www.pudn.com > udt.sdk.4.1.win32.zip > api.cpp

/*****************************************************************************
Copyright (c) 2001 - 2007, The Board of Trustees of the University of Illinois.
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:

* 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 "AS
IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
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EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*****************************************************************************/

/*****************************************************************************
written by
   Yunhong Gu, last updated 12/10/2007
*****************************************************************************/

#ifdef WIN32
   #include 
   #include 
#else
   #include 
#endif
#include "api.h"
#include "core.h"

using namespace std;

CUDTSocket::CUDTSocket():
m_pSelfAddr(NULL),
m_pPeerAddr(NULL),
m_pUDT(NULL),
m_pQueuedSockets(NULL),
m_pAcceptSockets(NULL)
{
   #ifndef WIN32
      pthread_mutex_init(&m_AcceptLock, NULL);
      pthread_cond_init(&m_AcceptCond, NULL);
   #else
      m_AcceptLock = CreateMutex(NULL, false, NULL);
      m_AcceptCond = CreateEvent(NULL, false, false, NULL);
   #endif
}

CUDTSocket::~CUDTSocket()
{
   if (AF_INET == m_iIPversion)
   {
      if (m_pSelfAddr)
         delete (sockaddr_in*)m_pSelfAddr;
      if (m_pPeerAddr)
         delete (sockaddr_in*)m_pPeerAddr;
   }
   else
   {
      if (m_pSelfAddr)
         delete (sockaddr_in6*)m_pSelfAddr;
      if (m_pPeerAddr)
         delete (sockaddr_in6*)m_pPeerAddr;
   }

   if (m_pUDT)
      delete m_pUDT;

   if (m_pQueuedSockets)
      delete m_pQueuedSockets;
   if (m_pAcceptSockets)
      delete m_pAcceptSockets;

   #ifndef WIN32
      pthread_mutex_destroy(&m_AcceptLock);
      pthread_cond_destroy(&m_AcceptCond);
   #else
      CloseHandle(m_AcceptLock);
      CloseHandle(m_AcceptCond);
   #endif
}

////////////////////////////////////////////////////////////////////////////////

CUDTUnited::CUDTUnited()
{
   srand((unsigned int)CTimer::getTime());
   m_SocketID = 1 + (int)((1 << 30) * (rand()/(RAND_MAX + 1.0)));

   #ifndef WIN32
      pthread_mutex_init(&m_ControlLock, NULL);
      pthread_mutex_init(&m_IDLock, NULL);
   #else
      m_ControlLock = CreateMutex(NULL, false, NULL);
      m_IDLock = CreateMutex(NULL, false, NULL);
   #endif

   #ifndef WIN32
      pthread_key_create(&m_TLSError, TLSDestroy);
   #else
      m_TLSError = TlsAlloc();
   #endif

   // Global initialization code
   #ifdef WIN32
      WORD wVersionRequested;
      WSADATA wsaData;
      wVersionRequested = MAKEWORD(2, 2);

      if (0 != WSAStartup(wVersionRequested, &wsaData))
         throw CUDTException(1, 0,  WSAGetLastError());
   #endif

   m_vMultiplexer.clear();
   m_pController = new CControl;

   m_bClosing = false;
   #ifndef WIN32
      pthread_create(&m_GCThread, NULL, garbageCollect, this);
   #else
      DWORD ThreadID;
      m_GCThread = CreateThread(NULL, 0, garbageCollect, this, NULL, &ThreadID);
   #endif
}

CUDTUnited::~CUDTUnited()
{
   m_bClosing = true;
   #ifndef WIN32
      pthread_join(m_GCThread, NULL);
   #else
      WaitForSingleObject(m_GCThread, INFINITE);
   #endif

   #ifndef WIN32
      pthread_mutex_destroy(&m_ControlLock);
      pthread_mutex_destroy(&m_IDLock);
   #else
      CloseHandle(m_ControlLock);
      CloseHandle(m_IDLock);
   #endif

   #ifndef WIN32
      pthread_key_delete(m_TLSError);
   #else
      TlsFree(m_TLSError);
   #endif

   m_vMultiplexer.clear();
   delete m_pController;

   // Global destruction code
   #ifdef WIN32
      WSACleanup();
   #endif
}

UDTSOCKET CUDTUnited::newSocket(const int& af, const int& type)
{
   if ((type != SOCK_STREAM) && (type != SOCK_DGRAM))
      throw CUDTException(5, 3, 0);

   CUDTSocket* ns = NULL;

   try
   {
      ns = new CUDTSocket;
      ns->m_pUDT = new CUDT;
      if (AF_INET == af)
      {
         ns->m_pSelfAddr = (sockaddr*)(new sockaddr_in);
         ((sockaddr_in*)(ns->m_pSelfAddr))->sin_port = 0;
      }
      else
      {
         ns->m_pSelfAddr = (sockaddr*)(new sockaddr_in6);
         ((sockaddr_in6*)(ns->m_pSelfAddr))->sin6_port = 0;
      }
   }
   catch (...)
   {
      delete ns;
      throw CUDTException(3, 2, 0);
   }

   #ifndef WIN32
      pthread_mutex_lock(&m_IDLock);
   #else
      WaitForSingleObject(m_IDLock, INFINITE);
   #endif
   ns->m_SocketID = -- m_SocketID;
   #ifndef WIN32
      pthread_mutex_unlock(&m_IDLock);
   #else
      ReleaseMutex(m_IDLock);
   #endif

   ns->m_Status = CUDTSocket::INIT;
   ns->m_ListenSocket = 0;
   ns->m_pUDT->m_SocketID = ns->m_SocketID;
   ns->m_pUDT->m_iSockType = (SOCK_STREAM == type) ? UDT_STREAM : UDT_DGRAM;
   ns->m_pUDT->m_iIPversion = ns->m_iIPversion = af;
   ns->m_pUDT->m_pController = m_pController;

   // protect the m_Sockets structure.
   #ifndef WIN32
      pthread_mutex_lock(&m_ControlLock);
   #else
      WaitForSingleObject(m_ControlLock, INFINITE);
   #endif
   try
   {
      m_Sockets[ns->m_SocketID] = ns;
   }
   catch (...)
   {
      //failure and rollback
      delete ns;
      ns = NULL;
   }
   #ifndef WIN32
      pthread_mutex_unlock(&m_ControlLock);
   #else
      ReleaseMutex(m_ControlLock);
   #endif

   if (NULL == ns)
      throw CUDTException(3, 2, 0);

   return ns->m_SocketID;
}

int CUDTUnited::newConnection(const UDTSOCKET listen, const sockaddr* peer, CHandShake* hs)
{
   CUDTSocket* ns;
   CUDTSocket* ls = locate(listen);

