RFR (xs) 8251209 [TESTBUG] CDS jvmti tests should use "@modules java.instrument"

[Alan Bateman]

On 07/08/2020 01:58, David Holmes wrote:
>
> It does in fact ensure that:
>
> "Otherwise, a test will not be run if the system being tested does not 
> contain all of the specified modules."
>
> http://openjdk.java.net/jtreg/tag-spec.html
>
> But as I said the module could be present in a JRE but you are still 
> using the MinimalVM.
Right, tests with `@modules java.instrument` will not be selected if the 
run-time under test doesn't contain this module.

It would be a bit strange to create a run-time image with a minimal VM 
build that doesn't have JVM TI but include java.instrument. All usages 
of -javaagent would be fatal because the JPLIS agent uses JVM TI. A long 
time ago there were calls for a way java.management and java.instrument 
to express that they required specific VM features but I don't think it 
came to anything. So nothing in jlink to catch this at link-time, at 
least for the case that there is only one libjvm in the generated 
run-time image. So technically I think the tests would need both 
@requires and @modules if someone really wanted to be able to run all 
tests with the minimal VM and expect jtreg to not select these tests.

-Alan.