Cleaned up parts of the code; added comments

This commit is contained in:
adamdunkels 2011-01-09 21:07:01 +00:00
parent a29d56874a
commit a0960154ba

View file

@ -28,7 +28,7 @@
*
* This file is part of the Contiki operating system.
*
* $Id: contikimac.c,v 1.45 2010/12/16 22:43:07 adamdunkels Exp $
* $Id: contikimac.c,v 1.46 2011/01/09 21:07:01 adamdunkels Exp $
*/
/**
@ -111,28 +111,68 @@ struct announcement_msg {
#define CYCLE_TIME (RTIMER_ARCH_SECOND / NETSTACK_RDC_CHANNEL_CHECK_RATE)
#endif
#define MAX_PHASE_STROBE_TIME RTIMER_ARCH_SECOND / 60
/* ContikiMAC performs periodic channel checks. Each channel check
consists of two or more CCA checks. CCA_COUNT_MAX is the number of
CCAs to be done for each periodic channel check. The default is
two.*/
#define CCA_COUNT_MAX 2
/* CCA_CHECK_TIME is the time it takes to perform a CCA check. */
#define CCA_CHECK_TIME RTIMER_ARCH_SECOND / 8192
/* CCA_SLEEP_TIME is the time between two successive CCA checks. */
#define CCA_SLEEP_TIME RTIMER_ARCH_SECOND / 2000
/* CHECK_TIME is the total time it takes to perform CCA_COUNT_MAX
CCAs. */
#define CHECK_TIME (CCA_COUNT_MAX * (CCA_CHECK_TIME + CCA_SLEEP_TIME))
#define STROBE_TIME (CYCLE_TIME + 2 * CHECK_TIME)
#define STREAM_CCA_COUNT (CYCLE_TIME / (CCA_SLEEP_TIME + CCA_CHECK_TIME) - CCA_COUNT_MAX)
#define GUARD_TIME 9 * CHECK_TIME
#define INTER_PACKET_INTERVAL RTIMER_ARCH_SECOND / 5000
#define AFTER_ACK_DETECTECT_WAIT_TIME RTIMER_ARCH_SECOND / 1500
/* LISTEN_TIME_AFTER_PACKET_DETECTED is the time that we keep checking
for activity after a potential packet has been detected by a CCA
check. */
#define LISTEN_TIME_AFTER_PACKET_DETECTED RTIMER_ARCH_SECOND / 80
/* MAX_SILENCE_PERIODS is the maximum amount of periods (a period is
CCA_CHECK_TIME + CCA_SLEEP_TIME) that we allow to be silent before
we turn of the radio. */
#define MAX_SILENCE_PERIODS 5
/* MAX_NONACTIVITY_PERIODS is the maximum number of periods we allow
the radio to be turned on without any packet being received, when
WITH_FAST_SLEEP is enabled. */
#define MAX_NONACTIVITY_PERIODS 10
/* STROBE_TIME is the maximum amount of time a transmitted packet
should be repeatedly transmitted as part of a transmission. */
#define STROBE_TIME (CYCLE_TIME + 2 * CHECK_TIME)
/* GUARD_TIME is the time before the expected phase of a neighbor that
a transmitted should begin transmitting packets. */
#define GUARD_TIME 9 * CHECK_TIME
/* INTER_PACKET_INTERVAL is the interval between two successive packet transmissions */
#define INTER_PACKET_INTERVAL RTIMER_ARCH_SECOND / 5000
/* AFTER_ACK_DETECTECT_WAIT_TIME is the time to wait after a potential
ACK packet has been detected until we can read it out from the
radio. */
#define AFTER_ACK_DETECTECT_WAIT_TIME RTIMER_ARCH_SECOND / 1500
/* MAX_PHASE_STROBE_TIME is the time that we transmit repeated packets
to a neighbor for which we have a phase lock. */
#define MAX_PHASE_STROBE_TIME RTIMER_ARCH_SECOND / 60
/* SHORTEST_PACKET_SIZE is the shortest packet that ContikiMAC
