Question

Can someone please tell me what is wrong with the following code? Ideally it should start a thread first and then wait for the set event. Instead of that it does not start the thread and just get stuck on WaitOne().

I am curious to know what happened to the thread and why?

class Program
{   
    static void Main(string[] args)
    {
        Testing t = Testing.Instance;
        Console.Read();
    }
}


class Testing
{
    private static AutoResetEvent evt = new AutoResetEvent(false);
    public static Testing Instance = new Testing();

    private Testing()
    {
        Create();
        evt.WaitOne();
        Console.WriteLine("out");
    }

    private void Create()
    {
        Console.WriteLine("Starting thread");
        new Thread(Print).Start();
    }

    private void Print()
    {
        Console.WriteLine("started");
        evt.Set();
    }
}

EDIT:
So far, the description provided by @BrokenGlass makes sense. but changing the code to the following code allows another thread can access the instance methods without constructor being completed.(Suggested by @NicoSchertler).

private static Testing _Instance;

public static Testing Instance
{
get
{
    if (_Instance == null)
        _Instance = new Testing();
    return _Instance;
}
}

Answer 1

I suspect the root cause of this behavior is that the spawned thread cannot access the Print method until the constructor has finished executing – but the constructor never finishes executing because it is waiting on the signal that is triggered only from the Print method.

Replacing the evt.WaitOne() with a long Thread.Sleep() call confirms the same behavior – the constructor must finish running before any instance method of the object may execute from another thread.