RFR: 8261413: Shenandoah: Disable class-unloading in I-U mode [v3]

[Aleksey Shipilev]

On Mon, 15 Feb 2021 21:12:53 GMT, Roman Kennke <rkennke at openjdk.org> wrote:

>> JDK-8261341 describes a serious problem with I-U mode and class-unloading. Let's disable class-unloading in I-U for now as a workaround.
>> 
>> Testing:
>>  - [x] hotspot_gc_shenandoah
>>  - [x] tier1 (+UseShenandoahGC +IU)
>>  - [x] runtime/CreateMirror/ArraysNewInstanceBug.java (+UseShenandoahGC +IU +aggressive) many times in a row w/o failure
>
> Roman Kennke has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Don't disable all class-unloading with I-U, disabling concurrent class-unloading is sufficient

Marked as reviewed by shade (Reviewer).

-------------

PR: https://git.openjdk.java.net/jdk/pull/2477