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?
-> 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
