NoClassDef error when trying to preload additional class in systemDirectory::initialize_preloaded_classes()

[Christian Thalinger]

On Jun 11, 2013, at 7:45 PM, Xiaoran Wang <xiaoran at x1a0ran.com> wrote:

> Thanks Christian. So I guess the best way would be to download jdk8 and build it without changes, and then instrument the hotspot JVM and build it with the jdk8 that's just built?

An easier way would be to use the same JDK you are building for as boot JDK.

-- Chris

> 
> 
> On Tue, Jun 11, 2013 at 7:19 PM, Christian Thalinger <christian.thalinger at oracle.com> wrote:
> 
> On Jun 11, 2013, at 2:06 PM, Xiaoran Wang <xiaoran at x1a0ran.com> wrote:
> 
> > I'm building openjdk 7u6 with ALT_BOOTDIR set to jdk7u21 downloaded from
> > java.com, but it still gave me weird build errors. So I removed all my
> > changes, and only added one symbol to vmSymbol.hpp, and then it gave me an
> > error again.
> >
> > added line:vmSymbol.hpp
> > template(foo_bar,                        "foo/bar")                       \
> >
> > cd linux_amd64_compiler2/product && ./test_gamma
> > Using java runtime at: /usr/lib/jvm/jdk1.7.0_21/jre
> 
> That's a long standing problem which we fixed in the 8 repositories:  test_gamma runs with the boot JDK.
> 
> In your case you are trying to run a HotSpot version from 7u6 with a 7u21 JDK.  Mix-and-match is not supported and may lead to problems like this.
> 
> -- Chris
> 
> > Error occurred during initialization of VM
> > java.lang.InternalError
> >    at sun.misc.Launcher.getFileURL(Launcher.java:463)
> >    at sun.misc.Launcher$ExtClassLoader.getExtURLs(Launcher.java:192)
> >    at sun.misc.Launcher$ExtClassLoader.<init>(Launcher.java:164)
> >    at sun.misc.Launcher$ExtClassLoader$1.run(Launcher.java:148)
> >    at sun.misc.Launcher$ExtClassLoader$1.run(Launcher.java:142)
> >    at java.security.AccessController.doPrivileged(Native Method)
> >    at sun.misc.Launcher$ExtClassLoader.getExtClassLoader(Launcher.java:141)
> >    at sun.misc.Launcher.<init>(Launcher.java:71)
> >    at sun.misc.Launcher.<clinit>(Launcher.java:57)
> >    at java.lang.ClassLoader.initSystemClassLoader(ClassLoader.java:1486)
> >    at java.lang.ClassLoader.getSystemClassLoader(ClassLoader.java:1468)
> >
> > So where seems to be the problem?
> >
> >
> >
> >
> > On Mon, Jun 10, 2013 at 11:09 PM, David Holmes <david.holmes at oracle.com>wrote:
> >
> >> What version of hotspot are you building? If it is current sources then
> >> you will need a JDK7 import JDK or even JDK8. You can't take current
> >> hotspot and place into a 6u JDK for example.
> >>
> >> David
> >>
> >>
> >> On 9/06/2013 6:06 AM, Xiaoran Wang wrote:
> >>
> >>> To followup, I tried to put foo/bar.class into $JAVA_HOME/jre/classes, now
> >>> the linux_amd64_compiler2/product/**test_gamma passed without error, but
> >>> another error occured from linux_amd64_compiler2/jvmg/**test_gamma,
> >>> which is
> >>> even more confusing.
> >>>
> >>> cd linux_amd64_compiler2/jvmg && ./test_gamma
> >>> java full version "1.6.0_22-b04"
> >>> Using java runtime at: /home/Documents/tools/hotspot-**
> >>> working-dir/java/jre
> >>> Error occurred during initialization of VM
> >>> java.lang.**NoSuchMethodException: java.lang.reflect.Method.**invoke
> >>>
> >>>
> >>> Can someone shed some light please?
> >>>
> >>>
> >>> On Sat, Jun 8, 2013 at 12:32 PM, Xiaoran Wang <xiaoran at x1a0ran.com>
> >>> wrote:
> >>>
> >>> Hi all,
> >>>>
> >>>> I'm instrumenting the hotspot JVM for research purposes and one of the
> >>>> steps is to preload some classes during JVM startup time so that I can
> >>>> use
> >>>> its KlassOop/KlassHandle later in the template Interpreter.
> >>>>
> >>>> I appended the new classes I wanted to load in systemDirectory.hpp, e.g.
> >>>>  *template(bar_klass,                foo_bar,             Pre) \*
> >>>>
> >>>> And its corresponding symbol in vmSymbols.hpp
> >>>> *template(foo_bar, "foo/bar")\*
> >>>>
> >>>>
> >>>> Then I put foo/bar.class into the corresponding rt.jar that will be used
> >>>> to build libjvm.so.
> >>>>
> >>>> However, when I built it, the "gamma" test always gives me an
> >>>> NoClassDefFoundError.
> >>>>
> >>>> cd linux_amd64_compiler2/product && ./test_gamma
> >>>> java full version "1.6.0_22-b04"
> >>>> Using java runtime at: /home/Documents/tools/hotspot-**
> >>>> working-dir/java/jre
> >>>> Error occurred during initialization of VM
> >>>> java/lang/**NoClassDefFoundError: foo/bar
> >>>>
> >>>>
> >>>> So my question is where should I put my custom class so that it can be
> >>>> preloaded during JVM startup in
> >>>> systemDirectory::initialize_**preloaded_classes?
> >>>>
> >>>> btw, I verified the rt.jar is the one JVM is loading because I tried to
> >>>> remove java/lang/Object from it and it complained about missing that
> >>>> class
> >>>> as well.
> >>>>
> >>>> Thank you
> >>>> Xiaoran
> >>>>
> >>>>
> 
>