awaiting a HubProxy.Invoke method makes the HubConnection.Dispose take 30 seconds to dispose

[maboivin]

I have a simple Hub in a an ASP.NET MVC5 web app. I'm using SignalR 2.0.0.

public class MyHub : Hub
{
    public void SendMessage(string message)
    {
        this.Clients.All.OnMessage(message);
    }
}

I have a simple client in .NET 4.5.

class Program
{
    static void Main(string[] args)
    {
        Run();

        Console.ReadKey();
    }

    static async void Run()
    {
        var url = "http://localhost:65479/";

        var tcs = new TaskCompletionSource<bool>();
        var sw = new Stopwatch();

        using (var hubConnection = new HubConnection(url))
        {
            var hubProxy = hubConnection.CreateHubProxy("MyHub");
            await hubConnection.Start();

            hubProxy.On<string>(
                "OnMessage",
                 message =>
                 {
                     Console.WriteLine(message);

                     tcs.SetResult(true);
                 });

            // When awaiting this call, it takes 30 seconds to dispose the hub connection.
            /*await*/ hubProxy.Invoke("SendMessage", "my message");

            // EDITED: Replaced tcs.Task.Wait(30 * 1000); with the following:
            await tcs.Task;

            sw.Start();
        }

        sw.Stop();

        // It takes 30 seconds to dispose...
        Console.WriteLine(sw.Elapsed);
    }
}

My issue is that when I await the call to hubProxy.Invoke(), the hub connection takes 30 seconds to dispose (which is the default timeout). But if I don't await the same call, it disposes fine. I have a simple project if needed to repro.

What should I do to dispose the connection without having to wait 30 seconds? Is it a bug or is my code wrong?

[davidfowl]

Try doing:

await tcs.Task

It's bad to mix sync and async code.

[maboivin]

Sorry, bad copy/paste. I previously tried it with .NET 4.0 and it was working fine without async calls. The original code was like you said "await tcs.Task" and it doesn't change anything, it still takes 30 seconds to dispose. I also tried the following code:

await tcs.Task.TimeoutAfter(30 * 1000);

and

static class TaskExtensions
{
    public static async Task<T> TimeoutAfter<T>(this Task<T> task, int timeoutInMillis)
    {
        using (var cancellationTokenSource = new CancellationTokenSource())
        {
            if (task == await Task.WhenAny(task, Task.Delay(timeoutInMillis, cancellationTokenSource.Token)))
            {
                cancellationTokenSource.Cancel();

                return await task;
            }
            else
            {
                throw new TimeoutException();
            }
        }
    }
}

[davidfowl]

By default calling dispose/stop can take up to 30 seconds as it tries to abort the connection gracefully. For some reason that is hanging and we can look into why. I assume you're using 2.0.0 rtw?

[maboivin]

You're right. I'm using 2.0.0 rtw. If you want me to upload a repro solution, let me know.

[gustavo-armenta]

tested repro and now connection disposes in less than one second