THIS IS A TEST INSTANCE. ALL YOUR CHANGES WILL BE LOST!!!!
...
For example, if we do some close work in deconstructor, the dependend parent raw ptr may be released. it will core.
6. Never use std::thread to create thread too frequently
If create or destroy too frequently, jemalloc may not behavior very well. Sometimes crash. like this:
Should use thread pool or std future or promise to do this.