questions on Word operations

[Deneau, Tom]

I would like to add a new Word method that can be used from an allocation Snippet I am trying to write.

The new method would look like:

	public Word atomicGetAndAddWord(int offset, int delta) {

	}

So given a Word (address), this would do an atomic get and add of delta on the word located at the address this.rawValue + offset.  Like j.u.c.atomic.getAndAdd, it would return the original word value at that address.

A couple of questions:

   *  Is the following a legal body for such a method?  I see that it compiles but is it legal to call toObject() on a Word value?  As used in the snippet the Word value would be the pointer returned by thread().  I noticed there is no unsafe.getAndAddLong(long address, long delta), only unsafe.getAndAddLong(Object o, long offset, long delta)

           return box(unsafe.getAndAddLong(toObject(), offset, delta));

   *  I notice all the Word methods have @Operation annotations but I don't really understand the semantics of this annotation.  What should be the annotation for this method?


   *  What is the purpose of the locationIdentity parameter on some of the word operations such as
  
       @Operation(opcode = Opcode.READ)
       public Word readWord(WordBase offset, LocationIdentity locationIdentity) {
           return box(unsafe.getAddress(add((Word) offset).unbox()));
       }

-- Tom