Commit 37f5e170 authored by Andreas Schmidt's avatar Andreas Schmidt
Browse files

Improve BBR. 

* more parameters are visible
* function names follow the ietf draft
* slight fixes
parent f58b26e5

prrt/cprrt.pxd

+3 −0
Original line number Diff line number Diff line
@@ -150,6 +150,9 @@ cdef extern from "proto/socket.h": 
    uint32_t PrrtSocket_get_bbr_state(PrrtSocket *s)

    uint64_t PrrtSocket_get_full_bw(PrrtSocket *s)

    bint PrrtSocket_get_filled_pipe(PrrtSocket *s)

    uint32_t PrrtSocket_get_cycle_index(PrrtSocket *s)

    float PrrtSocket_get_pacing_gain(PrrtSocket *s)





    bint PrrtSocket_get_app_limited(PrrtSocket *socket)

    bint PrrtSocket_enable_thread_pinning(PrrtSocket *socket)

prrt/proto/bbr.c

+55 −34
Original line number Diff line number Diff line
@@ -4,7 +4,7 @@ 
#include "receiver.h"





uint32_t BBR_Inflight(BBR* bbr, float gain)

prrtByteCount_t BBR_Inflight(BBR* bbr, float gain)

{

    if (bbr->rtprop == Inf)

        return InitialCwnd; /* no valid RTT samples yet */
@@ -20,10 +20,10 @@ void BBR_EnterStartup(BBR* bbr) 
    bbr->cwnd_gain = BBRHighGain;

}



void BBR_UpdateBtlBw(BBR* bbr, PrrtRateSample* rs, prrtByteCount_t packet_delivered, prrtByteCount_t delivered)

void BBR_UpdateBtlBw(BBR* bbr, PrrtRateSample* rs, PrrtPacketTracking* tracking)

{

    if (packet_delivered >= bbr->next_round_delivered) {

        bbr->next_round_delivered = delivered;

    if (tracking->bytes_delivered >= bbr->next_round_delivered) {

        bbr->next_round_delivered = tracking->delivered;

        bbr->round_count++;

        bbr->round_start = true;

    } else {
@@ -49,7 +49,7 @@ void BBR_CheckFullPipe(BBR* bbr, PrrtRateSample* rs) 
        bbr->filled_pipe = true;

}



bool BBR_IsNextCyclePhase(BBR* bbr, prrtSequenceNumber_t packets_lost, prrtSequenceNumber_t prior_inflight)

bool BBR_IsNextCyclePhase(BBR* bbr, prrtSequenceNumber_t packets_lost, prrtByteCount_t prior_inflight)

{

    bool is_full_length = (PrrtClock_get_current_time_us() - bbr->cycle_stamp) > bbr->rtprop;

    if (bbr->pacing_gain == 1)
@@ -68,7 +68,7 @@ void BBR_AdvanceCyclePhase(BBR* bbr) 
    debug(DEBUG_BBR, "Advanced cycle with gain: %f", bbr->pacing_gain);

}



void BBR_CheckCyclePhase(BBR* bbr, prrtSequenceNumber_t packets_lost, prrtSequenceNumber_t prior_inflight) {

void BBR_CheckCyclePhase(BBR* bbr, prrtSequenceNumber_t packets_lost, prrtByteCount_t prior_inflight) {

    if (bbr->state == PROBE_BW && BBR_IsNextCyclePhase(bbr, packets_lost, prior_inflight))

        BBR_AdvanceCyclePhase(bbr);

}
@@ -82,7 +82,7 @@ void BBR_EnterProbeBW(BBR* bbr) 
    BBR_AdvanceCyclePhase(bbr);

}



void BBR_CheckDrain(BBR* bbr, prrtSequenceNumber_t packets_in_flight)

void BBR_CheckDrain(BBR* bbr, prrtByteCount_t bytes_inflight)

{

    if (bbr->state == STARTUP && bbr->filled_pipe) {

        //Drain
@@ -90,7 +90,7 @@ void BBR_CheckDrain(BBR* bbr, prrtSequenceNumber_t packets_in_flight) 
        bbr->pacing_gain = 1 / BBRHighGain;  // pace slowly

        bbr->cwnd_gain = BBRHighGain;    // maintain cwnd

    }

    if (bbr->state == DRAIN && packets_in_flight <= BBR_Inflight(bbr, 1.0))

    if (bbr->state == DRAIN && bytes_inflight <= BBR_Inflight(bbr, 1.0))

