May a correct program be incorrectly synchronized?

Question

In answer of Does a correctly synchronized program still allow data race?(Part I), it gives us a good example: all executions of a program appear to be sequentially consistent, but it still has data race. It tells us why another direction of following conclusion in JLS is not true:

If a program has no data races, then all executions of the program will appear to be sequentially consistent.

Now take a look at another conclucsion in JLS:

A program is correctly synchronized if and only if all sequentially consistent executions are free of data races.

According to this conclusion,above example is not correctly synchronized, so may a correct program be incorrectly synchronized?

Answer 1

You would probably need to define first what a correct program is (not easy). JCiP proposes (in a different context):

a program is correct if it conforms to its specifications.

Using that definition, the example provided is correct. However, it is not correctly synchronized (there is a data race on hash).

==> a correct program may be incorrectly synchronized, as proved by that example.