added RestartAfterListenError

use server.ListenerSocket. RestartAfterListenError to automatically
restart the listener after it closes because of an error

Author: Jesper

src/Fleck/Interfaces/ISocket.cs

@@ -15,6 +15,7 @@ public interface ISocket
         int RemotePort { get; }
         Stream Stream { get; }
         bool NoDelay { get; set; }
+        bool RestartAfterListenError { get; set; }
         EndPoint LocalEndPoint { get; }
 
         Task<ISocket> Accept(Action<ISocket> callback, Action<Exception> error);

src/Fleck/SocketWrapper.cs

@@ -16,7 +16,8 @@ public class SocketWrapper : ISocket
         private Stream _stream;
         private CancellationTokenSource _tokenSource;
         private TaskFactory _taskFactory;
-        
+        private bool _restartAfterListenError;
+
         public string RemoteIpAddress
         {
             get
@@ -51,7 +52,7 @@ public Task Authenticate(X509Certificate2 certificate, SslProtocols enabledSslPr
             _stream = new QueuedStream(ssl);
             Func<AsyncCallback, object, IAsyncResult> begin =
                 (cb, s) => ssl.BeginAuthenticateAsServer(certificate, false, enabledSslProtocols, false, cb, s);
-                
+
             Task task = Task.Factory.FromAsync(begin, ssl.EndAuthenticateAsServer, null);
             task.ContinueWith(t => callback(), TaskContinuationOptions.NotOnFaulted)
                 .ContinueWith(t => error(t.Exception), TaskContinuationOptions.OnlyOnFaulted);
@@ -74,7 +75,7 @@ public bool Connected
         {
             get { return _socket.Connected; }
         }
-        
+
         public Stream Stream
         {
             get { return _stream; }
@@ -86,6 +87,12 @@ public bool NoDelay
             set { _socket.NoDelay = value; }
         }
 
+        public bool RestartAfterListenError
+        {
+            get { return _restartAfterListenError; }
+            set { _restartAfterListenError = value; }
+        }
+
         public EndPoint LocalEndPoint
         {
             get { return _socket.LocalEndPoint; }

src/Fleck/WebSocketServer.cs

@@ -99,7 +99,24 @@ public void Start(Action<IWebSocketConnection> config)
 
         private void ListenForClients()
         {
-            ListenerSocket.Accept(OnClientConnect, e => FleckLog.Error("Listener socket is closed", e));
+            ListenerSocket.Accept(OnClientConnect, e => {
+                FleckLog.Error("Listener socket is closed", e);
+                if(ListenerSocket.RestartAfterListenError){
+                    FleckLog.Info("Listener socket restarting");
+                    try
+                    {
+                        ListenerSocket.Dispose();
+                        var socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.IP);
+                        ListenerSocket = new SocketWrapper(socket);
+                        Start(_config);
+                        FleckLog.Info("Listener socket restarted");
+                    }
+                    catch (Exception ex)
+                    {
+                        FleckLog.Error("Listener could not be restarted", ex);
+                    }
+                }
+            });
         }
 
         private void OnClientConnect(ISocket clientSocket)