RFR: 8191861: Move and refactor hSpaceCounters

[Erik Helin]

On 11/24/2017 02:38 PM, Stefan Karlsson wrote:
> Hi all,
> 
> Please review this patch to move and refactor HSpaceCounters.
> 
> http://cr.openjdk.java.net/~stefank/8191861/webrev.01
> https://bugs.openjdk.java.net/browse/JDK-8191861
> 
> The patch moves hSpaceCounters.hpp/cpp out from gc/g1 into gc/shared, so 
> that it can be reused by other GCs.

Looks good, but could you please add a local variable for the expression

_young_collection_counters->name_space()

that is repeated three times now in g1MonitoringSupport.cpp. I don't 
need a re-review for this small additional change.

Thanks,
Erik

> The patch also removes the dependency between HSpaceCounters and 
> GenerationCounters. The passed in GenerationCounters object was only 
> used to provide the name_space of the perf counter. This patch changes 
> G1 to explicitly pass in the name_space string instead of the 
> GenerationCounters.
> 
> This patch builds upon these two patches:
> 
> http://mail.openjdk.java.net/pipermail/hotspot-dev/2017-November/029267.html 
> 
> 
> http://mail.openjdk.java.net/pipermail/hotspot-dev/2017-November/029268.html 
> 
> 
> Thanks,
> StefanK