[11u]: RFR: 8222914: Partial backport of JDK-8218266

[coleen.phillimore at oracle.com]

This looks good.  Well done putting all the pieces together.
Coleen

On 7/31/19 11:11 PM, Langer, Christoph wrote:
>
> Hi,
>
> please help to review the backport for JDK-8222914: Partial backport 
> of JDK-8218266.
>
> As the description in JDK-8222914 is very sparse, I had to do some 
> guesswork. Here’s what I’ve done:
>
> First of all, it mentions JDK-8215505 being in 11u. I checked this and 
> found the patch was not in OpenJDK 11u. The bug itself seems to be a 
> secret Oracle bug. So I applied the patch for JDK-8215505 from jdk/jdk 
> and resolved it. It basically removed void 
> Dictionary::clean_cached_protection_domains(DictionaryEntry* probe). I 
> had to help mercurial a little bit because it didn’t apply cleanly 
> since there was probably some mismatch around the removed code 
> compared to the original version.
>
> Then I looked at the upstream patch for JDK-8218266. I first of all 
> applied the changes to 
> test/hotspot/jtreg/runtime/Dictionary/ProtectionDomainCacheTest.java 
> and added some handwork to make it run (e.g. updates to JarUtils). 
> Then I could then see that the test fails in 11u-dev which ought to be 
> fixed by the changes in the hotspot/share/classfile area. The essence 
> of the fix seems to be merely to resurrect 
> Dictionary::clean_cached_protection_domains and call it at the right 
> spot. The first thing was not too complicated by taking the current 
> “Dictionary::clean_cached_protection_domains” from jdk/jdk and make it 
> fit to jdk11u-dev. But the place where it is invoked in jdk/jdk does 
> not really exist in jdk11u code level. I looked around and then 
> thought the best place would be to call it in 
> ClassLoaderDataGraph::do_unloading when a dead loader was seen. The 
> closure for the loaded CLDs does not yet exist in jdk11u and lots of 
> other things seem to have changed in that area from 11 until now which 
> is too much for backporting.
>
> TL;DR: The test fails in 11u-dev without the patch and passes afterwards.
>
> Webrev: http://cr.openjdk.java.net/~clanger/webrevs/8222914.11u-dev.0/
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8222914 
> <https://bugs.openjdk.java.net/browse/JDK-8222914>
>
> Thanks
>
> Christoph
>