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How to do a proper shutdown of worker service in this example

I have this workerservice which in essence is a TCP socket server.
This is my main where i select to set up the service depending on the OS.
public static void Main(string[] args)
{
Log log = new();
Socket socket = new SocketConnection().getSocket();
try
{
DataStorage.Instance.osPlatform = RuntimeInformation.OSDescription;
if (DataStorage.Instance.osPlatform.Contains("Win"))
{
Console.WriteLine("WinOS");
CreateHostBuilderWin(args).Build().Run();
}
else
{
Console.WriteLine("MacOS");
CreateHostBuilderMac(args).Build().Run();
}
}
catch (Exception ex)
{
log.write("Could not start SDS. ", ex);
}
log.write("Program is reached on shutdown", null);
}
public static void configureServices(HostBuilderContext context, IServiceCollection services)
{
services.AddHostedService<Worker>();
}
public static IHostBuilder CreateHostBuilderWin(string[] args) =>
Host.CreateDefaultBuilder(args)
.UseWindowsService()
.ConfigureServices((hostContext, services) =>
{
services.AddHostedService<Worker>();
});
public static IHostBuilder CreateHostBuilderMac(string[] args) =>
Host.CreateDefaultBuilder(args)
//Hvorfor dette?
.ConfigureServices(configureServices);
}
This is the Worker, where i start the clientServer with a socket as parameter. And here is the problem.
I cant seem to shutdown the service properly. I initialize and instantiate a Socket, and i want to dispose of it when the service is stopped or crashes.
The disposal takes plase in the EndSDS Class
using Microsoft.Extensions.Hosting;
using SDS.BusinessLogic;
using SDS.Singleton;
using System;
using System.Threading;
using System.Threading.Tasks;
using SDS.Service.Tools;
using System.Net.Sockets;
namespace SDS
{
public class Worker : BackgroundService
{
Log log = new();
ClientServer clientServer;
SocketConnection socket = new();
Socket listener;
EndSDS endSDS;
private readonly IHostApplicationLifetime _hostApplicationLifetime;
public Worker(IHostApplicationLifetime hostApplicationLifetime)
{
_hostApplicationLifetime = hostApplicationLifetime;
}
protected override async Task ExecuteAsync(CancellationToken stoppingToken) {
try{
while (!stoppingToken.IsCancellationRequested)
{
try
{
// hvis pludseligt det går galt med initialiseringen så skal SDS stoppe
// ved næste gennemløb
if (DataStorage.Instance.sdsInitialized)
{
log.write("startasync is reached", null);
listener = socket.getSocket();
log.write("Socket: " + listener.AddressFamily + " " + listener.RemoteEndPoint, null);
await clientServer.start(listener);
}
else
{
log.write("Sds not initialized properly", null);
}
}
catch (Exception ex)
{
log.write("Could not create Socket for server", ex);
}
}
}
finally
{
log.write("Finally reached", null);
_hostApplicationLifetime.StopApplication();
}
}
//log.write("Worker is reached on shutdown", null);
public override Task StartAsync(CancellationToken cancellationToken)
{
log.write("StartAsync is reached on startup", null);
clientServer = new();
return base.StartAsync(cancellationToken);
}
public override Task StopAsync(CancellationToken cancellationToken)
{
log.write("StopAsync is reached on shutdown", null);
endSDS = new EndSDS();
endSDS.start(listener);
return base.StopAsync(cancellationToken);
}
/* public override void Dispose()
{
log.write("Dispose is reached on shutdown", null);
endSDS.start(listener);
base.Dispose();
}*/
}
}
Here is the EndSDS class.
using SDS.Controllers;
using SDS.Singleton;
using SDS.Service.Tools;
using System.Net.Sockets;
using System;
namespace SDS.BusinessLogic
{
internal class EndSDS
{
private FilesController files = new();
private Log log = new();
internal EndSDS()
{
}
internal void start(Socket socket)
{
log.write("socket closing", null);
if (socket != null)
{
try
{
socket.Close();
socket.Dispose();
}
catch (Exception ex)
{
log.write("logclose exception. ", ex);
};
log.write("Socket Disposed", null);
}
log.write("SDS ended. ", null);
}
}
}
What happens is.
I start the service, and it starts properly because i can connect to it and talk to it. I can also see the "StartAsync is reached on startup" in the log
I stop the service, and StopAsync is not being run. Nothing happens. The log are not written to the logs.
I start the service, and it does not start the clientServer, as the port is not closed and i get a message saying that in the log.
I stop the service, and StopAsync runs, and everyting is ok.
rince and repeat.
Can anybody help me ?, i have no idea what the problem is.
Thankyou for your time.

