RFR: 8062247: Allow WhiteBox test to access JVM offsets

[Coleen Phillimore]

Hi Yumin,

Can you not create Java hashtables from C++?  This is really 
convoluted.  I think there may be a more direct way to encode these 
offsets and get their values.  Eg.  Have a WB API to 
get_offset("value")  and have a table coded in the WB api to associate 
the value string with the offset.  At worst, use a C++ hashtable to 
perform this association.

Because the WB api calls up to Java for each hashtable insert, it's not 
like calling back to WB api for the offset is going to be less efficient.

I don't like this change.

Thanks,
Coleen

On 10/28/2014 12:01 AM, Yumin Qi wrote:
> Please review
>
> bug: https://bugs.openjdk.java.net/browse/JDK-8062247
> webrev: http://cr.openjdk.java.net/~minqi/8062247/webrev00/
>
> Summary: Internal test failed since the variable offsets changed in 
> hotspot. The way to get offset in the test is hard-coded. To reduce 
> the risk of future changes of hotspot offsets, the fix add a WhiteBox 
> API function to get a map for FileMapHeaderInfo, which return the 
> members' offsets in a Hashtable.
>
> Tests: JPRT, jtreg.
>
> Thanks
> Yumin