>Copy it, then retry if needed. The reader needn't serialize. Sorry, this is not correct.
You can only "copy" (and/or avoid serialization) if you know that the element you are copying cannot be freed from underneath you (and you can't handle that in recovery because you have no way of knowing if your reference will blow up, let alone if someone else might have re-allocated the storage and is using it for some other purpose that you might or might not be able to detect). In the general case, readers need to serialize. Not against other readers, but against a writer. Peter Relson z/OS Core Technology Design