Sockets, Nullreference Exception

I am trying to use web socket with my bot to communicate with the server. But on run time it throws the System.NullReferenceException. I am running socket in background on a different thread so that it does not interfear with the bot.
I am using WebsocketSharp library.
First message comes in just fine but on second message it throws exception at following line in HumanCollaboratorDialog class.
await context.PostAsync(e.Data);
My Socket Stream Class is as following:
public static class SocketStream
{
public static WebSocket ws;
private static List<string> serverMsg = new List<string>();
public static void initializeSocket()
{
ws = new WebSocket("ws://Some IP:8080/human-collaborator/data");
Debug.WriteLine("****** INITIALIZED SOCKET (should happen only once) *****");
Task.Run(() => startSocketStream());
}
private static void startSocketStream()
{
int attempts = 0;
while (!ws.IsAlive)
{
try
{
attempts++;
ws.Connect();
}
catch (WebSocketException)
{
Debug.WriteLine("Connection attempts: " + attempts.ToString());
}
}
ws.OnOpen += (sender, args) =>
{
Debug.WriteLine("# SOCKET OPENED");
};
ws.OnError += (sender, args) =>
{
Debug.WriteLine("# SOME ERROR OCCURED");
};
ws.OnClose += (sender, args) =>
{
Debug.WriteLine("# SOCKET CLOSED");
};
}
}
I am calling the initializeSocket() method in Global.asx to run it on application level
public class WebApiApplication : System.Web.HttpApplication
{
protected void Application_Start()
{
GlobalConfiguration.Configure(WebApiConfig.Register);
SocketStream.initializeSocket();
}
}
My HumanCollaboratorDialog class is as following:
[Serializable]
public class HumanCollaboratorDialog : IDialog<object>
{
public async Task StartAsync(IDialogContext context)
{
context.Wait(this.MessageReceivedAsync);
}
private async Task MessageReceivedAsync(IDialogContext context, IAwaitable<IMessageActivity> result)
{
var message = await result;
SocketStream.ws.OnMessage += async (sender, e) =>
{
try
{
await context.PostAsync(e.Data);
}
catch (HttpRequestException ex)
{
throw ex;
}
};
Thread.Sleep(500);
string output = message.Text;
SocketStream.ws.Send(output);
Thread.Sleep(500);
context.Wait(MessageReceivedAsync);
}
}
My MessagesController has following POST method:
public virtual async Task<HttpResponseMessage> Post([FromBody]Activity activity)
{
if (activity.Type == ActivityTypes.Message)
{
await Conversation.SendAsync(activity, () => new HumanCollaboratorDialog());
}
else
{
HandleSystemMessage(activity);
}
var response = Request.CreateResponse(HttpStatusCode.OK);
return response;
}
Neithet e.Data nor context is empty. I think problem is with socket connection or may be i am doing something wrong in SocketStream class. following is the image

