RFR: 8264908: Investigate adding BOT range check in G1BlockOffsetTablePart::block_at_or_preceding [v3]

[Ivan Walulya]

On Wed, 14 Jul 2021 14:13:16 GMT, Thomas Schatzl <tschatzl at openjdk.org> wrote:

>> Ivan Walulya has refreshed the contents of this pull request, and previous commits have been removed. The incremental views will show differences compared to the previous content of the PR.
>
> src/hotspot/share/gc/g1/g1BlockOffsetTable.inline.hpp line 119:
> 
>> 117:   size_t index = _bot->index_for(addr);
>> 118:   // We must make sure that the offset table entry we use is valid.
>> 119:   assert(index < _next_offset_index, "Precondition");
> 
> I feel a bit uneasy that the caller (`block_start`) allows more than the callee (values `< _hr->end()`), but this is probably the change that is supposed to be coming?
> Looks good, but I would have preferred the original change or the upcoming change with some asserts included.

I can add the deferred change, instead of splitting it off into a separate PR.

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PR: https://git.openjdk.java.net/jdk/pull/4775