What Cases Require Synchronized Method Access in Java?

Question

In what cases is it necessary to synchronize access to instance members? I understand that access to static members of a class always needs to be synchronized- because they

Answer 1

In Java, operations on ints are atomic so no, in this case you don't need to synchronize if all you're doing is 1 write and 1 read at a time.

If these were longs or doubles, you do need to synchronize because it's possible for part of the long/double to be updated, then have another thread read, then finally the other part of the long/double updated.