What is the purpose of the Java keyword “volatile”?
The volatile keyword in Java is used to indicate that a variable may be concurrently modified by multiple threads, ensuring that operations on that variable are visible to all threads.
Specifically, the volatile keyword has the following effects:
- Visibility: When a variable is marked as volatile, any changes made to that variable will immediately be visible to other threads, ensuring synchronous operations on that variable between threads.
- Atomicity: The volatile keyword ensures the atomicity of individual read and write operations, guaranteeing that they occur independently and are not interrupted by other threads.
It is important to note that the volatile keyword only guarantees visibility and atomicity, but does not guarantee thread safety. If multiple threads are simultaneously performing compound operations on a variable, the volatile keyword may not ensure atomicity of the operations. In such cases, locks or the Atomic class should be used for synchronized processing.