I'm trying to upgrade a Windows desktop application from .Net Framework to .Net (Core) 6.0. As part of that, I need to use NetMQ instead of the old clrzmq. But every reference I find for how to do a simple request-response using the new API has been obsoleted by subsequent updates. I found working code at this question, but again, some of the methods used no longer exist. I attempted to convert the source reasonably and arrived at the below.
The server prints nothing; the client claims to be sending messages; Wireshark sees no messages on "port 5556". (I tagged Wireshark in case I'm using it wrong.)
I think if I can find out how this code should work I can properly convert my original application. Any help would be much appreciated.
Program.cs (by itself in its own solution, for the server):
using NetMQ;
using NetMQ.Sockets;
using NLog;
class Program
{
private static Logger _logger = LogManager.GetCurrentClassLogger();
static void Main(string[] args)
{
try
{
using (var responseSocket = new ResponseSocket())
{
responseSocket.Connect("tcp://localhost:5556");
var poller = new NetMQPoller();
responseSocket.ReceiveReady += RouterSocketOnReceiveReady;
poller.Add(responseSocket);
poller.Run();
}
}
catch (Exception e)
{
Console.WriteLine(e);
}
Console.ReadKey();
}
private static void RouterSocketOnReceiveReady(object? sender, NetMQSocketEventArgs netMqSocketEventArgs)
{
NetMQMessage? clientMessage = new();
bool result = netMqSocketEventArgs.Socket.TryReceiveMultipartMessage(new TimeSpan(0, 0, 0, 5),
ref clientMessage, 5);
if (result == false || clientMessage == null)
{
Console.WriteLine("Something went wrong?!");
return;
}
var address = clientMessage[0];
var address2 = clientMessage[1];
var clientMessageString = clientMessage[3].ConvertToString();
//_logger.Debug("Message from client received: '{0}'", clientMessageString);
Console.WriteLine(String.Format("Message from client received: '{0}'", clientMessageString));
netMqSocketEventArgs
.Socket.SendMoreFrame(address.Buffer)
.SendMoreFrame(address2.Buffer)
.SendMoreFrameEmpty()
.SendFrame("I have received your message");
}
}
CollectorDevice.cs (in the client project and solution):
using NetMQ;
using NetMQ.Sockets;
using NLog;
public class CollectorDevice : IDisposable
{
private NetMQPoller _poller;
private RouterSocket _frontendSocket;
private DealerSocket _backendSocket;
private readonly string _backEndAddress;
private readonly string _frontEndAddress;
private readonly int _expectedFrameCount;
private readonly ManualResetEvent _startSemaphore = new(false);
private readonly Thread _localThread;
private static Logger _logger = LogManager.GetCurrentClassLogger();
/// <summary>
/// Constructor
/// </summary>
/// <param name="backEndAddress"></param>
/// <param name="frontEndAddress"></param>
/// <param name="expectedFrameCount"></param>
public CollectorDevice(string backEndAddress, string frontEndAddress, int expectedFrameCount)
{
_expectedFrameCount = expectedFrameCount;
_backEndAddress = backEndAddress;
_frontEndAddress = frontEndAddress;
_frontendSocket = new RouterSocket(_frontEndAddress);
_backendSocket = new DealerSocket(_backEndAddress);
_backendSocket.ReceiveReady += OnBackEndReady;
_frontendSocket.ReceiveReady += OnFrontEndReady;
_poller = new NetMQPoller { _frontendSocket, _backendSocket };
_localThread = new Thread(DoWork) { Name = "IPC Collector Device Thread" };
}
public void Start()
{
_localThread.Start();
_startSemaphore.WaitOne();
}
public void Stop()
{
_poller.Stop();
}
#region Implementation of IDisposable
public void Dispose()
{
Stop();
}
#endregion
#region Private Methods
private void DoWork()
{
try
{
_startSemaphore.Set();
_poller.Run();
}
catch (Exception e)
{
_logger.Error(e);
}
}
private void OnBackEndReady(object? sender, NetMQSocketEventArgs e)
{
NetMQMessage message = _backendSocket.ReceiveMultipartMessage(_expectedFrameCount);
_frontendSocket.SendMultipartMessage(message);
}
private void OnFrontEndReady(object? sender, NetMQSocketEventArgs e)
{
NetMQMessage message = _frontendSocket.ReceiveMultipartMessage(_expectedFrameCount);
_backendSocket.SendMultipartMessage(message);
}
#endregion
}
Program.cs (also in the client project and solution):
using NetMQ;
using NetMQ.Sockets;
using NLog;
using System.Text;
class Program
{
private static Logger _logger = LogManager.GetCurrentClassLogger();
private static void Main(string[] args)
{
Console.WriteLine("Client. Please enter message for server. Enter 'QUIT' to turn off server");
Console.ReadKey();
var encoding = Encoding.ASCII;
using (var collectorDevice = new CollectorDevice("tcp://localhost:5556", "inproc://broker", 3))
{
collectorDevice.Start();
var tasks = new List<Task>();
for (int i = 0; i < 100; i++)
{
Console.WriteLine(i);
int j = i;
Task t = Task.Factory.StartNew(() =>
{
try
{
using (var requestSocket = new RequestSocket("inproc://broker"))
{
requestSocket.SendFrame(encoding.GetBytes(String.Format("Request client: {0} id: {1}", j, Task.CurrentId)));
_logger.Debug(String.Format("Request client: {0} id: {1}", j, Task.CurrentId));
Console.WriteLine(String.Format("Request client: {0} id: {1}", j, Task.CurrentId));
string responseMessage = requestSocket.ReceiveFrameString();
_logger.Debug(String.Format("Response from server: {0} id: {1} message: {2}", j, Task.CurrentId, responseMessage));
Console.WriteLine(String.Format("Response from server: {0} id: {1} message: {2}", j, Task.CurrentId, responseMessage));
}
}
catch (Exception e)
{
Console.WriteLine(e);
_logger.Error(e);
}
});
tasks.Add(t);
}
Task.WaitAll(tasks.ToArray());
}
}
}
