// Returned value:      //    Actual size of data received.   int64_t recvfile(std::ofstream& ofs, const int64_t& offset, const int64_t& size, const int& block = 7320000);      // Functionality:      //    Configure UDT options.      // Parameters:      //    0) [in] optName: The enum name of a UDT option.      //    1) [in] optval: The value to be set.      //    2) [in] optlen: size of "optval".      // Returned value:      //    None.   void setOpt(UDTOpt optName, const void* optval, const int& optlen);      // Functionality:      //    Read UDT options.      // Parameters:      //    0) [in] optName: The enum name of a UDT option.      //    1) [in] optval: The value to be returned.      //    2) [out] optlen: size of "optval".      // Returned value:      //    None.   void getOpt(UDTOpt optName, void* optval, int& optlen);      // Functionality:      //    read the performance data since last sample() call.      // Parameters:      //    0) [in, out] perf: pointer to a CPerfMon structure to record the performance data.      //    1) [in] clear: flag to decide if the local performance trace should be cleared.      // Returned value:      //    None.   void sample(CPerfMon* perf, bool clear = true);private:   static CUDTUnited s_UDTUnited;               // UDT global management basepublic:   static const UDTSOCKET INVALID_SOCK;         // invalid socket descriptor   static const int ERROR;                      // socket api error returned valueprivate: // Identification   UDTSOCKET m_SocketID;                        // UDT socket number   UDTSockType m_iSockType;                     // Type of the UDT connection (SOCK_STREAM or SOCK_DGRAM)   UDTSOCKET m_PeerID;				// peer id, for multiplexer   static const int m_iVersion;                 // UDT version, for compatibility useprivate: // Packet size and sequence number attributes   int m_iPktSize;                              // Maximum/regular packet size, in bytes   int m_iPayloadSize;                          // Maximum/regular payload size, in bytesprivate: // Options   int m_iMSS;                                  // Maximum Segment Size   bool m_bSynSending;                          // Sending syncronization mode   bool m_bSynRecving;                          // Receiving syncronization mode   int m_iFlightFlagSize;                       // Maximum number of packets in flight from the peer side   int m_iSndBufSize;                           // Maximum UDT sender buffer size   int m_iRcvBufSize;                           // Maximum UDT receiver buffer size   linger m_Linger;                             // Linger information on close   int m_iUDPSndBufSize;                        // UDP sending buffer size   int m_iUDPRcvBufSize;                        // UDP receiving buffer size   int m_iIPversion;                            // IP version   bool m_bRendezvous;                          // Rendezvous connection mode   int m_iSndTimeOut;                           // sending timeout in milliseconds   int m_iRcvTimeOut;                           // receiving timeout in milliseconds   bool m_bReuseAddr;				// reuse an exiting port or not, for UDP multiplexer   int64_t m_llMaxBW;				// maximum data transfer rate (threshold)private: // congestion control   CCCVirtualFactory* m_pCCFactory;             // Factory class to create a specific CC instance   CCC* m_pCC;                                  // congestion control class   CControl* m_pController;			// congestion control managerprivate: // Status   volatile bool m_bListening;                  // If the UDT entit is listening to connection   volatile bool m_bConnected;                  // Whether the connection is on or off   volatile bool m_bClosing;                    // If the UDT entity is closing   volatile bool m_bShutdown;                   // If the peer side has shutdown the connection   volatile bool m_bBroken;                     // If the connection has been broken   bool m_bOpened;                              // If the UDT entity has been opened   int m_iBrokenCounter;			// a counter (number of GC checks) to let the GC tag this socket as disconnected   int m_iEXPCount;                             // Expiration counter   int m_iBandwidth;                            // Estimated bandwidth   int m_iRTT;                                  // RTT   int m_iRTTVar;                               // RTT varianc   int m_iDeliveryRate;				// Packet arrival rate at the receiver sideprivate: // Sending related data   CSndBuffer* m_pSndBuffer;                    // Sender buffer   CSndLossList* m_pSndLossList;                // Sender loss list   CPktTimeWindow* m_pSndTimeWindow;            // Packet sending time window   volatile uint64_t m_ullInterval;             // Inter-packet time, in CPU clock cycles   uint64_t m_ullTimeDiff;                      // aggregate difference in inter-packet time   volatile int m_iFlowWindowSize;              // Flow control window size   volatile double m_dCongestionWindow;         // congestion window size   volatile int32_t m_iSndLastAck;              // Last ACK received   int32_t m_iSndLastDataAck;                   // The real last ACK that updates the sender buffer and loss list   int32_t m_iSndCurrSeqNo;                     // The largest sequence number that has been sent   int32_t m_iLastDecSeq;                       // Sequence number sent last decrease occurs   int32_t