Call for Discussion: New Project: Skara -- investigating source code management options for the JDK sources

Andrew Dinn adinn at
Mon Jul 30 08:22:51 UTC 2018

On 28/07/18 09:41, Peter Lawrey wrote:
> My impressions is, even for some of the most technical Java Champions it is
> impossible to become a committer.

Java Champions in what area of Java? Java is a big church and the
requirements to implement Java applications, implement Java JDK runtime
code or implement JVM code are /widely/ divergent. 'technical' is a
highly questionable way of talking about this. Is someone whose
'technical' expertise lies in the implementation of transactions going
to be able to help build a file system or a compiler?

> I have asked Java Champions who are actively working in the JVM or
> contributing directly but they found it easier to find/hire someone else to
> do the committing than become a committer.

That sentence doesn't parse very well as it seems to suggest these are
Java Champions who are active committers but then are not, instead
delegating to real committers. Your point has been lost, I am afraid.

> I have;
>  - the most answers for Java and JVM on StackOverflow,
>  - two high performance open source libraries with over 1,000 stars on
> Github,
>  - another library which got downloaded 6 million times last month
>  - built a self funded business which made £2.5m last year.

I am not at all sure why points on StackOverflow qualify you to commit
to the JVM? Coding a language virtual machine runtime is not a beauty
contest. Nor, indeed do the other qualifications appear particularly to
qualify you for this task. If you had previously been involved in VM or
compiler design/implementation or come up with a novel GC algorithm then
that experience would be highly relevant. The things you cite in no way
not guarantee that you will know which end of an OpenJDK JIRA to pick up
and what to do about it. They don't disqualify you, of course, but there
is a better, much more relevant standard (see below)

> I am eager to contribute, can code and understand business needs, but I
> have no idea how to become a committer without being hired into the JVM
> development team.

Well, there is a simple way to make this happen. You need to read the
code, find something which is broken or incomplete, read the code again,
raise a JIRA pointing out the problem, read the code again, create and
post a patch with a request for review, read the feedback (and the code
again), see the patch through review (no doubt, reading the code again
several times along the way) then rinse and repeat. Do that a few times
and you will become an official committer. Do it enough with a suitable
display of expertise and you will become a reviewer.

No one here is going to stop you understanding what needs fixing and
then fixing it. Indeed, if you are unsure how something works and ask an
intelligent question on any of the lists you /will/ be helped to arrive
at the understanding needed to fix problems. We even have a project
group (AdoptOpenJDK) whose sole purpose is to help make people perform
this task, providing guidance on where to look in the code, how to raise
an issue, where to post problems etc.

> What works for me is that some committers read my blog so things I write
> about get fixed in the next version indirectly.

Well, if you know enough to blog about real problems and you also know
how to code then the only thing stopping you from contributing fixes is
learning enough about the code to come up with your own fix and then
submitting it for inclusion. OpenJDK is an open source project and, as
we say in open source, show me the code.

> I would agree that the choice of technology is not the biggest barrier to
> entry.
> What we would need is a change of process if we are going to open up
> OpenJDK.
> A new platform might bring a change of mind set.

I'm sorry but I think the conclusion that we need a change of process
looks to me to be a complete non sequitur when your complaints above
don't even appear to recognise the existing process (as the farmer said,
you can't get there from here). I'm left very unsure as to whose mind
set it is that is actually misaligned.

> BTW I don't think it should be easy to be a committer.
It isn't. But that's not because there is no process to follow. It's
because the code base takes a long time to understand and improve.
That's not in the least bit surprising given what it does.


Andrew Dinn
Senior Principal Software Engineer
Red Hat UK Ltd
Registered in England and Wales under Company Registration No. 03798903
Directors: Michael Cunningham, Michael ("Mike") O'Neill, Eric Shander

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