Volatile keywords, atomicity, and visibility

1.volatile keywords

The key to understanding volatile is to understand the processor cache and main memory first.

If a domain is declared as volatile, then as long as the domain has a write operation, all read operations can see this modification, that is, the volatile domain of the write operation to main memory refresh.

Synchronizing synchronized also causes flushing to main memory, so it does not have to be set to volatile if a domain is protected entirely by synchronized.

2. Atomicity and visibility

Visibility of:

Atomic nature:

Volatile keywords, atomicity, and visibility