RFR: Fix object iteration over limit

[Aleksey Shipilev]

On 10/18/2017 01:09 PM, Aleksey Shipilev wrote:
> On 10/17/2017 09:13 PM, Zhengyu Gu wrote:
>> When iterating object using bitmap, we may pass TAMS limit if remaining oops under TAMS are not marked.
>>
>> http://cr.openjdk.java.net/~zgu/shenandoah/obj_itr/webrev.00/
> 
> I agree this is the bug (and a serious one, at that) -- thanks for catching this!
> I understand the fix, but let me see if there is a more concise solution.

What a mess. I think there are three places where we can hit this bug:
  http://cr.openjdk.java.net/~shade/shenandoah/markscan-tams-bug/webrev.01/

I think it would be cleaner to just rewrite marked_object_iterate. I can do this, if you want.

-Aleksey