Rhino 8 Grasshopper C# websockets script - connection not terminating

Grasshopper
, ,
1

Hi there,

I am trying to establish a websockets connection between grasshopper and unity using the websockets-sharp library. The grasshopper c# script is working and I am able to establish a connection with Unity but it is not terminating the connection on boolean toggle and I am able to confirm this via netstat. It’s only when I terminate the process or completely shut down Rhino that the server is stopped. I am pasting the commented script below.

Has anyone else experienced this problem? Any help would be greatly appreciated! :pray:

using System;
using WebSocketSharp;
using WebSocketSharp.Server;
using System.Net.Sockets;  // For SocketException handling
using Rhino.Geometry;

// WebSocket behavior for bi-directional communication
public class GrasshopperSocket : WebSocketBehavior
{
    protected override void OnMessage(MessageEventArgs e)
    {
        // When a message is received from Unity
        Console.WriteLine("Received from Unity: " + e.Data);

        // Send response back to Unity
        Send("Message from Grasshopper: " + e.Data);
    }

    // Custom method to send a message to the Unity client
    public void SendMessageToUnity(string message)
    {
        Send(message);
    }
}

public class WebSocketServerComponent
{
    private WebSocketServer _server;

    public WebSocketServerComponent(int port)
    {
        try
        {
            // Start WebSocket server at a specific port
            _server = new WebSocketServer($"ws://localhost:{port}");
            _server.AddWebSocketService<GrasshopperSocket>("/ghsocket");
            _server.Start();

            Console.WriteLine($"WebSocket server started at ws://localhost:{port}/ghsocket");
        }
        catch (SocketException ex)
        {
            // Handle socket exception, likely caused by the port being already in use
            Console.WriteLine($"SocketException: Could not start server on port {port}. It may be in use.");
            Console.WriteLine(ex.Message);
        }
    }

    // Method to stop the WebSocket server
    public void StopServer()
    {
        if (_server != null && _server.IsListening)
        {
            try
            {
                _server.Stop();
                Console.WriteLine("WebSocket server stopped.");
            }
            catch (Exception ex)
            {
                Console.WriteLine("Error stopping WebSocket server: " + ex.Message);
            }
            finally
            {
                _server = null;  // Clear the server reference
            }
        }
    }

    // Method to send a custom message to Unity via WebSocket
    public void SendMessage(string message)
    {
        if (_server != null && _server.IsListening)
        {
            // Send message to all connected clients
            foreach (var session in _server.WebSocketServices["/ghsocket"].Sessions.Sessions)
            {
                session.Context.WebSocket.Send(message);
            }
        }
    }
}

// Declare WebSocket server instance and state as class-level variables
WebSocketServerComponent server = null;
bool isRunning = false;
int port = 8080;  // Default port

// Main method for Grasshopper to start/stop server and send message
void ToggleWebSocketServer(bool toggleServer, string messageToSend, int portToUse)
{
    // Check if the toggle button is true (pressed)
    if (toggleServer && !isRunning)
    {
        // Start server on specified port
        server = new WebSocketServerComponent(portToUse);
        isRunning = true;
    }
    else if (!toggleServer && isRunning)
    {
        // Stop server
        server.StopServer();
        isRunning = false;
    }

    // Send the custom message if server is running
    if (isRunning && !string.IsNullOrEmpty(messageToSend))
    {
        server.SendMessage(messageToSend);
    }
}

// Grasshopper inputs
//bool toggleServer = false;   // Button input to toggle the server
//string messageToSend = "";   // Input message to send to Unity
//int portToUse = port;        // Input for port number (allow flexibility in Grasshopper)

// Call the function with Grasshopper inputs
ToggleWebSocketServer(toggleServer, messageToSend, portToUse);