RFR(S/M) : 8242310 : use reproducible random in hotspot compiler tests

[Igor Ignatyev]

Vladimir, Tobias,

thank you for review! could you please also review 8241707 (on hotspot-dev) which prevents me from pushing this patch?

-- Igor

> On Apr 8, 2020, at 11:54 AM, Vladimir Kozlov <vladimir.kozlov at oracle.com> wrote:
> 
> Looks good.
> 
> Thanks,
> Vladimir
> 
> On 4/7/20 6:04 PM, Igor Ignatyev wrote:
>> http://cr.openjdk.java.net/~iignatyev//8242310/webrev.00
>>> 282 lines changed: 123 ins; 24 del; 135 mod;
>> Hi all,
>> could you please review the patch which marks hotspot compiler tests w/ randomness k/w and uses Utils.getRandomInstance() instead of Random w/ _random_ seeds where possible? To identify tests which should be marked, I've used both static (in a form of analyzing classes which directly or indirectly depend on Random/SecureRandom/ThreadLocalRandom) and dynamic (by instrumenting the said classes to log tests which called their 'next' methods) analyses. I've decided *not* to mark tests which use SecureRandom only via File.createTemp* b/c in all such cases temp files are not used as a source of randomness, but rather just a reliable way to get a new/empty file/dir.
>> the patch also
>>  - replaces fixed seed w/ 42 (in the tests which don't really depend on a seed value) as it's most common fixed seed in hotspot test suite;
>>  - moves Utils.getRandomInstance() calls closer to usage, so 'To re-run test with same seed value please add ... ' won't be printed out by the tests which don't actually use random but use share classes which might use random.
>> webrevs: for the sake of reviewers, I've split the patch into parts, webrev.code.00 has only changes in the code, webrev.kw.00 -- only adds the k/w (and comments in few places where one might think k/w is needed), and webrev.00 contains all changes (including copyright year updates)
>> http://cr.openjdk.java.net/~iignatyev//8242310/webrev.code.00
>>> 109 lines changed: 41 ins; 24 del; 44 mod;
>> http://cr.openjdk.java.net/~iignatyev//8242310/webrev.kw.00
>>> 84 lines changed: 82 ins; 0 del; 2 mod;
>> http://cr.openjdk.java.net/~iignatyev//8242310/webrev.00
>>> 282 lines changed: 123 ins; 24 del; 135 mod;
>> NB the patch depends on 8241707[1], which is currently under review[2].
>> testing: test/hotspot/jtreg/compiler tests on {linux,windows,macosx}-x64
>> JBS: https://bugs.openjdk.java.net/browse/JDK-8242310
>> [1] https://bugs.openjdk.java.net/browse/JDK-8241707
>> [2] https://mail.openjdk.java.net/pipermail/hotspot-dev/2020-April/041300.html
>> Thanks,
>> -- Igor