How is the mechanism of atomic operations implemented and what happens when they are executed?

Atomic operations are operations that are executed entirely or not at all, without intermediate states visible to other threads. In Java, the mechanism of atomic operations is implemented through the java.util.concurrent.atomic class, such as AtomicInteger, AtomicLong, and others.

When performing an atomic operation:

• Guaranteed indivisible change of the value (e.g., increment).
• Use of low-level processor instructions (CAS — compare-and-swap) that ensure the operation is not interrupted.
• No need for locks, which increases performance in a multithreaded environment.

Example of using AtomicInteger:

import java.util.concurrent.atomic.AtomicInteger;

AtomicInteger counter = new AtomicInteger(0);

// Atomic increment
counter.incrementAndGet();

// Get current value
int value = counter.get();

Thus, atomic operations allow safe modification of shared variables without explicit synchronization.