What are the use cases of CAS in Java?

CAS, which stands for Compare And Swap, is a concurrency control algorithm commonly used in multi-threaded environments to synchronize operations on shared data. In Java, CAS is often used in the following scenarios:

1. Concurrent containers: CAS can be used to implement thread-safe collection classes, such as ConcurrentHashMap, ConcurrentLinkedQueue, etc.
2. Spin lock: CAS can be used to implement a spin lock, where it continuously attempts to acquire the lock until successful.
3. Atomic operation: CAS can be used to implement atomic operations such as atomic addition and subtraction, and atomic updates.
4. Thread pool: CAS can be used to implement control over the execution of tasks in the thread pool, such as task submission and execution.
5. Lock-free algorithm: CAS can be used to implement lock-free algorithms, such as lock-free queues, lock-free linked lists, and so on.

In general, CAS is suitable for scenarios in a multi-threaded environment that require thread safety and atomic operations. Because CAS operations are implemented based on hardware primitives, it has higher performance compared to using locks for concurrent control. However, it is important to note that CAS operations may encounter the ABA problem and require additional handling.