RFR: build: run build and tests in parallel

[Robin Westberg]

On Fri, 12 Feb 2021 13:08:33 GMT, Erik Helin <ehelin at openjdk.org> wrote:

> Hi all,
> 
> please review this patch that enables builds and tests to happen in parallel. I also tweaked the build a little:
> 
> - the Gradle daemon now gets an `Xmx` of `2048 Mb`
> - Gradle will run up to 100 tests in the same JVM before forking a new one
> - the JVM for compiling will be forked, reducing heap pressure on the Gradle daemon thread
> - enabled the file system watching feature for faster rebuilds
> 
> The results on my AMD Ryzen 5 3600 is that `sh gradlew clean && sh gradlew --info test` went from ~10 minutes to ~2 minutes :partying_face: �� 
> 
> Testing:
> - [x] `make images` on Linux x64
> - [x] `make test` on Linux x64
> 
> Thanks,
> Erik

Looks good!

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Marked as reviewed by rwestberg (Reviewer).

PR: https://git.openjdk.java.net/skara/pull/1009