Umbraco – WriteLock and ReadLock with ReaderWriterLockSlim

public static TResolver Current
{
  get
    {
      using (new ReadLock(ResolversLock))
        {
          if (_resolver == null)
            throw new InvalidOperationException(string.Format("Current has not been initialized on {0}. You must initialize Current before trying to read it.",
                                                              typeof(TResolver).FullName));
          return _resolver;
        }
    }
 
  set
    {
      using (Resolution.Configuration)
        using (new WriteLock(ResolversLock))
        {
          if (value == null)
            throw new ArgumentNullException("value");
          if (_resolver != null)
            throw new InvalidOperationException(string.Format("Current has already been initialized on {0}. It is not possible to re-initialize Current once it has been initialized.",
                                                              typeof(TResolver).FullName));
          _resolver = value;
        }
    }
}