is it legal to recreate a rooted reference to 'this' in a .net destructor?

Question

Is it legal to write the following in .net ?

   public class A
    {
        public int i = 0;
        ~A()
        {
            Aref = this;
        }
    }


    public static A Aref;
    static void Main(string[] args)
    {
        Aref = new A();
        int gen = GC.GetGeneration(Aref);
        Aref = null;
        GC.Collect(gen, GCCollectionMode.Forced);
        GC.WaitForPendingFinalizers();
        Console.WriteLine(Aref.i);
        Console.ReadLine();
    }

It works and writes '0' to the console as expected, but I'm wondering if it's guaranteed to always work.

Does someone know what's happening behind the scene?

Answer 1

It's called resurrection, and it's legal. Google for ".net object resurrection" (and terms like it) and you'll find stuff like:

Resurrection and the .NET Garbage collector

Object Resurrection

Just make sure these zombie objects don't come back and try to eat your brain or something. Like all necromancy, this is dangerous stuff. (Mostly because the finalizers higher up in the class hierarchy can have released some essential resource. Also note that the finalizer won't be run a second time if the object gets "unreferenced", unless you call GC.ReRegisterForFinalize.)