Asynchronous delegates - are the parameters always marshalled?

Question

If a parameter is a reference to an object, will the asynchronous invocation be passed the reference or a copy of the object (by marshalling)?

Answer 1

Why not code a small sample yourself and see?

(I believe "the reference" is the answer.)

Answer 2

If a parameter is a reference to an object (meaning a reference type) then what is passed to the method is a reference. However, this is not the case with a value type passed with the ref keyword. This article has relevant examples (figures 13 & 14): http://msdn.microsoft.com/en-us/magazine/cc301332.aspx

Marshalling pertains to communicating outside of the app domain, so it's not related to asynchronously-called delegates per se.

Answer 3

As far as I'm aware, there's no object marshalling that occurs just by calling a delegate asynchronously. Here's some code to show an asynchronous delegate call, passing an object reference.

public class Car
{
    public string Model { get; set; }
}

public delegate void TransformHandler(Car car);

public static void Transform(Car car)
{
    car.Model = "Holden";
}

static void Main(string[] args)
{
    Car car = new Car();
    car.Model = "Ford";

    new TransformHandler(Transform).BeginInvoke(car, null, null);

    Thread.Sleep(100);

    Console.WriteLine(car.Model); // Prints "Holden", so it wasn't marshalled
}