allows. Packets have to be a certain size to be able to be detected
by two consecutive CCA checks, and here is where we define this
shortest size. */
#define SHORTEST_PACKET_SIZE 43
#define MAX_SILENCE_PERIODS 5
#define MAX_NONACTIVITY_PERIODIC 10
/* The cycle time for announcements. */
#ifdef ANNOUNCEMENT_CONF_PERIOD
@ -333,6 +373,7 @@ powercycle(struct rtimer *t, void *ptr)
t0 = RTIMER_NOW();
if(we_are_sending == 0) {
powercycle_turn_radio_on();
// schedule_powercycle_fixed(t, t0 + CCA_CHECK_TIME);
#if 0
#if NURTIMER
while(RTIMER_CLOCK_LT(t0, RTIMER_NOW(), t0 + CCA_CHECK_TIME));
@ -352,6 +393,7 @@ powercycle(struct rtimer *t, void *ptr)
}
powercycle_turn_radio_off();
}
// schedule_powercycle_fixed(t, t0 + CCA_CHECK_TIME + CCA_SLEEP_TIME);
schedule_powercycle_fixed(t, RTIMER_NOW() + CCA_SLEEP_TIME);
/* COOJA_DEBUG_STR("yield\n");*/
PT_YIELD(&pt);
@ -391,17 +433,16 @@ powercycle(struct rtimer *t, void *ptr)
#endif /* CONTIKIMAC_CONF_COMPOWER */
break;
}
#if WITH_FAST_SLEEP
if(periods > MAX_NONACTIVITY_PERIODIC &&
!NETSTACK_RADIO.receiving_packet() &&
!NETSTACK_RADIO.pending_packet()) {
if(WITH_FAST_SLEEP &&
periods > MAX_NONACTIVITY_PERIODS &&
!(NETSTACK_RADIO.receiving_packet() ||
NETSTACK_RADIO.pending_packet())) {
powercycle_turn_radio_off();
#if CONTIKIMAC_CONF_COMPOWER
compower_accumulate(&compower_idle_activity);
#endif /* CONTIKIMAC_CONF_COMPOWER */
break;
}
#endif /* WITH_FAST_SLEEP */
if(NETSTACK_RADIO.pending_packet()) {
break;
}
@ -409,13 +450,17 @@ powercycle(struct rtimer *t, void *ptr)
schedule_powercycle(t, CCA_CHECK_TIME + CCA_SLEEP_TIME);
PT_YIELD(&pt);
}
if(radio_is_on && !(NETSTACK_RADIO.receiving_packet() ||
NETSTACK_RADIO.pending_packet())) {
if(radio_is_on) {
if(!(NETSTACK_RADIO.receiving_packet() ||
NETSTACK_RADIO.pending_packet()) ||
!RTIMER_CLOCK_LT(RTIMER_NOW(),
(start + LISTEN_TIME_AFTER_PACKET_DETECTED))) {
powercycle_turn_radio_off();
#if CONTIKIMAC_CONF_COMPOWER
compower_accumulate(&compower_idle_activity);
#endif /* CONTIKIMAC_CONF_COMPOWER */
}
}
} else {
#if CONTIKIMAC_CONF_COMPOWER
compower_accumulate(&compower_idle_activity);
@ -605,7 +650,7 @@ send_packet(mac_callback_t mac_callback, void *mac_callback_ptr)
}
packetbuf_set_attr(PACKETBUF_ATTR_MAC_ACK, 1);
#if WITH_CONTIKIMAC_HEADER
if(WITH_CONTIKIMAC_HEADER) {
hdrlen = packetbuf_totlen();
if(packetbuf_hdralloc(sizeof(struct hdr)) == 0) {
/* Failed to allocate space for contikimac header */
@ -625,7 +670,7 @@ send_packet(mac_callback_t mac_callback, void *mac_callback_ptr)
return MAC_TX_ERR_FATAL;
}
hdrlen += sizeof(struct hdr);
#else /* WITH_CONTIKIMAC_HEADER */
} else {
/* Create the MAC header for the data packet. */
hdrlen = NETSTACK_FRAMER.create();
if(hdrlen == 0) {
@ -633,7 +678,8 @@ send_packet(mac_callback_t mac_callback, void *mac_callback_ptr)
PRINTF("contikimac: send failed, too large header\n");
return MAC_TX_ERR_FATAL;
}
#endif /* WITH_CONTIKIMAC_HEADER */
}
/* Make sure that the packet is longer or equal to the shortest
packet length. */