GH-41867: [Java] Parallel to build JNI C++ code

[jinchengchenghh]

Rationale for this change

Accelerate the default JNI C++ build process

What changes are included in this PR?

Add -j to cmake build command

Are these changes tested?

Current tests covered.

Are there any user-facing changes?

No

• GitHub Issue: [Java] Parallel to build JNI C++ code #41867

[github-actions]

⚠️ GitHub issue #41867 has been automatically assigned in GitHub to PR creator.

[vibhatha]

should we also add some documentation regarding setting a fixed parallelism for Java users (in case of there are concerns on full resource utilization)?

[lidavidm]

@github-actions crossbow submit -g java

[github-actions]

Revision: 3c8bda8

Submitted crossbow builds: ursacomputing/crossbow @ actions-10f0171d4b

Task	Status
java-jars
test-conda-python-3.10-spark-v3.5.0
test-conda-python-3.11-spark-master
test-conda-python-3.8-spark-v3.5.0
verify-rc-source-java-linux-almalinux-8-amd64
verify-rc-source-java-linux-conda-latest-amd64
verify-rc-source-java-linux-ubuntu-20.04-amd64
verify-rc-source-java-linux-ubuntu-22.04-amd64
verify-rc-source-java-macos-amd64

[jinchengchenghh]

should we also add some documentation regarding setting a fixed parallelism for Java users (in case of there are concerns on full resource utilization)?

Do we need to add mvn -Dparallel=x to support setting a fixed parallelism? Or remember user in document they can build by CMAKE directly if they would not like to utilize resource fully?

[vibhatha]

mvn -Dparallel=x

I am not sure if this is a standard maven property? But if we can introduce such a variable to the root and document in development.rst, that would be very useful for most of the Java devs just use mvn install approach to build the project.

cc @lidavidm

[jinchengchenghh]

No, it will be arrow defined property. Current -j take effect under command mvn generate-resource. Maybe -DCPP_BUILD_PARALLEL is more reasonable.

[lidavidm]

Does CMAKE_PARALLEL_LEVEL not already work?

[lidavidm]

Sorry that should be CMAKE_BUILD_PARALLEL_LEVEL

[vibhatha]

Sorry that should be CMAKE_BUILD_PARALLEL_LEVEL

I haven't actually checked this. @jinchengchenghh could we verify this?

[vibhatha]

@jinchengchenghh need any help here?

[jinchengchenghh]

Sorry that should be CMAKE_BUILD_PARALLEL_LEVEL

It works, but I think the default parallel mode should be parallel build mode.
Java users may not check if cpp code is compiled parallism when they use mvn generate-resource to compile cpp code.

[lidavidm]

As is though, this forces parallelism which may also be undesirable

[jinchengchenghh]

ok, I will close this PR