[hibernate-dev] Hibernate & Java 5 ?

[Emmanuel Bernard]

I don't think it's critical to backport this for 1.4 JDK users. But if you want to spare cycles...

On 9 déc. 2009, at 12:48, Alex Snaps wrote:

> I have finished a first version of it all:
> It is supporting both jdk 1.4 and 1.5+. So that if the
> java.util.concurrent classes are present, it will use the new
> ConcurrentStatisticsImpl, otherwise will fallback to the current
> StatisticsImpl. As mentioned, I had to extract interfaces for
> EntityStatistics, CollectionStatistics, SecondLevelCacheStatistics and
> QueryStatistics.
> Now, there is still the issue of the dirty reads within the current
> StatisticsImpl. (no synchronization on read)...
> What would you guys think of fixing these with the
> backport-util-concurrent ? So that even the 1.4 jdk get better
> concurrency on these...
> That would include a new dependency... I'm also currently looking into
> not including the deps, and using the same tricks as they are doing to
> diminish contention...
> Their AtomicLong relies on synchronization, but at least every stat
> gets its own lock, versus everyone competing for the same one as it is
> currently the case.
> wdyt?
> 
> On Tue, Dec 1, 2009 at 3:59 PM, Steve Ebersole <steve at hibernate.org> wrote:
>> I guess I have just been waiting until we can actually leverage 1.5
>> features (ala utilize enums or expose generics/typing).  That will not
>> happen for 3.5.
>> 
>> Now statistics are encapsulated behind a set of interfaces (Statistics
>> and StatisticsImplementor).  We could make this alterable like I did for
>> JDBC 3/4 based on the JVM.  That would mean reflection code though.
>> 
>> I do not actually know of any real cases of Hiberate being used in 1.4
>> environments today.  So maybe we can just make it 1.5 compatible.
>> 
>> Votes?
>> 
>> 
>> On Tue, 2009-12-01 at 14:38 +0100, Alex Snaps wrote:
>>> We've been doing some improvement to the Hibernate statistics at
>>> Terracotta, when we realized how much the synchronization on it was
>>> impacting throughput in our tests.
>>> That is work we wanted to contribute back to you guys, should
>>> Hibernate Core be target at 1.5. As it seems that's not yet the case,
>>> so there isn't much you guys will be able to do with these changes...
>>> We discussed about that at Devoxx with Max and Emmanuel and thought it
>>> was okay to have 1.5 impl. of the specs (java.util.concurrent based)
>>> already. Apparently not :( What timeframe do you see 1.4 support being
>>> dropped?
>>> 
>>> On Tue, Dec 1, 2009 at 1:44 PM, Steve Ebersole <steve at hibernate.org> wrote:
>>>> I have issues reloading Maven-based projects in IntelliJ as well.  I
>>>> simply try to minimize the number of times I reload.
>>>> 
>>>> Hibernate is *built* with JDK 1.5, but not all the modules are 1.5
>>>> compatible.
>>>> 
>>>> What "statistics work" discussion?  I must have missed that.  But for
>>>> sure the hibernate-core module should remain 1.4 compatible.  Dropping
>>>> 1.4 support is on the roadmap, but not for 3.5
>>>> 
>>>> 
>>>> On Tue, 2009-12-01 at 11:32 +0100, Alex Snaps wrote:
>>>>> Hey,
>>>>> Doing a svn update of the Hibernate trunk, I realized I probably had
>>>>> changed the project to be Java5 manually as it reverted to 1.4
>>>>> (because of some pom.xml change) in IntelliJ.
>>>>> Talking to Max and Emmanuel at Devoxx I thought trunk was now to be
>>>>> Java 5? Is this not the case after all, or are poms only update when
>>>>> the first Java5 language/jdk feature sneaks in?
>>>>> As discussed we discussed, all the statistics work heavily rely on
>>>>> java.util.concurrent classes, so that is "more or less" important for
>>>>> that patch...
>>>>> Btw do you guys have a contributor agreement somewhere, I couldn't find it.
>>>>> Thanks,
>>>>> Alex
>>>>> 
>>>> --
>>>> Steve Ebersole <steve at hibernate.org>
>>>> Hibernate.org
>>>> 
>>>> 
>>> 
>>> 
>>> 
>> --
>> Steve Ebersole <steve at hibernate.org>
>> Hibernate.org
>> 
>> 
> 
> 
> 
> -- 
> Alex Snaps <alex.snaps at gmail.com>
> Software Engineer - Terracotta
> http://twitter.com/alexsnaps
> http://www.linkedin.com/in/alexsnaps
> 
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