Allocating reference type on a stack in C#

Makeref.cs

// This application stores managed object on stack
// See  https://blog.adamfurmanek.pl/2016/04/23/custom-memory-allocation-in-c-part-1
// Windbg internals:
/*
Load SOS:
.load C:\Windows\Microsoft.NET\Framework\v4.0.30319\sos.dll

Select proper thread:
~0s

Present all values:
!clrstack -i -a

Examine values of heapPoco and stack
Observe 0x0BADF00D on stack
Find EE Method of Poco class
heapPocoAddress: 0x2e13120
stackAddress: 0117f034
dd 0x2e13120    ; heapPocoAddress
!do 0x2e13120   ; heapPocoAddress
dd 0117f034     ; stack address
*/

using System;
using System.Threading;
using System.Threading.Tasks;

namespace Makeref
{
    class Poco
    {
        public int Field;

        public void WriteField()
        {
            Console.WriteLine(Field);
        }

        public override string ToString()
        {
            return Field.ToString();
        }

        ~Poco()
        {
            Console.WriteLine("Cleaning: " + Field);
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            Poco heapPoco = new Poco {Field = 5};
            Poco originalPoco = heapPoco;
            unsafe
            {
                var space = stackalloc int[10];
                for (int i = 0; i < 10; ++i)
                {
                    space[i] = 0xBADF00D;
                }
                TypedReference typedReference = __makeref(heapPoco);
                int* poco1Address = (int*)(*(int*)(*(int*)(&typedReference)) - 4);

                Console.WriteLine($"Got address of EE method: {((int) (poco1Address + 1)).ToString("X")} Value: {(*(poco1Address + 1)).ToString("X")}");
                Console.ReadLine();

                for (int i = 0; i < 3; ++i)
                {
                    Console.WriteLine($"Address {((int) poco1Address).ToString("X")} Value {(*poco1Address).ToString("X")}");
                    space[i] = *poco1Address;
                    poco1Address = poco1Address + 1;
                }
                Console.WriteLine("Rewritten values");
                Console.ReadLine();

                *((int*)*((int*)&typedReference)) = (int)(&(space[1]));

                Console.WriteLine($"Set reference to stack: {(int)&(space[1])}");
                Console.ReadLine();

                Poco stackPoco = __refvalue(typedReference, Poco);
                //Poco stackPoco = heapPoco; - This is the same

                Console.WriteLine("Got poco on stack. Displaying values:");
                Console.Write("Heap: ");
                originalPoco.WriteField();
                Console.Write("Stack: ");
                stackPoco.WriteField();
                Console.WriteLine("Modifying values using references. Displaying values:");
                originalPoco.Field = 555;
                stackPoco.Field = 444;
                Console.Write("Heap: ");
                originalPoco.WriteField();
                Console.Write("Stack: ");
                stackPoco.WriteField();
                Console.WriteLine("Modifying value using array on a stack. Displaying values:");
                space[2] = 333;
                Console.Write("Heap: ");
                originalPoco.WriteField();
                Console.Write("Stack: ");
                stackPoco.WriteField();
                Console.ReadLine();

                Console.WriteLine("Calling virtual method:");
                Console.WriteLine("Heap: " + originalPoco.ToString());
                Console.WriteLine("Stack: " + stackPoco.ToString());
                Console.ReadLine();


                Console.WriteLine("Displaying object types:");
                Console.WriteLine(originalPoco.GetType());
                Console.WriteLine(stackPoco.GetType());
                Console.ReadLine();

                Console.WriteLine("Displaying GC generations:");
                Console.WriteLine(GC.GetGeneration(originalPoco));
                Console.WriteLine(GC.GetGeneration(stackPoco));
                //GC.ReRegisterForFinalize(stackPoco); - bad idea
                Console.ReadLine();

                Console.WriteLine("Threading:");
                Console.WriteLine($"Taking lock in base: {DateTime.Now}");
                lock (stackPoco)
                {
                    Console.WriteLine($"Lock in base aquired: {DateTime.Now}");

                    Task.Factory.StartNew(() =>
                    {
                        Console.WriteLine($"Taking lock in child: {DateTime.Now}");
                        lock (stackPoco)
                        {
                            Console.WriteLine($"Lock in child aquired: {DateTime.Now}");
                        }
                        Console.WriteLine($"Lock in child released: {DateTime.Now}");
                    });

                    Thread.Sleep(2000);
                }
                Console.WriteLine($"Lock in base released: {DateTime.Now}");
                Console.ReadLine();

                Console.WriteLine("End");
            }
        }
    }
}

Genial 👌