Sending message from one C# console application to another

Question

First of all, I've read all related topics and they gave general idea but implementation doesn't work for me:
Send strings from one console application to another
How to send input to the console as if the user is typing?
Sending input/getting output from a console application (C#/WinForms)
I have a console application that is doing some actions in background until cancellation is requested. Typical usage scenario is :
1) Execute application
2) Enter input data
3) Issue start command
4) After some time passes, enter stop command
5) Exit application
Child application Program.cs :

static void Main()
{
    Console.WriteLine("Enter input parameter : ");
    var inputParameter = Console.ReadLine();
    Console.WriteLine("Entered : " + inputParameter);

    var tokenSource = new CancellationTokenSource();
    var token = tokenSource.Token;
    Task.Factory.StartNew(() =>
        {
            while (true)
            {
                if (token.IsCancellationRequested)
                {
                    Console.WriteLine("Stopping actions");
                    return;
                }
                // Simulating some actions
                Console.Write("*");
            }
        }, token);
    if (Console.ReadKey().KeyChar == 'c')
    {
        tokenSource.Cancel();
        Console.WriteLine("Stop command");
    }
    Console.WriteLine("Finished");
    Console.ReadLine();
}

What I'm looking for is some sort of host utility to control this application - spawn multiple instances and perform required user actions on each instance. Host application Program.cs :

static void Main()
{
    const string exe = "Child.exe";
    var exePath = System.IO.Path.GetFullPath(exe);
    var startInfo = new ProcessStartInfo(exePath)
    {
        RedirectStandardOutput = true,
        RedirectStandardInput = true,
        WindowStyle = ProcessWindowStyle.Hidden,
        WindowStyle = ProcessWindowStyle.Maximized,
        CreateNoWindow = true,
        UseShellExecute = false
    };

    var childProcess = new Process { StartInfo = startInfo };
    childProcess.OutputDataReceived += readProcess_OutputDataReceived;
    childProcess.Start();
    childProcess.BeginOutputReadLine();
    Console.WriteLine("Waiting 5s for child process to start...");
    Thread.Sleep(5000);

    Console.WriteLine("Enter input");
    var msg = Console.ReadLine();
    // Sending input parameter
    childProcess.StandardInput.WriteLine(msg);
    // Sending start command aka any key
    childProcess.StandardInput.Write("s");
    // Wait 5s while child application is working
    Thread.Sleep(5000);
    // Issue stop command
    childProcess.StandardInput.Write("c");
    // Wait for child application to stop
    Thread.Sleep(20000);
    childProcess.WaitForExit();
    Console.WriteLine("Batch finished");    
    Console.ReadLine();
}

When I run this tool, after first input it crashes with "has stopped working" error and prompt to send memory dump to Microsoft. Output window in VS shows no exceptions.
Guess this problem occurs somewhere between applications and may be because of output stream buffer overflow (child app is writing a lot of stars each second which mimics real output which may be huge) and I yet have no idea how to fix it. I don't really need to pass child's output to host (only send start-stop commands to child), but commenting RedirectStandardOutput and OutputDataReceived doesn't fix this problem. Any ideas how to make this work?

Answer 1

I would recommend using NamedPipeServerStream and NamedPipeClientStream, which allows you to open a stream which will communicate between processes on a given machine.

First, this will create a pipe server stream and wait for someone to connect to it:

    var stream = new NamedPipeServerStream(this.PipeName, PipeDirection.InOut);
    stream.WaitForConnection();
    return stream;

Then, this will connect to that stream (from your other process), allowing you to read / write in either direction:

    var stream = new NamedPipeClientStream(".", this.PipeName, PipeDirection.InOut);
    stream.Connect(100);
    return stream;