RFR(s): 8203343: VM.{metaspace|classloaders|classhierarchy...} jcmd should show invocation targets for Generated{Method|Constructor}AccessorImpl classes

[Thomas Stüfe]

Thanks Coleen!

On Thu, Jun 14, 2018, 18:04 <coleen.phillimore at oracle.com> wrote:

>
> This was a good find of David's.  Thank you for fixing the test.
> Coleen
>
> On 6/14/18 7:30 AM, Thomas Stüfe wrote:
> > Hi all,
> >
> > hopefully last changes, with feedback added from Coleen and David.
> >
> > Only changes in the provided regression test: I run it now with
> > -Dsun.reflect.noInflation to make the test independent from the
> > reflection inflation threshold. I also corrected the copyright dates.
> >
> > Delta:
> http://cr.openjdk.java.net/~stuefe/webrevs/8203343-VM.metaspace-show-reflection-invocation-targets/webrev.01-to-02/webrev/
> > Full:
> http://cr.openjdk.java.net/~stuefe/webrevs/8203343-VM.metaspace-show-reflection-invocation-targets/webrev.02/webrev/
> >
> > Thank you,
> >
> > Thomas
> >
> >
> > On Wed, Jun 6, 2018 at 6:05 PM, Thomas Stüfe <thomas.stuefe at gmail.com>
> wrote:
> >> Dear all,
> >>
> >> may I please have feedback and if possible reviews for this small
> addition:
> >>
> >> CR: https://bugs.openjdk.java.net/browse/JDK-8203343
> >> Webrev:
> http://cr.openjdk.java.net/~stuefe/webrevs/8203343-VM.metaspace-show-reflection-invocation-targets/webrev.00/webrev/
> >>
> >> (Note: this patch goes atop of
> >> https://bugs.openjdk.java.net/browse/JDK-8203682, which is currently
> >> up for RFR).
> >>
> >> ---
> >>
> >> When analyzing situations involving a lot of reflection, one often
> >> stares at walls of "GeneratedXXXAccessorXXX" classes. These names are
> >> generated and not at all helpful in analyzing the problem (e.g. which
> >> component in a server node does this much reflection and hence uses so
> >> much metaspace).
> >>
> >> This patch adds the ability to print out invocation targets
> >> additionally to class names if the class is a generated accessor - for
> >> now this ability has been added to VM.metaspace, VM.classloaders and
> >> VM.class_hierarchy.
> >>
> >> Example output from "VM.class_hierarchy":
> >>
> >> <snip>
> >> |--jdk.internal.reflect.MagicAccessorImpl/null
> >> <snip>
> >> |  |--jdk.internal.reflect.ConstructorAccessorImpl/null
> >> |  |
> |--jdk.internal.reflect.GeneratedConstructorAccessor18/0x00007f9ee8350c10
> >> (invokes:
> org/springframework/boot/context/properties/ConfigurationPropertiesBindingPostProcessorRegistrar::<init>
> >> ()V)
> >> |  |
> |--jdk.internal.reflect.GeneratedConstructorAccessor17/0x00007f9ee8349c00
> >> (invokes:
> org/springframework/boot/context/properties/EnableConfigurationPropertiesImportSelector$ConfigurationPropertiesBeanRegistrar::<init>
> >> ()V)
> >> <snip>
> >> |  |--jdk.internal.reflect.MethodAccessorImpl/null
> >> |  |
> |--jdk.internal.reflect.GeneratedMethodAccessor23/0x00007f9ec8329b60
> >> (invokes: org/apache/tomcat/util/modeler/AttributeInfo::setIs (Z)V)
> >> |  |
> |--jdk.internal.reflect.GeneratedMethodAccessor22/0x00007f9ee831bc70
> >> (invokes:
> org/springframework/boot/autoconfigure/SpringBootApplication::exclude
> >> ()[Ljava/lang/Class;)
> >> <snip>
> >>
> >> See here more examples:
> >>
> >> "VM.class_hierarchy"
> >>
> http://cr.openjdk.java.net/~stuefe/webrevs/8203343-VM.metaspace-show-reflection-invocation-targets/example-VM.class_hierarchy.txt
> >>
> >> "VM.classloaders show-classes"
> >>
> http://cr.openjdk.java.net/~stuefe/webrevs/8203343-VM.metaspace-show-reflection-invocation-targets/example-VM.classloaders.txt
> >>
> >>
> >> ----
> >>
> >> Note: I am not sure if this is a fit for hotspot-runtime or
> >> serviceability. Sorry for crossposting.
> >>
> >> Thank you,
> >>
> >> Thomas
>
>