RFR: Keep root bits until the end of partial

[Zhengyu Gu]

Probably should encapsulate the logic inside root_regions->clear()?

-Zhengyu

On 06/14/2017 09:36 AM, Aleksey Shipilev wrote:
> Actually that was wrong. We still need to clean root bits at the first step,
> because partial may get cancelled on OOME, leaving roots set indefinitely:
>   http://cr.openjdk.java.net/~shade/shenandoah/partial-keeproots/webrev.02/
>
> -Aleksey
>
> On 06/14/2017 03:34 PM, Zhengyu Gu wrote:
>> Okay.
>>
>> -Zhengyu
>>
>> On 06/14/2017 09:31 AM, Aleksey Shipilev wrote:
>>> We need to keep region->is_root bit until partial is over, because otherwise
>>> hs_err from the mid-partial crash looks misleading: it could say that some
>>> region is not root, while it actually is!
>>>
>>> See:
>>>   http://cr.openjdk.java.net/~shade/shenandoah/partial-keeproots/webrev.01/
>>>
>>> Thanks,
>>> -Aleksey
>>>
>
>