m_iSndLastAck2;                      // Last ACK2 sent back   uint64_t m_ullSndLastAck2Time;               // The time when last ACK2 was sent back   int32_t m_iISN;                              // Initial Sequence Numberprivate: // Receiving related data   CRcvBuffer* m_pRcvBuffer;                    // Receiver buffer   CRcvLossList* m_pRcvLossList;                // Receiver loss list   CACKWindow* m_pACKWindow;                    // ACK history window   CPktTimeWindow* m_pRcvTimeWindow;            // Packet arrival time window   int32_t m_iRcvLastAck;                       // Last sent ACK   uint64_t m_ullLastAckTime;                   // Timestamp of last ACK   int32_t m_iRcvLastAckAck;                    // Last sent ACK that has been acknowledged   int32_t m_iAckSeqNo;                         // Last ACK sequence number   int32_t m_iRcvCurrSeqNo;                     // Largest received sequence number   uint64_t m_ullLastWarningTime;               // Last time that a warning message is sent   int32_t m_iPeerISN;                          // Initial Sequence Number of the peer sideprivate: // synchronization: mutexes and conditions   pthread_mutex_t m_ConnectionLock;            // used to synchronize connection operation   pthread_cond_t m_SendBlockCond;              // used to block "send" call   pthread_mutex_t m_SendBlockLock;             // lock associated to m_SendBlockCond   pthread_mutex_t m_AckLock;                   // used to protected sender's loss list when processing ACK   pthread_cond_t m_RecvDataCond;               // used to block "recv" when there is no data   pthread_mutex_t m_RecvDataLock;              // lock associated to m_RecvDataCond   pthread_mutex_t m_SendLock;                  // used to synchronize "send" call   pthread_mutex_t m_RecvLock;                  // used to synchronize "recv" call   void initSynch();   void destroySynch();   void releaseSynch();private: // Generation and processing of packets   void sendCtrl(const int& pkttype, void* lparam = NULL, void* rparam = NULL, const int& size = 0);   void processCtrl(CPacket& ctrlpkt);   int packData(CPacket& packet, uint64_t& ts);   int processData(CUnit* unit);   int listen(sockaddr* addr, CPacket& packet);private: // Trace   uint64_t m_StartTime;                        // timestamp when the UDT entity is started   int64_t m_llSentTotal;                       // total number of sent data packets, including retransmissions   int64_t m_llRecvTotal;                       // total number of received packets   int m_iSndLossTotal;                         // total number of lost packets (sender side)   int m_iRcvLossTotal;                         // total number of lost packets (receiver side)   int m_iRetransTotal;                         // total number of retransmitted packets   int m_iSentACKTotal;                         // total number of sent ACK packets   int m_iRecvACKTotal;                         // total number of received ACK packets   int m_iSentNAKTotal;                         // total number of sent NAK packets   int m_iRecvNAKTotal;                         // total number of received NAK packets   uint64_t m_LastSampleTime;                   // last performance sample time   int64_t m_llTraceSent;                       // number of pakctes sent in the last trace interval   int64_t m_llTraceRecv;                       // number of pakctes received in the last trace interval   int m_iTraceSndLoss;                         // number of lost packets in the last trace interval (sender side)   int m_iTraceRcvLoss;                         // number of lost packets in the last trace interval (receiver side)   int m_iTraceRetrans;                         // number of retransmitted packets in the last trace interval   int m_iSentACK;                              // number of ACKs sent in the last trace interval   int m_iRecvACK;                              // number of ACKs received in the last trace interval   int m_iSentNAK;                              // number of NAKs sent in the last trace interval   int m_iRecvNAK;                              // number of NAKs received in the last trace intervalprivate: // Timers   uint64_t m_ullCPUFrequency;                  // CPU clock frequency, used for Timer   static const int m_iSYNInterval;             // Periodical Rate Control Interval, 10 ms   static const int m_iSelfClockInterval;       // ACK interval for self-clocking   uint64_t m_ullNextACKTime;			// Next ACK time, in CPU clock cycles   uint64_t m_ullNextNAKTime;			// Next NAK time   uint64_t m_ullNextEXPTime;			// Next timeout   volatile uint64_t m_ullSYNInt;		// SYN interval   volatile uint64_t m_ullACKInt;		// ACK interval   volatile uint64_t m_ullNAKInt;		// NAK interval   volatile uint64_t m_ullEXPInt;		// EXP interval   volatile uint64_t m_ullMinEXPInt;		// Minimum EXP interval   int m_iPktCount;				// packet counter for ACK   int m_iLightACKCount;			// light ACK counter   uint64_t m_ullTargetTime;			// target time of next packet sending   void checkTimers();private: // for UDP multiplexer   CSndQueue* m_pSndQueue;			// packet sending queue   CRcvQueue* m_pRcvQueue;			// packet receivinf queue   sockaddr* m_pPeerAddr;			// peer address   CSNode* m_pSNode;				// node information for UDT list used in snd queue   CRNode* m_pRNode;                            // node information for UDT list used in rcv queue};#endif