mirror of
https://github.com/overte-org/overte.git
synced 2025-08-04 20:06:48 +02:00
some initial cleanup in CongestionControl
This commit is contained in:
Stephen Birarda
parent
d344ba5743
commit
89e32e4a6b
2 changed files with 29 additions and 27 deletions
|
|
@ -11,16 +11,17 @@
|
|||
|
||||
#include "CongestionControl.h"
|
||||
|
||||
#include <SharedUtil.h>
|
||||
#include <NumericalConstants.h>
|
||||
|
||||
using namespace udt;
|
||||
using namespace std::chrono;
|
||||
|
||||
void DefaultCC::init() {
|
||||
_lastRCTime = usecTimestampNow();
|
||||
_lastRCTime = high_resolution_clock::now();
|
||||
setAckTimer(synInterval());
|
||||
|
||||
_lastAck = _sendCurrSeqNum;
|
||||
_lastDecSeq = SequenceNumber{ SequenceNumber::MAX };
|
||||
_lastDecreaseMaxSeq = SequenceNumber { SequenceNumber::MAX };
|
||||
|
||||
_congestionWindowSize = 16.0;
|
||||
_packetSendPeriod = 1.0;
|
||||
|
|
@ -35,12 +36,12 @@ void DefaultCC::onACK(SequenceNumber ackNum) {
|
|||
// for long time.
|
||||
const double min_inc = 0.01;
|
||||
|
||||
uint64_t currtime = usecTimestampNow();
|
||||
if (currtime - _lastRCTime < (uint64_t)synInterval()) {
|
||||
auto now = high_resolution_clock::now();
|
||||
if (duration_cast<microseconds>(now - _lastRCTime).count() < synInterval()) {
|
||||
return;
|
||||
}
|
||||
|
||||
_lastRCTime = currtime;
|
||||
_lastRCTime = now;
|
||||
|
||||
if (_slowStart) {
|
||||
_congestionWindowSize += seqlen(_lastAck, ackNum);
|
||||
|
|
@ -48,14 +49,14 @@ void DefaultCC::onACK(SequenceNumber ackNum) {
|
|||
|
||||
if (_congestionWindowSize > _maxCongestionWindowSize) {
|
||||
_slowStart = false;
|
||||
if (_recvieveRate > 0) {
|
||||
_packetSendPeriod = 1000000.0 / _recvieveRate;
|
||||
if (_receiveRate > 0) {
|
||||
_packetSendPeriod = USECS_PER_SECOND / _receiveRate;
|
||||
} else {
|
||||
_packetSendPeriod = (_rtt + synInterval()) / _congestionWindowSize;
|
||||
}
|
||||
}
|
||||
} else {
|
||||
_congestionWindowSize = _recvieveRate / 1000000.0 * (_rtt + synInterval()) + 16;
|
||||
_congestionWindowSize = _receiveRate / USECS_PER_SECOND * (_rtt + synInterval()) + 16;
|
||||
}
|
||||
|
||||
// During Slow Start, no rate increase
|
||||
|
|
@ -69,7 +70,7 @@ void DefaultCC::onACK(SequenceNumber ackNum) {
|
|||
}
|
||||
|
||||
B = (int64_t)(_bandwidth - 1000000.0 / _packetSendPeriod);
|
||||
if ((_packetSendPeriod > _lastDecPeriod) && ((_bandwidth / 9) < B)) {
|
||||
if ((_packetSendPeriod > _lastDecreasePeriod) && ((_bandwidth / 9) < B)) {
|
||||
B = _bandwidth / 9;
|
||||
}
|
||||
if (B <= 0) {
|
||||
|
|
@ -92,9 +93,9 @@ void DefaultCC::onLoss(SequenceNumber rangeStart, SequenceNumber rangeEnd) {
|
|||
//Slow Start stopped, if it hasn't yet
|
||||
if (_slowStart) {
|
||||
_slowStart = false;
|
||||
if (_recvieveRate > 0) {
|
||||
if (_receiveRate > 0) {
|
||||
// Set the sending rate to the receiving rate.
