the interval:
* [time, time + 2^backoff_exponent * time[ */
time = time + (random_rand() % (backoff_transmissions * time));
if(n->transmissions < metadata->max_transmissions) {
PRINTF("csma: retransmitting with time %lu %p\n", time, q);
ctimer_set(&n->transmit_timer, time,
transmit_packet_list, n);
/* This is needed to correctly attribute energy that we spent
transmitting this packet. */
queuebuf_update_attr_from_packetbuf(q->buf);
} else {
PRINTF("csma: drop with status %d after %d transmissions, %d collisions\n",
status, n->transmissions, n->collisions);
free_packet(n, q, status);
mac_call_sent_callback(sent, cptr, status, num_tx);
}
} else {
if(status == MAC_TX_OK) {
PRINTF("csma: rexmit ok %d\n", n->transmissions);
} else {
PRINTF("csma: rexmit failed %d: %d\n", n->transmissions, status);
}
free_packet(n, q, status);
mac_call_sent_callback(sent, cptr, status, num_tx);
}
} else {
PRINTF("csma: no metadata\n");
}
} else {
PRINTF("csma: seqno %d not found\n", packetbuf_attr(PACKETBUF_ATTR_MAC_SEQNO));
tx_done(status, q, n);
break;
}
}
/*---------------------------------------------------------------------------*/
@ -346,8 +391,7 @@ send_packet(mac_callback_t sent, void *ptr)
/* Init neighbor entry */
linkaddr_copy(&n->addr, addr);
n->transmissions = 0;
n->collisions = 0;
n->deferrals = 0;
n->collisions = CSMA_MIN_BE;
/* Init packet list for this neighbor */
LIST_STRUCT_INIT(n, queued_packet_list);
/* Add neighbor to the list */
@ -368,7 +412,7 @@ send_packet(mac_callback_t sent, void *ptr)
/* Neighbor and packet successfully allocated */
if(packetbuf_attr(PACKETBUF_ATTR_MAX_MAC_TRANSMISSIONS) == 0) {
/* Use default configuration for max transmissions */
metadata->max_transmissions = CSMA_MAX_MAC_TRANSMISSIONS;
metadata->max_transmissions = CSMA_MAX_MAX_FRAME_RETRIES + 1;
} else {
metadata->max_transmissions =
packetbuf_attr(PACKETBUF_ATTR_MAX_MAC_TRANSMISSIONS);
@ -389,7 +433,7 @@ send_packet(mac_callback_t sent, void *ptr)
list_length(n->queued_packet_list), memb_numfree(&packet_memb));
/* If q is the first packet in the neighbor's queue, send asap */
if(list_head(n->queued_packet_list) == q) {
ctimer_set(&n->transmit_timer, 0, transmit_packet_list, n);
schedule_transmission(n);
}
return;
}

3
platform/cooja/contiki-conf.h
View File

@ -168,9 +168,6 @@
#define SICSLOWPAN_CONF_MAXAGE 8
#endif /* SICSLOWPAN_CONF_FRAG */
#define SICSLOWPAN_CONF_MAX_ADDR_CONTEXTS 2
#ifndef SICSLOWPAN_CONF_MAX_MAC_TRANSMISSIONS
#define SICSLOWPAN_CONF_MAX_MAC_TRANSMISSIONS 8
#endif /* SICSLOWPAN_CONF_MAX_MAC_TRANSMISSIONS */
#endif /* NETSTACK_CONF_WITH_IPV6 */

3
platform/exp5438/contiki-conf.h
View File

@ -174,9 +174,6 @@
#define SICSLOWPAN_CONF_MAXAGE 8
#endif /* SICSLOWPAN_CONF_FRAG */
#define SICSLOWPAN_CONF_MAX_ADDR_CONTEXTS 2
#ifndef SICSLOWPAN_CONF_MAX_MAC_TRANSMISSIONS
#define SICSLOWPAN_CONF_MAX_MAC_TRANSMISSIONS 5
#endif /* SICSLOWPAN_CONF_MAX_MAC_TRANSMISSIONS */
#else /* NETSTACK_CONF_WITH_IPV6 */
#define UIP_CONF_IP_FORWARD 1
#define UIP_CONF_BUFFER_SIZE 108