        BBR_EnterProbeBW(bbr);  // we estimate queue is drained

}
@@ -115,29 +115,29 @@ void BBR_RestoreCwnd(BBR* bbr) 
    bbr->cwnd = bbr->cwnd > bbr->prior_cwnd ? bbr->cwnd : bbr->prior_cwnd;

}



void BBR_UpdateRTprop(BBR* bbr, prrtTimedelta_t rtt, prrtByteCount_t delivered, prrtSequenceNumber_t packets_in_flight)

void BBR_UpdateRTprop(BBR* bbr, prrtTimedelta_t rtt)

{

    bbr->rtprop_expired = PrrtClock_get_current_time_us() > (bbr->rtprop_stamp + RTpropFilterLen);

    if (rtt >= 0 && (rtt <= bbr->rtprop || bbr->rtprop_expired)) {

        bbr->rtprop = rtt;

        bbr->rtprop_stamp = PrrtClock_get_current_time_us();

    }

}



    if (bbr->state != PROBE_RTT && bbr->rtprop_expired && !bbr->idle_restart) {

void BBR_EnterProbeRTT(BBR *bbr) {

    bbr->state = PROBE_RTT;

    bbr->pacing_gain = 1;

    bbr->cwnd_gain = 1;

        BBR_SaveCwnd(bbr);

        bbr->probe_rtt_done_stamp = 0;

}



    if (bbr->state == PROBE_RTT) {

void BBR_HandleProbeRTT(BBR *bbr, PrrtPacketTracking *tracking) {

    tracking->app_limited = (tracking->delivered + tracking->pipe) ? : 1;

    /* Ignore low rate samples during ProbeRTT: */

    prrtTimestamp_t now = PrrtClock_get_current_time_us();

        if (bbr->probe_rtt_done_stamp == 0 && packets_in_flight <= BBRMinPipeCwnd) {

    if (bbr->probe_rtt_done_stamp == 0 && tracking->pipe <= BBRMinPipeCwnd) {

        bbr->probe_rtt_done_stamp = now + ProbeRTTDuration;

        bbr->probe_rtt_round_done = false;

            bbr->next_round_delivered = delivered;

        bbr->next_round_delivered = tracking->delivered;

    } else if (bbr->probe_rtt_done_stamp != 0) {

        if (bbr->round_start)

            bbr->probe_rtt_round_done = true;
@@ -148,16 +148,30 @@ void BBR_UpdateRTprop(BBR* bbr, prrtTimedelta_t rtt, prrtByteCount_t delivered, 
        }

    }

}



void BBR_CheckProbeRTT(BBR *bbr, PrrtPacketTracking *tracking) {



    if (bbr->state != PROBE_RTT && bbr->rtprop_expired && !bbr->idle_restart) {

        BBR_EnterProbeRTT(bbr);

        BBR_SaveCwnd(bbr);

        bbr->probe_rtt_done_stamp = 0;

    }



    if (bbr->state == PROBE_RTT) {

        BBR_HandleProbeRTT(bbr, tracking);

    }

    bbr->idle_restart = false;

}



void BBR_UpdateModel(BBR* bbr, PrrtChannelStateInformation* csi, PrrtRateSample* rs, PrrtPacketTracking* packetTracking)

void BBR_UpdateModelAndState(BBR *bbr, PrrtChannelStateInformation *csi, PrrtRateSample *rs,

                             PrrtPacketTracking *packetTracking)

{

    BBR_UpdateBtlBw(bbr, rs, packetTracking->bytes_delivered, packetTracking->delivered);

    BBR_UpdateBtlBw(bbr, rs, packetTracking);

    BBR_CheckCyclePhase(bbr, packetTracking->packets_lost, packetTracking->prior_inflight);

    BBR_CheckFullPipe(bbr, rs);

    BBR_CheckDrain(bbr, packetTracking->packets_lost);

    BBR_UpdateRTprop(bbr, PrrtChannelStateInformation_get_rtprop(csi), packetTracking->delivered, packetTracking->packets_in_flight);

    BBR_CheckDrain(bbr, packetTracking->pipe);

    BBR_UpdateRTprop(bbr, PrrtChannelStateInformation_get_rtprop(csi));

    BBR_CheckProbeRTT(bbr, packetTracking);