|
||||
_packetSendPeriod = 1000000.0 / _recvieveRate;
|
||||
_packetSendPeriod = USECS_PER_SECOND / _receiveRate;
|
||||
return;
|
||||
}
|
||||
// If no receiving rate is observed, we have to compute the sending
|
||||
|
|
@ -105,33 +106,33 @@ void DefaultCC::onLoss(SequenceNumber rangeStart, SequenceNumber rangeEnd) {
|
|||
|
||||
_loss = true;
|
||||
|
||||
if (rangeStart > _lastDecSeq) {
|
||||
_lastDecPeriod = _packetSendPeriod;
|
||||
if (rangeStart > _lastDecreaseMaxSeq) {
|
||||
_lastDecreasePeriod = _packetSendPeriod;
|
||||
_packetSendPeriod = ceil(_packetSendPeriod * 1.125);
|
||||
|
||||
_avgNAKNum = (int)ceil(_avgNAKNum * 0.875 + _nakCount * 0.125);
|
||||
_nakCount = 1;
|
||||
_decCount = 1;
|
||||
|
||||
_lastDecSeq = _sendCurrSeqNum;
|
||||
_lastDecreaseMaxSeq = _sendCurrSeqNum;
|
||||
|
||||
// remove global synchronization using randomization
|
||||
srand((uint32_t)_lastDecSeq);
|
||||
srand((uint32_t)_lastDecreaseMaxSeq);
|
||||
_decRandom = (int)ceil(_avgNAKNum * (double(rand()) / RAND_MAX));
|
||||
if (_decRandom < 1)
|
||||
_decRandom = 1;
|
||||
} else if ((_decCount ++ < 5) && (0 == (++ _nakCount % _decRandom))) {
|
||||
} 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);
|
||||
_lastDecSeq = _sendCurrSeqNum;
|
||||
_lastDecreaseMaxSeq = _sendCurrSeqNum;
|
||||
}
|
||||
}
|
||||
|
||||
void DefaultCC::onTimeout() {
|
||||
if (_slowStart) {
|
||||
_slowStart = false;
|
||||
if (_recvieveRate > 0) {
|
||||
_packetSendPeriod = 1000000.0 / _recvieveRate;
|
||||
if (_receiveRate > 0) {
|
||||
_packetSendPeriod = USECS_PER_SECOND / _receiveRate;
|
||||
} else {
|
||||
_packetSendPeriod = _congestionWindowSize / (_rtt + synInterval());
|
||||
}
|
||||
|
|
|
|||
|
|
@ -12,6 +12,7 @@
|
|||
#ifndef hifi_CongestionControl_h
|
||||
#define hifi_CongestionControl_h
|
||||
|
||||
#include <chrono>
|
||||
#include <vector>
|
||||
|
||||
#include "LossList.h"
|
||||
|
|
@ -52,7 +53,7 @@ protected:
|
|||
|
||||
int _mss = 0; // Maximum Packet Size, including all packet headers
|
||||
SequenceNumber _sendCurrSeqNum; // current maximum seq num sent out
|
||||
int _recvieveRate = 0; // packet arrive rate at receiver side, packets per second
|
||||
int _receiveRate = 0; // packet arrive rate at receiver side, packets per second
|
||||
int _rtt = 0; // current estimated RTT, microsecond
|
||||
|
||||
private:
|
||||
|
|
@ -62,9 +63,9 @@ private:
|
|||
void setMss(int mss) { _mss = mss; }
|
||||
void setMaxCongestionWindowSize(int window) { _maxCongestionWindowSize = window; }
|
||||
void setBandwidth(int bandwidth) { _bandwidth = bandwidth; }
|
||||
void setSndCurrSeqNum(SequenceNumber seqNum) { _sendCurrSeqNum = seqNum; }
|
||||
void setRcvRate(int rate) { _recvieveRate = rate; }
|
||||
void setRtt(int rtt) { _rtt = rtt; }
|
||||
void setSendCurrentSequenceNumber(SequenceNumber seqNum) { _sendCurrSeqNum = seqNum; }
|
||||
void setReceiveRate(int rate) { _receiveRate = rate; }
|
||||
void setRTT(int rtt) { _rtt = rtt; }
|
||||
|
||||
int _ackPeriod = 0; // Periodical timer to send an ACK, in milliseconds
|
||||
int _ackInterval = 0; // How many packets to send one ACK, in packets
|
||||
|
|
@ -103,12 +104,12 @@ public:
|
|||
virtual void onTimeout();
|
||||
|
||||
private:
|
||||
uint64_t _lastRCTime = 0; // last rate increase time
|
||||
std::chrono::high_resolution_clock::time_point _lastRCTime; // last rate increase time
|
||||
bool _slowStart = true; // if in slow start phase
|
||||
SequenceNumber _lastAck; // last ACKed seq num
|
||||
bool _loss = false; // if loss happened since last rate increase
|
||||
SequenceNumber _lastDecSeq; // max pkt seq num sent out when last decrease happened
|
||||
double _lastDecPeriod = 1; // value of pktsndperiod when last decrease happened
|
||||
SequenceNumber _lastDecreaseMaxSeq; // max pkt seq num sent out when last decrease happened
|
||||
double _lastDecreasePeriod = 1; // value of _packetSendPeriod when last decrease happened
|
||||
int _nakCount = 0; // NAK counter
|
||||
int _decRandom = 1; // random threshold on decrease by number of loss events
|
||||
int _avgNAKNum = 0; // average number of NAKs per congestion
|
||||
|
|
|
|||
Loading…
Reference in a new issue