# Answers

## Question 1

Atomic variables are thread-safe variables provided by Java.

They allow multiple threads to update a value safely without using synchronized blocks or locks.

Regular variables do not provide this protection and may cause race conditions.

## Question 2

Four classes from the `java.util.concurrent.atomic` package are:

- AtomicInteger
- AtomicLong
- AtomicBoolean
- AtomicReference

`AtomicInteger` is used for thread-safe integer operations such as incrementing or decrementing a counter.

## Question 3

Atomic variables are useful for simple operations on a single variable.

For more complex operations involving multiple variables or multiple steps, locks are usually a better choice.

## Question 4

Yes. A program can be free of race conditions but still have poor performance.

Too much synchronization, lock contention, and thread management overhead can slow down the program.

## Question 5

Adding more threads does not always improve performance because threads compete for CPU time and shared resources.

In some cases, too many threads can actually reduce performance.

## Question 6

Deadlocks are difficult to detect because they depend on thread scheduling.

A program may work correctly many times and then suddenly deadlock under different execution conditions.