> Yes it does (thru' AbstractConveter which it extends) - I can remove
> that reference completely by just making the getDefaultType() method
> abstract and having each implementation implement it.
>
Just an idea... You could just have the Abstract class holding a
WeakReference and then:
WeakReference clazz;
public void setClazz(Class clazz)
{
this.clazz = new WeakReference(clazz);
}
public Class getClazz()
{
return (Class) clazz.get();
}
Niall Pemberton wrote:
Woops, should have gone to dev@ list
---------- Forwarded message ----------
From: Niall Pemberton <[EMAIL PROTECTED]>
Date: Aug 7, 2007 2:36 AM
Subject: Re: Circular Reference on WeakHashMap
To: Clebert Suconic <[EMAIL PROTECTED]>
On 8/7/07, Clebert Suconic <[EMAIL PROTECTED]> wrote:
The solution seems simpler than I thought though...
After looking at the report again...
[EMAIL PROTECTED]
ClassConverter probably has a reference to Class... I thought this was
a reflection object.
It should be WeakReference<Class>.
Yes it does (thru' AbstractConveter which it extends) - I can remove
that reference completely by just making the getDefaultType() method
abstract and having each implementation implement it.
And... inspect your code for any other reflection usages.
OK when I get back I was going to have a play with JVMTIInterface - looks good.
Niall
Niall Pemberton wrote:
On 8/6/07, Clebert Suconic <[EMAIL PROTECTED]> wrote:
I have been investigating WeakHashMaps on BeanUtils 1.8 as part of a
investigation on this:
http://jira.jboss.com/jira/browse/JBAS-2299
Thanks for getting back to us so quickly.
(Which is not actually an issue with JBAS, but an issue when using
BeanUtils as part of the classPath).
There is a circular reference on the WeakHashMap, The WeakHashMap will
have the ClassLoader as the key, and it will have a reference back to
the Key from one of the Reflection objects. This doesn't work! (Please..
no discussions about this point.. if you don't believe me, do some
testing with simple stuff before discussing this and come back to me
only after that)
OK I will.
[EMAIL PROTECTED]
!--- [EMAIL PROTECTED]
!--- !--- class sun.reflect.GeneratedConstructorAccessor38
!--- !--- !--- [Ljava.lang.Object;@10800875
!--- !--- !--- !--- [EMAIL PROTECTED]
!--- !--- !--- !--- !--- [EMAIL PROTECTED]
!--- !--- !--- !--- !--- !--- class
sun.reflect.GeneratedConstructorAccessor38
!--- !--- !--- !--- !--- !--- !--- class java.lang.Class
!--- !--- !--- !--- !--- !--- !--- !---
[EMAIL PROTECTED]
!--- !--- !--- !--- !--- !--- !--- !--- !---
[EMAIL PROTECTED]
!--- !--- !--- !--- !--- !--- !--- !--- !--- !---
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!--- !--- !--- !--- !--- !--- !--- !--- !--- !--- !---
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!--- !--- !--- !--- !--- !--- !--- !--- !--- !--- !--- !---
[Ljava.util.HashMap$Entry;@28236766
!--- !--- !--- !--- !--- !--- !--- !--- !--- !--- !--- !--- !---
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!--- !--- !--- !--- !--- !--- !--- !--- !--- !--- !--- !--- !--- !---
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!--- !--- !--- !--- !--- !--- !--- !--- !--- !--- !--- !--- !--- !---
!--- [EMAIL PROTECTED]
!---!---!---!---!---!---!---!---!---!---!---!---!---!---!---!---
FieldReference private java.lang.Object
[EMAIL PROTECTED]
Detail
I'm not familiar with JBoss's JVMTIInterface or its output - and it
seems to be somewhat messed up in posting here - so I've (hopefully)
cleaned it up and re-posted in a Jira ticket I've opened for this
here:
https://issues.apache.org/jira/browse/BEANUTILS-291
I don't know if I'm preaching to the choir, but just in case this is new
information to someone... you should aways keep Reflection referenced as
SoftReferences (if you really have to). Reflection is aways a new object
so a WeakReference is too weak.
Preach away - I have no great knowledge of this stuff.
On JBossSerialization I have solved this using an interesting way. I
called it PersistentReference. I'm using SoftReferences, and keeping the
information to recreate it case the SoftReference is cleared:
http://fisheye.jboss.org/browse/JBoss/jboss-serialization/src/org/jboss/serial/references/PersistentReference.java?r=1.3
And also... you guys should write a testcase to validate if the Caching
is being cleared. (I don't know if you have one).
http://anonsvn.jboss.org/repos/jbossserialization/trunk/tests/org/jboss/serial/memory/MemoryLeakTestCase.java
You don't need to use the jboss-profiler API for this.. just create a
WeakReference to a new ClassLoader, and validate if it was released at
the end after some exercizing some code on this caching. You will
probably need to fill your memory almost to 100% on the test as
SoftReference are only gone when the memory is low.
Unfortunately I'm away on holiday soon for 3 weeks (12th August to 2nd
September) - so unless someone else picks this up - ii don't have time
to look at this until after that. Do you mind if we move the
discussion over to that Jira ticket I opened though?
Niall
Clebert Suconic
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