Re: RFR: 8160950 Agent JAR added to app class loader rather than system class loader when running with -Djava.system.class.loader

[David Holmes]

On 8/09/2016 5:38 PM, Alan Bateman wrote:
On 08/09/2016 08:22, David Holmes wrote:
Hi Serguei,
On 8/09/2016 5:27 AM, serguei.spit...@oracle.com wrote:
Please, review the fix for:
  https://bugs.openjdk.java.net/browse/JDK-8160950

Webrev:

http://cr.openjdk.java.net/~sspitsyn/webrevs/2016/jdk/8160950-JLI-WLS.jdk2/



Summary:
  When running a java application with the options
`-javaagent:myagent.jar -Djava.system.classloader=MyClassLoader`
  then the myagent.jar is added to the application class loader rather
than the custom system class loader.

I'm confused, the "system" class loader is the "application" class
loader.
You can configure a system property to run with a custom system class
loader (details in the ClassLoader javadoc). It's rarely used which is
why this bug has been around for so long and nobody noticed. When you do
run with a custom system class loader then it means you startup with 4
class loaders (system, application, platform, boot).

I'd overlooked that the default system loader is used as the parent of 
the custom system loader. But it will be very confusing if you refer to 
the built-in loader as the "application" loader because the 
"application" loader and the "system" loader have always been 
synonymous: the loader that loads the application main class.

Thanks,
David

-Alan