Github user vrozov commented on the issue:
https://github.com/apache/drill/pull/1105
@ilooner @arina-ielchiieva How `innerNext()` and `close()` can execute
concurrently? Does not `FragmentExecutor.hasCloseoutThread` ensure that either
`close()` is called on the `run()` thread or `run()` exits if the fragment is
already cancelled?---
