AtomicInteger

AtomicInteger 和AtomicBoolean 类似

什么时候使用AtomicInteger

一般我们可以把它作为一个原子计数器来使用，例，生成伪随机数

public class AtomicPseudoRandom extends PseudoRandom {
    private final AtomicInteger seed;

    AtomicPseudoRandom(int seed) {
        this.seed = new AtomicInteger(seed);
    }

    public int nextInt(int n) {
        while (true) {
            int s = seed.get();
            int nextSeed = calculateNext(s);
            if (seed.compareAndSet(s, nextSeed)) {
                int remainder = s % n;
                return remainder > 0 ? remainder : remainder + n;
            }
        }
    }
}

public class PseudoRandom {
    int calculateNext(int prev) {
        prev ^= prev << 6;
        prev ^= prev >>> 21;
        prev ^= (prev << 7);
        return prev;
    }
}