3
platform/jn516x/contiki-conf.h
View File

@ -154,9 +154,6 @@
#define SICSLOWPAN_CONF_MAXAGE 8
#endif /* SICSLOWPAN_CONF_FRAG */
#define SICSLOWPAN_CONF_MAX_ADDR_CONTEXTS 2
#ifndef SICSLOWPAN_CONF_MAX_MAC_TRANSMISSIONS
#define SICSLOWPAN_CONF_MAX_MAC_TRANSMISSIONS 5
#endif /* SICSLOWPAN_CONF_MAX_MAC_TRANSMISSIONS */
#define UIP_CONF_ICMP_DEST_UNREACH 1
#define UIP_CONF_DHCP_LIGHT

3
platform/native/contiki-conf.h
View File

@ -110,9 +110,6 @@ typedef unsigned short uip_stats_t;
#define SICSLOWPAN_CONF_MAXAGE 8
#endif /* SICSLOWPAN_CONF_FRAG */
#define SICSLOWPAN_CONF_MAX_ADDR_CONTEXTS 2
#ifndef SICSLOWPAN_CONF_MAX_MAC_TRANSMISSIONS
#define SICSLOWPAN_CONF_MAX_MAC_TRANSMISSIONS 5
#endif /* SICSLOWPAN_CONF_MAX_MAC_TRANSMISSIONS */
#define UIP_CONF_IPV6_CHECKS 1
#define UIP_CONF_IPV6_QUEUE_PKT 1

3
platform/sky/contiki-conf.h
View File

@ -179,9 +179,6 @@
#define SICSLOWPAN_CONF_MAXAGE 8
#endif /* SICSLOWPAN_CONF_FRAG */
#define SICSLOWPAN_CONF_MAX_ADDR_CONTEXTS 2
#ifndef SICSLOWPAN_CONF_MAX_MAC_TRANSMISSIONS
#define SICSLOWPAN_CONF_MAX_MAC_TRANSMISSIONS 5
#endif /* SICSLOWPAN_CONF_MAX_MAC_TRANSMISSIONS */
#else /* NETSTACK_CONF_WITH_IPV6 */
#define UIP_CONF_IP_FORWARD 1
#define UIP_CONF_BUFFER_SIZE 108

4
platform/stm32nucleo-spirit1/contiki-conf.h
View File

@ -106,10 +106,6 @@
#define SICSLOWPAN_CONF_MAXAGE 4
#define SICSLOWPAN_CONF_MAX_ADDR_CONTEXTS 2
#ifndef SICSLOWPAN_CONF_MAX_MAC_TRANSMISSIONS
#define SICSLOWPAN_CONF_MAX_MAC_TRANSMISSIONS 5
#endif /* SICSLOWPAN_CONF_MAX_MAC_TRANSMISSIONS */
#define UIP_CONF_ICMP_DEST_UNREACH 1
#define UIP_CONF_DHCP_LIGHT

3
platform/wismote/contiki-conf.h
View File

@ -157,9 +157,6 @@
#define SICSLOWPAN_CONF_MAXAGE 8
#endif /* SICSLOWPAN_CONF_FRAG */
#define SICSLOWPAN_CONF_MAX_ADDR_CONTEXTS 2
#ifndef SICSLOWPAN_CONF_MAX_MAC_TRANSMISSIONS
#define SICSLOWPAN_CONF_MAX_MAC_TRANSMISSIONS 5
#endif /* SICSLOWPAN_CONF_MAX_MAC_TRANSMISSIONS */
#else /* NETSTACK_CONF_WITH_IPV6 */
#define UIP_CONF_IP_FORWARD 1
#define UIP_CONF_BUFFER_SIZE 108