There is two issue fixed in this pr:
**The first issue** is the C++ code rule of `do not call virtual function in constructor or deconstructor`.
The deconstructor function of `ArrowReaderWrap` call the virtual function named `close()`.
When deconstructing, it will never call `ParquetReaderWrap::close()` just call the `ArrowReaderWrap::close()`
**The second issue** is parallelism deconstructing for `ParquetReaderWrap` and `prefetch_batch`.
`prefetch_batch` use `thread.detach()` to separate the control from `ParquetReaderWrap`, but it rely on some local vars from `ParquetReaderWrap` such as **`_closed ` /`_total_groups ` and `_reader`**
In this case, `ParquetReaderWrap` may call deconstructor before `prefetch_batch` and then get the core dump.
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