🐛 priority queue: properly sync the waiter manipulation

[fossedihelm]

As described in #3363, there are some circumstances under which GetWithPriority does not return the correct/expected element.

This can happen when a GetWithPriority is executed and the Ascend of the queue is not completed yet, causing not all the items of the BTree to evaluate the same w.waiters.Load() value.

Adding a lock to manipulate the waiters will solve the issue. Since the lock is required, there is no need to use an atomic.Int64 anymore.

Fixes: #3363

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: fossedihelm / name: Federico Fossemò (bef0907)

[k8s-ci-robot]

Welcome @fossedihelm!

It looks like this is your first PR to kubernetes-sigs/controller-runtime 🎉. Please refer to our pull request process documentation to help your PR have a smooth ride to approval.

You will be prompted by a bot to use commands during the review process. Do not be afraid to follow the prompts! It is okay to experiment. Here is the bot commands documentation.

You can also check if kubernetes-sigs/controller-runtime has its own contribution guidelines.

You may want to refer to our testing guide if you run into trouble with your tests not passing.

If you are having difficulty getting your pull request seen, please follow the recommended escalation practices. Also, for tips and tricks in the contribution process you may want to read the Kubernetes contributor cheat sheet. We want to make sure your contribution gets all the attention it needs!

Thank you, and welcome to Kubernetes. 😃

[k8s-ci-robot]

Hi @fossedihelm. Thanks for your PR.

I'm waiting for a github.com member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

I understand the commands that are listed here.

Details

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository.

[vladikr]

/cc

[k8s-ci-robot]

@vladikr: GitHub didn't allow me to request PR reviews from the following users: vladikr.

Note that only kubernetes-sigs members and repo collaborators can review this PR, and authors cannot review their own PRs.

Details

In response to this:

/cc

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository.

[alvaroaleman]

/ok-to-test

Please sign the CLA so we can accept your contribution

[fossedihelm]

@alvaroaleman Signed :) Thanks

[alvaroaleman]

/cherrypick release-0.22

[k8s-infra-cherrypick-robot]

@alvaroaleman: once the present PR merges, I will cherry-pick it on top of release-0.22 in a new PR and assign it to you.

Details

In response to this:

/cherrypick release-0.22

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository.

[alvaroaleman]

thanks!

[k8s-ci-robot]

LGTM label has been added.

Details

Git tree hash: 5508fa28ebb9007be1ae0bf5797fd80ec2fb2dc1

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: alvaroaleman, fossedihelm

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Details

Needs approval from an approver in each of these files:

• OWNERS [alvaroaleman]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[k8s-infra-cherrypick-robot]

@alvaroaleman: #3368 failed to apply on top of branch "release-0.22":

Applying: priority queue: properly sync the `waiter` manipulation
Using index info to reconstruct a base tree...
M	pkg/controller/priorityqueue/priorityqueue_test.go
Falling back to patching base and 3-way merge...
Auto-merging pkg/controller/priorityqueue/priorityqueue_test.go
CONFLICT (content): Merge conflict in pkg/controller/priorityqueue/priorityqueue_test.go
error: Failed to merge in the changes.
hint: Use 'git am --show-current-patch=diff' to see the failed patch
hint: When you have resolved this problem, run "git am --continue".
hint: If you prefer to skip this patch, run "git am --skip" instead.
hint: To restore the original branch and stop patching, run "git am --abort".
hint: Disable this message with "git config advice.mergeConflict false"
Patch failed at 0001 priority queue: properly sync the `waiter` manipulation

Details

In response to this:

/cherrypick release-0.22

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository.

[sbueringer]

Thx!

/lgtm