AtomicIntegerFieldUpdaterDemo.java

package ch4.s4;

import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.AtomicIntegerFieldUpdater;

public class AtomicIntegerFieldUpdaterDemo {
    public static class Candidate {
        int id;
        volatile int score;
    }

    public final static AtomicIntegerFieldUpdater<Candidate> scoreUpdater =
            AtomicIntegerFieldUpdater.newUpdater(Candidate.class, "score");
    public static AtomicInteger allscore = new AtomicInteger(0);

    public static void main(String[] args) throws InterruptedException {
        final Candidate stu = new Candidate();
        Thread[] t = new Thread[10000];
        for (int i = 0; i < 10000; i++) {
            t[i] = new Thread() {

                public void run() {
                    if (Math.random() > 0.4) {
                        scoreUpdater.incrementAndGet(stu);
                        allscore.incrementAndGet();
                    }
                }
            };
            t[i].start();
        }
        for (int i = 0; i < 10000; i++) {
            t[i].join();
        }
        System.out.println("score=" + stu.score);
        System.out.println("allscore=" + allscore);
    }
}