AtomicReference自旋加CAS保证对象引用原子性

AtomicReference类提供了对象引用的非阻塞原子性读写操作，并且提供了其他一些高级的用法，对象的引用其实是一个4字节的数字，代表着在JVM堆内存中的引用地址，对一个4字节数字的读取操作和写入操作本身就是原子性的

package AtomicTest;import disruptor.WwwApplication;
import lombok.extern.slf4j.Slf4j;
import org.junit.jupiter.api.Test;
import org.springframework.boot.test.context.SpringBootTest;import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.*;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.AtomicReference;/*** desc:* author:wangqiangac* date:2024/1/5 15:49*/
@Slf4j
@SpringBootTest(classes= WwwApplication.class)
public class AtomicReferenceTest {//volatile DebitCard debitCard = new DebitCard("WangQiang", 0);AtomicInteger atomicInteger = new AtomicInteger(0);private static AtomicReference debitCardRef = new AtomicReference(new DebitCard("WangQiang",0));@Testpublic void test() throws InterruptedException, ExecutionException {ThreadPoolBuilder threadPoolBuilder = new ThreadPoolBuilder();threadPoolBuilder.setCorePoolSize(50).setMaxPoolSize(100).setKeepAliveSeconds(120).setQueueCapacity(20).setThreadNamePrefix("王强的线程").setPrestartAllCoreThreads(true).setRejectedExecutionHandler(new BlockPolicy());ThreadPoolExecutor threadPoolExecutor = threadPoolBuilder.builderThreadPoolExecutor();List<Callable<DebitCard>> callables = new ArrayList<>();for (int i = 0; i < 8; i++) {callables.add(()->{atomicInteger.getAndIncrement();DebitCard debitCard = null;DebitCard extracted = extracted();return extracted;});}List<Future<DebitCard>> futures = threadPoolExecutor.invokeAll(callables);for (Future f: futures) {log.error(f.get().toString());}log.error(debitCardRef.get().toString()+"atomicInteger:"+atomicInteger.get());}private static DebitCard extracted() {DebitCard debitCard;debitCard = (DebitCard) debitCardRef.get();DebitCard debitCards = new DebitCard(debitCard.getAccount(),debitCard.getAmount()+1);if(debitCardRef.compareAndSet(debitCard, debitCards)){log.error(debitCards.toString());return debitCards;}else{log.error("和期望的不一样");extracted();return new DebitCard("出现和期望值不一样自旋了",888);}}
}