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c#.net-3.5named-pipes

System.IO.Exception: Pipe is broken


I have two .NET applications that talk to each other over a named pipe. Everything is great the first time through, but after the first message is sent, and the server is going to listen again, the WaitForConnection() method throws a System.IO.Exception with message Pipe is broken.
Why am I getting this exception here? This is my first time working with pipes, but a similar pattern has worked for me in the past with sockets.

Code ahoy!
Server:

using System.IO.Pipes;

static void main()
{
    var pipe = new NamedPipeServerStream("pipename", PipeDirection.In);
    while (true)
    {
        pipe.Listen();
        string str = new StreamReader(pipe).ReadToEnd();
        Console.Write("{0}", str);
    }
}

Client:

public void sendDownPipe(string str)
{
    using (var pipe = new NamedPipeClientStream(".", "pipename", PipeDirection.Out))
    {
        using (var stream = new StreamWriter(pipe))
        {
            stream.Write(str);
        }
    }
}

The first call to sendDownPipe gets the server to print the message I send just fine, but when it loops back up to listen again, it poops.


Solution

  • I'll post my code that seems to work - I was curious since I never did anything with pipes. I didn't find the class you name for the server-side in the relevant namespace, so here's the code based on the NamedPipeServerStream. The callback stuff is just because I couldn't be bothered with two projects.

    NamedPipeServerStream s = new NamedPipeServerStream("p", PipeDirection.In);
    Action<NamedPipeServerStream> a = callBack;
    a.BeginInvoke(s, ar => { }, null);
    ...
    private void callBack(NamedPipeServerStream pipe)
    {
      while (true)
      {
        pipe.WaitForConnection();
        StreamReader sr = new StreamReader(pipe);
        Console.WriteLine(sr.ReadToEnd());
        pipe.Disconnect();
      }
    }
    

    And the client does this:

    using (var pipe = new NamedPipeClientStream(".", "p", PipeDirection.Out))
    using (var stream = new StreamWriter(pipe))
    {
      pipe.Connect();
      stream.Write("Hello");
    }
    

    I can repeat above block multiple times with the server running, no prob.