HttpContext.Current.Session is null in thread

Hello, I have a problem with my code. I'm doing a function that lasts about 3/4 hours in length, and so I decided to do that function on a thread so it does not block the overall system operation. after some research I found some solutions and tested it. But during this function I access the database and when I do this my thread crashes error:

  

HttpContext.Current.Session is null

I then searched for some means of passing the context and the session and I got to these 2 results:

var ctx = HttpContext.Current;
        ThreadPool.QueueUserWorkItem(new WaitCallback(ExecuteLongOperation), ctx);

e:

     HttpContext ctx = HttpContext.Current;
    Thread t = new Thread(new ThreadStart(() =>
    {
        HttpContext.Current = ctx;
        ExecuteLongOperation();
    }));
    t.Start();

Until this point the HttpContext.Current.Session has the session with value, all right.

and in my method:

  private void ExecuteLongOperation(object state)
    {
        try
        {
            HttpContext.Current = (HttpContext)state;  .....}

And when I give a quickwatch in the HttpContext.Current.Session, it remains null.

What am I doing wrong? I tried to pass the session but it is read-only.

Any suggestions? Thanks