   // if this connection has already been processed
   if (NULL != (ns = locate(listen, peer, hs->m_iID, hs->m_iISN)))
   {
      if (ns->m_pUDT->m_bBroken)
      {
         // last connection from the "peer" address has been broken
         ns->m_Status = CUDTSocket::CLOSED;
         ns->m_TimeStamp = CTimer::getTime();

         #ifndef WIN32
            pthread_mutex_lock(&(ls->m_AcceptLock));
         #else
            WaitForSingleObject(ls->m_AcceptLock, INFINITE);
         #endif
         ls->m_pQueuedSockets->erase(ns->m_SocketID);
         ls->m_pAcceptSockets->erase(ns->m_SocketID);
         #ifndef WIN32
            pthread_mutex_unlock(&(ls->m_AcceptLock));
         #else
            ReleaseMutex(ls->m_AcceptLock);
         #endif
      }
      else
      {
         // connection already exist, this is a repeated connection request
         // respond with existing HS information

         hs->m_iISN = ns->m_pUDT->m_iISN;
         hs->m_iMSS = ns->m_pUDT->m_iMSS;
         hs->m_iFlightFlagSize = ns->m_pUDT->m_iFlightFlagSize;
         hs->m_iReqType = -1;
         hs->m_iID = ns->m_SocketID;

         return 0;

         //except for this situation a new connection should be started
      }
   }

   // exceeding backlog, refuse the connection request
   if (ls->m_pQueuedSockets->size() >= ls->m_uiBackLog)
      return -1;

   try
   {
      ns = new CUDTSocket;
      ns->m_pUDT = new CUDT(*(ls->m_pUDT));
      if (AF_INET == ls->m_iIPversion)
      {
         ns->m_pSelfAddr = (sockaddr*)(new sockaddr_in);
         ((sockaddr_in*)(ns->m_pSelfAddr))->sin_port = 0;
         ns->m_pPeerAddr = (sockaddr*)(new sockaddr_in);
         memcpy(ns->m_pPeerAddr, peer, sizeof(sockaddr_in));
      }
      else
      {
         ns->m_pSelfAddr = (sockaddr*)(new sockaddr_in6);
         ((sockaddr_in6*)(ns->m_pSelfAddr))->sin6_port = 0;
         ns->m_pPeerAddr = (sockaddr*)(new sockaddr_in6);
         memcpy(ns->m_pPeerAddr, peer, sizeof(sockaddr_in6));
      }
   }
   catch (...)
   {
      delete ns;
      return -1;
   }

   #ifndef WIN32
      pthread_mutex_lock(&m_IDLock);
   #else
      WaitForSingleObject(m_IDLock, INFINITE);
   #endif
   ns->m_SocketID = -- m_SocketID;
   #ifndef WIN32
      pthread_mutex_unlock(&m_IDLock);
   #else
      ReleaseMutex(m_IDLock);
   #endif

   ns->m_ListenSocket = listen;
   ns->m_iIPversion = ls->m_iIPversion;
   ns->m_pUDT->m_SocketID = ns->m_SocketID;
   ns->m_PeerID = hs->m_iID;
   ns->m_iISN = hs->m_iISN;

   int error = 0;

   try
   {
      // bind to the same addr of listening socket
      ns->m_pUDT->open();
      updateMux(ns->m_pUDT, ls);
      ns->m_pUDT->connect(peer, hs);
   }
   catch (...)
   {
      error = 1;
      goto ERR_ROLLBACK;
   }

   ns->m_Status = CUDTSocket::CONNECTED;

   // copy address information of local node
   ns->m_pUDT->m_pSndQueue->m_pChannel->getSockAddr(ns->m_pSelfAddr);

   // protect the m_Sockets structure.
   #ifndef WIN32
      pthread_mutex_lock(&m_ControlLock);
   #else
      WaitForSingleObject(m_ControlLock, INFINITE);
   #endif
   try
   {
      m_Sockets[ns->m_SocketID] = ns;
   }
   catch (...)
   {
      error = 2;
   }
   #ifndef WIN32
      pthread_mutex_unlock(&m_ControlLock);
   #else
      ReleaseMutex(m_ControlLock);
   #endif

   #ifndef WIN32
      pthread_mutex_lock(&(ls->m_AcceptLock));
   #else
      WaitForSingleObject(ls->m_AcceptLock, INFINITE);
   #endif
   try
   {
      ls->m_pQueuedSockets->insert(ns->m_SocketID);
   }
   catch (...)
   {
      error = 3;
   }
   #ifndef WIN32
      pthread_mutex_unlock(&(ls->m_AcceptLock));
   #else
      ReleaseMutex(ls->m_AcceptLock);
   #endif

   CTimer::triggerEvent();

   ERR_ROLLBACK:
   if (error > 0)
   {
      ns->m_pUDT->close();
      if (error > 1)
         m_Sockets.erase(ns->m_SocketID);
      delete ns;

      return -1;
   }

   // wake up a waiting accept() call
   #ifndef WIN32
      pthread_cond_signal(&(ls->m_AcceptCond));
   #else
      SetEvent(ls->m_AcceptCond);
   #endif

   return 1;
}

CUDT* CUDTUnited::lookup(const UDTSOCKET u)
{
   // protects the m_Sockets structure
   CGuard cg(m_ControlLock);

   map::iterator i = m_Sockets.find(u);

   if ((i == m_Sockets.end()) || (i->second->m_Status == CUDTSocket::CLOSED))
      throw CUDTException(5, 4, 0);

   return i->second->m_pUDT;
}

CUDTSocket::UDTSTATUS CUDTUnited::getStatus(const UDTSOCKET u)
{
   // protects the m_Sockets structure
   CGuard cg(m_ControlLock);

   map::iterator i = m_Sockets.find(u);

   if (i == m_Sockets.end())
      return CUDTSocket::INIT;

   if (i->second->m_pUDT->m_bBroken)
      return CUDTSocket::BROKEN;

   return i->second->m_Status;   
}

int CUDTUnited::bind(const UDTSOCKET u, const sockaddr* name, const int& namelen)
{
   CUDTSocket* s = locate(u);

   if (NULL == s)
      throw CUDTException(5, 4, 0);

