RaceConditionDemo.java

// 1. RACE CONDITION - Multiple threads accessing shared data without synchronization
// Problem: Two threads increment counter simultaneously, causing incorrect results
public class RaceConditionDemo {
    static class Counter {
        private int count = 0; // Shared resource without synchronization
        
        public void increment() {
            // Read count
            // Increment (if count = 5, temp = 6)
            // Write back to count
            // Without synchronization, this is NOT atomic!
            count++; 
        }
        
        public int getCount() {
            return count;
        }
    }

    public static void main(String[] args) throws InterruptedException {
        Counter counter = new Counter();
        
        // Create two threads that both increment the same counter 1000 times
        Runnable task = () -> {
            for (int i = 0; i < 1000; i++) {
                counter.increment(); // Race condition occurs here!
            }
        };
        
        Thread t1 = new Thread(task);
        Thread t2 = new Thread(task);
        
        t1.start();
        t2.start();
        
        t1.join(); // Wait for both threads to finish
        t2.join();
        
        // Expected: 2000, but likely will be less due to race condition
        System.out.println("Final count: " + counter.getCount() + " (Expected: 2000)");
    }
}