## 列车运行计算

1、占用、 列车 车头 过了信号灯 变成红色
2、列车 车尾离开 进路 型号等 空闲状态

## 共享数据+锁

```java
private static Map<String, CacheState> stateCache=new ConcurrentHashMap<>();
private final ReentrantReadWriteLock cacheLock=new ReentrantReadWriteLock(true);
private final Lock writeLock=cacheLock.writeLock();
private final Lock readLock=cacheLock.readLock();
```