How should “Double-Checked Locking” be implemented in Delphi?

In C#, the following code (from this page) can be used to lazily instantiate a singleton class in a thread safe way:

  class Foo {
        private volatile Helper helper = null;
        public Helper getHelper() {
            if (helper == null) {
                lock(this) {
                    if (helper == null)
                        helper = new Helper();
                }
            }
            return helper;
        }
    }

What would be the equivalent thread safe Delphi code?

The article also mentions two problems with Double Checked Locking in Java:

• it is possible that the new object is constructed before the helper reference is made to point at the newly created object meaning that two objects are created
• it is possible that the helper reference is made to point at a block of memory while the object is still being created meaning that a reference to an incomplete object will be returned

So while the code of the C# and the Java version in the mentioned article look almost identical, only the C# version works as expected. Which leads to the additional question if these two problems also exist in a Delphi version of Double-Checked Locking?