Problem/Motivation
Drupal's Lock backends are owned by a particular process. It would be nice to have a lock backend that could be owned by a batch process, such that it could reacquire it's lock on successive page loads.
Steps to reproduce
Proposed resolution
Create a BatchLockBackend service to implement this.
Remaining tasks
Do it.
User interface changes
API changes
a new lock.batch service would be created.