Backport #14651
There is potentially a race with a slow starting internal
queue causing a NPE if Has is checked before the internal
queue has been setup.
This PR adds a lock on the Has() fn.
Fix#14311
Signed-off-by: Andrew Thornton <art27@cantab.net>
Co-authored-by: 6543 <6543@obermui.de>
* Upgrade levelqueue to version 0.2.0
This adds functionality for Unique Queues
* Add UniqueQueue interface and functions to create them
* Add UniqueQueue implementations
* Move TestPullRequests over to use UniqueQueue
* Reduce code duplication
* Add bytefifos
* Ensure invalid types are logged
* Fix close race in PersistableChannelQueue Shutdown