serialize.cpp uses objArrayOopDesc::base_offset_in_bytes(T_BYTE)

[Keith McGuigan]

Christian Thalinger wrote:
> Keith McGuigan wrote:
>> I suspect that's a bug that should be able to be safely converted to a 
>> T_OBJECT.
>>
>> The code you reference in serialize.cpp is used to write out and read in 
>> data to/from the shared class archive file for class data sharing (CDS). 
>>   It writes out a number of constants in the header of the file and then 
>> verifies that these constants haven't changed when the archive file is 
>> read back in.  If you change this from T_BYTE to T_OBJECT, it will 
>> likely change that value (unless we're real lucky with the alignments), 
>> and this may prevent archive files created before your change from being 
>> loaded into VMs after your change.  I think that's ok, though, since 
>> deployments run -Xshare:dump (creating a new archive) whenever a new JDK 
>> is installed.
> 
> Thanks for the explanation, that seems reasonable to me.  Should I open
> a CR and propose a patch on hotspot-runtime-dev (Tom told me that this
> code is owned by the runtime team)?

Sure.

--
- Keith