   // cannot bind a socket more than once
   if (CUDTSocket::INIT != s->m_Status)
      throw CUDTException(5, 0, 0);

   // check the size of SOCKADDR structure
   if (AF_INET == s->m_iIPversion)
   {
      if (namelen != sizeof(sockaddr_in))
         throw CUDTException(5, 3, 0);
   }
   else
   {
      if (namelen != sizeof(sockaddr_in6))
         throw CUDTException(5, 3, 0);
   }

   s->m_pUDT->open();
   updateMux(s->m_pUDT, name);
   s->m_Status = CUDTSocket::OPENED;

   // copy address information of local node
   s->m_pUDT->m_pSndQueue->m_pChannel->getSockAddr(s->m_pSelfAddr);

   return 0;
}

int CUDTUnited::listen(const UDTSOCKET u, const int& backlog)
{
   CUDTSocket* s = locate(u);

   if (NULL == s)
      throw CUDTException(5, 4, 0);

   // do nothing if the socket is already listening
   if (CUDTSocket::LISTENING == s->m_Status)
      return 0;

   // a socket can listen only if is in OPENED status
   if (CUDTSocket::OPENED != s->m_Status)
      throw CUDTException(5, 5, 0);

   // listen is not supported in rendezvous connection setup
   if (s->m_pUDT->m_bRendezvous)
      throw CUDTException(5, 7, 0);

   if (backlog <= 0)
      throw CUDTException(5, 3, 0);

   s->m_uiBackLog = backlog;

   try
   {
      s->m_pQueuedSockets = new set;
      s->m_pAcceptSockets = new set;
   }
   catch (...)
   {
      delete s->m_pQueuedSockets;
      throw CUDTException(3, 2, 0);
   }

   s->m_pUDT->listen();

   s->m_Status = CUDTSocket::LISTENING;

   return 0;
}

UDTSOCKET CUDTUnited::accept(const UDTSOCKET listen, sockaddr* addr, int* addrlen)
{
   if ((NULL != addr) && (NULL == addrlen))
      throw CUDTException(5, 3, 0);

   CUDTSocket* ls = locate(listen);

   if (ls == NULL)
      throw CUDTException(5, 4, 0);

   // the "listen" socket must be in LISTENING status
   if (CUDTSocket::LISTENING != ls->m_Status)
      throw CUDTException(5, 6, 0);

   // no "accept" in rendezvous connection setup
   if (ls->m_pUDT->m_bRendezvous)
      throw CUDTException(5, 7, 0);

   UDTSOCKET u = CUDT::INVALID_SOCK;
   bool accepted = false;

   // !!only one conection can be set up each time!!
   #ifndef WIN32
      while (!accepted)
      {
         pthread_mutex_lock(&(ls->m_AcceptLock));

         if (ls->m_pQueuedSockets->size() > 0)
         {
            u = *(ls->m_pQueuedSockets->begin());
            ls->m_pAcceptSockets->insert(ls->m_pAcceptSockets->end(), u);
            ls->m_pQueuedSockets->erase(ls->m_pQueuedSockets->begin());

            accepted = true;
         }
         else if (!ls->m_pUDT->m_bSynRecving)
            accepted = true;
         else if (CUDTSocket::LISTENING == ls->m_Status)
            pthread_cond_wait(&(ls->m_AcceptCond), &(ls->m_AcceptLock));

         if (CUDTSocket::LISTENING != ls->m_Status)
            accepted = true;

         pthread_mutex_unlock(&(ls->m_AcceptLock));
      }
   #else
      while (!accepted)
      {
         WaitForSingleObject(ls->m_AcceptLock, INFINITE);

         if (ls->m_pQueuedSockets->size() > 0)
         {
            u = *(ls->m_pQueuedSockets->begin());
            ls->m_pAcceptSockets->insert(ls->m_pAcceptSockets->end(), u);
            ls->m_pQueuedSockets->erase(ls->m_pQueuedSockets->begin());

            accepted = true;
         }
         else if (!ls->m_pUDT->m_bSynRecving)
            accepted = true;

         ReleaseMutex(ls->m_AcceptLock);

         if  (!accepted & (CUDTSocket::LISTENING == ls->m_Status))
            WaitForSingleObject(ls->m_AcceptCond, INFINITE);

         if (CUDTSocket::LISTENING != ls->m_Status)
         {
            SetEvent(ls->m_AcceptCond);
            accepted = true;
         }
      }
   #endif

   if (u == CUDT::INVALID_SOCK)
   {
      // non-blocking receiving, no connection available
      if (!ls->m_pUDT->m_bSynRecving)
         throw CUDTException(6, 2, 0);

      // listening socket is closed
      throw CUDTException(5, 6, 0);
   }

   if (AF_INET == locate(u)->m_iIPversion)
      *addrlen = sizeof(sockaddr_in);
   else
      *addrlen = sizeof(sockaddr_in6);

   // copy address information of peer node
   memcpy(addr, locate(u)->m_pPeerAddr, *addrlen);

   return u;
}

int CUDTUnited::connect(const UDTSOCKET u, const sockaddr* name, const int& namelen)
{
   CUDTSocket* s = locate(u);

   if (NULL == s)
      throw CUDTException(5, 4, 0);

   // check the size of SOCKADDR structure
   if (AF_INET == s->m_iIPversion)
   {
      if (namelen != sizeof(sockaddr_in))
         throw CUDTException(5, 3, 0);
   }
   else
   {
      if (namelen != sizeof(sockaddr_in6))
         throw CUDTException(5, 3, 0);
   }

   // a socket can "connect" only if it is in INIT or OPENED status
   if (CUDTSocket::INIT == s->m_Status)
   {
      if (!s->m_pUDT->m_bRendezvous)
      {
         s->m_pUDT->open();
         updateMux(s->m_pUDT);
         s->m_Status = CUDTSocket::OPENED;
      }
      else
         throw CUDTException(5, 8, 0);
   }
   else if (CUDTSocket::OPENED != s->m_Status)
      throw CUDTException(5, 2, 0);

   s->m_pUDT->connect(name);
   s->m_Status = CUDTSocket::CONNECTED;

   // copy address information of local node
   s->m_pUDT->m_pSndQueue->m_pChannel->getSockAddr(s->m_pSelfAddr);

