RFR: Verifier should use non-optimized root scans

[Aleksey Shipilev]

On 07/04/2017 06:47 PM, Roman Kennke wrote:
> Am 04.07.2017 um 18:28 schrieb Aleksey Shipilev:
>> Dealing with bugs in the optimized code cache iterator is bad without having a
>> verifier that does *not* walk through the iterator in question. It makes sense
>> to use "slow" root scan to verify everything without touching
>> Shenandoah-specific code.
>>
>> Webrev:
>>   http://cr.openjdk.java.net/~shade/shenandoah/verifier-slow-roots/webrev.01/
>>
>> Testing: hotspot_gc_shenandoah
>>
>> Thanks,
>> -Aleksey
>>
>>
> This is a good idea! Please push!

I actually blew it: we need to hand over stack from RP to reachability scan. But
we can also accept multiple root scans. Plus add some monitoring:
 http://cr.openjdk.java.net/~shade/shenandoah/verifier-slow-roots/webrev.02/

Thanks,
-Aleksey