c# fast generic initializer update

using System;
using System.Threading;
using System.Linq.Expressions;
using System.Collections.Generic;

public static class FastActivator{
    private static bool Initialized = false;
    private static bool _isCreatingCache = false;
    private static Dictionary<Type, Func<object>> Cache;

    public static void CreateCache()
    {
        if (Initialized)
            return;

        Cache = new Dictionary<Type, Func<object>>();
        _isCreatingCache = true;
        var thr = new Thread(()=>
        {
            foreach (var asm in AppDomain.CurrentDomain.GetAssemblies())
            {
                foreach(var t in asm.GetTypes())
                {
                    if (t.GetConstructor(Type.EmptyTypes) != null && !t.ContainsGenericParameters)
                    {
                        Cache[t] = Expression.Lambda<Func<object>>(Expression.New(t)).Compile();
                    }
                }
            }
            _isCreatingCache = false;
            Initialized = true;
        });
        thr.Start();
    }

    public static object CreateInstance(Type t)
    {
        if (!Initialized)
        {
            if (!_isCreatingCache)
                CreateCache();
        }

        if (!Cache.ContainsKey(t))
        {
            var shouldUnInit = (t.GetConstructor(Type.EmptyTypes) == null);
            if (shouldUnInit)
            {
                return System.Runtime.Serialization.FormatterServices.GetUninitializedObject(t);
            }
            else
            {
                return Activator.CreateInstance(t);
            }
        }
        return Cache[t]();
    }

    public static T CreateInstance<T>()
    {
        if (!Initialized)
        {
            if (!_isCreatingCache)
                CreateCache();
        }

        var t = typeof(T);
        if (!Cache.ContainsKey(t))
        {
            var shouldUnInit = (t.GetConstructor(Type.EmptyTypes) == null);
            if (shouldUnInit)
            {
                return (T)System.Runtime.Serialization.FormatterServices.GetUninitializedObject(t);
            }
            else
            {
                return Activator.CreateInstance<T>();
            }
        }
        return (T)Cache[t]();
    }

    public static Array CreateArray(Type type, int len)
    {
        return Activator.CreateInstance(type, new object[] { len }) as Array;
    }
}