RFR: 8203923: Add @requires feature to check flag values for the running JVM

[Stefan Karlsson]

On 2018-05-29 18:14, Vladimir Kozlov wrote:
> Looks good.

Thanks for reviewing.

>
> When you do tests changes you need to filter out running Graal with 
> ZGC because it does not support it yet.

Yes.

Thanks,
StefanK

>
> Vladimir
>
> On 5/29/18 7:21 AM, Stefan Karlsson wrote:
>> Hi all,
>>
>> Please review this patch to add @requires vm.opt.final.<vm flag 
>> name>, as a way to filter jtreg tests on the final value of flags in 
>> the test VM.
>>
>> http://cr.openjdk.java.net/~stefank/8203923/webrev.01/
>> https://bugs.openjdk.java.net/browse/JDK-8203923
>>
>> This patch is needed to allow tests to be filtered out when ZGC is run.
>>
>> ZGC doesn't support UseCompressedOops (and currently doesn't support 
>> ClassUnloading). Instead of adding @requires vm.gc != "Z" for tests 
>> that rely on ClassUnloading, I think it's nicer to write @requires 
>> vm.opt.final.ClassUnloading.
>>
>> This will filter out the test if any of the following conditions are 
>> met:
>> 1) The currently executing VM doesn't support ClassUnloading
>> 2) -XX:-ClassUnloading is passed to the test
>>
>> The second case can today be handled by @requires 
>> vm.opt.ClassUnloading == NULL | vm.opt.ClassUnloading == true, or 
>> maybe simpler @requires vm.opt.ClassUnloading != false, but if you 
>> need both @requires vm.opt.final.ClassUnloading should be used.
>>
>> The current solution requires the queried flags to be listed in 
>> vmOptFinalFlags. Maybe there's a way to get this to cover all flags 
>> automatically?
>>
>> Thanks,
>> StefanK