   // record peer address
   if (AF_INET == s->m_iIPversion)
   {
      s->m_pPeerAddr = (sockaddr*)(new sockaddr_in);
      memcpy(s->m_pPeerAddr, name, sizeof(sockaddr_in));
   }
   else
   {
      s->m_pPeerAddr = (sockaddr*)(new sockaddr_in6);
      memcpy(s->m_pPeerAddr, name, sizeof(sockaddr_in6));
   }

   return 0;
}

int CUDTUnited::close(const UDTSOCKET u)
{
   CUDTSocket* s = locate(u);

   // silently drop a request to close an invalid ID, rather than return error   
   if (NULL == s)
      return 0;

   s->m_pUDT->close();

   // a socket will not be immediated removed when it is closed
   // in order to prevent other methods from accessing invalid address
   // a timer is started and the socket will be removed after approximately 1 second
   s->m_TimeStamp = CTimer::getTime();

   CUDTSocket::UDTSTATUS os = s->m_Status;

   // synchronize with garbage collection.
   #ifndef WIN32
      pthread_mutex_lock(&m_ControlLock);
   #else
      WaitForSingleObject(m_ControlLock, INFINITE);
   #endif
   s->m_Status = CUDTSocket::CLOSED;
   #ifndef WIN32
      pthread_mutex_unlock(&m_ControlLock);
   #else
      ReleaseMutex(m_ControlLock);
   #endif

   // broadcast all "accept" waiting
   if (CUDTSocket::LISTENING == os)
   {
      #ifndef WIN32
         pthread_mutex_lock(&(s->m_AcceptLock));
         pthread_mutex_unlock(&(s->m_AcceptLock));
         pthread_cond_broadcast(&(s->m_AcceptCond));
      #else
         SetEvent(s->m_AcceptCond);
      #endif
   }

   CTimer::triggerEvent();

   return 0;
}

int CUDTUnited::getpeername(const UDTSOCKET u, sockaddr* name, int* namelen)
{
   if (CUDTSocket::CONNECTED != getStatus(u))
      throw CUDTException(2, 2, 0);

   CUDTSocket* s = locate(u);

   if (NULL == s)
      throw CUDTException(5, 4, 0);

   if (!s->m_pUDT->m_bConnected || s->m_pUDT->m_bBroken)
      throw CUDTException(2, 2, 0);

   if (AF_INET == s->m_iIPversion)
      *namelen = sizeof(sockaddr_in);
   else
      *namelen = sizeof(sockaddr_in6);

   // copy address information of peer node
   memcpy(name, s->m_pPeerAddr, *namelen);

   return 0;
}

int CUDTUnited::getsockname(const UDTSOCKET u, sockaddr* name, int* namelen)
{
   CUDTSocket* s = locate(u);

   if (NULL == s)
      throw CUDTException(5, 4, 0);

   if (CUDTSocket::INIT == s->m_Status)
      throw CUDTException(2, 2, 0);

   if (AF_INET == s->m_iIPversion)
      *namelen = sizeof(sockaddr_in);
   else
      *namelen = sizeof(sockaddr_in6);

   // copy address information of local node
   memcpy(name, s->m_pSelfAddr, *namelen);

   return 0;
}

int CUDTUnited::select(ud_set* readfds, ud_set* writefds, ud_set* exceptfds, const timeval* timeout)
{
   uint64_t entertime = CTimer::getTime();

   uint64_t to;
   if (NULL == timeout)
      to = 0xFFFFFFFFFFFFFFFFULL;
   else
      to = timeout->tv_sec * 1000000 + timeout->tv_usec;

   // initialize results
   int count = 0;
   set rs, ws, es;

   // retrieve related UDT sockets
   vector ru, wu, eu;
   CUDTSocket* s;
   if (NULL != readfds)
      for (set::iterator i1 = readfds->begin(); i1 != readfds->end(); ++ i1)
      {
         if (CUDTSocket::BROKEN == getStatus(*i1))
         {
            rs.insert(*i1);
            ++ count;
         }
         else if (NULL == (s = locate(*i1)))
            throw CUDTException(5, 4, 0);
         else
            ru.insert(ru.end(), s);
      }
   if (NULL != writefds)
      for (set::iterator i2 = writefds->begin(); i2 != writefds->end(); ++ i2)
      {
         if (CUDTSocket::BROKEN == getStatus(*i2))
         {
            ws.insert(*i2);
            ++ count;
         }
         else if (NULL == (s = locate(*i2)))
            throw CUDTException(5, 4, 0);
         else
            wu.insert(wu.end(), s);
      }
   if (NULL != exceptfds)
      for (set::iterator i3 = exceptfds->begin(); i3 != exceptfds->end(); ++ i3)
      {
         if (CUDTSocket::BROKEN == getStatus(*i3))
         {
            es.insert(*i3);
            ++ count;
         }
         else if (NULL == (s = locate(*i3)))
            throw CUDTException(5, 4, 0);
         else
            eu.insert(eu.end(), s);
      }

   do
   {
      // query read sockets
      for (vector::iterator j1 = ru.begin(); j1 != ru.end(); ++ j1)
      {
         s = *j1;

         if ((s->m_pUDT->m_bConnected && (s->m_pUDT->m_pRcvBuffer->getRcvDataSize() > 0) && ((s->m_pUDT->m_iSockType == UDT_STREAM) || (s->m_pUDT->m_pRcvBuffer->getRcvMsgNum() > 0)))
            || (!s->m_pUDT->m_bListening && (s->m_pUDT->m_bBroken || !s->m_pUDT->m_bConnected))
            || (s->m_pUDT->m_bListening && (s->m_pQueuedSockets->size() > 0))
            || (s->m_Status == CUDTSocket::CLOSED))
         {
            rs.insert(s->m_SocketID);
            ++ count;
         }
      }

      // query write sockets
      for (vector::iterator j2 = wu.begin(); j2 != wu.end(); ++ j2)
      {
         s = *j2;

         if ((s->m_pUDT->m_bConnected && (s->m_pUDT->m_pSndBuffer->getCurrBufSize() < s->m_pUDT->m_iSndBufSize))
            || s->m_pUDT->m_bBroken || !s->m_pUDT->m_bConnected || (s->m_Status == CUDTSocket::CLOSED))
         {
            ws.insert(s->m_SocketID);
            ++ count;
         }
      }

      // query expections on sockets
      for (vector::iterator j3 = eu.begin(); j3 != eu.end(); ++ j3)
      {
         // check connection request status, not supported now
      }

      if (0 < count)
         break;

