Question

I have to make a Instant Messenger server in C#. The server is a ConsoleApplication project. And I want to make a server that runs in 3 threads. I will explain in the code below.

The question is how can I invoke a function from a separate thread, or make an event on a separate thread?

This is the main server class.

public class GiNetServer
{
     public void Start()
     {
         netServer  = new NetServer();
         msgHandler = new NetMsgHandler();

         netServer.NewNetMsg += msgHandler.HandleMsg;

         Work();
     }

     private void Work()
     {
         while(true)  //This runs in the MainThread
           sleep(1);
     }
}

The NetServer class creates 2 Threads: acceptClientsThread and receiveMessagesThread.
The receive thread calls the NewNetMsg.

public class NetServer
{

     public event NewNetMsgEventHandler NewNetMsg;

     public NetServer()
     {
          acceptClientsThread = new Thread(ListenForClients);
          receiveMessageThread = new Thread(Receive);
          //and of course starts them here...
     }

     private void Receive()
     {
          while(true)
          {
               Heartbeat();
          }
     }

     private void Heartbeat()
     {
          foreach(netClient in clientsList)
          {
               if (netClient.DataAvalible)
               {
                   netClient.Recive();
               }
               if (!netClient.IsBufferEmpty())
               {
                   nextMsg = netClient.NextMessage();
                   if (nextMsg != null)
                       NewNetMsg(netClient, nextMsg);  //Call the event!
               }
          }
     }
}

How can I make the msgHandler.HandleMsg function run in a separate thread or in the MainThread?

Like this, HandleMsg runs in the receiveMessagesThread.

The code above is pseudocode-ish. If there is anything ambigous please let me know.

Answer 1

There are a lot of different ways to move the HandleMsg call onto a different thread, depending on what your requirements are. The simplest way would be to raise the NewNetMsg event on a different thread using the ThreadPool:

ThreadPool.QueueUserWorkItem(s => NewNetMsg(netClient, nextMsg));

You could also use the Task Parallel Library (TPL). You could also add the event to a ConcurrentQueue that is processed by a dedicated background thread. And there are more options. Without more details it is impossible to give a more specific recommendation.