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nor the names of its contributors may be used to
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
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*****************************************************************************/
/*****************************************************************************
written by
Yunhong Gu, last updated 07/09/2009
*****************************************************************************/
#include "core.h"
#include "ccc.h"
#include <cmath>
#include <cstring>
CCC::CCC():
m_iSYNInterval(CUDT::m_iSYNInterval),
m_dPktSndPeriod(1.0),
m_dCWndSize(16.0),
m_iBandwidth(),
m_dMaxCWndSize(),
m_iMSS(),
m_iSndCurrSeqNo(),
m_iRcvRate(),
m_iRTT(),
m_pcParam(NULL),
m_iPSize(0),
m_UDT(),
m_iACKPeriod(0),
m_iACKInterval(0),
m_bUserDefinedRTO(false),
m_iRTO(-1),
m_PerfInfo()
{
}
CCC::~CCC()
{
delete [] m_pcParam;
}
void CCC::setACKTimer(const int& msINT)
{
m_iACKPeriod = msINT;
if (m_iACKPeriod > m_iSYNInterval)
m_iACKPeriod = m_iSYNInterval;
}
void CCC::setACKInterval(const int& pktINT)
{
m_iACKInterval = pktINT;
}
void CCC::setRTO(const int& usRTO)
{
m_bUserDefinedRTO = true;
m_iRTO = usRTO;
}
void CCC::sendCustomMsg(CPacket& pkt) const
{
CUDT* u = CUDT::getUDTHandle(m_UDT);
if (NULL != u)
{
pkt.m_iID = u->m_PeerID;
u->m_pSndQueue->sendto(u->m_pPeerAddr, pkt);
}
}
const CPerfMon* CCC::getPerfInfo()
{
CUDT* u = CUDT::getUDTHandle(m_UDT);
if (NULL != u)
u->sample(&m_PerfInfo, false);
return &m_PerfInfo;
}
void CCC::setMSS(const int& mss)
{
m_iMSS = mss;
}
void CCC::setBandwidth(const int& bw)
{
m_iBandwidth = bw;
}
void CCC::setSndCurrSeqNo(const int32_t& seqno)
{
m_iSndCurrSeqNo = seqno;
}
void CCC::setRcvRate(const int& rcvrate)
{
m_iRcvRate = rcvrate;
}
void CCC::setMaxCWndSize(const int& cwnd)
{
m_dMaxCWndSize = cwnd;
}
void CCC::setRTT(const int& rtt)
{
m_iRTT = rtt;
}
void CCC::setUserParam(const char* param, const int& size)
{
delete [] m_pcParam;
m_pcParam = new char[size];
memcpy(m_pcParam, param, size);
m_iPSize = size;
}
//
CUDTCC::CUDTCC():
m_iRCInterval(),
m_LastRCTime(),
m_bSlowStart(),
m_iLastAck(),
m_bLoss(),
m_iLastDecSeq(),
m_dLastDecPeriod(),
m_iNAKCount(),
m_iDecRandom(),
m_iAvgNAKNum(),
m_iDecCount()
{
}
void CUDTCC::init()
{
m_iRCInterval = m_iSYNInterval;
m_LastRCTime = CTimer::getTime();
setACKTimer(m_iRCInterval);
m_bSlowStart = true;
m_iLastAck = m_iSndCurrSeqNo;
m_bLoss = false;
m_iLastDecSeq = CSeqNo::decseq(m_iLastAck);
m_dLastDecPeriod = 1;
m_iAvgNAKNum = 0;
m_iNAKCount = 0;
m_iDecRandom = 1;
m_dCWndSize = 16;
m_dPktSndPeriod = 1;
}
void CUDTCC::onACK(const int32_t& ack)
{
