TcpEx: server-side connection locking issue

test.cs

// http://zyan.com.de
//
// Compile using: csc test.cs /r:Zyan.Communication.dll
//
// Start up test.exe several times.
// The first process is the server, the rest are clients.
//

using System;
using System.Collections.Concurrent;
using System.Diagnostics;
using System.Linq;
using System.Reflection;
using System.Threading;
using Zyan.Communication;
using Zyan.Communication.Protocols.Tcp;

class GlobalLockSuspicionTest
{
	static void Main()
	{
		try
		{
			StartServer();
		}
		catch
		{
			StartClient();
		}
	}

	// ------------ Server code --------------

	static void StartServer()
	{
		var proto = new TcpDuplexServerProtocolSetup(4321);

		using (var host = new ZyanComponentHost(nameof(GlobalLockSuspicionTest), proto))
		{
			host.RegisterComponent<IService, Service>();
			host.SubscriptionCanceled += (s, e) => Console.WriteLine("Subscription canceled: {0}.{1}", e.ComponentType, e.DelegateMemberName);

			Console.WriteLine("Server started. Press ENTER to quit.");
			Console.Title = nameof(GlobalLockSuspicionTest) + " - Server #" + Process.GetCurrentProcess().Id;

			var ps = new TcpDuplexClientProtocolSetup();
			ThreadPool.QueueUserWorkItem(x => TryExternalConnection(ps, "example.com", 4322));
			ThreadPool.QueueUserWorkItem(x => TryExternalConnection(ps, "example.com", 4323));
			ThreadPool.QueueUserWorkItem(x => TryExternalConnection(ps, "example.com", 4324));

			Console.ReadLine();
		}
	}

	static void TryExternalConnection(TcpDuplexClientProtocolSetup proto, string host, int port)
	{
		var url = proto.FormatUrl(host, port, nameof(GlobalLockSuspicionTest));
		try
		{
			new ZyanConnection(url);
		}
		catch (Exception ex)
		{
			Console.WriteLine("Connection to {0} failed. Exception: {1}, Error message: {2}", url, ex.GetType(), ex.Message);
		}
	}

	public class Service : IService
	{
		private static int Counter { get; set; }

		public string Hello()
		{
			Counter++;
			Console.WriteLine("Called: " + Counter);
			return "Hello: " + Counter;
		}

		public void ExternalConnection()
		{
			try
			{
				var proto = new TcpDuplexClientProtocolSetup();
				var url = proto.FormatUrl("example.com", 4321, nameof(GlobalLockSuspicionTest));
				new ZyanConnection(url);
			}
			catch (Exception ex)
			{
				Console.WriteLine("Connection failed. Error message: {0}", ex.Message);
				throw;
			}
		}
	}

	// ------------ Shared code --------------

	public interface IService
	{
		string Hello();

		void ExternalConnection();
	}

	// ------------ Client code --------------

	static void StartClient()
	{
		Console.Title = nameof(GlobalLockSuspicionTest) + " - Client #" + Process.GetCurrentProcess().Id;

		var proto = new TcpDuplexClientProtocolSetup();
		var url = proto.FormatUrl("localhost", 4321, nameof(GlobalLockSuspicionTest));
		Console.WriteLine("Connecting to {0}...", url);

		var sw = Stopwatch.StartNew();
		using (var conn = new ZyanConnection(url))
		{
			sw.Stop();
			Console.WriteLine("Connected. Time elapsed: {0}", sw.Elapsed);

			var proxy = conn.CreateProxy<IService>();

			Console.WriteLine("Client started. Commands: H = hello, P = poll, C = connect to example.com, S = ask server to connect to example.com, ^C to quit.");
			while (true)
			{
				var command = Console.ReadLine();
				switch (command.ToLower().FirstOrDefault())
				{
					case 'h':
						var result = proxy.Hello();
						Console.WriteLine("Server reply: {0}", result);
						break;

					case 'p':
						Console.WriteLine("Polling...");
						ThreadPool.QueueUserWorkItem(x => Poll(proxy));
						break;

					case 'c':
						Console.WriteLine("Connecting to example.com...");
						ThreadPool.QueueUserWorkItem(x => Connect());
						break;

					case 's':
						Console.WriteLine("Asking server to connect to example.com...");
						ThreadPool.QueueUserWorkItem(x => ExternalConnection(proxy));
						break;

					default:
						Console.WriteLine("Unknown command");
						break;
				}
			}
		}
	}

	static void ExternalConnection(IService proxy)
	{
		try
		{
			proxy.ExternalConnection();
		}
		catch (Exception ex)
		{
			Console.WriteLine("Connection failed. Error message: {0}", ex.Message);
		}
	}

	static void Connect()
	{
		try
		{
			var proto = new TcpDuplexClientProtocolSetup();
			var url = proto.FormatUrl("example.com", 4321, nameof(GlobalLockSuspicionTest));
			new ZyanConnection(url);
		}
		catch (Exception ex)
		{
			Console.WriteLine("Connection failed. Error message: {0}", ex.Message);
		}
	}

	static void Poll(IService proxy)
	{
		for (var i = 0; i < 100; i++)
		{
			try
			{
				Thread.Sleep(TimeSpan.FromSeconds(1));
				Console.WriteLine("Iteration #{0}: server reply: {1}", i, proxy.Hello());
			}
			catch (Exception ex)
			{
				while (ex is TargetInvocationException && ex.InnerException != null)
				{
					ex = ex.InnerException;
				}

				Console.WriteLine("Polling failure: should never happen. Error message: {0}", ex.Message);
			}
		}
	}
}

On Zyan v2.14 and below, the client cannot connect to server until the server fails to connect to example.com.

Related issue: zyanfx/Zyan#87