/*****************************************************************************Copyright (c) 2001 - 2008, The Board of Trustees of the University of Illinois.All rights reserved.Redistribution and use in source and binary forms, with or withoutmodification, are permitted provided that the following conditions aremet:* Redistributions of source code must retain the above  copyright notice, this list of conditions and the  following disclaimer.* Redistributions in binary form must reproduce the  above copyright notice, this list of conditions  and the following disclaimer in the documentation  and/or other materials provided with the distribution.* Neither the name of the University of Illinois  nor the names of its contributors may be used to  endorse or promote products derived from this  software without specific prior written permission.THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "ASIS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULARPURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER ORCONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, ORPROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OFLIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDINGNEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THISSOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.*****************************************************************************//*****************************************************************************written by   Yunhong Gu, last updated 12/01/2008*****************************************************************************/#include "core.h"#include "ccc.h"#include <cmath>CCC::CCC():m_iSYNInterval(CUDT::m_iSYNInterval),m_dPktSndPeriod(1.0),m_dCWndSize(16.0),m_pcParam(NULL),m_iPSize(0),m_iACKPeriod(0),m_iACKInterval(0),m_bUserDefinedRTO(false),m_iRTO(-1){}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)      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);}//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(rand() * double(m_iAvgNAKNum) / (RAND_MAX + 1.0));      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);   }}