Your bot is a web service. Messages are sent to the service by the client (a web page, an application, another service, etc.) and received in the MessagesController's Post method. There's no need to have the socket code on the server for what you're trying to do. Web Sockets are useful for receiving messages on a client from the bot via a Direct Line connection.
Here is an example of using the Bot Framework's Direct Line Client and creating a web socket connection. Notice how the web socket is created from a conversation's StreamUrl:
DirectLineClientCredentials creds = new DirectLineClientCredentials(directLineSecret);
DirectLineClient directLineClient = new DirectLineClient(creds);
Conversation conversation = await directLineClient.Conversations.StartConversationAsync();
using (var webSocketClient = new WebSocket(conversation.StreamUrl))
{
webSocketClient.OnMessage += WebSocketClient_OnMessage;
webSocketClient.Connect();
while (true)
{
string input = Console.ReadLine().Trim();
if (input.ToLower() == "exit")
{
break;
}
else
{
if (input.Length > 0)
{
Activity userMessage = new Activity
{
From = new ChannelAccount(fromUser),
Text = input,
Type = ActivityTypes.Message
};
await directLineClient.Conversations.PostActivityAsync(conversation.ConversationId, userMessage);
}
}
}
}
private static void WebSocketClient_OnMessage(object sender, MessageEventArgs e)
{
// avoid null reference exception when no data received
if (string.IsNullOrWhiteSpace(e.Data))
{
return;
}
var activitySet = JsonConvert.DeserializeObject<ActivitySet>(e.Data);
var activities = from x in activitySet.Activities
where x.From.Id == botId
select x;
foreach (Activity activity in activities)
{
Console.WriteLine(activity.Text);
}
}
This is from a console application that is using the Direct Line to communicate with the Bot and is listening for messages using web sockets here:
https://github.com/Microsoft/BotBuilder-Samples/tree/master/CSharp/core-DirectLineWebSockets

SignalR remote client

I want to connect to signalr with a client thats on a different pc. This means i wont be using localhost. I already made a simple networkdiscovery to get the correct ip address but it seems signalr does not allow remote clients to connect even though I already use CorsOptions.AllowAll.
class Startup
{
public void Configuration(IAppBuilder app)
{
var hubConfiguration = new HubConfiguration
{
#if DEBUG
EnableDetailedErrors = true
#else
EnableDetailedErrors = false
#endif
};
app.UseCors(CorsOptions.AllowAll);
app.MapSignalR(hubConfiguration);
}
}
Iam using duality which is a 2d game engine. Here is the server:
public class SignalRServer : Component, ICmpInitializable
{
private IDisposable _signalRServer;
public int _port { get; set; } = 8080;
public void StopServer()
{
if (_signalRServer != null)
_signalRServer.Dispose();
}
public void OnInit(InitContext context)
{
if (context == InitContext.Activate && DualityApp.ExecContext == DualityApp.ExecutionContext.Game)
{
var networkDiscovery = new NetworkDiscovery(_port, "TestGame"); //Network discovery to get the ip adres of the server if one is found
IPEndPoint ipEndPoint;
if (networkDiscovery.LookForServer(out ipEndPoint))
{
try
{
ConnectToServer(ipEndPoint).Wait();
Debug.WriteLine($"Connection established to {ipEndPoint}");
}
catch (Exception ex)
{
Debug.WriteLine("Could not find server");
}
}
else //No server was found so we create one
{
Debug.WriteLine("Starting signalR server");
string url = $"http://*:{_port}"; //To test go to http://localhost:8080/signalr/hubs
networkDiscovery.Start();
_signalRServer = WebApp.Start<Startup>(url);
}
}
}
private async Task ConnectToServer(IPEndPoint ipEndPoint)
{
var hubConnection = new HubConnection($"http://{ipEndPoint}/");
IHubProxy hubProxy = hubConnection.CreateHubProxy(nameof(MyHub));
hubProxy.On<string, string>(nameof(MyHub.Send), (name, message) =>
{
Debug.WriteLine("Incoming data: {0} {1}", name, message);
});
ServicePointManager.DefaultConnectionLimit = 10;
await hubConnection.Start();
}
public void OnShutdown(ShutdownContext context)
{
StopServer();
}
}
And the hub:
public class MyHub : Hub
{
public void Send(string name, string message)
{
Clients.All.addMessage(name, message);
}
public override Task OnConnected()
{
Debug.WriteLine("Client connected: " + Context.ConnectionId);
Send("Server", $"Client with id {Context.ConnectionId} has connected");
return base.OnConnected();
}
public override Task OnDisconnected(bool stopCalled)
{
Debug.WriteLine("Client disconnected: " + Context.ConnectionId);
return base.OnDisconnected(stopCalled);
}
}

