RE: [aspectj-dev] Minor API request for BcelObjectType

["Larry Zhou" <lzhou@xxxxxxxxxx>]

Title: Message

 

First, our goal is to use AspectJ directly from jar files, make no code changes at all. Nowadays, what we do is get the source code, make the change and then build & use the jar.

 

Second, our change here is all about memory. We basically want to have a destructor-like thing in BcelObjectType, so we can reclaim the majority of memory back, even BcelObjectType instance is still live there,  particularly we need to make sure the ref to JavaClass is nullified, since that is the big memory hog.

finishedWith seems to be a perfect fit. But unfortunately, everything is commented out there. so we need to implement finishedWith in MyBcelObjectType to do clean up.

If in the future, all things in finishedWith are uncommented, we don't need the 1) from my original request list anymore, since we can call it directly.

 

Maybe another way to substitute my 1) is to make protected method dispose() which nullify every data member of BcelObjectType.

 

public void finishedWith() {

// dispose();

}

 

protected void dispose() {

  javaClass = null;

 ... = null;

 

...  = null;

}

 

but we still need methods/fields/interfaces/isObject to be protected, so they can be accessed from subclass.

 

Third, our own way of using it. In our situation, we know when a particular BcelObjectType is not needed anymore.

so we can make it a ghost one, that is no superclass, no interfaces, no methods/fields.

like this:

isObject = true; // means superclass = null;

interfaces = ResolvedTypeX.NONE

fields/methods = ResolvedMember.NONE;

 

Of course, every other data member is null as well. By doing this, we reclaim the memory back.

 

 

I hope these help you. Let me know if you have more questions.

 

Thanks,

 

Larry

-----Original Message-----
From: aspectj-dev-admin@xxxxxxxxxxx [mailto:aspectj-dev-admin@xxxxxxxxxxx] On Behalf Of Andrew Clement
Sent: Thursday, January 06, 2005 2:54 PM
To: aspectj-dev@xxxxxxxxxxx
Subject: [SPAM] Re: [aspectj-dev] Minor API request for BcelObjectType

Just before we raise an enhancement request and look at doing this for you, I'd be interested in a bit more detail.  You mention 'our own way of using AspectJ', can you give any more details?  It's just that if some proposed improvements to BcelObjectType (or the management of BcelObjectType objects) would be beneficial to everyone, I'd be keen to roll them directly into the AspectJ codebase.

thanks,
Andy.
---
Andy Clement
AspectJ Committer
clemas@xxxxxxxxxx

"Larry Zhou" <lzhou@xxxxxxxxxx>
Sent by: aspectj-dev-admin@xxxxxxxxxxx

06/01/2005 22:03

Please respond to
aspectj-dev@xxxxxxxxxxx

To	<aspectj-dev@xxxxxxxxxxx>
cc
Subject	[aspectj-dev] Minor API request for BcelObjectType

Hi,

We have been using AspectJ successfully in our development. AspectJ helps us a great deal. Thanks.

We had this memory issue with AspectJ, since every JavaClass instance was kept live all the time. To put it in real number, for example, to start weblogic app server 8.1.3 for integration, the extra memory usage by AspectJ was about 150M to 180M.

We would like to request the following changes for modifiers in BcelObjectType.java, ( No functionality change at all )
1) first 15 private data members changed from private to protected
2) constructor changed from package access to protected.
3) method getJavaClass changed from package to public. ( Even setJavaClass is public )

That way, we can subclass BcelObjectType, make it MyBcelObjectType, then kill this object when appropriate due to our own way of using AspectJ, we are able to cut the memory usage by 90% to around 15M now.

Let me know if you have any questions about my request.

Thanks a lot,

Larry