Ensure handler factory on connection listener is invoked once per transport.

src/Listener/ConnectionListener.cs

@@ -133,6 +133,8 @@ namespace Amqp.Listener
         /// <summary>
         /// Gets or sets a factory that creates a <see cref="IHandler"/> for an accepted connection.
         /// </summary>
+        /// <remarks>The delegate is called once for each accepted transport. It allows for creating
+        /// a handler per connection if needed (<see cref="Amqp.Connection.Handler"/>).</remarks>
         public Func<ConnectionListener, IHandler> HandlerFactory
         {
             get;
@@ -237,7 +239,7 @@ namespace Amqp.Listener
             throw new ArgumentNullException("certificate");
         }
 
-        async Task HandleTransportAsync(IAsyncTransport transport, object context)
+        async Task HandleTransportAsync(IAsyncTransport transport, IHandler handler, object context)
         {
             IPrincipal principal = null;
             if (this.saslSettings != null)
@@ -247,7 +249,6 @@ namespace Amqp.Listener
                 principal = profile.GetPrincipal();
             }
 
-            IHandler handler = this.HandlerFactory?.Invoke(this);
             var connection = new ListenerConnection(this, this.address, handler, transport);
             if (principal == null)
             {
@@ -631,7 +632,7 @@ namespace Amqp.Listener
 
                     IAsyncTransport transport = await this.CreateTransportAsync(socket);
 
-                    await this.Listener.HandleTransportAsync(transport, socket);
+                    await this.Listener.HandleTransportAsync(transport, handler, socket);
                 }
                 catch (Exception exception)
                 {
@@ -736,7 +737,8 @@ namespace Amqp.Listener
                     try
                     {
                         var transport = await this.provider.CreateAsync(this.Listener.address);
-                        await this.Listener.HandleTransportAsync(transport, null);
+                        IHandler handler = this.Listener.HandlerFactory?.Invoke(this.Listener);
+                        await this.Listener.HandleTransportAsync(transport, handler, null);
                     }
                     catch (ObjectDisposedException)
                     {
@@ -805,11 +807,11 @@ namespace Amqp.Listener
                 this.httpListener.Close();
             }
 
-            async Task HandleListenerContextAsync(HttpListenerContext context)
+            async Task HandleListenerContextAsync(HttpListenerContext context, IHandler handler)
             {
                 try
                 {
-                    int status = await this.CreateTransportAsync(context);
+                    int status = await this.CreateTransportAsync(context, handler);
                     if (status != 0)
                     {
                         Trace.WriteLine(TraceLevel.Error, "Failed to create ws transport ", status);
@@ -826,7 +828,7 @@ namespace Amqp.Listener
                 }
             }
 
-            async Task<int> CreateTransportAsync(HttpListenerContext context)
+            async Task<int> CreateTransportAsync(HttpListenerContext context, IHandler handler)
             {
                 X509Certificate2 clientCertificate = null;
 
@@ -888,14 +890,13 @@ namespace Amqp.Listener
                 }
 
                 var wsContext = await context.AcceptWebSocketAsync(subProtocol);
-                IHandler handler = this.Listener.HandlerFactory?.Invoke(this.Listener);
                 if (handler != null && handler.CanHandle(EventId.WebSocketAccept))
                 {
                     handler.Handle(Event.Create(EventId.WebSocketAccept, null, context: wsContext));
                 }
 
                 var wsTransport = new ListenerWebSocketTransport(wsContext.WebSocket, principal);
-                await this.Listener.HandleTransportAsync(wsTransport, wsContext.WebSocket);
+                await this.Listener.HandleTransportAsync(wsTransport, handler, wsContext.WebSocket);
 
                 return 0;
             }
@@ -914,7 +915,7 @@ namespace Amqp.Listener
                             handler.Handle(Event.Create(EventId.HttpAccept, null, context: context));
                         }
 
-                        var task = this.HandleListenerContextAsync(context);
+                        var task = this.HandleListenerContextAsync(context, handler);
                     }
                     catch (Exception exception)
                     {