Disconnected TCPServer thread won't terminate

[kbriggs]

I'm having an issue trying to terminate Indy threads from rogue connections on my game server's TCP port which I use for a WebSocket connection. In the OnConnect event I read headers required to establish a valid websocket and I have ReadTimeout set to 10000 so it doesn't get stuck there from bots that are just probing the port. If I get valid headers I assign an object to AContext.Data, otherwise I just Exit and disconnect them in the OnExecute event. I use madExcept's NameThread command along to way to track the progress of the connection. Here is my OnExecute event:

Code:

class procedure WSServerEvents.OnExecute(AContext: TIdContext);
var st: string;
begin
  Sleep(10);  // prevent CPU max
  try
    if Assigned(AContext.Data) = False then
    begin
      MadExcept.NameThread(GetCurrentThreadID, 'WebSocket Rogue (' + AContext.Binding.PeerIP + ')');
      AContext.Connection.Disconnect;  // rogue connection
    end else
    begin
      if TConnectRec(AContext.Data).isAdmin then AdminSessionExecute(AContext)
      else PlayerSessionExecute(AContext);
    end;
  except
    on E: Exception do
    begin
      if E is EIdException then raise else
      begin
        LogData.AddError('WSServerExecute error: ' + E.Message);
        st := StringReplace(madExcept.GetCrashStackTrace, #13#10, ' - ', [rfReplaceAll]);
        LogData.AddError('WSServerExecute stack trace: ' + st);
        raise;
      end;
    end;
  end;
end;

Notice I update the thread name right before disconnecting.  And they do disconnect because when I run TCPView on my server, no one is connected to me. But those rogue threads never terminate and they build up over time and never stop unless I take the game server offline. And I know they don't terminate because my app has a function that retrieves all the live threads assigned to my app. I then use madExcept's GetThreadName command to get the names I assigned to them. Here's what that looks like:

   

Most of those IPs are from Russia. Why are these threads not terminating after the disconnect?

---

By the way, this is my OnDisconnect event, which should just Exit immediately for these rogue connections:

Code:

class procedure WSServerEvents.OnDisconnect(AContext: TIdContext);
begin
  if Assigned(AContext.Data) = False then Exit;
  try
    if TConnectRec(AContext.Data).isAdmin then AdminSessionDisconnect(AContext)
    else PlayerSessionDisconnect(AContext);
  except
    on E: Exception do
    begin
      if E is EIdException then raise else
      begin
        LogData.AddError('WSServerDisconnect error: ' + E.Message);
        raise;
      end;
    end;
  end;
end;