uint64_t currtime = CTimer::getTime();
if (currtime - m_LastRCTime < (uint64_t)m_iRCInterval)
return;
m_LastRCTime = currtime;
if (m_bSlowStart)
{
m_dCWndSize += CSeqNo::seqlen(m_iLastAck, ack);
m_iLastAck = ack;
if (m_dCWndSize > m_dMaxCWndSize)
{
m_bSlowStart = false;
if (m_iRcvRate > 0)
m_dPktSndPeriod = 1000000.0 / m_iRcvRate;
else
m_dPktSndPeriod = m_dCWndSize / (m_iRTT + m_iRCInterval);
}
}
else
m_dCWndSize = m_iRcvRate / 1000000.0 * (m_iRTT + m_iRCInterval) + 16;
// During Slow Start, no rate increase
if (m_bSlowStart)
return;
if (m_bLoss)
{
m_bLoss = false;
return;
}
int64_t B = (int64_t)(m_iBandwidth - 1000000.0 / m_dPktSndPeriod);
if ((m_dPktSndPeriod > m_dLastDecPeriod) && ((m_iBandwidth / 9) < B))
B = m_iBandwidth / 9;
double inc;
if (B <= 0)
inc = 1.0 / m_iMSS;
else
{
// inc = max(10 ^ ceil(log10( B * MSS * 8 ) * Beta / MSS, 1/MSS)
// Beta = 1.5 * 10^(-6)
inc = pow(10.0, ceil(log10(B * m_iMSS * 8.0))) * 0.0000015 / m_iMSS;
if (inc < 1.0/m_iMSS)
inc = 1.0/m_iMSS;
}
m_dPktSndPeriod = (m_dPktSndPeriod * m_iRCInterval) / (m_dPktSndPeriod * inc + m_iRCInterval);
//set maximum transfer rate
if ((NULL != m_pcParam) && (m_iPSize == 8))
{
int64_t maxSR = *(int64_t*)m_pcParam;
if (maxSR <= 0)
return;
double minSP = 1000000.0 / (double(maxSR) / m_iMSS);
if (m_dPktSndPeriod < minSP)
m_dPktSndPeriod = minSP;
}
}
void CUDTCC::onLoss(const int32_t* losslist, const int&)
{
//Slow Start stopped, if it hasn't yet
if (m_bSlowStart)
{
m_bSlowStart = false;
if (m_iRcvRate > 0)
m_dPktSndPeriod = 1000000.0 / m_iRcvRate;
else
m_dPktSndPeriod = m_dCWndSize / (m_iRTT + m_iRCInterval);
}
m_bLoss = true;
if (CSeqNo::seqcmp(losslist[0] & 0x7FFFFFFF, m_iLastDecSeq) > 0)
{
m_dLastDecPeriod = m_dPktSndPeriod;
m_dPktSndPeriod = ceil(m_dPktSndPeriod * 1.125);
m_iAvgNAKNum = (int)ceil(m_iAvgNAKNum * 0.875 + m_iNAKCount * 0.125);
m_iNAKCount = 1;
m_iDecCount = 1;
m_iLastDecSeq = m_iSndCurrSeqNo;
// remove global synchronization using randomization
srand(m_iLastDecSeq);
m_iDecRandom = (int)ceil(m_iAvgNAKNum * (double(rand()) / RAND_MAX));
if (m_iDecRandom < 1)
m_iDecRandom = 1;
}
else if ((m_iDecCount ++ < 5) && (0 == (++ m_iNAKCount % m_iDecRandom)))
{
// 0.875^5 = 0.51, rate should not be decreased by more than half within a congestion period
m_dPktSndPeriod = ceil(m_dPktSndPeriod * 1.125);
m_iLastDecSeq = m_iSndCurrSeqNo;
}
}
void CUDTCC::onTimeout()
{
if (m_bSlowStart)
{
m_bSlowStart = false;
if (m_iRcvRate > 0)
m_dPktSndPeriod = 1000000.0 / m_iRcvRate;
else
m_dPktSndPeriod = m_dCWndSize / (m_iRTT + m_iRCInterval);
}
else
{
/*
m_dLastDecPeriod = m_dPktSndPeriod;
m_dPktSndPeriod = ceil(m_dPktSndPeriod * 2);
m_iLastDecSeq = m_iLastAck;
*/
}
}