Take 4: 8225716: G1 GC: Undefined behaviour in G1BlockOffsetTablePart::block_at_or_preceding

[Andrew Haley]

Please.  :-)

http://cr.openjdk.java.net/~aph/8225716-4/

On 6/18/19 3:48 PM, Andrew Haley wrote:
> On 6/17/19 9:20 PM, Thomas Schatzl wrote:
>>> It *might* be a (pre-existing) bug that the heap memory range
>>> predicates don't accept pointer to volatile. But looking at the
>>> asserts you needed to fix, my reaction is to question their utility,
>>> and wonder if they should just be removed.  What do others think?
>>>
>>   not seeing that they are particularly useful, so good to just remove
>> to me too.
> 
> OK.
> 
> I take it, though, that we still need the check_index() in
> 
> void G1BlockOffsetTable::set_offset_array(size_t index, u_char offset) {
>   check_index(index, "index out of range");
>   Atomic::store(offset, &_offset_array[index]);
> }
> 
> ... and therefore we're still going to need a raw version of
> set_offset_array() because zero_bottom_entry_raw() is called before the
> HeapRegion is initialized, and therefore check_index() will fail.
> 


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