How do I close the connection nicely?

[Hulkstance]

If I do the following in the Client:

tcpConnection.Close(Network.Enums.CloseReason.ClientClosed);

it closes the connection but the connection remains there, you can see that in Process Hacker in Network tab. Any solution for this?

[Toemsel]

Does the server receive the close event? Do you use the ClientConnectionContainer?

[Hulkstance]

It does. It receives ClientClosed.

[Toemsel]

Ok, I will invest the issue. What software do you use to filter running child threads?

[Hulkstance]

Process Hacker. It shows the remaining connection. And by the way, if you reconnect to the server, it closes the remaining connection and opens a new one. Probably something is wrong with Close method.

Code here:

// Server
_serverConnectionContainer = ConnectionFactory.CreateServerConnectionContainer(1234, false);

_serverConnectionContainer.ConnectionLost += (a, b, c) => Console.WriteLine($"{a.IPRemoteEndPoint} disconnected. Reason: {c}.");
_serverConnectionContainer.ConnectionEstablished += connectionEstablished;

_serverConnectionContainer.Start();

private static void connectionEstablished(Connection connection, ConnectionType type)
{
	Console.WriteLine($"{connection.IPRemoteEndPoint} connected. Online: {_serverConnectionContainer.Count}.");

	connection.RegisterRawDataHandler("file", (rawData, con) =>
	{
		Console.WriteLine("Received file size: {rawData.Data.Length}");

		connection.SendRawData("file_received", Encoding.UTF8.GetBytes("Hello from Server. File was received."));
	});

	connection.RegisterRawDataHandler("message", (rawData, con) => {
		Console.WriteLine("Received message: {rawData.ToUTF8String()}");
	});
}

// Client code
ConnectionResult connectionResult = ConnectionResult.TCPConnectionNotAlive;
TcpConnection tcpConnection = ConnectionFactory.CreateTcpConnection("127.0.0.1", 1234, out connectionResult);

if (connectionResult == ConnectionResult.Connected)
{
	tcpConnection.SendRawData("file", File.ReadAllBytes(path));
	tcpConnection.SendRawData("message", Encoding.UTF8.GetBytes("Hello, Server!"));

	tcpConnection.RegisterRawDataHandler("file_received", (rawData, con) =>
	{
		string serverMessage = rawData.ToUTF8String();

		tcpConnection.Close(Network.Enums.CloseReason.ClientClosed);
	});
}```

[Hulkstance]

I debugged it and seems to be invokePacketThread.AbortSave(); throwing ThreadAbortException.

In InvokeWork(), you can see that it received the CloseRequest but it fails to abort the thread at HandleDefaultPackets(toDelegate); and later in ExternalClose(closeRequest.CloseReason);. It leads to AbortSave(). In other words, invokePacketThread cannot be aborted. Perhaps, because it was aborted somewhere earlier?

I added Thread.ResetAbort(); in AbortSave() to make it work which is not the best solution. You can check your code.

This is all I did:

    /// <summary>
    /// Provides additional functionality to the <see cref="Thread"/> class, that isn't available under .NET Standard 2.0.
    /// </summary>
    internal static class ThreadExtensions
    {
        #region Methods

        /// <summary>
        /// Allows for a <see cref="Thread"/> object to be aborted in a program running under the .NET Standard C# implementation.
        /// </summary>
        /// <param name="thread">The <see cref="Thread"/> instance this extension method affects.</param>
        /// <returns>Whether the <see cref="Thread.Abort(object)"/> method raised an exception.</returns>
        internal static bool AbortSave(this Thread thread)
        {
            try
            {
                thread.Abort();
                return false;
            }
            catch
            {
                Thread.ResetAbort();
                return true;
            }
        }

        #endregion Methods
    }

[Toemsel]

Thanks for the invest. While trying to resolve the issue, I encountered that .NET Core doesn't support Thread.Abort. Besides switching completely to a task related behaviour, I try to find a workaround.

[Hulkstance]

No problem. This is a solution meanwhile.

[Toemsel]

I wasn't able to find any remaining threads after closing the connection.
On .NET 4.6 > and >.NET Core the AbortSave() does abort the network threads successfully.
Maybe you didn't set "AutoReconnect" to false, in order to prevent a reconnection?

Thread.ResetAbort() isn't a solution, since it aborts the abortion.

Please add some screenshots, highlighting the remaining threads. Or, even better, provide an example illustrating the issue.

[AntonVonDelta]

This is a real issue. My app is not working. The connection remains and even tieouts and appears as a different message when debugging(because it timeouts further in time). Is there a fix for this?

[Toemsel]

.NET or .NET Core?

Can you provide a minimalistic example?

[Toemsel]

Related to #55