RFR: 8225716: G1 GC: Undefined behaviour in G1BlockOffsetTablePart::block_at_or_preceding

[Andrew Haley]

On 6/14/19 1:06 PM, Thomas Schatzl wrote:

> Btw, please push the final fix into the jdk/jdk13 repos (I assume we
> will manage reviewing this in time ;)). In any case this is serious
> enough to get it into the product asap.

Here, with all comments in this thread take into account:

http://cr.openjdk.java.net/~aph/8225716-2/

One thing which gave me pause was the need to cast away const when
calling memset_with_concurrent_readers(). I don't think it's actually
wrong, given that memset_with_concurrent_readers() has the
specification we need: we don't need strict volatile behaviour in the
sense of ordering. We just need to be sure that there are no
intermediate values other than what we ask for.

-- 
Andrew Haley
Java Platform Lead Engineer
Red Hat UK Ltd. <https://www.redhat.com>
https://keybase.io/andrewhaley
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