What are the performance differences between synchronized and volatile in Java?

What are the performance differences between synchronized and volatile in Java?

Synchronized blocks can lead to thread contention, which may slow down performance, while volatile variables have less overhead.

Can you explain how synchronized affects thread safety?

Synchronized ensures that only one thread can access a block of code at a time, providing thread safety by preventing race conditions.

What about volatile? How does it ensure visibility?

Volatile guarantees that changes made by one thread are visible to others immediately, but it doesn't provide atomicity.

In what scenarios should I use synchronized over volatile?

Use synchronized when you need to protect critical sections of code and ensure atomic operations, while volatile is suitable for simple flags.

Are there any performance benchmarks comparing the two?

Yes, benchmarks show that volatile can be faster in scenarios where only visibility is needed, but synchronized is safer for complex operations.