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

[Christian Thalinger]

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
>>>> 
>>>>