Race condition when creating the FileReadStatus

There are certain conditions that can lead to a BatchUpdateException when reading file or updating files (that would trigger read status to change).

The exception can be displayed with various exceptions depending on the database driver being used. Examples:

• java.sql.BatchUpdateException: Duplicate entry '9-1' for key 2
• Duplicate entry '1476-4608' for key 'cru_participant'

This is caused due to incorrect assumptions in the code. It is reproducable by:

• create a review with 2 files
• start the review
• add a reviewer
• read the first file as the reviewer
• in 2 separate threads:
  • add a new revision to the second file
  • add a different new revision to the second file

This can cause a race condition. The symptom of the failure is that the second update will fail. The user will be given a message saying that the update failed and that the action will need to be performed again.