      CTimer::waitForEvent();
   } while (to > CTimer::getTime() - entertime);

   if (NULL != readfds)
      *readfds = rs;

   if (NULL != writefds)
      *writefds = ws;

   if (NULL != exceptfds)
      *exceptfds = es;

   return count;
}

CUDTSocket* CUDTUnited::locate(const UDTSOCKET u)
{
   CGuard cg(m_ControlLock);

   map::iterator i = m_Sockets.find(u);

   if ( (i == m_Sockets.end()) || (i->second->m_Status == CUDTSocket::CLOSED))
      return NULL;

   return i->second;
}

CUDTSocket* CUDTUnited::locate(const UDTSOCKET u, const sockaddr* peer, const UDTSOCKET& id, const int32_t& isn)
{
   CGuard cg(m_ControlLock);

   map::iterator i = m_Sockets.find(u);

   CGuard ag(i->second->m_AcceptLock);

   // look up the "peer" address in queued sockets set
   for (set::iterator j1 = i->second->m_pQueuedSockets->begin(); j1 != i->second->m_pQueuedSockets->end(); ++ j1)
   {
      map::iterator k1 = m_Sockets.find(*j1);

      if (CIPAddress::ipcmp(peer, k1->second->m_pPeerAddr, i->second->m_iIPversion))
      {
         if ((id == k1->second->m_PeerID) && (isn == k1->second->m_iISN))
            return k1->second;
      }
   }

   // look up the "peer" address in accept sockets set
   for (set::iterator j2 = i->second->m_pAcceptSockets->begin(); j2 != i->second->m_pAcceptSockets->end(); ++ j2)
   {
      map::iterator k2 = m_Sockets.find(*j2);

      if (CIPAddress::ipcmp(peer, k2->second->m_pPeerAddr, i->second->m_iIPversion))
      {
         if ((id == k2->second->m_PeerID) && (isn == k2->second->m_iISN))
            return k2->second;
      }
   }

   return NULL;
}

void CUDTUnited::checkBrokenSockets()
{
   CGuard cg(m_ControlLock);

   // set of sockets To Be Removed
   set tbr;

   for (map::iterator i = m_Sockets.begin(); i != m_Sockets.end(); ++ i)
   {
      if (CUDTSocket::CLOSED != i->second->m_Status)
      {
         // check broken connection
         if (i->second->m_pUDT->m_bBroken)
         {
            //close broken connections and start removal timer
            i->second->m_Status = CUDTSocket::CLOSED;
            i->second->m_TimeStamp = CTimer::getTime();

            // remove from listener's queue
            map::iterator ls = m_Sockets.find(i->second->m_ListenSocket);
            if (ls != m_Sockets.end())
            {
               #ifndef WIN32
                  pthread_mutex_lock(&(ls->second->m_AcceptLock));
               #else
                  WaitForSingleObject(ls->second->m_AcceptLock, INFINITE);
               #endif
               ls->second->m_pQueuedSockets->erase(i->second->m_SocketID);
               #ifndef WIN32
                  pthread_mutex_unlock(&(ls->second->m_AcceptLock));
               #else
                  ReleaseMutex(ls->second->m_AcceptLock);
               #endif
            }
         }
      }
      else
      {
         // timeout 1 second to destroy a socket AND it has been removed from RcvUList
         if ((CTimer::getTime() - i->second->m_TimeStamp > 1000000) && ((NULL == i->second->m_pUDT->m_pRNode) || !i->second->m_pUDT->m_pRNode->m_bOnList))
            tbr.insert(i->second->m_SocketID);

         // sockets cannot be removed here because it will invalidate the map iterator
      }
   }

   // remove those timeout sockets
   for (set::iterator k = tbr.begin(); k != tbr.end(); ++ k)
      removeSocket(*k);
}

void CUDTUnited::removeSocket(const UDTSOCKET u)
{
   map::iterator i = m_Sockets.find(u);

   // invalid socket ID
   if (i == m_Sockets.end())
      return;

   // decrease multiplexer reference count, and remove it if necessary
   int port;
   if (AF_INET == i->second->m_iIPversion)
      port = ntohs(((sockaddr_in*)(i->second->m_pSelfAddr))->sin_port);
   else
      port = ntohs(((sockaddr_in6*)(i->second->m_pSelfAddr))->sin6_port);

   vector::iterator m;
   for (m = m_vMultiplexer.begin(); m != m_vMultiplexer.end(); ++ m)
      if (port == m->m_iPort)
         break;

   if (0 != i->second->m_ListenSocket)
   {
      // if it is an accepted socket, remove it from the listener's queue
      map::iterator ls = m_Sockets.find(i->second->m_ListenSocket);
      if (ls != m_Sockets.end())
      {
         #ifndef WIN32
            pthread_mutex_lock(&(ls->second->m_AcceptLock));
         #else
            WaitForSingleObject(ls->second->m_AcceptLock, INFINITE);
         #endif
         ls->second->m_pAcceptSockets->erase(u);
         #ifndef WIN32
            pthread_mutex_unlock(&(ls->second->m_AcceptLock));
         #else
            ReleaseMutex(ls->second->m_AcceptLock);
         #endif
      }
   }
   else if (NULL != i->second->m_pQueuedSockets)
   {
      #ifndef WIN32
         pthread_mutex_lock(&(i->second->m_AcceptLock));
      #else
         WaitForSingleObject(i->second->m_AcceptLock, INFINITE);
      #endif
      // if it is a listener, remove all un-accepted sockets in its queue
      for (set::iterator q = i->second->m_pQueuedSockets->begin(); q != i->second->m_pQueuedSockets->end(); ++ q)
      {
         m_Sockets[*q]->m_pUDT->close();
         delete m_Sockets[*q];
         m_Sockets.erase(*q);

         if (m != m_vMultiplexer.end())
            m->m_iRefCount --;
      }
      #ifndef WIN32
         pthread_mutex_unlock(&(i->second->m_AcceptLock));
      #else
         ReleaseMutex(i->second->m_AcceptLock);
      #endif
   }

