Low-Level Concurrency: Atomics and Memory Models

Perform atomic read-modify-write operations using `std::atomic`.

Explain the 'happens-before' relationship in concurrent programming.

Apply `memory_order_relaxed` for operations without ordering constraints.

Use `memory_order_acquire` and `memory_order_release` to synchronize memory between threads.

Distinguish between sequential consistency and relaxed memory models.

Implement a spin-lock using atomic compare-and-swap (`compare_exchange_strong`).

Identify when to use different memory orderings to balance safety and performance.

Explain the ABA problem in lock-free algorithms.