Re: [aspectj-users] Bytecode Caching in AspectJ

[Andy Clement <andrew.clement@xxxxxxxxx>]

IIRC you shouldn't have to turn permissions on to get it to run.
However some of the configurable behaviour won't be configurable if
you don't enable some permissions.  For example AspectJ needs to be
able to access system properties to check some configuration settings.

What precise permission is it complaining about? (and where?)

cheers,
Andy

On 29 July 2012 23:07, Jeevitha Muthusamy <mail2jeevithamk@xxxxxxxxx> wrote:
> Thanks Andy !!
>
> We have faced java security permission issue while enabling Aspect code in
> Websphere Application server.
>
> Is it mandatory to set java security  permissions to enable aspects for
> Websphere or for all application serversr??
>
> Please let me know some aspectj features since 1.5.4,  that is applicable
> and effective in Java 6.
>
> Thanks,
> Jeevitha
>
>
>
> On Sat, Jul 28, 2012 at 4:10 AM, Andy Clement <andrew.clement@xxxxxxxxx>
> wrote:
>>
>> On 23 July 2012 01:54, Jeevitha Muthusamy <mail2jeevithamk@xxxxxxxxx>
>> wrote:
>> >    May I know what is Bytecode Caching in AspectJ1.7 and its benefits??
>>
>> The caching is currently best described here:
>> https://bugs.eclipse.org/bugs/show_bug.cgi?id=367673
>>
>> It is a per classloader cache of woven bytecode that avoids re-weaving
>> on subsequent restarts.
>>
>> >    And when caching is enabled, what exactly is cached??
>>
>> Per the readme and that bug, the caching is enabled when you turn on
>> the system property:
>>  -Daj.weaving.cache.enabled=true
>>
>> The woven bytecode is cached on a per classloader basis.  On a
>> subsequent JVM restart
>> the cached woven bytecode will be used instead of repeating the weaving
>> process.
>>
>> >   What is the life of Caching? Is it automatically refreshed or is
>> > Static?
>>
>> It is not a super intelligent cache.  If the incoming classes change
>> (in length) then the
>> cache will not be used (as it looks like this class needs reweaving),
>> but changing the
>> set of aspects will not cause reweaving to happen (IIRC).  So this is
>> for a system
>> that is pretty static in terms of aspects but you want faster startup
>> on secondary starts.
>>
>> >   Is there any Memory  limit for Caching? ie. If only to certain extent
>> > Caching is done or is unlimited??
>>
>> disk space is the limiting factor I believe.
>>
>> >   Is there any constraints(Where this feature is most applicable? ) to
>> > use
>> > this feature?
>>
>> If you have a system where the set of aspects are fixed, this can work
>> well for you.
>> The bug report contains some performance metrics showing you the benefits.
>>
>> >   It will be more helpful, if any use-cases provided or any documents
>> > regarding this feature!!
>>
>> Unfortunately the only real docs are in the bugzilla, I haven't had the
>> time
>> to integrate anything into the main docs.
>>
>> There are further changes coming into this area on two fronts:
>>
>> - 'asynchronous' caching. It has become apparent that storing entries
>> on the disk in the first start is a bottle-neck and slowing down that
>> initial start.  aynchronous caching will do the storing in a thread.
>> - assume common aspects across all classloaders to give a further
>> boost.  If your system meets this requirement then the cache will
>> actually be consulted during the initial start if it sees two
>> classloaders loading the same class (only one will suffer the weaving
>> cost).  This can make the initial start faster than without caching
>> (as well as speeding up the latter restarts).
>>
>> Andy
>> _______________________________________________
>> aspectj-users mailing list
>> aspectj-users@xxxxxxxxxxx
>> https://dev.eclipse.org/mailman/listinfo/aspectj-users
>
>
>
> _______________________________________________
> aspectj-users mailing list
> aspectj-users@xxxxxxxxxxx
> https://dev.eclipse.org/mailman/listinfo/aspectj-users
>