Hi,

On 23.10.2010, at 01:25, Richard S. Hall wrote:

> Resurrecting an old thread from us...@felix...
> 
> Stuart, I'm trying to create a test case to create this scenario, but am 
> having no luck. All I did was create a proxy and then try to call its method 
> a lot of times. I never see a class load request to the module class loader 
> for sun.reflect even though the proxy class was defined using it. Is there 
> something I'm missing?
> 
> I'm trying to rewrite/simplify our rules for implicit boot delegation and we 
> have some code in the current version to try to handle Proxy when it is on 
> the call stack, however, I don't see why we have it or how it helps.
> 
> Clement, was this issue actually just a bug in iPOJO 
> (https://issues.apache.org/jira/browse/FELIX-2416) and had nothing to do with 
> the framework?

It was a bug in the framework. I did nothing in this area. Issac reported that 
it was working with the framework 3.1.0-SNAPSHOT.


Regards,

Clement

> 
> -> richard
> 
> On 6/17/10 1:29, Stuart McCulloch wrote:
>> 2010/6/17 Issac Noé García<[email protected]>
>> 
>>> Hi, this is my first post here,
>>> I have a bug I can solve :(
>>> The context:
>>> The platform: I'm using iPOJO 1.6.2, Felix 2.0.5, Jetty 1.0.1, XMLRPC or
>>> JsonRPC
>>> The application :
>>> I have two iPOJO components (service-exporter and real-service)
>>> service-exporter requires the real-service and expose it as a Json RPC
>>> service.
>>> 
>>> Its a simple application the real-service is like a "hello world"example.
>>> And I use a frontend using jscript to call the json service, and everything
>>> is OK, but only 15 calls!!  I need to update the bundle to have it running
>>> again (another 15 calls)
>>> Later, I changed the JSON RPC exporter for an XMLRPC exporter to see if it
>>> was an Jabsorb problem. but it throws the exception after 15 services calls
>>>  too.
>>> 
>>> Someone has an idea about what its happening here?
>>> 
>> it's a proxy classloader issue, we encountered the same thing with Guice a
>> while ago:
>> 
>>    http://code.google.com/p/google-guice/issues/detail?id=417
>> 
>> basically the issue is that after ~15 method calls the Sun JDK proxy code
>> switches
>> from using native reflection to a generated class (the class is better for
>> JIT compiling
>> but it takes longer to create than a few native reflection calls, hence the
>> threshold)
>> 
>> to make this switch the proxy instance needs access to the "sun.reflect"
>> classes,
>> which are usually available from the boot classloader via parent delegation
>> - but if
>> the proxy instance was created by an OSGi bundle then it could end up using
>> the
>> bundle's classloader (depending on the type being proxied)
>> 
>> this is where it gets problematic - if the proxy is using a bundle
>> classloader and
>> that bundle doesn't import "sun.reflect" then it won't be able to see this
>> package
>> and you get that exception... and the bundle typically won't import
>> "sun.reflect"
>> as it's a hidden JVM implementation issue
>> 
>> so what to do? for Guice we already use a custom (bridge) classloader for
>> bundle
>> created proxies, so we simple added a shortcut to load any "sun.reflect"
>> classes
>> via the system classloader - maybe iPOJO could so something similar?
>> 
>> otherwise there is a simple workaround, which is to set this framework
>> property:
>> 
>>    org.osgi.framework.bootdelegation=sun.reflect
>> 
>> in the Felix configuration file - then all bundles will be able to see the
>> "sun.reflect"
>> package without having to import it (some use a wider pattern of
>> "sun.*,com.sun.*")
>> 
>> HTH
>> 
>> the trace exception is here:
>>> java.lang.NoClassDefFoundError: sun/reflect/MethodAccessorImpl
>>> at sun.misc.Unsafe.defineClass(Native Method)
>>> at sun.reflect.ClassDefiner.defineClass(ClassDefiner.java:45)
>>>  at
>>> sun.reflect.MethodAccessorGenerator$1.run(MethodAccessorGenerator.java:381)
>>> at java.security.AccessController.doPrivileged(Native Method)
>>>  at
>>> 
>>> sun.reflect.MethodAccessorGenerator.generate(MethodAccessorGenerator.java:377)
>>> at
>>> 
>>> sun.reflect.MethodAccessorGenerator.generateMethod(MethodAccessorGenerator.java:59)
>>>  at
>>> 
>>> sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:28)
>>> at
>>> 
>>> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
>>>  at java.lang.reflect.Method.invoke(Method.java:597)
>>> at
>>> 
>>> org.apache.xmlrpc.server.ReflectiveXmlRpcHandler.invoke(ReflectiveXmlRpcHandler.java:115)
>>>  at
>>> 
>>> org.apache.xmlrpc.server.ReflectiveXmlRpcHandler.execute(ReflectiveXmlRpcHandler.java:106)
>>> at
>>> 
>>> org.apache.xmlrpc.server.XmlRpcServerWorker.execute(XmlRpcServerWorker.java:46)
>>>  at org.apache.xmlrpc.server.XmlRpcServer.execute(XmlRpcServer.java:86)
>>> at
>>> 
>>> org.apache.xmlrpc.server.XmlRpcStreamServer.execute(XmlRpcStreamServer.java:200)
>>>  at
>>> 
>>> org.apache.xmlrpc.webserver.XmlRpcServletServer.execute(XmlRpcServletServer.java:112)
>>> at org.apache.xmlrpc.webserver.XmlRpcServlet.doPost(XmlRpcServlet.java:196)
>>>  at javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
>>> at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
>>>  at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:502)
>>> at
>>> 
>>> org.mortbay.jetty.servlet.OsgiServletHolder.handle(OsgiServletHolder.java:101)
>>>  at
>>> org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:363)
>>> at
>>> 
>>> org.mortbay.jetty.servlet.OsgiServletHandler.handle(OsgiServletHandler.java:117)
>>>  at
>>> org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:181)
>>> at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:766)
>>>  at
>>> org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
>>> at org.mortbay.jetty.Server.handle(Server.java:324)
>>>  at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:534)
>>> at
>>> 
>>> org.mortbay.jetty.HttpConnection$RequestHandler.content(HttpConnection.java:879)
>>>  at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:741)
>>> at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:213)
>>>  at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:403)
>>> at
>>> 
>>> org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:409)
>>>  at
>>> 
>>> org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:522)
>>> Caused by: java.lang.ClassNotFoundException: sun.reflect.MethodAccessorImpl
>>>  at
>>> 
>>> org.apache.felix.framework.ModuleImpl.findClassOrResourceByDelegation(ModuleImpl.java:814)
>>> at org.apache.felix.framework.ModuleImpl.access$100(ModuleImpl.java:61)
>>>  at
>>> 
>>> org.apache.felix.framework.ModuleImpl$ModuleClassLoader.loadClass(ModuleImpl.java:1733)
>>> at java.lang.ClassLoader.loadClass(ClassLoader.java:248)
>>>  at
>>> 
>>> org.apache.felix.ipojo.handlers.dependency.Dependency$SmartProxyFactory.loadClass(Dependency.java:900)
>>> ... 33 more
>>> 
>>> --
>>> Issac Noé García Garza
>>> 

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