On Apr 6, 2010, at 11:40 AM, Kristian Rosenvold wrote:
> I am going to commit my changes for MNG-3004 to M3 for beta 1.
> The change consists of the following:
>
> * A modularization of the DefaultLifecycleExecutor into smaller
> components. This is primarily done with the intention of extracting
> execution strategy somewhat from the rest of the logic.
> // builds for beta 1 (MNG-3004)
> * Three differenent execution strategies:
> A) Linear ("Classic")
> B) Parallel (Based on Dan's original implemementation)
> C) Weave (Still experimental)
>
> The command line -T option activates parallel running, and the argument
> is in the form
> -T <[nThreads, a float][C][W]|auto>
>
> The C flag scales threads according to CPU cores, this is why nThreads
> is a float
> The W flag activates weave mode (undocumented)
> Examples:
> "mvn -T auto install "
> autoconfigures threads based on cpu count (1 thread per core).
> "mvn -T 1.5C install"
> Runs with 6 threads on a 4 core computer.
> Runs with 2 threads on a single core computer.
> "mvn -T 1.87CW install"
> Runs with 7 threads weave mode on a 4 core computer.
>
> Better suggestions welcome ;) Bikeshedding opportunities galore ;)
>
> Risks/Consequences
> =====
> * I'm not particularly worried about functional regressions in Linear
> mode, and Parallel mode is also stable.
> * This does not mean the full set of maven plugins necessarily works in
> parallel mode; I expect there will be issues with plugins that I have
> not uncovered as of yet.
If you think that in Linear mode you're going to affect the behavior that we
have right now that's a bit of a problem. I thought the point of this mode was
to have almost zero risk while people could experiment with the || and weave
options?
> * There is a risk that I have removed some methods from
> DefaultLifecycleExecutor that may have to be re-added (if they were not
> documented as being externally in-use, I have removed them)
I think the ITs will uncover anything pretty quickly. Between you and Benjamin
I'm not too worried.
> * From a maven-core perspective, I see no reason to flag "parallel" as
> experimental.
Until it runs in the wild for a bit I think we have to.
> * Weave mode is still experimental (and is not added to any official
> API's - but parallel is). It's clearly pushing close to the limits of
> what the JVM handles. I will be extending my testing onto Windows to
> check behaviour on different platforms. My goal is to get this stable
> before 3.0 final. The modularization of the lifecycle executor ensures
> that most further changes will be contained to the single
> "LifecycleWeaveBuilder" class (which encapsulates most of "weave" mode).
If people don't activate this option it doesn't affect them. I don't think this
is a big deal.
> * Weave mode has some minor issues that are intentionally left TODO,
> pending that the overall stability goals can be reached.
> * I will be updating surefire to include the parallel->forkmode>=once
> check.
> * The change includes decent test coverage; no existing its were harmed
> and quite a few new unit-tests have been added. I will elaborate these
> even further in the weeks to come.
>
> I'm not calling a vote on this, but now is the time for objections. I
> will commit this in about 24 hours time unless there's any significant
> objections. The current patch is at
> http://github.com/krosenvold/maven3,
> and if nothing else, I know Benjamin will be at it with his microscope
> afterwards ;)
>
> The only last thing I'll do now is to read/search through the core
> plugins looking for references to methods I have deleted in
> DefaultLifecyleExecutor.
I say go for it. We're not in a dire rush and Stuart is also working on getting
the core working on Guice so you and Stuart should coordinate as I think you
might have some overlapping bits. Once it's all in, if the ITs all pass I'm
pretty confident at this point that they model reality to a high degree.
>
> Kristian
>
>
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: [email protected]
> For additional commands, e-mail: [email protected]
>
Thanks,
Jason
----------------------------------------------------------
Jason van Zyl
Founder, Apache Maven
http://twitter.com/jvanzyl
----------------------------------------------------------
