What is a race condition?

Race condition occurs when multiple threads or processes access and modify shared data simultaneously without proper synchronization, leading to unpredictable program behavior.

For example, if two threads increment a shared counter at the same time without locks, the final value may be incorrect.

Example in Java:

class Counter {
    private int count = 0;

    public void increment() {
        count = count + 1; // non-atomic operation
    }

    public int getCount() {
        return count;
    }
}

If multiple threads call increment() simultaneously, the final value of count may be less than expected due to a race condition.

To prevent this, synchronization is used, for example, the synchronized keyword or atomic classes from java.util.concurrent.atomic.