RFR: 8151670: Unexpected concurrent refinement deactivation and reactivation

Kim Barrett kim.barrett at oracle.com
Wed Mar 23 07:41:24 UTC 2016


> On Mar 22, 2016, at 12:45 PM, Jon Masamitsu <jon.masamitsu at oracle.com> wrote:
> 
> Kim,
> 
> Looks correct.  I assume there will be a new version with a few
> changes from Mikael's comments.

Thanks Jon.  Replies below.

New webrev:
full: http://cr.openjdk.java.net/~kbarrett/8151670/webrev.01/
incr: http://cr.openjdk.java.net/~kbarrett/8151670/webrev.01.inc/

> Couple of minor points.
> 
> http://cr.openjdk.java.net/~kbarrett/8151670/webrev.00/src/share/vm/gc/g1/dirtyCardQueue.hpp.frames.html
> 
> Extra "to" (end of 84 and beginning of 85).
>>   84   // function.  If "consume" is true, the node's index is updated to
>> 85 // to exclude the processed elements, e.g. up to the element for

Fixed.

> http://cr.openjdk.java.net/~kbarrett/8151670/webrev.00/src/share/vm/gc/g1/dirtyCardQueue.cpp.frames.html
> 
> Instead of
> 
>> 186 assert(node->index() == buffer_size(), "apply said fully consumed");
> 
> maybe something a little more wordy
> 
> assert (node->index() == buffer_size(), "Buffer was not fully processed as claimed: index " SIZE_FORMAT " buffer_size " SIZE_FORMAT, node->index(), buffer_size());
> 
> Would this assertion actually fit better at the end of
> 
> 153 bool DirtyCardQueueSet::apply_closure_to_buffer(CardTableEntryClosure* cl,
> 
> 174   }
> 
> assert (!result || node->index() == buffer_size(), "Buffer was not fully processed as claimed: index " SIZE_FORMAT " buffer_size " SIZE_FORMAT, node->index(), buffer_size());
> 175 return result;
> 176 }
> 
> so that you don't need it in apply_closure_to_completed_buffer()
> and mut_process_buffer()?

I added an assertion helper that provides more information, and called from the two
with the previous limited content asserts.  I don’t think apply_closure_to_buffer is the
right place for it; it’s the other two places that are making decisions that will be wrong
if that assertion doesn’t hold.



More information about the hotspot-gc-dev mailing list