Commit e5807511 authored by rna's avatar rna
Browse files

~= clock sync

parent d6f46156

prrt/proto/clock.c

+14 −18
Original line number Diff line number Diff line 
#include <sys/time.h>

#include <stdlib.h>

#include "../util/time.h"

#include "../util/common.h"

#include "clock.h"
@@ -19,50 +20,45 @@ prrtTimestamp_t PrrtClock_get_prrt_time_us(PrrtClock *clock) 
        prrtTimestamp_t lastMeasurement = clock->lastMeasurement;

        prrtTimeDifference_t diff = diff_abs_ts(currentTime, lastMeasurement);

        prrtTimeDifference_t skew = (diff * clock->skew) / 400;

        return (prrtTimestamp_t) virtualTime + clock->meanDeviation + skew;

        return (prrtTimestamp_t) (virtualTime + clock->meanDeviation + skew);

    } else {

        return currentTime;

    }

}





bool PrrtClock_update(PrrtClock *clock, uint32_t referenceTime, uint32_t rtt)

bool PrrtClock_update(PrrtClock *clock, uint32_t referenceTime, uint32_t propagation_delay)

{

    prrtTimestamp_t virtualTime = PrrtClock_get_prrt_time_us(clock);

    prrtTimestamp_t currentTime = PrrtClock_get_current_time_us();

    prrtTimestamp_t virtualTime = clock->virtualTime;

    prrtTimeDifference_t clockSkew = clock->skew;

    prrtTimedelta_t delay = rtt/2; // half the rtt

    prrtTimeDifference_t phaseError = referenceTime - virtualTime + delay;

    //printf("V: %13u, C: %13u, S: %13d, R: %13u, E: %13d, D: %3u L: %u\n", virtualTime, currentTime, clockSkew, referenceTime, phaseError, delay, clock->lastMeasurement);

    int64_t clockSkew = clock->skew;

    prrtTimedelta_t delay = propagation_delay / 2; // half the rtt

    int64_t phaseError = PrrtTimestamp_cmp(referenceTime, virtualTime) + delay;

    //printf("V: %13u, C: %13u, S: %13d, R: %13u, E: %13ld, D: %3u L: %u\n", virtualTime, currentTime, clockSkew, referenceTime, phaseError, delay, clock->lastMeasurement);



    if(abs(phaseError) > 10000) {

    if(labs(phaseError) > 10000) {

        clock->meanDeviation = 0;

        clock->skew = 0;

        clock->lastMeasurement = currentTime;

        clock->virtualTime = currentTime;

    }



    prrtTimeDifference_t deviationSum = (prrtTimeDifference_t) (phaseError + 3 * clock->meanDeviation); // TODO: why 3?

    int64_t deviationSum =(phaseError + 3 * clock->meanDeviation); // TODO: why 3?

    prrtTimeDifference_t meanDeviation = (prrtTimeDifference_t) (deviationSum / 4); // TODO: find out why???

    prrtTimeDifference_t period = diff_abs_ts(currentTime, clock->lastMeasurement);

    int64_t period = PrrtTimestamp_cmp(currentTime, clock->lastMeasurement);



    if(period > 0) {

        clockSkew = (meanDeviation / period) + 15 * clock->skew;

        clockSkew = (prrtTimeDifference_t) (clockSkew / 16);

    }



    virtualTime = virtualTime + meanDeviation + period * clockSkew / 400;

    virtualTime = clock->virtualTime + meanDeviation + period * clockSkew / 400;



    clock->meanDeviation = meanDeviation;

    clock->skew = clockSkew;

    clock->skew = (prrtTimeDifference_t) clockSkew;

    clock->lastMeasurement = currentTime;

    clock->virtualTime = virtualTime;



    if(abs(phaseError) > 10000) {

        clock->virtualTime = currentTime;

    }



    //printf("V: %13u, C: %13u; S: %13d; M: %13d, P:%13u\n", virtualTime, currentTime, clockSkew, meanDeviation, period);

    //printf("V: %13u, C: %13u; S: %13d; M: %13d, P:%13u\n\n", virtualTime, currentTime, clockSkew, meanDeviation, period);

    return true;

}

prrt/proto/clock.h

+1 −1
Original line number Diff line number Diff line
@@ -26,7 +26,7 @@ prrtTimestamp_t PrrtClock_get_current_time_us(void); 


prrtTimestamp_t PrrtClock_get_prrt_time_us(PrrtClock *clock);



bool PrrtClock_update(PrrtClock *clock, prrtTimestamp_t referenceTime, prrtTimedelta_t rtt);

bool PrrtClock_update(PrrtClock *clock, prrtTimestamp_t referenceTime, prrtTimedelta_t propagation_delay);



#define diff_abs_ts(timeA, timeB) (prrtTimeDifference_t) abs(((prrtTimeDifference_t) timeA) - ((prrtTimeDifference_t)timeB))

prrt/receiver.c

+4 −0
Original line number Diff line number Diff line
@@ -129,6 +129,10 @@ int main(int argc, char **argv) { 
        buffer[n] = '\0';

        unsigned int seqno;

        sscanf(buffer, "%u", &seqno);

        prrtTimestamp_t current_time = PrrtClock_get_current_time_us();

        prrtTimestamp_t prrt_time = PrrtClock_get_prrt_time_us(&s->clock);

        printf("C: %d\nP: %d\nD: \n%d\n\n", current_time, prrt_time, prrt_time - current_time);



        debug(DEBUG_RECEIVER, "[B (n: %3d, i: %3d)] %s", n, i, buffer);

        i++;

    }