What are the differences between volatile and synchronized in Java?

What are the differences between volatile and synchronized in Java?

Volatile and synchronized are both used for thread safety in Java, but they serve different purposes. Volatile ensures that a variable's value is always read from and written to the main memory, making it visible to all threads. Synchronized, on the other hand, is a block or method that locks the object, allowing only one thread to execute it at a time.

Can you give me an example of when to use volatile?

Sure! Use volatile when you have a flag variable that multiple threads read and write to, and you want to ensure that changes made by one thread are visible to others immediately, like a simple stop signal.

What about synchronized? When should I use it?

Use synchronized when you need to protect a block of code or a method that modifies shared resources, ensuring that only one thread can access it at a time to prevent data inconsistency.

Are there performance implications for using synchronized?

Yes, synchronized can lead to performance overhead due to thread contention and context switching. If many threads are trying to access a synchronized block, it can create bottlenecks.