Re: [DISCUSS] use backport-concurrent instead of repackaged concurrent classes

[Brian McCallister]

On Jun 4, 2007, at 6:58 PM, Patrick Linskey wrote:
To date, OpenJPA has done minimal repackaging (currently only the EDU
classes). I'm wary of changing this policy, especially considering how
few classes we repackage. In fact, I think that not repackaging the
backport classes is a good thing, as it lets people easily plug in the
faster Java 5 version without having to then re-repackage those
classes and recompile them.

Any other opinions?

It is case by case, of course. As mentioned, backport is probably not  
worth repackaging. My tendency, for small libraries, is to prefer  
repackaging :-)

-Brian


-Patrick

On 6/4/07, Brian McCallister <[EMAIL PROTECTED]> wrote:

On Jun 4, 2007, at 6:39 PM, Patrick Linskey wrote:

> I'm allergic to re-namespacing... why do you think that we should
> do so?

Avoiding collisions. The majority case is that people don't care
about the extra 327k but they care a lot about not hitting conflicts
with libraries. Dug Lea's libraries are not a great example of this,
but Hibernate *is* a good example -- it relies on EHCache by default,
going from 3.0 to 3.1 to 3.2 is a major non-backwards compatible
change, and you cannot use EHCache 1.2 with 3.0, so you are trapped
unable to upgrade dependencies. Weblogic and ANTLR (a couple versions
back) is another great example.

Basically, if you are a library (which OpenJPA is) you want to
minimize the degree to which you place constraints on the runtime
environment of your users. I can easily imagine someone using a home-
rolled build of the concurrent backport which was subtly
incompatible. Yes, your user could renamespace then, but it is better
if they *never have the issue*

-Brian

>
> -Patrick
>
> On 6/4/07, Brian McCallister <[EMAIL PROTECTED]> wrote:
>> I would suggest using backports and repackaging -- though I have
>> trouble imaging the interfaces on backports changing. I,  
personally,
>> am of the opinion that if at all possible, small dependencies  
should
>> be re-namespaced and bundled.
>>
>> -Brian
>>
>> On Jun 4, 2007, at 4:22 PM, Patrick Linskey wrote:
>>
>> > Hi,
>> >
>> > In the process of doing some concurrency-related work on
>> OpenJPA, I've
>> > run across the need for a ReentrantReadWriteLock, akin to what
>> is in
>> > Java 5's java.util.concurrent package, Emory University's
>> > edu.emory.mathcs.backport package, and Doug Lea's  
EDU.oswego.cs.dl
>> > package.
>> >
>> > Currently, OpenJPA has repackaged copies of some of the code  
from
>> > EDU.oswego.cs.dl, but not everything. I'd like to get rid of the
>> > repackaged copies, and move to the versions in
>> > edu.emory.mathcs.backport. According to Doug Lea's website, the
>> > backport classes are preferable to the EDU.oswego.cs.dl  
classes at
>> > this point.
>> >
>> > This change is independent of future changes to allow for
>> pluggability
>> > of the concurrent implementation, and only impacts those classes
>> that
>> > we are already directly repackaging.
>> >
>> > Thoughts?
>> >
>> > -Patrick
>> >
>> > --
>> > Patrick Linskey
>> > 202 669 5907
>>
>>
>
>
> --
> Patrick Linskey
> 202 669 5907




--
Patrick Linskey
202 669 5907