Can you explain what atomic variables are and how they differ from regular ones?

Atomic variables are special types of variables whose operations are performed as indivisible (atomic) actions. This means that when working with such variables, it is impossible to obtain an intermediate state, and operations are not interrupted by other threads.

Unlike regular variables, atomic variables guarantee correctness in multithreaded access without the need to use locks (synchronized, mutex, etc.). For example, in Java, there is the AtomicInteger class, which allows safely increasing the value of a variable from different threads.

Example in Java:

import java.util.concurrent.atomic.AtomicInteger;

AtomicInteger counter = new AtomicInteger(0);
counter.incrementAndGet(); // atomic increment by 1

Thus, atomic variables simplify working with concurrent access and improve performance by avoiding the overhead of synchronization.