Mirrors/overte
3
0
Fork 0
mirror of https://github.com/overte-org/overte.git synced 2025-04-25 00:56:48 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions 2

some more cleanup in congestion control

Browse source
This commit is contained in:
Stephen Birarda 2015-07-29 11:48:00 -07:00
parent 169cb97db5
commit c35fa6eaae
2 changed files with 24 additions and 15 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

37
libraries/networking/src/udt/CongestionControl.cpp
View file

@ -28,13 +28,13 @@ void DefaultCC::init() {
}
void DefaultCC::onACK(SequenceNumber ackNum) {
int64_t B = 0;
double inc = 0;
double increase = 0;
// Note: 1/24/2012
// The minimum increase parameter is increased from "1.0 / _mss" to 0.01
// because the original was too small and caused sending rate to stay at low level
// for long time.
const double min_inc = 0.01;
const double minimumIncrease = 0.01;
auto now = high_resolution_clock::now();
if (duration_cast<microseconds>(now - _lastRCTime).count() < synInterval()) {
@ -69,24 +69,30 @@ void DefaultCC::onACK(SequenceNumber ackNum) {
return;
}
B = (int64_t)(_bandwidth - USECS_PER_SECOND/ _packetSendPeriod);
if ((_packetSendPeriod > _lastDecreasePeriod) && ((_bandwidth / 9) < B)) {
B = _bandwidth / 9;
int capacitySpeedDelta = (int) (_bandwidth - USECS_PER_SECOND / _packetSendPeriod);
if ((_packetSendPeriod > _lastDecreasePeriod) && ((_bandwidth / 9) < capacitySpeedDelta)) {
capacitySpeedDelta = _bandwidth / 9;
}
if (B <= 0) {
inc = min_inc;
if (capacitySpeedDelta <= 0) {
increase = minimumIncrease;
} else {
// inc = max(10 ^ ceil(log10( B * MSS * 8 ) * Beta / MSS, 1/MSS)
// inc = max(10 ^ ceil(log10(B * MSS * 8 ) * Beta / MSS, minimumIncrease)
// B = estimated link capacity
// Beta = 1.5 * 10^(-6)
inc = pow(10.0, ceil(log10(B * _mss * 8.0))) * 0.0000015 / _mss;
static const double BETA = 0.0000015;
static const double BITS_PER_BYTE = 8.0;
if (inc < min_inc) {
inc = min_inc;
increase = pow(10.0, ceil(log10(capacitySpeedDelta * _mss * BITS_PER_BYTE))) * BETA / _mss;
if (increase < minimumIncrease) {
increase = minimumIncrease;
}
}
_packetSendPeriod = (_packetSendPeriod * synInterval()) / (_packetSendPeriod * inc + synInterval());
_packetSendPeriod = (_packetSendPeriod * synInterval()) / (_packetSendPeriod * increase + synInterval());
}
void DefaultCC::onLoss(SequenceNumber rangeStart, SequenceNumber rangeEnd) {
@ -119,8 +125,11 @@ void DefaultCC::onLoss(SequenceNumber rangeStart, SequenceNumber rangeEnd) {
// remove global synchronization using randomization
srand((uint32_t)_lastDecreaseMaxSeq);
_decRandom = (int)ceil(_avgNAKNum * (double(rand()) / RAND_MAX));
if (_decRandom < 1)
if (_decRandom < 1) {
_decRandom = 1;
}
} else if ((_decCount ++ < 5) && (0 == (++ _nakCount % _decRandom))) {
// 0.875^5 = 0.51, rate should not be decreased by more than half within a congestion period
_packetSendPeriod = ceil(_packetSendPeriod * 1.125);

2
libraries/networking/src/udt/CongestionControl.h
View file

@ -60,7 +60,7 @@ private:
CongestionControl(const CongestionControl& other) = delete;
CongestionControl& operator=(const CongestionControl& other) = delete;
void setMss(int mss) { _mss = mss; }
void setMSS(int mss) { _mss = mss; }
void setMaxCongestionWindowSize(int window) { _maxCongestionWindowSize = window; }
void setBandwidth(int bandwidth) { _bandwidth = bandwidth; }
void setSendCurrentSequenceNumber(SequenceNumber seqNum) { _sendCurrSeqNum = seqNum; }