Comment 2 for bug 1887357

Reviewed: https://review.opendev.org/740638
Committed: https://git.openstack.org/cgit/openstack/mistral/commit/?id=4f617856b6976244cb4bc588356a1170bcf73379
Submitter: Zuul
Branch: master

commit 4f617856b6976244cb4bc588356a1170bcf73379
Author: Renat Akhmerov <email address hidden>
Date: Mon Jul 13 15:44:36 2020 +0700

    Add a protection for list commands from parallel deletes

    * While fetching a list of object in the REST layer we now check
      if the object has already been deleted in parallel (by catching
      the corresponding exception caused by lazy loading) and don't
      include it into the result set.
    * Added the corresponding test that uses mocking and two synchronized
      threads to reproduce this corner case.
    * Minor style changes.

    Change-Id: Ia92d799a421e07542f270223c1add2aae7b32aab
    Closes-Bug: #1887357