I'm writing a client/server application in C#, and it's going great. For now, everything works and it's all pretty robust. My problem is that I run into some delays when sending packets across the connection.
On the client side I'm doing this:
NetworkStream ns = tcpClient.GetStream();
// Send packet
byte[] sizePacket = BitConverter.GetBytes(request.Length);
byte[] requestWithHeader = new byte[sizePacket.Length + request.Length];
sizePacket.CopyTo(requestWithHeader, 0);
request.CopyTo(requestWithHeader, sizePacket.Length);
ns.Write(requestWithHeader, 0, requestWithHeader.Length);
// Receive response
ns.Read(sizePacket, 0, sizePacket.Length);
int responseLength = BitConverter.ToInt32(sizePacket, 0);
byte[] response = new byte[responseLength];
int bytesReceived = 0;
while (bytesReceived < responseLength)
{
int bytesRead = ns.Read(response, bytesReceived, responseLength - bytesReceived);
bytesReceived += bytesRead;
}
(Left out some exception catching etc.) The server does the opposite, i.e. it blocks on NetworkStream.Read() until it has a whole request, then processes it and sends a response using Write().
The raw speed of Write()/Read() isn't a problem (i.e. sending large packets is fast), but sending several small packets, one after another, without closing the connection, can be terribly slow (delays of 50-100 ms). What's strange is that these delays show up on LAN connections with typical ping times <1 ms, but they do not occur if the server is running on localhost, even though the ping time would effectively be the same (at least the difference should not be on the order of 100 ms). That would make sense to me if I were reopening the connection on every packet, causing lots of handshaking, but I'm not. It's just as if the server going into a wait state throws it out of sync with the client, and then it stumbles a bit as it reestablishes what is essentially a lost connection.
So, am I doing it wrong? Is there a way to keep the connection between TcpServer and TcpClient synchronised so the server is always ready to receive data? (And vice versa: sometimes processing the request from the client takes a few ms, and then the client doesn't seem to be ready to receive the response from the server until it's had a few moments to wake up after blocking on Read().)
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