Re: [hibernate-dev] Optimizing reflection optimization
Carlo deWolfe found that one of the big perf problems with Java
reflection is that it is constantly doing security checks with the
security manager and every get/find request makes a copy of the
method/field objects. He had a hack for this, but you'll have to
consult him on what it is. The JBoss Reflections project might have it.
I think once this hack is intiated, it is an improvement over Javassist.
If you think about it, Java VM has to build up this information anyways...
Steve Ebersole wrote:
I ran this same exact comparison before and I seem to recall much
different results. Unfortunately I no longer have that code. This was
part of
http://opensource.atlassian.com/projects/hibernate/browse/HHH-227
Can you make sure you "prime" or "warm up" the jvm before you start
taking measurements?
On Thu, 2010-05-27 at 15:39 +0300, Кирилл Кленский wrote:
> Hi,
>
> My measurements have indicated that there is a performance gain. I have
> measured the time spent in setPropertyValues and getPropertyValues.
> The optimized version was 4 times faster in these methods giving an
> estimated application performance increase of about 3%.
> Optimizing getPropertyValue and setPropertyValue could give 1.5% more
> according to our rough calculations.
>
> Kirill
>
> 26 мая 2010 г. 23:53 пользователь Emmanuel Bernard
> <emmanuel(a)hibernate.xn--org>-8fga3f8au1a3a:
>
>> Hi,
>> Have you noticed a perf difference in your application with and without the
>> patch?
>> I am wondering if modern VMs have catched up with what Javassist does.
>>
>> On 26 mai 2010, at 18:29, Кирилл Кленский wrote:
>>
>>> 1. I have noticed that
>>> org.hibernate.bytecode.javassist.BulkAccessorFactory.findAccessors(...)
>> is
>>> searching for accessor methods in the optimized entity class only. This
>>> means that the methods from the superclasses are not visible during
>>> BulkAccessor creation unless overridden by child classes. By enhancing
>> the
>>> algorithm to search down the inheritance tree we could avoid creation of
>>> redundant methods which increase the code verbosity a lot. In our case
>>> almost all the entities are inherited from the base classes having the
>>> common entity properties defined, so the reflection optimization does not
>>> work for any of them until we override the inherited methods in all the
>>> child classes. The implementation is trivial, but I have got a ready
>>> prototype if anybody is interested.
>>
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--
Bill Burke
JBoss, a division of Red Hat
http://bill.burkecentral.com