I am quoting from Oracle's Atomic Access
- Reads and writes are atomic for reference variables and for most primitive variables (all types except long and double).
- Reads and writes are atomic for all variables declared
volatile(including long and double variables).
I understand how
volatile works. But mentioning the requirement to declare
volatile explicitly for
double variables to get atomic access in the second statement, is making
volatile declaration for reference variables and for most primitive variables (all types except long and double) in the first statement optional.
But I am seeing codes which use explicit
volatile declaration in
int primitive type to achieve atomic access; and not doing so not guaranteeing atomic access.
int variable1; // no atomic access volatile int variable2; // atomic access
Am I missing something?