CODEWITHSUNDEEP
c#socketsnetwork-programming
user271077
user271077

Reputation: 1006

Expect TCP to fail when the remote endpoint is not connected C#

using .net sockets. I am trying to determine whether the socket is connected or not. there for I expect the send operation to fail if the remote endpoint is not connected. practically I do not get an exception on the send but the send passes successfully only after a while the send will fail. is there any explanation for this? what else can i do in order to get the connection state?

my code is very simple based on this ` 

Int32 port = 13000;
TcpClient client = new TcpClient(server, port);

// Translate the passed message into ASCII and store it as a Byte array.
Byte[] data = System.Text.Encoding.ASCII.GetBytes(message);         

// Get a client stream for reading and writing.

// Stream stream = client.GetStream();

NetworkStream stream = client.GetStream();

// Send the message to the connected TcpServer. 
stream.Write(data, 0, data.Length);

Console.WriteLine("Sent: {0}", message);         

// Receive the TcpServer.response.

// Buffer to store the response bytes.
data = new Byte[256];

// String to store the response ASCII representation.
String responseData = String.Empty;

// Read the first batch of the TcpServer response bytes.
Int32 bytes = stream.Read(data, 0, data.Length);
responseData = System.Text.Encoding.ASCII.GetString(data, 0, bytes);
Console.WriteLine("Received: {0}", responseData);         

// Close everything.
client.Close();    `

Upvotes: 0

Views: 586

Answers (1)

user207421
user207421

Reputation: 310980

There is no 'connection state' in TCP. The only reliable way to detect a broken connection is to try to write to it repeatedly: eventually a broken connection will cause ECONNRESET or whatever that maps to in your programming language. You should also use a read timeout when reading, of some value like double the expected latency of the longest request, and treat that as a broken connection or at least a broken transaction as well, but this is problematic if transaction latencies vary wildly.

Upvotes: 1

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