多线程操作--AtomicInteger

主函数：

public static void main(String[] args) throws InterruptedException
{
final MultiThreadVolatile test = new MultiThreadVolatile();
ExecutorService executorService = Executors.newFixedThreadPool(150);
for (int i =0 ; i < 100000; i++){
executorService.execute(new Runnable() {
@Override
public void run() {
test.increase();
}
});
}

executorService.shutdown();
executorService.awaitTermination(100*1000, TimeUnit.DAYS);
System.out.println(test.getCount());

}

能正确运行的代码，每次结果都是100000：

public class MultiThreadVolatile {
private AtomicInteger count = new AtomicInteger(0);
public int getCount(){
return count.get();
}
public void increase(){
count.incrementAndGet();
}

}


肯定出问题的代码A:
public class MultiThreadVolatile {
private Integer count = 0;
public int getCount(){
return count;
}
public void increase(){
count++;
}

}

可能出问题的代码B:
public class MultiThreadVolatile {
private volatile Integer count = 0;
public int getCount(){
return count;
}
public void increase(){
count++;
}

}