Summary:
max_evicted_seq_ could be updated in the middle of the read in ::IsInSnapshot. The code to be correct in presence of this update would be complicated. The patch simplifies it by checking the value of max_evicted_seq_ before and after looking into commit_cache_ and retries in the unlucky case that it was changed.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4955
Differential Revision: D13999556
Pulled By: maysamyabandeh
fbshipit-source-id: 7a1bdfa95ea8b5d8d73ddff3263ed31d7297b39c