用ＳＯＣＫＥＴ编程时，怎样设定超过２０秒ＳＯＣＫＥＴ没有连接上就发一个通知？

Question

用ＳＯＣＫＥＴ编程时，怎样设定ＳＯＣＫＥＴ超过２０秒没有连接上就发一个通知？

Answer 1

FD_SET readfds;
readfds.fd_count=1;
readfds.fd_array[0]=Service_Socket;
timeval theval;
theval.tv_sec=60;//20
theval.tv_usec=0;
if (select(0, &readfds,NULL,NULL,&theval)<=0)
{
//发送通知包
}

Answer 2

另开一个线程
DWORDThread1(...)
{
    if ( WaitForSingleObject(hEvent,20000) == TIME_OUT )
         ...........
}

Answer 3

if (WSAStartup(MAKEWORD(2,2),&wsd))
  {
    printf("WSAStartup run failed,errno=%d!\n",GetLastError());
    return 1;
  }
  if ((sClient=socket(AF_INET,SOCK_STREAM,IPPROTO_TCP))==SOCKET_ERROR)
  {
    printf("socket run failed,errno=%d!\n",WSAGetLastError());
    WSACleanup();
    return 1;   
  }
  memset(&local,0,sizeof(struct sockaddr_in));
  local.sin_family=AF_INET;
  local.sin_port=htons(8889);
  local.sin_addr.s_addr=inet_addr("127.0.0.1");
  if (bind(sClient,(struct sockaddr *)&local,sizeof(local))==SOCKET_ERROR)
  {
    printf("bind run failed,errno=%d!\n",WSAGetLastError());
    closesocket(sClient);
    WSACleanup();
    return 1;
  }
  memset(&server,0,sizeof(struct sockaddr_in));
  server.sin_family=AF_INET;
  server.sin_port=htons(iPort);
  if ((server.sin_addr.s_addr=inet_addr(SIPInfo))==INADDR_NONE)
  {
    if ((host=gethostbyname(SIPInfo))==NULL)
    {
      printf("gethostbyname run failed,errno=%d!\n",WSAGetLastError());
  closesocket(sClient);
      WSACleanup();
      return 1;
    }
    memcpy(&(server.sin_addr),host->h_addr_list[0],host->h_length);
    if (server.sin_addr.s_addr==INADDR_NONE)
{
  printf("invalid server ip address,errno=%d!\n",WSAGetLastError());
  closesocket(sClient);
      WSACleanup();
      return 1;
    }
  }
  if (ioctlsocket(sClient,FIONBIO,&NonBlock)==SOCKET_ERROR)//将client socket设为非阻塞
  {
    printf("ioctlsocket run failed,errno=%d!\n",WSAGetLastError());
    closesocket(sClient);
    WSACleanup();
    return 1; 
  }
  FD_ZERO(&WriteSet);
  FD_SET(sClient,&WriteSet);
  FD_ZERO(&ExceptSet);
  FD_SET(sClient,&ExceptSet);
  tout.tv_sec=20;
  tout.tv_usec=0;
  connect(sClient,(const struct sockaddr *)&server,sizeof(server));
  if (select(0,NULL,&WriteSet,&ExceptSet,&tout)<1)
  {
    printf("select run failed,errno=%d!\n",WSAGetLastError());//errno为0则超时，否则select运行失败
    closesocket(sClient);
    WSACleanup();
    return 1; 
  }
  if (FD_ISSET(sClient,&ExceptSet))
  { 
    printf("connect failed,errno=%d!\n",WSAGetLastError());
    closesocket(sClient);
    WSACleanup();
    return 1; 
  }
  if (FD_ISSET(sClient,&WriteSet))
    printf("connect successfully,server ip address is:%s,port is:%d.\n",inet_ntoa(server.sin_addr),ntohs(server.sin_port));

Answer 4

socket //创建socket
setsockopt//设置异步
connect//
while (time < 20s) if (select返回) return; else sleep

Answer 5

用异步的,开一个timer计时，另设一个变量作为超市的通知变量