[JENKINS-67237] BuildTrigger waits until the dependency graph has been updated - 2nd attempt

[Si-So]

See JENKINS-67237.

The first PR caused this regression. This PR is the 2nd attempt at solving JENKINS-67237 without causing a regression.

Proposed changelog entries

• When triggering a new build while the build graph is currently being re-computed, jenkins waits for the re-computation to finish. This gurantees that recently updated build triggers are executed.

Proposed upgrade guidelines

N/A

Submitter checklist

• (If applicable) Jira issue is well described
• Changelog entries and upgrade guidelines are appropriate for the audience affected by the change (users or developer, depending on the change) and are in the imperative mood. Examples
  • Fill-in the Proposed changelog entries section only if there are breaking changes or other changes which may require extra steps from users during the upgrade
• Appropriate autotests or explanation to why this change has no tests
• New public classes, fields, and methods are annotated with @Restricted or have @since TODO Javadoc, as appropriate.
• For dependency updates: links to external changelogs and, if possible, full diffs

Desired reviewers

@res0nance
@timja

Maintainer checklist

Before the changes are marked as ready-for-merge:

• There are at least 2 approvals for the pull request and no outstanding requests for change
• Conversations in the pull request are over OR it is explicit that a reviewer does not block the change
• Changelog entries in the PR title and/or Proposed changelog entries are accurate, human-readable, and in the imperative mood
• Proper changelog labels are set so that the changelog can be generated automatically
• If the change needs additional upgrade steps from users, upgrade-guide-needed label is set and there is a Proposed upgrade guidelines section in the PR title. (example)
• If it would make sense to backport the change to LTS, a Jira issue must exist, be a Bug or Improvement, and be labeled as lts-candidate to be considered (see query).

[Si-So]

I created a TC to detect the regression. I expect that only the new TC will fail during the currently running build.

I have also prepared a fix for the regression that I will push once the currently running build is done.

[Si-So]

As predicted only the newly added TC failed.

I have now pushed a fix for the regression and expect no failing unit tests during this run.

[res0nance]

Because of how this works, potentially a call to rebuildDependencyGraphAsync will block which defeats the original purpose of the function. This needs a rethink

[Si-So]

Thanks yet again for your feedback. I just pushed a new commit.

I also noticed another bug: getFutureDependencyGraph does not return the most recent dependency graph if the most recent dependency graph has been calculated synchronously. This is problematic because BuildTrigger.execute assumes that getFutureDependencyGraph will always return the most recent dependency graph. To fix this problem calculatingFutureDependencyGraph is now set to null in scheduleCalculationOfFutureDependencyGraph after the calculation has finished.

[res0nance]

LGTM

[basil]

I pushed a minor commit to clean up the formatting. Thanks for taking care of this!

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This PR is now ready for merge. We will merge it after approximately 24 hours if there is no negative feedback. Please see the merge process documentation for more information about the merge process. Thanks!

[basil]

The skip-changelog label was added by mistake.