LockContext map Concurrent Question

- [ ] I have searched the [issues](https://github.com/codingapi/tx-lcn/issues) of this repository and believe that this is not a duplicate.

### 1. Bug Description
LockContext
private Map map;
private LockContext() {
map = new ConcurrentHashMap<>();

cacheList = new CopyOnWriteArrayList<>();

freeList = new LinkedList<>();
}

map is ConcurrentHashMap 但是你在操作这个元素时 加锁防止脏读，污写 ，完全没必要了

### 4. Tour Idea
既然是ConcurrentHashMap 完全可以把synchronized 锁去掉，而且不会脏读,重复添加， 这样做牺牲性能了