Add PMIX_QUERY_ABI_VERSION

[jjhursey]

• Ref Issue Defining a PMIx ABI #365
• Add a PMIX_QUERY_ABI_VERSION attribute that can be passed to
  PMIx_Query_info to access the ABI version implementated by the
  associated PMIx library.

[jjhursey]

Left to do:

• Implement this in OpenPMIx for folks to experiment with.
• Post an example of how this attribute could be used. Maybe as a use case?

[rhc54]

Implement this in OpenPMIx for folks to experiment with.

The query_info functions currently rely on the proc having called PMIx_Init first. I'd suggest just having those functions start by doing a quick check for this attribute and responding immediately if found so you don't require the "init".

[jjhursey]

That's a good idea. I've added some text in the latest commit to account for that.

[jjhursey]

I filed the implementation of this in openpmix/openpmix#2551 with some examples in the examples/ directory.

[jjhursey]

Refs:

• OpenPMIx implementation: Add PMIX_QUERY_ABI_VERSION key for PMIx_Query_info openpmix/openpmix#2551
• PMIx ABI Example: ABI dlopen example pmix-abi#10

[jjhursey]

Please use emoji reactions ON THIS COMMENT to indicate your position on this proposal.

• You do not need to vote on every proposal
• If you have no opinion, don't vote - that is also useful data
• If you've already commented on this issue, please still vote so
  we know your current thoughts
• Not all proposals solve exactly the same problem, so we may end
  up accepting proposals that appear to have some overlap
  This is not a binding majority-rule vote, but it will be a very
  significant input into the corresponding ASC decision.

Here are the meanings for the emojis:

• Hooray or Rocket: I support this so strongly that I
  want to be an advocate for it
• Heart: I think this is an ideal solution
• Thumbs up: I'd be happy with this solution
• Confused: I'd rather we not do this, but I can tolerate it
• Thumbs down: I'd be actively unhappy, and may even consider
  other technologies instead
  If you want to explain in more detail, feel free to add another
  comment, but please also vote on this comment.

[jjhursey]

I just pushed an additional commit to split the stable and provisional into two attributes.
The link to the versioning section is in a comment because it depends on PR #375 - we will address that at a later stage.

[jjhursey]

PMIx ASC 2Q 2022

• Passed the first vote: 8 yes / 0 no / 3 abstain
• This is eligible for second vote in the 3Q 2022 ASC quarterly meeting

[jjhursey]

Reference implementations:

• OpenPMIx: Update the PMIx ABI Query attributes to match the standard openpmix/openpmix#2617
  • Prior, earlier implementation: Add PMIX_QUERY_ABI_VERSION key for PMIx_Query_info openpmix/openpmix#2551
• PMIx ABI Repo example: ABI dlopen example pmix-abi#10

[jjhursey]

PMIx ASC 3Q 2022

• Passed the second vote: 8 yes / 0 no / 0 abstain
• This will be included in the next major release.

[jjhursey]

Rebased branch. The only new addition was the last commit (per discussion with the group) to add a cross-reference to the versioning language which was brought in as part of PR #375.