what if the self._conn closed already? encountered an error - "pyodbc.ProgrammingError: Attempt to use a closed connection"

[JudeHuang2004]

aioodbc/aioodbc/connection.py

Line 223 in 9e4e562

self._conn.close()

[duh386]

The same error:

File "/home/httpd/src/core/impala.py", line 47, in get_connection
    conn = await asyncio.wait_for(self.pool.acquire(), timeout=cfg.impala_connect_timeout)  
File "/usr/local/lib/python3.8/asyncio/tasks.py", line 494, in wait_for    
    return fut.result()  
File "/usr/local/lib/python3.8/site-packages/aioodbc/utils.py", line 49, in throw    
    return self._coro.throw(typ)  
File "/usr/local/lib/python3.8/site-packages/aioodbc/pool.py", line 124, in _acquire    
    await self._fill_free_pool(True)  
File "/usr/local/lib/python3.8/site-packages/aioodbc/pool.py", line 140, in _fill_free_pool    
    await conn.close()  
File "/usr/local/lib/python3.8/site-packages/aioodbc/connection.py", line 137, in close    
    c = await self._execute(self._conn.close)  
File "/usr/local/lib/python3.8/concurrent/futures/thread.py", line 57, in run    
    result = self.fn(*self.args, **self.kwargs)
pyodbc.ProgrammingError: Attempt to use a closed connection.