Foo.java

package empty;

import java.util.concurrent.atomic.AtomicInteger;

public class Foo {
    int x = 0;
    volatile int y = 0;

    public static void main(String[] args) throws InterruptedException {
        AtomicInteger counter = new AtomicInteger(0);
        for (int i = 0; i < 1000; i++) {
            Foo foo = new Foo();
            Thread t1 = new Thread(() -> {
                foo.x = 1;
                foo.y = 1;
            });
            Thread t2 = new Thread(()-> {
                while (foo.y != 1) {
                    if (foo.x == 1) counter.incrementAndGet();
                }
            });
            t1.start();
            t2.start();
            t1.join();
            t2.join();
        }
        // выводится рандомное число
        System.out.println(counter.get());
    }
}