[MNG-7156] Parallel build can cause issues between clean and forked g…

[gnodet]

…oals

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[bmarwell]

Will this also resolve -DdeployAtEnd=true?

[gnodet]

Will this also resolve -DdeployAtEnd=true?

I don't understand. This only adds a locking mechanism to avoid conflicts caused by parallel execution between the normal lifecycle and forked lifecycles, which can cause the same project to be build twice concurrently. This has nothing to do with deployAtEnd afaik.

[MartinKanters]

Nice proposal, I left some comments. Also, I think it's worth it to create at least an integration test. It might be annoying to build an IT, but covering this just in unit tests will be much harder.

[cstamas]

Cool, I think I saw some of issues while using mvnd that should be solved...

[gnodet]

Cool, I think I saw some of issues while using mvnd that should be solved...

Fwiw, it's not really urgent, as it has already been integrated into mvnd ...
https://github.com/mvndaemon/mvnd/blob/master/daemon/src/main/java/org/mvndaemon/mvnd/execution/LockingEventSpy.java

[famod]

Two things:

• I think this is now more "urgent" (for 3.8.x) given the discussion in [MNG-7285] [3.8.x] Replace ThreadLocal in MavenProject with locking in MojoExecutor to fix MNG-6843 #578
• There could be a system property to opt out of this, just in case (for some incubation time)

[michael-o]

Would it make sense to use SessionData#computeIfAbsent() if we release Resolver and integrate?

[michael-o]

So this revolves around the idea that all elements subject to a project cannot be modified while the lock is obtained, so everything else concurrently is halted?
So as far as I understand this PR is global while PR #578 is rather local?

[gnodet]

So this revolves around the idea that all elements subject to a project cannot be modified while the lock is obtained, so everything else concurrently is halted?
So as far as I understand this PR is global while PR #578 is rather local?

I had a closer look at both problems and proposed solutions. They are indeed related but for two different use cases. The This one #476 address the use case for synchronising between a standard lifecycle and a forked lifecycle, while #578 synchronises between a mojo execution for a given project and a mojo execution that has the reactor flag set.
Both are related because they both address concurrency execution between projects.

I'll work on a PR that addresses both problem at the same time.

[gnodet]

Superseded by #628 for 3.x and #627 for master.