The Java Memory Model (JMM): Understanding Memory Management

The Java Memory Model (JMM) defines how threads interact with memory in a multi-threaded environment. It ensures visibility and ordering of changes made by one thread to shared variables. JMM rules help prevent inconsistencies like stale reads and race conditions.

Here’s an example involving volatile variables:

class SharedData {
    private volatile boolean flag = true;
    
    public void changeFlag() {
        flag = false;
    }
}

In this example, the `volatile` keyword ensures that changes to `flag` are visible across threads. Understanding JMM is crucial for writing thread-safe Java code and avoiding common concurrency issues.