RFR (S): 8214277: Use merged G1ArchiveRegionMap for open and closed archive heap regions

[Kim Barrett]

> On Jan 8, 2020, at 8:38 AM, Thomas Schatzl <thomas.schatzl at oracle.com> wrote:
> 
> Hi all,
> 
>  could I have reviews for this small cleanup/simplification that merges the open and closed archive region map into a single one?
> 
> CR:
> https://bugs.openjdk.java.net/browse/JDK-8214277
> Webrev:
> http://cr.openjdk.java.net/~tschatzl/8214277/webrev/
> Testing:
> hs-tier1-5 (almost done, no issues), local gc/g1 jtreg
> 
> Thanks,
>  Thomas

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src/hotspot/share/gc/g1/g1Allocator.inline.hpp
 151 inline void G1ArchiveAllocator::clear_range_archive(MemRegion range, bool open) {

clear_range_archive no longer uses the open argument for anything
other than logging.  Is it worth keeping?

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src/hotspot/share/gc/g1/g1Allocator.inline.hpp 
 186   return (archive_check_enabled() &&
 187          (_archive_region_map.get_by_address((HeapWord*)object) != G1ArchiveRegionMap::NoArchive));

The indentation of line 187 is confusing; the indentation suggests the
open paren there is at the same nesting level as the one on the
preceeding line directly above.  The first open paren on line 186 and
the associated close could just be removed.

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src/hotspot/share/gc/g1/g1Allocator.inline.hpp 
 162   // This is the out-of-line part of is_closed_archive_object test, done separately
 163   // to avoid additional performance impact when the check is not enabled.

Pre-existing: Given that it is in an inline definition, the accuracy
of this comment seems questionable.

------------------------------------------------------------------------------

Jiangli already pointed out that _open_archive_region_map is no longer
used.