Added tests for max connection limitation.

Changed ConnectionError to an event instead of a delegate.

src/DtronixMessageQueue.Tests/Transports/TransportClientConnectorTests.cs

@@ -60,7 +60,7 @@ namespace DtronixMessageQueue.Tests.Transports
             var (listener, connector) = CreateClientServer(type);
             ClientConfig.ConnectionTimeout = 100;
 
-            connector.ConnectionError = () =>
+            connector.ConnectionError += (sender, args) => 
             {
                 TestComplete.Set();
             };

src/DtronixMessageQueue.Tests/Transports/TransportListenerTests.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Text;
+using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.VisualStudio.TestPlatform.ObjectModel;
 using NUnit.Framework;
@@ -171,5 +172,57 @@ namespace DtronixMessageQueue.Tests.Transports
 
             WaitTestComplete();
         }
+
+        [TestCase(Protocol.Tcp)]
+        [TestCase(Protocol.TcpTransparent)]
+        [TestCase(Protocol.TcpTls)]
+        public void ServerAcceptsMultipleConnections(Protocol type)
+        {
+            var (listener, connector) = CreateClientServer(type);
+            var connector2 = CreateClient(type);
+            var totalConnections = 0;
+
+            listener.Started += (sender, args) =>
+            {
+                connector.Connect();
+                connector2.Connect();
+            };
+
+            listener.Connected += (sender, args) =>
+            {
+                var currentTotal = Interlocked.Increment(ref totalConnections);
+                if(currentTotal == 2)
+                    TestComplete.Set();
+            };
+            listener.Start();
+
+            WaitTestComplete();
+        }
+
+        [TestCase(Protocol.Tcp)]
+        [TestCase(Protocol.TcpTransparent)]
+        [TestCase(Protocol.TcpTls)]
+        public void ServerLimitsMultipleConnections(Protocol type)
+        {
+            ServerConfig.MaxConnections = 1;
+
+            var (listener, connector) = CreateClientServer(type);
+            var connector2 = CreateClient(type);
+
+            listener.Started += (sender, args) =>
+            {
+                connector.Connect();
+            };
+
+            connector.Connected += (sender, args) => { connector2.Connect(); };
+            connector2.Connected += (sender, args) =>
+            {
+                args.Session.Disconnected += (o, eventArgs) => TestComplete.Set();
+            };
+
+            listener.Start();
+
+            WaitTestComplete();
+        }
     }
 }

src/DtronixMessageQueue.Tests/Transports/TransportTestBase.cs

@@ -228,7 +228,7 @@ namespace DtronixMessageQueue.Tests.Transports
         }
 
 
-        protected void WaitTestComplete(int time = 200000)
+        protected void WaitTestComplete(int time = 2000)
         {
             if (!TestComplete.Wait(time))
                 throw new TimeoutException($"Test timed out at {time}ms");

src/DtronixMessageQueue/Layers/Application/ApplicationClientConnector.cs

@@ -9,8 +9,8 @@ namespace DtronixMessageQueue.Layers.Application
         protected IClientConnector Connector;
 
         public event EventHandler<SessionEventArgs> Connected;
+        public event EventHandler ConnectionError;
 
-        public Action ConnectionError { get; set; }
 
         public ISession Session { get; private set; }
 
@@ -20,12 +20,12 @@ namespace DtronixMessageQueue.Layers.Application
         {
             Connector = factory.CreateConnector(OnSessionCreated);
 
-            Connector.ConnectionError = OnConnectorConnectionError;
+            Connector.ConnectionError += OnConnectorConnectionError;
         }
 
-        private void OnConnectorConnectionError()
+        private void OnConnectorConnectionError(object sender, EventArgs e)
         {
-            ConnectionError?.Invoke();
+            ConnectionError?.Invoke(this, EventArgs.Empty);
         }
 
         protected abstract ApplicationSession CreateSession([NotNull] ITransportSession session);

src/DtronixMessageQueue/Layers/Application/Tls/TlsApplicationSession.cs

@@ -58,7 +58,7 @@ namespace DtronixMessageQueue.Layers.Application.Tls
                 {
                     await _tlsStream.AuthenticateAsClientAsync(new SslClientAuthenticationOptions
                         {
-                            TargetHost = "tlstest" // TODO: Change!
+                            TargetHost = "tlstest2" // TODO: Change!
                         },
                         _cancellationTokenSource.Token);
                 }

src/DtronixMessageQueue/Layers/IClientConnector.cs

@@ -12,7 +12,7 @@ namespace DtronixMessageQueue.Layers
         /// <summary>
         /// Fired when the connecting client fails to connect to the server.
         /// </summary>
-        Action ConnectionError { get; set; }
+        event EventHandler ConnectionError;
         
         ISession Session { get; }
 

src/DtronixMessageQueue/Layers/Transports/Tcp/TcpTransportClientConnector.cs

@@ -22,8 +22,8 @@ namespace DtronixMessageQueue.Layers.Transports.Tcp
         }
 
         public event EventHandler<SessionEventArgs> Connected;
+        public event EventHandler ConnectionError;
 
-        public Action ConnectionError { get; set; }
 
         public ISession Session { get; private set; }
 
@@ -103,7 +103,7 @@ namespace DtronixMessageQueue.Layers.Transports.Tcp
                 timedOut = true;
                 _connecting = false;
                 session?.Disconnect();
-                ConnectionError?.Invoke();
+                ConnectionError?.Invoke(this, EventArgs.Empty);
             }, connectionTimeoutCancellation.Token);
         }
     }

src/DtronixMessageQueue/Layers/Transports/Tcp/TcpTransportListener.cs

@@ -160,6 +160,7 @@ namespace DtronixMessageQueue.Layers.Transports.Tcp
             {
                 try
                 {
+                    Config.Logger.Info($"Listener rejected connection due to being at max allowed sessions: {Config.MaxConnections}.");
                     e.AcceptSocket.Disconnect(false);
                 }
                 catch