Running Loom tests

Fabio Tudone fabtud at
Sat Oct 20 13:09:11 UTC 2018

Quick update: I brought the LiveFrames test out of the tree and run it as a
java app; it looks like "-XX:+FullGCALot" is the option making it
unbearably slow (and so possibly causing the timeout here).

On Sat, Oct 20, 2018 at 3:37 PM Fabio Tudone <fabtud at> wrote:

> Hi, some info from a brief experience (as well as some questions) about
> running Loom tests.
> As far as I can see existing tests are found in
> "test/jdk/java/lang/[Continuation|Fiber]" and are TestNG-based but run via
> JTReg (more info and download linke here
> and "doc/testing.[md|html]" explains the new way JTReg tests can be run.
> For example, I could run some tests with "make run-test
> TEST=test/jdk/java/lang/Fiber/ JTREG="JOBS=1;VM_OPTIONS=-Xdebug
> -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=5005"".
> BTW enabling debugging slows down things a lot for some reason and I
> cannot always connect, let alone halt in breakpoints; anyone has test
> debugging info to offer and maybe some devenv setup wisdom as well? I
> usually use IJIdea Community, what do you use and how? E.g. do you first
> write them in a separate workspace and then adapt them for JTReg  and the
> JDK tree and retry running them from there?
> As a side note, I think the Graal guys are really doing the collaboration
> right, e.g. (apart from the cool website)
> and and
> I'd really love if Loom got closer to that kind of setup (and I'd be glad
> to help with that).
> Also it looks like some tests fail unless the build has debug enabled (due
> to missing "-XX:+SafepointALot": I suppose it adds more safepoints than
> usual but why and where?) so the build should be configured with something
> like "sh configure --with-jtreg=/opt/my_jtreg_bin_untar/ --enable-debug".
> If you already built one I suggest you just delete everything in "build"
> and start over with debug enabled because it is just easier, else you'll
> need to specify the configuration you want to use for every target (and I'm
> not sure at all how it would work with tests).
> Anyway "java/lang/Continuation/Driver" fails anyway here due to a timeout
> error (attaching trace), has someone already encountered that?
> @Ron any chance that you or someone with access can include such info the
> project page?
> Finally I understand that Duncan MacGregor has contributed Graal support
> for Loom but I couldn't find that code, does someone have any pointers to
> it?
> Thanks,
> -- Fabio

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