Retain ProtectionDomain for instrumented classes

[twundke]

I'm using runtime AOP as a part of JBoss Cache. This is all contained within a standalone application that uses custom class loaders and custom ProtectionDomain objects. The problem that I'm seeing is that AOP-generated classes lose their associated protection domain, which in my case contains various additional fields that my application requires.

This problem is easy to verify as AspectManager.transform doesn't pass on the ProtectionDomain object when calling the translate method. The protection domain is simply lost.

Would it be possible to assign to the transformed class the same protection domain object as the original class?

Thanks.

Tim.

[starksm64]

File a bug report as we cannot be throwing away the protection domain.
http://jira.jboss.com/jira/browse/JBAOP

[bill.burke]

This is not true. The ClassLoader creates the class and it has the ProtectionDomain. A special ProtectionDomain is created for dynamically created classes though.

[starksm64]

Give a concrete example that illustrates where the PD is getting lost then Tim.

[twundke]

Sorry I wasn't clearer in my original post. It's been a while since I looked at this issue.

My particular problem is that the generated field wrapper inner classes don't get assigned the correct protection domain. Here's a stack trace that shows the problem occuring.

 getDefaultDomain():1583, ClassLoader.java
 preDefineClass():483, ClassLoader.java
 defineClass():614, ClassLoader.java
 defineClass():465, ClassLoader.java
 invoke0():-1, NativeMethodAccessorImpl.java
 invoke():39, NativeMethodAccessorImpl.java
 invoke():25, DelegatingMethodAccessorImpl.java
 invoke():585, Method.java
 toClass():52, StandaloneClassPool.java
 toClass():962, CtClass.java
 compileOrLoadClass():119, TransformerCommon.java
 createOptimizedInvocationClass():572, FieldAccessTransformer.java
 buildOptimizedReadWrapper():358, FieldAccessTransformer.java
 buildOptimizedWrappers():342, FieldAccessTransformer.java
 buildFieldWrappers():232, FieldAccessTransformer.java
 buildFieldWrappers():65, FieldAccessTransformer.java
 transform():592, Instrumentor.java
 translate():572, AspectManager.java
 transform():490, AspectManager.java
 aspectTransform():100, AopAgent.java
 transform():141, AopAgent.java
 transform():122, TransformerManager.java
 transform():155, InstrumentationImpl.java
 defineClass1():-1, ClassLoader.java
 defineClass():620, ClassLoader.java
 defineClass():320, BaseURLClassLoader.java
 access$000():38, BaseURLClassLoader.java
 run():108, BaseURLClassLoader.java
 run():98, BaseURLClassLoader.java
 doPrivileged():-1, AccessController.java
 findClass():96, BaseURLClassLoader.java
 findClassInternal():168, BaseClassLoader.java
 findClassInternal():146, BaseClassLoader.java
 findClassInternal():49, FrameworkClassLoader.java
 loadClass():280, BaseClassLoader.java
 loadClass():251, ClassLoader.java
 loadClassInternal():319, ClassLoader.java
 initialiseDomains():117, DomainManagerImpl.java
 <init>():78, DomainManagerImpl.java
 start():153, FrameworkController.java
 invoke0():-1, NativeMethodAccessorImpl.java
 invoke():39, NativeMethodAccessorImpl.java
 invoke():25, DelegatingMethodAccessorImpl.java
 invoke():585, Method.java
 initialiseFramework():366, FrameworkLoader.java
 main():463, FrameworkLoader.java

The toClass method of StandaloneClassPool does the following:

 Class cl = Class.forName("java.lang.ClassLoader");
 java.lang.reflect.Method method
 = cl.getDeclaredMethod("defineClass",
 new Class[]{String.class, byte[].class,
 int.class, int.class});

My classloader doesn't get a chance to define the class, causing the field wrappers to be assigned a default protection domain.

So, what's actually needed is for the class pool to use the correct classloader when calling defineClass.

Hope that helps.

Tim.

[starksm64]

The following issue has been created to validate or reject this:
http://jira.jboss.com/jira/browse/JBAOP-126

[twundke]

Thanks Scott. I'm happy to help with the implementation of the fix if needed.

Tim.