RFR 8055098: WB API should be extended to provide information about size and age of object.

[Thomas Schatzl]

Hi Leonid,

On Tue, 2014-08-19 at 16:44 +0400, Leonid Mesnik wrote:
> Dear All
> 
> Could I have review for this patch.
> issue: https://bugs.openjdk.java.net/browse/JDK-8055098
> webrev: http://cr.openjdk.java.net/~jcoomes/8u/lmesnik/8055098-wbapi/
> This patch applied clearly to jdk8u and jdk9. This is RFR for 
> integration into jdk9/hs-gc. The RFR for backporting I'll send after fix 
> is integrated into jdk9.
> 
> Fix:
> WB API was extended by methods which allow to know object size and if it 
> is in old generation. Also whitebox method which added young GC was 
> added. Fix included unit test.
> Testing: JPRT for 8u and 9, adhoc testing with different GCs.

  some comments about the test, the other changes look good:

- TestWBGC.java should probably get a 2014 copyright date

- the test does not have a bug id

- could you set the tenuring threshold for this test to 1 so that the
likelihood that the object is promoted is higher? Different collectors
may have different default tenuring thresholds.

I.e. actually, adding -XX:+AlwaysTenure should be sufficient.

Thanks,
  Thomas