Java: The Volatile Keyword

Volatile writes create a happens-before relationship.

In Java's concurrency model, a write to a volatile variable establishes a happens-before relationship with subsequent reads of that variable. This means that any changes made before writing to the volatile variable are visible to other threads that read it afterward. For instance, if a thread writes to a volatile 'ready' flag after updating shared data, another thread will see both the updated shared data and the new value of 'ready'.