Connecting Silverlight client to SignalR server

I've been driving myself nuts trying to resolve this issue so really hoping someone has some insight.
I have a console application which runs/hosts my signalR server.
I have already successfully connected to it using a web(javascript) client and a windows forms client with no trouble at all.
BUT for the life of me I cannot get a silverlight client to connect to it. Initially I was getting a
'System.Security.SecurityException' occurred in Microsoft.Threading.Tasks error
on
await Connection.Start();
I managed to fix that by force sending the clientaccesspolicy file using code i found on a random thread.
THREAD
However the connection still never establishes. The status goes thru connecting, disconnected, connection closed.
I am at my wits end as to why this won't work. Any input is appreciated. Code below.
MainPage.xaml.cs
public partial class MainPage : UserControl
{
private SignalRClient client;
public MainPage()
{
InitializeComponent();
dataGrid1.ItemsSource = new ItemsCollection();
client = new SignalRClient();
client.RunAsync();
Debug.WriteLine("Init Done");
}
}
-
SignalRClient.cs
public class SignalRClient
{
private HubConnection Connection { get; set; }
private IHubProxy HubProxy { get; set; }
const string url = "http://localhost:8080/";
public SignalRClient()
{
}
public async void RunAsync()
{
Connection = new HubConnection(url, useDefaultUrl: true);
Connection.Closed += Connection_Closed;
Connection.StateChanged += ConnectionDidSomething;
HubProxy = Connection.CreateHubProxy("TickerHub");
HubProxy.On<string>("receiveAllData", data => Debug.WriteLine("RECDATA={0}", data));
try
{
await Connection.Start();
}
catch (HttpClientException e)
{
Debug.WriteLine("Unable to connect to server.1 {0}", e.Message);
return;
}
catch (HttpRequestException e)
{
Debug.WriteLine("Unable to connect to server.2 {0}", e.Message);
return;
}
}
-
Server
class Program
{
static void Main(string[] args)
{
string url = "http://localhost:8080/";
using (WebApp.Start(url))
{
Console.WriteLine("SignalR server running on {0}", url);
Console.ReadLine();
}
Console.ReadLine();
}
}
class Startup
{
public void Configuration(IAppBuilder app)
{
Console.WriteLine("Configuration");
//Tried this approach too
/*app.Map("/signalr", map =>
{
map.UseCors(CorsOptions.AllowAll);
var hubConfiguration = new HubConfiguration
{
EnableJSONP = true
};
map.RunSignalR(hubConfiguration);
});*/
app.UseCors(CorsOptions.AllowAll);
app.MapSignalR<ClientAccessPolicyConnection>("/clientaccesspolicy.xml");
}
}
-
TickerHub.cs
public class TickerHub : Hub
{
public override Task OnConnected()
{
string connectionID = Context.ConnectionId;
Console.WriteLine("New Connection:" + connectionID);
InitNewClient(connectionID);
return base.OnConnected();
}
//send all data to newly connected client
public void InitNewClient(string connectionID)
{
}
//client requested all data
public void GetAllData()
{
Console.WriteLine("Get Data Triggered");
Clients.All.receiveAllData("TESTING123");
}
}

