Sharing Objects - Java Concurrency in Practice - page 56

You may be surprised at how badly this harmless-looking example could fail. Because of vis-
ibility problems, the Holder could appear to another thread to be in an inconsistent state,
even though its invariants were properly established by its constructor! This improper pub-
lication could allow another thread to observe a partially constructed object .
3.5.1. Improper Publication: When Good Objects Go Bad
You cannot rely on the integrity of partially constructed objects. An observing thread could
see the object in an inconsistent state, and then later see its state suddenly change, even
though it has not been modified since publication. In fact, if the Holder in Listing 3.15 is
published using the unsafe publication idiom in Listing 3.14 , and a thread other than the pub-
lishing thread were to call assertSanity , it could throw AssertionError ! [15]
Listing 3.15. Class at Risk of Failure if Not Properly Published.