C#•6mo ago

NamedPipeClientStream.ReadAsync() continuously reads after the first message arrives

How come NamedPipeClientStream.ReadAsync continuously reads 0 bytes after the first message arrives? Basically is there a way to have it asynchronously wait until more data arrives after the first message?

2 Replies

Omnissiah•6mo ago

uhm im pretty sure if the result is 0 there are no more bytes, stream is finished (like, marked finished from the other side)

nathanAjacobsOP•6mo ago

I don't believe I'm intentionally finishing the server stream, here is my code:

public class ServerPipe : IDisposable
{
    readonly SemaphoreSlim semapohre = new SemaphoreSlim(0, 1);

    readonly NamedPipeServerStream server;

    readonly StreamWriter writer;

    private volatile bool _disposed;

    public ServerPipe()
    {
        server = new NamedPipeServerStream("MyTestPipe", PipeDirection.Out);
        writer = new StreamWriter(server, System.Text.Encoding.Unicode);
        _ = WaitForConnectiionAsync();
    }

    private async Task WaitForConnectiionAsync()
    {
        try
        {
            await server.WaitForConnectionAsync().ConfigureAwait(false);
            semapohre.Release();
        }
        catch (Exception ex)
        {
            Debug.LogException(ex);
        }
    }

    public async void WriteMessage(string message)
    {
        if (_disposed)
            return;

        try
        {
            await semapohre.WaitAsync().ConfigureAwait(false);
            await writer.WriteLineAsync(message).ConfigureAwait(false);
            await writer.FlushAsync().ConfigureAwait(false);
        }
        catch (Exception ex)
        {
            Debug.LogException(ex);
        }
        finally
        {
            semapohre.Release();
            Dispose();
        }
    }

    public void Dispose()
    {
        _disposed = true;
        semapohre.Dispose();
        writer.Dispose();
        server.Dispose();
    }
}

public class ClientPipe : IDisposable
{
    readonly NamedPipeClientStream client;
    readonly StreamReader reader;

    public ClientPipe()
    {
        client = new NamedPipeClientStream(".", "MyTestPipe", PipeDirection.In);
        reader = new StreamReader(client);
        _ = RunReadLoopAsync();
    }

    private async Task RunReadLoopAsync()
    {
        try
        {
            await client.ConnectAsync();

            while (true)
            {
                string line = await reader.ReadLineAsync();
                Debug.Log(line);
            }
        }
        catch (Exception ex)
        {
            Debug.LogException(ex);
        }
    }

    public void Dispose()
    {
        reader.Dispose();
        client.Dispose();
    }
}

public class ServerPipe : IDisposable
{
    readonly SemaphoreSlim semapohre = new SemaphoreSlim(0, 1);

    readonly NamedPipeServerStream server;

    readonly StreamWriter writer;

    private volatile bool _disposed;

    public ServerPipe()
    {
        server = new NamedPipeServerStream("MyTestPipe", PipeDirection.Out);
        writer = new StreamWriter(server, System.Text.Encoding.Unicode);
        _ = WaitForConnectiionAsync();
    }

    private async Task WaitForConnectiionAsync()
    {
        try
        {
            await server.WaitForConnectionAsync().ConfigureAwait(false);
            semapohre.Release();
        }
        catch (Exception ex)
        {
            Debug.LogException(ex);
        }
    }

    public async void WriteMessage(string message)
    {
        if (_disposed)
            return;

        try
        {
            await semapohre.WaitAsync().ConfigureAwait(false);
            await writer.WriteLineAsync(message).ConfigureAwait(false);
            await writer.FlushAsync().ConfigureAwait(false);
        }
        catch (Exception ex)
        {
            Debug.LogException(ex);
        }
        finally
        {
            semapohre.Release();
            Dispose();
        }
    }

    public void Dispose()
    {
        _disposed = true;
        semapohre.Dispose();
        writer.Dispose();
        server.Dispose();
    }
}

public class ClientPipe : IDisposable
{
    readonly NamedPipeClientStream client;
    readonly StreamReader reader;

    public ClientPipe()
    {
        client = new NamedPipeClientStream(".", "MyTestPipe", PipeDirection.In);
        reader = new StreamReader(client);
        _ = RunReadLoopAsync();
    }

    private async Task RunReadLoopAsync()
    {
        try
        {
            await client.ConnectAsync();

            while (true)
            {
                string line = await reader.ReadLineAsync();
                Debug.Log(line);
            }
        }
        catch (Exception ex)
        {
            Debug.LogException(ex);
        }
    }

    public void Dispose()
    {
        reader.Dispose();
        client.Dispose();
    }
}

After the first message arrives it continuously reads null as the line I was being dumb and called dispose in the finally block instead of the catch

Gaming

Programming

NamedPipeClientStream.ReadAsync() continuously reads after the first message arrives