Question

This is example code in java.

Shared interfaces:

import java.rmi.Remote;
import java.rmi.RemoteException;

public interface Compute extends Remote {
  public Object executeTask(Task t) throws RemoteException;
}

Task (this will be passed as parameter):

import java.io.Serializable;

public interface Task extends Serializable {
  public Object execute();
}

Server:

import java.rmi.Naming;
import java.rmi.RMISecurityManager;
import java.rmi.RemoteException;
import java.rmi.server.UnicastRemoteObject;

public class ComputeEngine extends UnicastRemoteObject implements Compute {

  public ComputeEngine() throws RemoteException {
    super();
  }

  public Object executeTask(Task t) {
    return t.execute();
  }

  public static void main(String[] args) {
    setRmiCodebase();
    System.setSecurityManager(new RMISecurityManager());
    try {
      Compute engine = new ComputeEngine();
      Naming.rebind("//localhost:1099/Compute", engine);
      System.out.println("ComputeEngine started.");
    } catch (Exception ex) {
      ex.printStackTrace();
    }
  }

  private static void setRmiCodebase() {
    String codebase = System.getProperty("java.rmi.server.codebase");
    if (codebase != null)
      return;
    // set codebase based on location of this clsas (is it in jar or filesistem?)
  }

}

Client:

import java.math.BigDecimal;
/**
* Calculates Pi to arbitrary number of digits:
*/
public class Pi implements Task {

  public Pi(int digits) {
    this.digits = digits;
  }

  public Object execute() {
    return computePi(digits);
  }

  public static BigDecimal computePi(int digits) {
    // compute Pi
  }

}

Client main:

import java.math.BigDecimal;
import java.rmi.Naming;
import java.rmi.RMISecurityManager;

public class ComputePi {

  public static void main(String[] args) {
    setRmiCodebase();
    System.setSecurityManager(new RMISecurityManager());
    try {
      Compute comp = (Compute)Naming.lookup("//localhost:1099/Compute");
      Pi task = new Pi(100);
      BigDecimal pi = (BigDecimal)comp.executeTask(task);
      System.out.println(pi);
    } catch (Exception ex) {
      ex.printStackTrace();
    }
  }

  private static void setRmiCodebase() {
    String codebase = System.getProperty("java.rmi.server.codebase");
    if (codebase != null)
      return;
    // set codebase based on location of this clsas (is it in jar or filesistem?)
  }
}

As you can see, code (not just data) from client is transfered to server and executed there and result of computation is returned. Server does not know that class Pi exists, it only knows about Task interface.

I need something like this to work in .net environment (C# if it is important). WCF would be nice, but I am looking for the most straightforward solution, so WCF is not compulsory. I am not sure even what keyword to use to google documetation or solution for this.

Any help will be appreciated.

Answer 1

.NET does not natively support “sending code” to be executed on another computer. Typically the necessary code would be compiled to assemblies and pre-installed on the server before it is called by the client. This is true of both remoting and WCF. You could have a two-way remoting situation where the server calls back to a method on the client via WCF, but I suspect this is not what you want. The only way I’m aware of to really run dynamic code on the server is to generate dynamic code, send it to the server as a string, and then have the server compile it to an in-memory assembly on the fly and then execute it. If you are interested in doing so, take a look at my answer to a similar question:

Autovivified properties?

However, it’s not exactly something I would suggest in most cases. I would suggest you rethink your design, first, to see if there is any way to do what you need in a typical “.NET way”.