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simple tdma rtimer implemetation

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fros4943 2007-09-18 10:37:17 +00:00
parent 19b3035e36
commit aa99049af0
1 changed files with 133 additions and 115 deletions
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234
core/net/mac/tdma_mac.c
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@ -28,169 +28,185 @@
* *
* This file is part of the Contiki operating system. * This file is part of the Contiki operating system.
* *
* $Id: tdma_mac.c,v 1.1 2007/08/31 13:42:22 fros4943 Exp $ * $Id: tdma_mac.c,v 1.2 2007/09/18 10:37:17 fros4943 Exp $
*/ */
#include "contiki.h" #include "contiki.h"
#include "net/mac/tdma_mac.h" #include "net/mac/tdma_mac.h"
#include "net/rime/rimebuf.h" #include "net/rime/rimebuf.h"
#include "net/uip-fw.h" #include "net/uip-fw.h"
#include "sys/rtimer.h"
#include "net/rime.h"
#include "lib/memb.h" #include "lib/memb.h"
#include "lib/list.h" #include "lib/list.h"
#include "dev/leds.h"
#include "node-id.h" #include "node-id.h"
#include <string.h> #include <string.h>
#include <stdio.h> #include <stdio.h>
static const struct radio_driver *radio;
static void (* receiver_callback)(const struct mac_driver *);
static int id_counter = 0;
#define DEBUG 1 #define DEBUG 1
#if DEBUG #if DEBUG
/*#include "printf2log.h"*/ /* XXX COOJA specifics */ #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__) #define PRINTF(...) printf(__VA_ARGS__)
#else #else
#define DLEDS_ON(x)
#define DLEDS_OFF(x)
#define DLEDS_TOGGLE(x)
#define PRINTF(...) #define PRINTF(...)
#endif #endif
/* TDMA configuration */ /* TDMA configuration */
#define MAX_BUFFERED_PACKETS 6 #define NR_SLOTS 3
#define SLOT_LENGTH (RTIMER_SECOND/3)
#define NR_SLOTS 10 #define GUARD_PERIOD (RTIMER_SECOND/12)
#define SLOT_LENGTH (CLOCK_SECOND) /* Slot length */
#define GUARD_PERIOD (CLOCK_SECOND / 2) /* Approx. packet transmission time */
#define MY_SLOT (node_id % NR_SLOTS) #define MY_SLOT (node_id % NR_SLOTS)
#define PERIOD_LENGTH (SLOT_LENGTH*NR_SLOTS) #define PERIOD_LENGTH RTIMER_SECOND
enum { /* Buffers */
EVENT_PACKET_BUFFERED #define NUM_PACKETS 8
}; u8_t lastqueued = 0;
u8_t nextsend = 0;
u8_t freeslot = 0;
struct queuebuf* data[NUM_PACKETS];
int id[NUM_PACKETS];
struct buf_packet { static struct rtimer rtimer;
struct buf_packet *next; u8_t timer_on = 0;
struct queuebuf *queued_packet;
int id;
struct etimer etimer;
};
LIST(buf_packet_list); static const struct radio_driver *radio;
MEMB(buf_packet_mem, struct buf_packet, MAX_BUFFERED_PACKETS); static void (* receiver_callback)(const struct mac_driver *);
static int id_counter = 0;
PROCESS(tdma_process, "TDMA process"); static int sent_counter = 0;
/*---------------------------------------------------------------------------*/ /*---------------------------------------------------------------------------*/
PROCESS_THREAD(tdma_process, ev, data) static char
transmitter(struct rtimer *t, void *ptr)
{ {
PROCESS_BEGIN(); int r;
rtimer_clock_t now, rest, period_start, slot_start;
while(1) { /* Calculate slot start time */
PROCESS_YIELD(); now = RTIMER_NOW();
if(ev == EVENT_PACKET_BUFFERED || ev == PROCESS_EVENT_TIMER) {
struct buf_packet *packet;
/* Locate packet */
for(packet = list_head(buf_packet_list); packet != NULL; packet = packet->next) {
if (etimer_expired(&packet->etimer)) {
int ret, rest, period_start, my_next_slot;
clock_time_t now;
/* Calculate time of our next slot */
now = clock_time();
rest = now % PERIOD_LENGTH; rest = now % PERIOD_LENGTH;
period_start = now - rest; period_start = now - rest;
my_next_slot = period_start + MY_SLOT*SLOT_LENGTH; slot_start = period_start + MY_SLOT*SLOT_LENGTH;
/* Transmit if inside our slot, with enough time left */ /* Check if we are inside our slot */
if ((now == my_next_slot) || if (now < slot_start ||
(now > my_next_slot && (now - my_next_slot) < (SLOT_LENGTH-GUARD_PERIOD))) now > slot_start + SLOT_LENGTH - GUARD_PERIOD)
{ {
PRINTF("SCHEDULE We can deliver right now (%i), slot = (%i <-> %i)\n", now, my_next_slot, my_next_slot + SLOT_LENGTH); 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 else