}



void BBR_UpdateTargetCwnd(BBR* bbr)
@@ -211,7 +225,7 @@ void BBR_SetPacingRate(BBR* bbr) 


void BBR_OnACK(BBR* bbr, PrrtChannelStateInformation* csi, PrrtRateSample* rs, PrrtPacketTracking* packetTracking)

{

    BBR_UpdateModel(bbr, csi, rs, packetTracking);

    BBR_UpdateModelAndState(bbr, csi, rs, packetTracking);



    BBR_SetPacingRate(bbr);
@@ -223,8 +237,7 @@ BBR* BBR_Init(void) 
    BBR* bbr = calloc(1, sizeof(BBR));

    check_mem(bbr);

    bbr->btlBwFilter = WindowedFilter_Init(true);

    //bbr->rtprop = SRTT ? SRTT : Inf;

    bbr->rtprop = UINT32_MAX;

    bbr->rtprop = Inf;

    bbr->rtprop_stamp = PrrtClock_get_current_time_us();

    bbr->probe_rtt_done_stamp = 0;

    bbr->probe_rtt_round_done = false;
@@ -283,6 +296,14 @@ uint32_t BBR_getState(BBR* bbr) { 
    return bbr->state;

}



uint32_t BBR_getCycleIndex(BBR* bbr) {

    return bbr->cycle_index;

}



float BBR_getPacingGain(BBR* bbr) {

    return bbr->pacing_gain;

}



bool BBR_getFilledPipe(BBR* bbr) {

    return bbr->filled_pipe;

}

prrt/proto/bbr.h

+6 −6
Original line number Diff line number Diff line
@@ -10,16 +10,14 @@ 
#include "types/rateSample.h"

#include "../util/windowedFilter.h"



#define BtlBwFilterLen 10

#define MTU 1500

#define RTpropFilterLen 10000000    //10s

#define BBRHighGain ((2885 / 1000) + 1)

#define ProbeRTTInterval 10

#define InitialCwnd 10

#define InitialCwnd (10 * MTU)

#define BBRGainCycleLen 8

#define BBRMinPipeCwnd 4

//#define BBRMinPipeCwnd 200

#define BBRMinPipeCwnd (4 * MTU)

#define ProbeRTTDuration 200000 //200ms

#define Inf 0 //TODO: What is Inf

#define Inf UINT32_MAX



enum bbr_state {

    STARTUP,
@@ -80,6 +78,8 @@ uint32_t BBR_getCwnd(BBR* bbr); 
prrtDeliveryRate_t BBR_getBtlBw(BBR* bbr);

uint32_t BBR_getState(BBR* bbr);

uint64_t BBR_getFullBw(BBR* bbr);

float BBR_getPacingGain(BBR* bbr);

uint32_t BBR_getCycleIndex(BBR* bbr);

bool BBR_getFilledPipe(BBR* bbr);

uint32_t BBR_getRTProp(BBR* bbr);

prrt/proto/receiver.c

+1 −1
Original line number Diff line number Diff line
@@ -185,7 +185,7 @@ bool PrrtReceiver_updateAndGenerateRateSample(PrrtReceiver *recv, prrtSequenceNu 


    recv->packetTracking->packets_delivered++;

    recv->packetTracking->packets_in_flight = (prrtSequenceNumber_t) (PrrtInFlightPacketStore_get_queue_size(recv->dataInflightPacketStore) + PrrtInFlightPacketStore_get_queue_size(recv->redundancyInflightPacketStore));

    recv->packetTracking->prior_inflight = recv->packetTracking->packets_in_flight;

    recv->packetTracking->prior_inflight = recv->packetTracking->pipe;

    if(recv->rateSample != NULL && result) {

        BBR_OnACK(recv->bbr, recv->csi, recv->rateSample, recv->packetTracking);

    }

prrt/proto/socket.c

+7 −0
Original line number Diff line number Diff line
@@ -614,6 +614,13 @@ uint64_t PrrtSocket_get_full_bw(PrrtSocket *s) { 
    return BBR_getFullBw(s->receiver->bbr);

}



float PrrtSocket_get_pacing_gain(PrrtSocket *s) {

    return BBR_getPacingGain(s->receiver->bbr);

}



uint32_t PrrtSocket_get_cycle_index(PrrtSocket *s) {

    return BBR_getCycleIndex(s->receiver->bbr);

}



bool PrrtSocket_get_app_limited(PrrtSocket *s) {

    return PrrtChannelStateInformation_get_app_limited(s->receiver->csi);