Java volatile Keyword Explained

In Java, the volatile keyword is used to ensure the visibility of variables in a multi-threaded environment and prevent reordering. Specifically, the volatile keyword serves the following purposes:

1. Visibility: Ensure that when one thread modifies the value of a variable, other threads can immediately see the latest value. This is because variables marked as volatile are stored in the main memory, and each time they are read, the most updated value is retrieved from the main memory.
2. Prevent reordering: The volatile keyword can prevent the compiler and processor from reordering operations on the variable being modified. This ensures that the execution order of the code aligns with the programmer’s expectations.

It’s important to note that the volatile keyword is only applicable for read and write operations on single variables, and it does not guarantee the atomicity of compound operations. If atomicity of compound operations is needed, consider using the synchronized keyword or the Atomic class.