   // delete this one
   m_Sockets[u]->m_pUDT->close();
   delete m_Sockets[u];
   m_Sockets.erase(u);

   if (m == m_vMultiplexer.end())
      return;

   m->m_iRefCount --;
   if (0 == m->m_iRefCount)
   {
      m->m_pChannel->close();
      delete m->m_pSndQueue;
      delete m->m_pRcvQueue;
      delete m->m_pTimer;
      delete m->m_pChannel;
      m_vMultiplexer.erase(m);
   }
}

void CUDTUnited::setError(CUDTException* e)
{
   #ifndef WIN32
      delete (CUDTException*)pthread_getspecific(m_TLSError);
      pthread_setspecific(m_TLSError, e);
   #else
      delete (CUDTException*)TlsGetValue(m_TLSError);
      TlsSetValue(m_TLSError, e);
   #endif
}

CUDTException* CUDTUnited::getError()
{
   #ifndef WIN32
      if(NULL == pthread_getspecific(m_TLSError))
         pthread_setspecific(m_TLSError, new CUDTException);
      return (CUDTException*)pthread_getspecific(m_TLSError);
   #else
      if(NULL == TlsGetValue(m_TLSError))
         TlsSetValue(m_TLSError, new CUDTException);
      return (CUDTException*)TlsGetValue(m_TLSError);
   #endif
}

void CUDTUnited::updateMux(CUDT* u, const sockaddr* addr)
{
   CGuard cg(m_ControlLock);

   if (u->m_bReuseAddr)
   {
      int port = 0;
      if (NULL != addr)
         port = (AF_INET == u->m_iIPversion) ? ntohs(((sockaddr_in*)addr)->sin_port) : ntohs(((sockaddr_in6*)addr)->sin6_port);

      // find a reusable address
      for (vector::iterator i = m_vMultiplexer.begin(); i != m_vMultiplexer.end(); ++ i)
      {
         if ((i->m_iIPversion == u->m_iIPversion) && (i->m_iMSS == u->m_iMSS) && i->m_bReusable)
         {
            if ((0 == port) || (i->m_iPort == port))
            {
               // reuse the existing multiplexer
               ++ i->m_iRefCount;
               u->m_pSndQueue = i->m_pSndQueue;
               u->m_pRcvQueue = i->m_pRcvQueue;
               return;
            }
         }
      }
   }

   // a new multiplexer is needed
   CMultiplexer m;
   m.m_iMSS = u->m_iMSS;
   m.m_iIPversion = u->m_iIPversion;
   m.m_iRefCount = 1;
   m.m_bReusable = u->m_bReuseAddr;

   m.m_pChannel = new CChannel(u->m_iIPversion);
   m.m_pChannel->setSndBufSize(u->m_iUDPSndBufSize);
   m.m_pChannel->setRcvBufSize(u->m_iUDPRcvBufSize);

   try
   {
      m.m_pChannel->open(addr);
   }
   catch (CUDTException& e)
   {
      m.m_pChannel->close();
      delete m.m_pChannel;
      throw e;
   }

   sockaddr* sa = (AF_INET == u->m_iIPversion) ? (sockaddr*) new sockaddr_in : (sockaddr*) new sockaddr_in6;
   m.m_pChannel->getSockAddr(sa);
   m.m_iPort = (AF_INET == u->m_iIPversion) ? ntohs(((sockaddr_in*)sa)->sin_port) : ntohs(((sockaddr_in6*)sa)->sin6_port);
   if (AF_INET == u->m_iIPversion) delete (sockaddr_in*)sa; else delete (sockaddr_in6*)sa;

   m.m_pTimer = new CTimer;

   m.m_pSndQueue = new CSndQueue;
   m.m_pSndQueue->init(m.m_pChannel, m.m_pTimer);
   m.m_pRcvQueue = new CRcvQueue;
   m.m_pRcvQueue->init((m.m_iMSS > 1500) ? 32 : 128, u->m_iPayloadSize, m.m_iIPversion, 1024, m.m_pChannel, m.m_pTimer);

   m_vMultiplexer.insert(m_vMultiplexer.end(), m);

   u->m_pSndQueue = m.m_pSndQueue;
   u->m_pRcvQueue = m.m_pRcvQueue;
}

void CUDTUnited::updateMux(CUDT* u, const CUDTSocket* ls)
{
   CGuard cg(m_ControlLock);

   int port = (AF_INET == ls->m_iIPversion) ? ntohs(((sockaddr_in*)ls->m_pSelfAddr)->sin_port) : ntohs(((sockaddr_in6*)ls->m_pSelfAddr)->sin6_port);

   // find the listener's address
   for (vector::iterator i = m_vMultiplexer.begin(); i != m_vMultiplexer.end(); ++ i)
   {
      if (i->m_iPort == port)
      {
         // reuse the existing multiplexer
         ++ i->m_iRefCount;
         u->m_pSndQueue = i->m_pSndQueue;
         u->m_pRcvQueue = i->m_pRcvQueue;
         return;
      }
   }
}

#ifndef WIN32
   void* CUDTUnited::garbageCollect(void* p)
#else
   DWORD WINAPI CUDTUnited::garbageCollect(LPVOID p)
#endif
{
   CUDTUnited* self = (CUDTUnited*)p;

   while (!self->m_bClosing)
   {
      self->checkBrokenSockets();
      #ifndef WIN32
         sleep(1);
      #else
         Sleep(1);
      #endif
   }

   #ifndef WIN32
      return NULL;
   #else
      return 0;
   #endif   
}

////////////////////////////////////////////////////////////////////////////////

UDTSOCKET CUDT::socket(int af, int type, int)
{
   try
   {
      return s_UDTUnited.newSocket(af, type);
   }
   catch (CUDTException& e)
   {
      s_UDTUnited.setError(new CUDTException(e));
      return INVALID_SOCK;
   }
   catch (bad_alloc&)
   {
      s_UDTUnited.setError(new CUDTException(3, 2, 0));
      return INVALID_SOCK;
   }
   catch (...)
   {
      s_UDTUnited.setError(new CUDTException(-1, 0, 0));
      return INVALID_SOCK;
   }
}

int CUDT::bind(UDTSOCKET u, const sockaddr* name, int namelen)
{
   try
   {
      return s_UDTUnited.bind(u, name, namelen);
   }
   catch (CUDTException& e)
   {
      s_UDTUnited.setError(new CUDTException(e));
      return ERROR;
   }
   catch (bad_alloc&)
   {
      s_UDTUnited.setError(new CUDTException(3, 2, 0));
      return ERROR;
   }
   catch (...)
   {
      s_UDTUnited.setError(new CUDTException(-1, 0, 0));
      return ERROR;
   }
}

int CUDT::listen(UDTSOCKET u, int backlog)
{
   try
   {
      return s_UDTUnited.listen(u, backlog);
   }
   catch (CUDTException& e)
   {
      s_UDTUnited.setError(new CUDTException(e));
      return ERROR;
   }
   catch (bad_alloc&)
   {
      s_UDTUnited.setError(new CUDTException(3, 2, 0));
      return ERROR;
   }
   catch (...)
   {
      s_UDTUnited.setError(new CUDTException(-1, 0, 0));
      return ERROR;
   }
}

