外部控制器每30ms通过TCP / IP套接字发送120字节的消息.
应用程序通过标准的tcp / ip socket recv函数接收此消息.
它在 Linux& OSX(recv每30ms返回120个字节的消息).
在Windows下,recv大约每1秒返回~3500字节缓冲区.其余时间它返回0.
Windows下的Wireshark显示每隔30ms就会发送一次消息.

如何让windows tcp socket正常工作(没有延迟)？

PS：我玩过TCP_NODELAY& TcpAckFrequency已经. Wireshark显示一切正常.所以我认为这是一些Windows优化,应该关闭.

读 –

int WMaster::DataRead(void)
{
if (!open_ok)  return 0;
if (!CheckSocket())
{
    PrintErrNo();
    return 0;
}
iResult = recv(ConnectSocket,(char *)input_buff,sizeof(input_buff),0);

nError=WSAGetLastError();
if(nError==0) return iResult;
if(nError==WSAEWOULDBLOCK) return iResult;

PrintErrNo();
return 0;
}

初始化-

ConnectSocket = INVALID_SOCKET;

iResult = WSAStartup(MAKEWORD(2,2),&wsaData);
ConnectSocket = socket(AF_INET,SOCK_STREAM,IPPROTO_TCP);
ZeroMemory(&clientService,sizeof(clientService));
clientService.sin_family = AF_INET;
clientService.sin_addr.s_addr = inet_addr( deviceName.toLatin1().constData() );
clientService.sin_port = htons( port);

iResult = setsockopt(ConnectSocket,IPPROTO_TCP,TCP_NODELAY,(char *) &flag,sizeof (int));

u_long iMode=1;
iResult=ioctlsocket(ConnectSocket,FIONBIO,&iMode);

iResult = ::connect( ConnectSocket,(SOCKADDR*) &clientService,sizeof(clientService) );

CheckSocket –

bool WMaster::CheckSocket(void)
{
socklen_t len = sizeof (int);
int retval = getsockopt (ConnectSocket,SOL_SOCKET,SO_ERROR,(char*)(&valopt),&len );
if (retval!=0)
{
   open_ok=false;
   return false;
};
return true;
}