What are the best practices for using compare-and-swap?

What are the best practices for using compare-and-swap?

Compare-and-swap (CAS) is a powerful atomic operation used in concurrent programming. Best practices include ensuring that the operation is used in a loop to handle retries, minimizing the critical section, and avoiding unnecessary contention by using it wisely in data structures.

Can you explain how to implement it in a multi-threaded environment?

Certainly! In a multi-threaded environment, you can implement CAS by using it within a loop that checks if the value has changed since you last read it. If it has, you retry the operation. This ensures that you only update the value if it hasn't been modified by another thread.

What are some common pitfalls to avoid?

Common pitfalls include not handling the case where the value changes between reads and writes, leading to infinite loops, and using CAS in performance-critical paths without proper benchmarking.

Are there any alternatives to compare-and-swap?

Yes, alternatives include load-link/store-conditional (LL/SC), mutexes, and other locking mechanisms, depending on the use case and performance requirements.