{ {
if (now > my_next_slot) { PRINTF("RADIO Transmit failed for #%i, total=%i\n", id[nextsend], sent_counter);
my_next_slot += PERIOD_LENGTH; DLEDS_TOGGLE(LEDS_RED);
} }
int distance = my_next_slot - now; nextsend = (nextsend + 1) % NUM_PACKETS;
etimer_set(&packet->etimer, distance);
PRINTF("SCHEDULE Packet #%i rescheduled at %i to %i\n", packet->id, clock_time(), my_next_slot); /* Recalculate new slot */
continue; if (RTIMER_NOW() > slot_start + SLOT_LENGTH - GUARD_PERIOD)
{
PRINTF("TIMER No more time to transmit\n");
break;
}
} }
/* Clear Rime buffer */ /* Calculate time of our next slot */
rimebuf_clear(); slot_start += PERIOD_LENGTH;
PRINTF("TIMER Rescheduling until %u\n", slot_start);
/* Restore packet from buffer */ r = rtimer_set(&rtimer, slot_start, 1,
if(packet->queued_packet != NULL) { (void (*)(struct rtimer *, void *))transmitter, NULL);
queuebuf_to_rimebuf(packet->queued_packet); if(r)
queuebuf_free(packet->queued_packet); {
PRINTF("TIMER Error #2: %d\n", r);
} }
/* Send packet */ return 0;
PRINTF("TDMA_PROC Packet #%i send starting at %i\n", packet->id, clock_time());
ret = radio->send(rimebuf_hdrptr(), rimebuf_totlen());
if (ret == UIP_FW_OK) {
/* Remove transmitted packet */
list_remove(buf_packet_list, packet);
memb_free(&buf_packet_mem, packet);
PRINTF("BUFFER Packet removed, memory freed\n");
PRINTF("TDMA_PROC Packet #%i sent at %i\n", packet->id, clock_time());
} else {
/* Reschedule packet */
etimer_set(&packet->etimer, SLOT_LENGTH);
PRINTF("TDMA_PROC Packet #%i forced rescheduled\n", packet->id);
}
}
}
}
}
PROCESS_END();
} }
/*---------------------------------------------------------------------------*/ /*---------------------------------------------------------------------------*/
static int static int
send(void) send(void)
{ {
struct buf_packet *packet; int r;
id_counter++;
packet = (struct buf_packet *)memb_alloc(&buf_packet_mem); /* Clean up already sent packets */
if (packet == NULL) { while (lastqueued != nextsend)
PRINTF("BUFFER No memory available, packet dropped\n"); {
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; return UIP_FW_DROPPED;
} }
/* Add to buffered packets list */ /* Allocate queue buf for packet */
list_add(buf_packet_list, packet); data[freeslot] = queuebuf_new_from_rimebuf();
PRINTF("BUFFER Packet added, memory allocated\n"); id[freeslot] = id_counter;
if (data[freeslot] == NULL)
/* Store packet data */ {
packet->queued_packet = queuebuf_new_from_rimebuf(); PRINTF("BUFFER Queuebuffer full, dropping packet #%i\n", id[freeslot]);
if (packet->queued_packet == NULL) {
list_remove(buf_packet_list, packet);
memb_free(&buf_packet_mem, packet);
PRINTF("BUFFER No queue memory available, packet dropped\n");
return UIP_FW_DROPPED; return UIP_FW_DROPPED;
} }
PRINTF("BUFFER Wrote packet #%i to buffer \n", id[freeslot]);
PROCESS_CONTEXT_BEGIN(&tdma_process); freeslot = (freeslot + 1) % NUM_PACKETS;
etimer_set(&packet->etimer, 0);
PROCESS_CONTEXT_END(&tdma_process);
/* TODO ID only used for debugging */ if (!timer_on)
packet->id = id_counter++; {
PRINTF("TIMER Starting timer\n");
/* Clear Rime buffer */ r = rtimer_set(&rtimer, RTIMER_NOW() + RTIMER_SECOND, 1,
rimebuf_clear(); (void (*)(struct rtimer *, void *))transmitter, NULL);
if(r)
process_post(&tdma_process, EVENT_PACKET_BUFFERED, NULL); {
PRINTF("TIMER Error #3: %d\n", r);
}
else
{
timer_on = 1;
}
}
return UIP_FW_OK; /* TODO Return what? */ return UIP_FW_OK; /* TODO Return what? */
} }
/*---------------------------------------------------------------------------*/ /*---------------------------------------------------------------------------*/
static void static void
@ -230,9 +246,11 @@ off(void)
void void
tdma_mac_init(const struct radio_driver *d) tdma_mac_init(const struct radio_driver *d)
{ {
memb_init(&buf_packet_mem); int i;
list_init(buf_packet_list); for (i=0; i < NUM_PACKETS; i++)
process_start(&tdma_process, NULL); {
data[i] = NULL;
}
radio = d; radio = d;
radio->set_receive_function(input); radio->set_receive_function(input);