What methods ensure safety when writing multithreaded programs?

To ensure the safety and correctness of multithreaded programs in Java, the following methods are used:

• Synchronization (synchronized) — blocks access to critical sections of code to prevent simultaneous modification of shared data.
• Using volatile — guarantees visibility of variable changes between threads.
• Classes from java.util.concurrent — for example, ReentrantLock, Semaphore, CountDownLatch for more flexible thread management.
• Immutable objects — objects whose state does not change after creation are safe for access from different threads.
• Atomic operations — classes from java.util.concurrent.atomic allow performing operations without locks.

Example of using synchronized:

public class Counter {
    private int count = 0;

    public synchronized void increment() {
        count++;
    }

    public synchronized int getCount() {
        return count;
    }
}