RFC: JDK 9 Sandbox Forest Proposal

[Mike Duigou]

Hello all;

I've been instigating internal discussions with the Oracle OpenJDK developers about where to do OpenJDK development work for JEP-scale efforts. The scope, duration, and necessary collaboration of JEP-scale efforts makes it appropriate for collaboration to be done using an open, shared version control system rather than just using privately shared patches. As incubation development work it is not appropriate though for this work to be hosted in the jdk9/dev main-line repos. We need a public place to collaborate on issues and features before they are ready for final integration into the main-line JDK repos.

It is possible for any OpenJDK developer to request a new OpenJDK project, but the OpenJDK project process seems entirely too heavy-weight to have full OpenJDK projects and/or forests for every issue, feature, exploration or prototype. The problem is both the creation process overhead for new projects as well as the various ongoing administration and maintenance issues attendant with ongoing projects. For larger efforts it is still entirely appropriate to create an OpenJDK project. An extremely rough guide is that if the result of an effort will be a new JDK module or API package then it is probably big enough to deserve a separate project. For everything smaller, shorter or more speculative than is appropriate for a project this new sandbox forest will provide a comfortable home.

This proposal has been through a few rounds of internal review and refinement and I believe is nearly ready for activation. Ideally the new sandbox forest would be available for use in early October.

Feedback and suggestions welcome.

Cheers,

Mike


Proposal:

- Create a new forest in the JDK 9 project for developers to use for experiments, new features, prototypes or any other non-trivial efforts. 


Goals: 

- Open          : Use OpenJDK public infrastructure
- Low-friction  : Minimal start-cost and no delays
- Collaboration : Individual efforts can self-organize and self-regulate
- Approachable  : Community members can easily locate, review, comment and participate
- Participation : Open to all JDK 9 Reviewers, Committers and Authors(*)
- Light-weight  : Minimal required policy, simpler pre-push rules than main-line jdk9/dev forest
- Visible       : Links from JEP or issue page and sharable URIs to repo, branches and changesets

(*) Authors will require a Committer or Reviewer to push changesets for them.


Constraints:

- Policies are consistent with OpenJDK bylaws and JDK 9 project rule.
- Future OpenJDK bylaws changes may make things easier but we won't block waiting for changes.
- Use the JDK 9 project membership and roles.


Specifics:

- New "sandbox" forest in JDK 9 project is a clone/child of jdk9/dev forest.
- Eligible committers are JDK 9 committers as this is a forest in the JDK 9 project.
- Each repo in the forest has a branch (possibly default) that is lockstep updated from parent jdk9/dev repo via cron job syncing or triggered.
- Neither jcheck nor hgupdater is enabled for this forest. 
- All development happens on branches. Committers can create whatever branches in this forest they wish. Branch names "JEP-XXX" and "JDK-XXXXXXX" are, by courtesy, reserved for use of the corresponding JBS issues. Branch names prefixed with an OpenJDK username and a delimiter, by courtesy, are reserved for use of that OpenJDK user.
- JBS allows web links to be associated with issues. This can be used to identify the location of development branch for an issue.
- Branch owners determine the pre-commit review policy (if any) for their branches.
- Branch owners are responsible for reparenting/rebasing their branch to the provided upstream lockstep-with-dev branch however often they wish.
- There will be no pushes or promotions from this forest to any other forest. 
- Integration to the main-line jdk9/dev forest repos will be via the the current JDK 9 changeset review and approval process.
- Nightlies, testing, CI, etc. are the responsibility of the individual branch owners.
- Since the work in this forest is unreviewed, experimental, prototype or exploratory there is no commitment whatsoever that anything in this forest eventually be part of JDK 9 or any other release.
- The forest will be frozen at the release of JDK 9 and possibly deleted sometime thereafter. Feature owners would be responsible for archiving or migrating anything that they wish to retain. Notice and warning will be given on jdk9-dev mailing list to which all JDK 9 project committers are presumed to subscribe.
- Changesets pushed to the sandbox forest do not count as "significant contributions" for the purposes of JDK 9 project role eligibility.


Desirable Future Changes:

- Allow changesets to be pushed to branches in the sandbox forest by users with Author role. This new privilege would be consistent with other Author privileges such as uploading to cr.openjdk.java.net, editing bug reports, and modifying the wiki. Allowing Authors to push changesets would require a modification to the OpenJDK bylaws so we cannot currently implement this policy.


Contributors (in no particular order):

Stuart Marks, Alan Bateman, Joe Darcy, Paul Sandoz, Mark Reinhold, John Rose, Brian Beck, Brian Goetz, Roger Riggs and Chris Hegarty all reviewed earlier drafts of this proposal and provided insight and encouragement.