ChallengeThe invisible concurrency bug

time to read 1 min | 33 words

A customer reported an error when a certain query was run concurrently. It took a while, but we finally found the piece of code that is responsible for this:

Can you spot it?

More posts in "Challenge" series:

  1. (03 Jan 2020) Spot the bug in the stream–answer
  2. (15 Feb 2010) Where is the optimization?