RFR (M): 8184346: Clean up G1CMBitmap

[Roman Kennke]

Hi Thomas,

> Hi all,
>
>   can I have reviews for this change that tries to clean up (and only
> clean up) the G1CMBitMap class (and the surrounding helper classes) a
> bit?
>
> What has been done:
> - fix naming
> - improve visibility of methods
> - remove superfluous code
> - make G1CMBitMapClosure pass a HeapWord* instead of a bitmap index,
> avoiding that the user code is cluttered with conversions from bitmap
> indices to HeapWords
> - remove inheritance between G1CMBitMap and G1CMBitMapRO, similar to
> the BitMap class make G1CMBitMapRO a "view" of G1CMBitMap.
> - remove unused code in G1CMBitMapRO
> - move method implementations into .inline.hpp file
The changes look good to me.

+ return _cm->nextMarkBitMap()->is_marked((HeapWord *)obj);

I'd write that as

(HeapWord*) obj

but I'm never quite sure what style is preferable in Hotspot ;-)


Are changes in  g1FromCardCache.cpp/.hpp unrelated?

> The next CR JDK-8184347 will deal with moving G1CMBitmap* into separate
> files.
And while you're at it, you may want to move it to gc/shared and renamed
it to something like MarkBitmap?
https://bugs.openjdk.java.net/browse/JDK-8180193

Best regards,
Roman (not official reviewer)

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://mail.openjdk.org/pipermail/hotspot-gc-dev/attachments/20170714/66445313/attachment.htm>