I figured it out! Hopefully this helps someone in the future.
Its quite simple. This is what you need to have in your startup class configuration method.
Below that is the code required to send the clientaccesspolicy.xml.
class Startup
{
public void Configuration(IAppBuilder app)
{
// Branch the pipeline here for requests that start with "/signalr"
app.Map("/signalr", map =>
{
// Setup the CORS middleware to run before SignalR.
// By default this will allow all origins. You can
// configure the set of origins and/or http verbs by
// providing a cors options with a different policy.
map.UseCors(CorsOptions.AllowAll);
var hubConfiguration = new HubConfiguration
{
// You can enable JSONP by uncommenting line below.
// JSONP requests are insecure but some older browsers (and some
// versions of IE) require JSONP to work cross domain
EnableJSONP = true
};
// Run the SignalR pipeline. We're not using MapSignalR
// since this branch already runs under the "/signalr"
// path.
map.RunSignalR(hubConfiguration);
});
app.UseCors(CorsOptions.AllowAll);
app.MapSignalR<ClientAccessPolicyConnection>("/clientaccesspolicy.xml");
}
}
-
public class ClientAccessPolicyConnection : PersistentConnection
{
public override Task ProcessRequest(Microsoft.AspNet.SignalR.Hosting.HostContext context)
{
string[] urlArray = context.Request.Url.ToString().Split('/');
string path = urlArray[urlArray.Length - 1];
if (path.Equals("clientaccesspolicy.xml", StringComparison.InvariantCultureIgnoreCase))
{
//Convert policy to byteArray
var array = Encoding.UTF8.GetBytes(ClientAccessPolicy);
var segment = new ArraySegment<byte>(array);
//Write response
context.Response.ContentType = "text/xml";
context.Response.Write(segment);
//Return empty task to escape from SignalR's default Connection/Transport checks.
return EmptyTask;
}
return EmptyTask;
}
private static readonly Task EmptyTask = MakeTask<object>(null);
public static Task<T> MakeTask<T>(T value)
{
var tcs = new TaskCompletionSource<T>();
tcs.SetResult(value);
return tcs.Task;
}
public static readonly string ClientAccessPolicy =
"<?xml version=\"1.0\" encoding=\"utf-8\"?>"
+ "<access-policy>"
+ "<cross-domain-access>"
+ "<policy>"
+ "<allow-from http-request-headers=\"*\">"
+ "<domain uri=\"*\"/>"
+ "</allow-from>"
+ "<grant-to>"
+ "<resource path=\"/\" include-subpaths=\"true\"/>"
+ "</grant-to>"
+ "</policy>"
+ "</cross-domain-access>"
+ "</access-policy>";
}

global object that needs to be referenced in a message handler

I have a signalr client that I want to be global.
I think creating the signalr client in the Init() of the endpointconfig would be best.
public class EndpointConfig : IConfigureThisEndpoint, AsA_Server, IWantCustomInitialization
{
public static HubConnection hubConnection;
public static IHubProxy hubProxy;
public void Init()
{
Configure.With()
.DefiningEventsAs(t => t.Namespace != null && t.Namespace.Contains(".Events."))
.DefiningMessagesAs(t => t.Namespace != null && t.Namespace.Contains(".Messages."))
.StructureMapBuilder(new Container(new DependencyRegistry()));
Configure.Serialization.Json();
hubConnection = new HubConnection("http://localhost:58120");
hubProxy = hubConnection.CreateHubProxy("AmsHub");
hubProxy.On<string>("receiveServerPush", x => System.Diagnostics.Debug.WriteLine(x));
hubConnection.Start().Wait();
}
public class DependencyRegistry : Registry
{
public DependencyRegistry()
{
Scan(x =>
{
x.AssembliesFromApplicationBaseDirectory();
x.ExcludeNamespace("StructureMap");
x.WithDefaultConventions();
});
}
}
}
What I'm confused about, is how am I supposed to reference the hubConnection and hubProxy in a message handler? I seems like I'm jerry rigging NServicebus.
public class TestHandler : IHandleMessages<AMS.Infrastructure.Events.IEvent>
{
public void Handle(AMS.Infrastructure.Events.IEvent message)
{
EndpointConfig.hubProxy.Invoke("ServerFunction", "yodle");
}
}
PS: the reason I need the connection and proxy to be global is because spawning up a new hubConnection is expensive according to the signalr people. They highly discourage creating and destroying hubconnections over and over again. They found that making the hubconnection global/static(?) ok though.