UDTSOCKET CUDT::accept(UDTSOCKET u, sockaddr* addr, int* addrlen)
{
   try
   {
      return s_UDTUnited.accept(u, addr, addrlen);
   }
   catch (CUDTException& e)
   {
      s_UDTUnited.setError(new CUDTException(e));
      return INVALID_SOCK;
   }
   catch (...)
   {
      s_UDTUnited.setError(new CUDTException(-1, 0, 0));
      return INVALID_SOCK;
   }
}

int CUDT::connect(UDTSOCKET u, const sockaddr* name, int namelen)
{
   try
   {
      return s_UDTUnited.connect(u, name, namelen);
   }
   catch (CUDTException e)
   {
      s_UDTUnited.setError(new CUDTException(e));
      return ERROR;
   }
   catch (bad_alloc&)
   {
      s_UDTUnited.setError(new CUDTException(3, 2, 0));
      return ERROR;
   }
   catch (...)
   {
      s_UDTUnited.setError(new CUDTException(-1, 0, 0));
      return ERROR;
   }
}

int CUDT::close(UDTSOCKET u)
{
   try
   {
      return s_UDTUnited.close(u);
   }
   catch (CUDTException e)
   {
      s_UDTUnited.setError(new CUDTException(e));
      return ERROR;
   }
   catch (...)
   {
      s_UDTUnited.setError(new CUDTException(-1, 0, 0));
      return ERROR;
   }
}

int CUDT::getpeername(UDTSOCKET u, sockaddr* name, int* namelen)
{
   try
   {
      return s_UDTUnited.getpeername(u, name, namelen);
   }
   catch (CUDTException e)
   {
      s_UDTUnited.setError(new CUDTException(e));
      return ERROR;
   }
   catch (...)
   {
      s_UDTUnited.setError(new CUDTException(-1, 0, 0));
      return ERROR;
   }
}

int CUDT::getsockname(UDTSOCKET u, sockaddr* name, int* namelen)
{
   try
   {
      return s_UDTUnited.getsockname(u, name, namelen);;
   }
   catch (CUDTException e)
   {
      s_UDTUnited.setError(new CUDTException(e));
      return ERROR;
   }
   catch (...)
   {
      s_UDTUnited.setError(new CUDTException(-1, 0, 0));
      return ERROR;
   }
}

int CUDT::getsockopt(UDTSOCKET u, int, UDTOpt optname, void* optval, int* optlen)
{
   try
   {
      CUDT* udt = s_UDTUnited.lookup(u);

      udt->getOpt(optname, optval, *optlen);

      return 0;
   }
   catch (CUDTException e)
   {
      s_UDTUnited.setError(new CUDTException(e));
      return ERROR;
   }
   catch (...)
   {
      s_UDTUnited.setError(new CUDTException(-1, 0, 0));
      return ERROR;
   }
}

int CUDT::setsockopt(UDTSOCKET u, int, UDTOpt optname, const void* optval, int optlen)
{
   try
   {
      CUDT* udt = s_UDTUnited.lookup(u);

      udt->setOpt(optname, optval, optlen);

      return 0;
   }
   catch (CUDTException e)
   {
      s_UDTUnited.setError(new CUDTException(e));
      return ERROR;
   }
   catch (...)
   {
      s_UDTUnited.setError(new CUDTException(-1, 0, 0));
      return ERROR;
   }
}

int CUDT::send(UDTSOCKET u, const char* buf, int len, int)
{
   if (CUDTSocket::BROKEN == s_UDTUnited.getStatus(u))
   {
      s_UDTUnited.setError(new CUDTException(2, 1, 0));
      return ERROR;
   }

   try
   {
      CUDT* udt = s_UDTUnited.lookup(u);

      return udt->send((char*)buf, len);
   }
   catch (CUDTException e)
   {
      s_UDTUnited.setError(new CUDTException(e));
      return ERROR;
   }
   catch (bad_alloc&)
   {
      s_UDTUnited.setError(new CUDTException(3, 2, 0));
      return ERROR;
   }
   catch (...)
   {
      s_UDTUnited.setError(new CUDTException(-1, 0, 0));
      return ERROR;
   }
}

int CUDT::recv(UDTSOCKET u, char* buf, int len, int)
{
   if (CUDTSocket::BROKEN == s_UDTUnited.getStatus(u))
   {
      s_UDTUnited.setError(new CUDTException(2, 1, 0));
      return ERROR;
   }

   try
   {
      CUDT* udt = s_UDTUnited.lookup(u);

      return udt->recv(buf, len);
   }
   catch (CUDTException e)
   {
      s_UDTUnited.setError(new CUDTException(e));
      return ERROR;
   }
   catch (...)
   {
      s_UDTUnited.setError(new CUDTException(-1, 0, 0));
      return ERROR;
   }
}

int CUDT::sendmsg(UDTSOCKET u, const char* buf, int len, int ttl, bool inorder)
{
   if (CUDTSocket::BROKEN == s_UDTUnited.getStatus(u))
   {
      s_UDTUnited.setError(new CUDTException(2, 1, 0));
      return ERROR;
   }

   try
   {
      CUDT* udt = s_UDTUnited.lookup(u);

      return udt->sendmsg((char*)buf, len, ttl, inorder);
   }
   catch (CUDTException e)
   {
      s_UDTUnited.setError(new CUDTException(e));
      return ERROR;
   }
   catch (bad_alloc&)
   {
      s_UDTUnited.setError(new CUDTException(3, 2, 0));
      return ERROR;
   }
   catch (...)
   {
      s_UDTUnited.setError(new CUDTException(-1, 0, 0));
      return ERROR;
   }
}

int CUDT::recvmsg(UDTSOCKET u, char* buf, int len)
{
   if (CUDTSocket::BROKEN == s_UDTUnited.getStatus(u))
   {
      s_UDTUnited.setError(new CUDTException(2, 1, 0));
      return ERROR;
   }

   try
   {
      CUDT* udt = s_UDTUnited.lookup(u);

