Socket programmering

Jeg har lavet en simpel webserver. Og den kører nogenlunde. Dog et lille problem - den æder 40% af cpu tiden. Jeg anvder NON-Blocking sockets og SELECT !!!
Nogle konstruktive forslag til hvordan prob. løses?

MVH

Thomas Hansen
Nedenfor er min source:
void WebServer(void)
{
  int servSock;                    // Socket descriptor for server
  int clntSock;                    // Socket descriptor for client
  struct sockaddr_in echoServAddr; // Local address
  struct sockaddr_in echoClntAddr; // Client address
  unsigned short echoServPort;    // Server port
  int servLen;                    // Length of server address data structure 
  int n_received;                      //
  fd_set fd_read, fd_write;
  long arg;
  typedef struct timeval
  {
    int tv_sec;    // second
    int tv_usec;  // microseconds
  } TIMEVAL;
  //timeval select_to;
  // int visitcount = 1;
  TIMEVAL select_to;
 
  echoServPort = 80;              // Port 80 - WWW
 
   
  // Create socket for incoming connections
  if ((servSock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
    return;
 
  // Construct local address structure
  memset(&echoServAddr, 0, sizeof(echoServAddr));  // Zero out structure
  echoServAddr.sin_family = AF_INET;                // Internet address family
  echoServAddr.sin_addr.s_addr = htonl(INADDR_ANY); // Any incoming interface
  echoServAddr.sin_port = htons(echoServPort);      // Local port

  // Bind to the local address
  if (bind(servSock, (struct sockaddr *) &echoServAddr, sizeof(echoServAddr)) < 0)
    DieWithError("bind() failed");
 
  // Set socket to nonblocking
  arg = 1;    // enables non blocking mode
  if (ioctlsocket(servSock, FIONBIO,(PFDWORD)&arg)!= 0)  // All options off
  {
    closesocket(servSock);
    return;
  }
 
  // Mark the socket so it will listen for incoming connections
  if (listen(servSock, MAXPENDING) < 0)
    DieWithError("listen() failed");
 
  while(1)
    {     
      // Socket list for select is set up here !
      FD_ZERO(&fd_read);               
      FD_SET(servSock, &fd_read);
     
      // Wait for connection to be ready !
      if (select(1,(PFDSET)&fd_read,(PFDSET)0,(PFDSET)0,(PTIMEVAL)0) !=1)
        continue;
       
      // Accept available connected socket !
      servLen = sizeof((echoClntAddr));
      //if ((clntSock = accept(servSock, (PSOCKADDR)&echoClntAddr,(PFINT)&servLen))<0)
      if ((clntSock = accept(servSock, (PSOCKADDR)&echoServAddr,(PFINT)&servLen))<0)  // Tvivl om echoServAdr?
        continue;
     
      // Set socket to nonblocking mode
      // Force recv to return an error if no data is available.
      // Force send to return an error if it needs to block ->
      // send needs only to block if it can't fit all output data into output window.
      arg = 1;    // enables non blocking mode
      if (ioctlsocket(clntSock, FIONBIO,(PFDWORD)&arg)!= 0)  // All options off
      {
          closesocket(clntSock);
        continue;
      }
      // Set up socket list for select
      FD_ZERO(&fd_read);
      FD_SET(clntSock,&fd_read);
     
      // Wait for any data to be available
      if (select(1,(PFDSET)&fd_read,(PFDSET)0, (PFDSET)0,(PCTIMEVAL)0)!=1)
      {
        closesocket(clntSock);
        continue;
      }
           
      // Get data and ....
      while ((n_received = recv(clntSock,buf,BUFSIZE,0))>0)
      {
          // set up socket list for select
          FD_ZERO(&fd_write);
          FD_SET(clntSock,&fd_write);
         
          // Wait 20 sec. for previos sent to complete. ie. waits until all ouput data has been asked !
          select_to.tv_sec  = 90;
          select_to.tv_usec = 0;
          if (select(1,NULL,(PFDSET)&fd_write,NULL,(PCTIMEVAL)&select_to) != 1)
          //if (select(1,NULL,(PFDSET)&fd_write,NULL, NULL) != 1)
          {
            closesocket (clntSock);
            continue;              // select error
          }
         
          // send output data
          send(clntSock,defaultside, strlen(defaultside),0);
         
          // setup socket list for select !
          FD_ZERO(&fd_read);
          FD_SET(clntSock,&fd_read);
         
          // Wait for any data to be available
          if (select(1,(PFDSET)&fd_read,(PFDSET)0, (PFDSET)0,(PCTIMEVAL)0)!=1)
        {
          closesocket(clntSock);
          continue;
        }
        closesocket(clntSock);
        printf("clntSock Close\n");
      }
      close(servSock);     
    }
   
    /* NOT REACHED */
}