Writing long and double is not atomic in Java?

Question

Reading and writing of a single variable is atomic (language guarantee!), unless the variable is of type long or double.

I was reading

Answer 1

Many programmers must have read this statement in "3.1.2. Non-Atomic 64bit Operations" in java concurrency in practice . I have referred the latest JLS 17.7. Non-Atomic Treatment of double and long. They still nowhere claim that 64 bit jVM are norm these days. So 64 bit operations are broken into 32 bit operations that break atomicity and dangerous to use in multithreaded environment until declared volatile . Long and double are 64 bit long in java. So writing and reading operations are not atomic in java.