RFR 8231146: Heap object size

Roger Riggs Roger.Riggs at oracle.com
Thu Sep 19 17:35:28 UTC 2019

Hi Remi,

In j.u.Objects it will be more likely to be given the challenge it deserves
to be promoted in the long run.

With inline classes there are lots of different sizes depending on the 
inline array elements, embedded in another inline, embedded in a 
reference type,
with or without padding,  and depending on compressed oops or not, and 
other implementation
specific conditions.  So a single method isn't going to fill the need.
Regardless, it needs more thought about what it means.

Thanks, Roger

On 9/19/19 12:56 PM, Remi Forax wrote:
> Hi Roger,
> why not using sun.misc.Unsafe instead of j.u.Objects ?
> Rémi
> ----- Mail original -----
>> De: "Roger Riggs" <Roger.Riggs at oracle.com>
>> À: "valhalla-dev" <valhalla-dev at openjdk.java.net>
>> Envoyé: Mardi 17 Septembre 2019 22:00:57
>> Objet: RFR 8231146: Heap object size
>> Please review and comment:
>> This request adds a (probably temporary) API to return the heap size of
>> an object.
>> In prototyping with inline classes it will be useful to know an
>> approximation of the size of an object in the heap while prototyping
>> various tradoffs in performance and data structures.
>> Webrev:
>>    http://cr.openjdk.java.net/~rriggs/webrev-object-size-8231146/
>> Thanks, Roger

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