CRR (S): 7121623: G1: always be able to reliably calculate the length of a forwarded chunked array

Srinivas Ramakrishna ysr1729 at
Wed Dec 21 06:34:37 UTC 2011

Hi Tony --

For some reason, I cannot seem to be able to view either of the CR's you
mention below, and thus
lack the requisite background context for this change. The localized change
however looks fine,
and it is nice to distinguish the two states of the array in this way by
means of the sign of the length field.

One question is whether, for the sake of debugging & representational
uniformity, it would make sense to use the same
encoding in the other collectors that do this chunking (even though I
understand they may not have
the need to deal with 6484965, whatever that might be :-)

-- ramki

On Wed, Dec 14, 2011 at 2:17 PM, Tony Printezis
<tony.printezis at>wrote:

> Hi all,
> Can I have a couple of code review for this small change?
> The CR has a bit more explanation. The short version is that I'm now
> encoding the "start index of the next chunk" in the from-space length field
> of a chunked array (say *that* quickly!) as a negative value to always be
> able to distinguish it from the real length. This will simplify the code
> for the CR John is currently working on (6484965) but it's a small,
> self-contained change so it's good to get it code reviewed and pushed
> separately.
> Tony
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