In this case, your Hub Connection/Proxy really are unrelated to the EndPointConfiguration class. They don't use nor require any data from this type in order to function.
I would recommend placing them in their own lazy initialized singleton, and start them automatically upon first access. This would look like:
public class Hub
{
private static Lazy<Hub> instance = new Lazy<Hub>(() => new Hub());
public static Hub Instance { get { return instance.Value; } }
private Hub()
{
this.Connection = new HubConnection("http://localhost:58120");
this.Proxy = Connection.CreateHubProxy("AmsHub");
this.Proxy.On<string>("receiveServerPush", x => System.Diagnostics.Debug.WriteLine(x));
this.Connection.Start().Wait();
}
public HubConnection Connection { get; private set; }
public IHubProxy Proxy { get; private set; }
}
Your consumers then just use:
public class TestHandler : IHandleMessages<AMS.Infrastructure.Events.IEvent>
{
public void Handle(AMS.Infrastructure.Events.IEvent message)
{
Hub.Instance.Proxy.Invoke("ServerFunction", "yodle");
}
}
This has the benefit of not creating and starting until first use, and isolates this type into it's own class.
Given that you're also handling the subscription internally, you also could, optionally, encapsulate your methods to simplify usage:
public class Hub
{
private static Lazy<Hub> instance = new Lazy<Hub>(() => new Hub());
public static Hub Instance { get { return instance.Value; } }
private Hub()
{
this.Connection = new HubConnection("http://localhost:58120");
this.Proxy = Connection.CreateHubProxy("AmsHub");
this.Proxy.On<string>("receiveServerPush", x => System.Diagnostics.Debug.WriteLine(x));
this.Connection.Start().Wait();
}
private HubConnection Connection { get; set; }
private IHubProxy Proxy { get; set; }
public static Task Invoke(string method, params Object[] args)
{
return Instance.Proxy.Invoke(method, args);
}
public static Task<T> Invoke<T>(string method, params Object[] args)
{
return Instance.Proxy.Invoke<T>(method, args);
}
}
With the above, you could just use: Hub.Invoke("ServerFunction", "yodle");

#reed-copsey Old post, but thanks for your reply, it helped me a lot.
In my case I am creating an Azure Function, which will connect to an SignalR Hub which is part of an ASP.NET MVC site. I needed the connection to be secure / authenticated before sending a notification.
So my example included authenticating and getting a cookie.
public class Hub
{
private static readonly string HOMEPAGE = ConfigurationManager.AppSettings["Homepage"];
private static readonly string NOTIFICATION_USER = ConfigurationManager.AppSettings["NotificationUser"];
private static readonly string NOTIFICATION_PASSWORD = ConfigurationManager.AppSettings["NotificationPassword"];
private static Lazy<Hub> instance = new Lazy<Hub>(() => new Hub());
public static Hub Instance { get { return instance.Value; } }
private Hub()
{
ClientHandler = new HttpClientHandler();
ClientHandler.CookieContainer = new CookieContainer();
using (Client = new HttpClient(ClientHandler))
{
var content = string.Format("Email={0}&Password={1}", NOTIFICATION_USER, NOTIFICATION_PASSWORD);
var response = this.Client.PostAsync(HOMEPAGE + "/Account/Login", new StringContent(content, Encoding.UTF8, "application/x-www-form-urlencoded")).Result;
}
Connection = new HubConnection($"{HOMEPAGE}/");
Connection.CookieContainer = ClientHandler.CookieContainer;
Proxy = Connection.CreateHubProxy("notificationsHub");
//this.Proxy.On<string>("receiveServerPush", x => System.Diagnostics.Debug.WriteLine(x));
Connection.Start().Wait();
}
public HttpClientHandler ClientHandler { get; private set; }
public HttpClient Client { get; private set; }
public HubConnection Connection { get; private set; }
public IHubProxy Proxy { get; private set; }
public static Task Invoke(string method, params Object[] args)
{
return Instance.Proxy.Invoke(method, args);
}
public static Task<T> Invoke<T>(string method, params Object[] args)
{
return Instance.Proxy.Invoke<T>(method, args);
}
}