      return udt->recvmsg(buf, len);
   }
   catch (CUDTException e)
   {
      s_UDTUnited.setError(new CUDTException(e));
      return ERROR;
   }
   catch (...)
   {
      s_UDTUnited.setError(new CUDTException(-1, 0, 0));
      return ERROR;
   }
}

int64_t CUDT::sendfile(UDTSOCKET u, ifstream& ifs, const int64_t& offset, const int64_t& size, const int& block)
{
   if (CUDTSocket::BROKEN == s_UDTUnited.getStatus(u))
   {
      s_UDTUnited.setError(new CUDTException(2, 1, 0));
      return ERROR;
   }

   try
   {
      CUDT* udt = s_UDTUnited.lookup(u);

      return udt->sendfile(ifs, offset, size, block);
   }
   catch (CUDTException e)
   {
      s_UDTUnited.setError(new CUDTException(e));
      return ERROR;
   }
   catch (bad_alloc&)
   {
      s_UDTUnited.setError(new CUDTException(3, 2, 0));
      return ERROR;
   }
   catch (...)
   {
      s_UDTUnited.setError(new CUDTException(-1, 0, 0));
      return ERROR;
   }
}

int64_t CUDT::recvfile(UDTSOCKET u, ofstream& ofs, const int64_t& offset, const int64_t& size, const int& block)
{
   if (CUDTSocket::BROKEN == s_UDTUnited.getStatus(u))
   {
      s_UDTUnited.setError(new CUDTException(2, 1, 0));
      return ERROR;
   }

   try
   {
      CUDT* udt = s_UDTUnited.lookup(u);

      return udt->recvfile(ofs, offset, size, block);
   }
   catch (CUDTException e)
   {
      s_UDTUnited.setError(new CUDTException(e));
      return ERROR;
   }
   catch (...)
   {
      s_UDTUnited.setError(new CUDTException(-1, 0, 0));
      return ERROR;
   }
}

int CUDT::select(int, ud_set* readfds, ud_set* writefds, ud_set* exceptfds, const timeval* timeout)
{
   if ((NULL == readfds) && (NULL == writefds) && (NULL == exceptfds))
   {
      s_UDTUnited.setError(new CUDTException(5, 3, 0));
      return ERROR;
   }

   try
   {
      return s_UDTUnited.select(readfds, writefds, exceptfds, timeout);
   }
   catch (CUDTException e)
   {
      s_UDTUnited.setError(new CUDTException(e));
      return ERROR;
   }
   catch (bad_alloc&)
   {
      s_UDTUnited.setError(new CUDTException(3, 2, 0));
      return ERROR;
   }
   catch (...)
   {
      s_UDTUnited.setError(new CUDTException(-1, 0, 0));
      return ERROR;
   }
}

CUDTException& CUDT::getlasterror()
{
   return *s_UDTUnited.getError();
}

int CUDT::perfmon(UDTSOCKET u, CPerfMon* perf, bool clear)
{
   if (CUDTSocket::BROKEN == s_UDTUnited.getStatus(u))
   {
      s_UDTUnited.setError(new CUDTException(2, 1, 0));
      return ERROR;
   }

   try
   {
      CUDT* udt = s_UDTUnited.lookup(u);

      udt->sample(perf, clear);

      return 0;
   }
   catch (CUDTException e)
   {
      s_UDTUnited.setError(new CUDTException(e));
      return ERROR;
   }
   catch (...)
   {
      s_UDTUnited.setError(new CUDTException(-1, 0, 0));
      return ERROR;
   }
}

CUDT* CUDT::getUDTHandle(UDTSOCKET u)
{
   return s_UDTUnited.lookup(u);
}

////////////////////////////////////////////////////////////////////////////////

namespace UDT
{

UDTSOCKET socket(int af, int type, int protocol)
{
   return CUDT::socket(af, type, protocol);
}

int bind(UDTSOCKET u, const struct sockaddr* name, int namelen)
{
   return CUDT::bind(u, name, namelen);
}

int listen(UDTSOCKET u, int backlog)
{
   return CUDT::listen(u, backlog);
}

UDTSOCKET accept(UDTSOCKET u, struct sockaddr* addr, int* addrlen)
{
   return CUDT::accept(u, addr, addrlen);
}

int connect(UDTSOCKET u, const struct sockaddr* name, int namelen)
{
   return CUDT::connect(u, name, namelen);
}

int close(UDTSOCKET u)
{
   return CUDT::close(u);
}

int getpeername(UDTSOCKET u, struct sockaddr* name, int* namelen)
{
   return CUDT::getpeername(u, name, namelen);
}

int getsockname(UDTSOCKET u, struct sockaddr* name, int* namelen)
{
   return CUDT::getsockname(u, name, namelen);
}

int getsockopt(UDTSOCKET u, int level, SOCKOPT optname, void* optval, int* optlen)
{
   return CUDT::getsockopt(u, level, optname, optval, optlen);
}

int setsockopt(UDTSOCKET u, int level, SOCKOPT optname, const void* optval, int optlen)
{
   return CUDT::setsockopt(u, level, optname, optval, optlen);
}

int send(UDTSOCKET u, const char* buf, int len, int flags)
{
   return CUDT::send(u, buf, len, flags);
}

int recv(UDTSOCKET u, char* buf, int len, int flags)
{
   return CUDT::recv(u, buf, len, flags);
}

int sendmsg(UDTSOCKET u, const char* buf, int len, int ttl, bool inorder)
{
   return CUDT::sendmsg(u, buf, len, ttl, inorder);
}

int recvmsg(UDTSOCKET u, char* buf, int len)
{
   return CUDT::recvmsg(u, buf, len);
}

int64_t sendfile(UDTSOCKET u, ifstream& ifs, int64_t offset, int64_t size, int block)
{
   return CUDT::sendfile(u, ifs, offset, size, block);
}

int64_t recvfile(UDTSOCKET u, ofstream& ofs, int64_t offset, int64_t size, int block)
{
   return CUDT::recvfile(u, ofs, offset, size, block);
}

int select(int nfds, UDSET* readfds, UDSET* writefds, UDSET* exceptfds, const struct timeval* timeout)
{
   return CUDT::select(nfds, readfds, writefds, exceptfds, timeout);
}

ERRORINFO& getlasterror()
{
   return CUDT::getlasterror();
}

int perfmon(UDTSOCKET u, TRACEINFO* perf, bool clear)
{
   return CUDT::perfmon(u, perf, clear);
}

}