JDK Bug System | Webbug Group | 8 months ago
Your exception is missing from the Samebug knowledge base.
Here are the best solutions we found on the Internet.
Click on the to mark the helpful solution and get rewards for you help.
  1. 0

    FULL PRODUCT VERSION : java version "1.8.0_102" Java(TM) SE Runtime Environment (build 1.8.0_102-b14) Java HotSpot(TM) 64-Bit Server VM (build 25.102-b14, mixed mode) FULL OS VERSION : Linux 4.6.2-1-ARCH #1 SMP PREEMPT Wed Jun 8 08:40:59 CEST 2016 x86_64 GNU/Linux A DESCRIPTION OF THE PROBLEM : This is about Java agent, or Java Instrumentation. I created a ClassFileTransformer which does basically nothing. It looks like public class LoggingTransformer implements ClassFileTransformer { static int transformCount = 0; public LoggingTransformer() { } public byte[] transform(ClassLoader loader, String className, Class classBeingRedefined, ProtectionDomain protectionDomain, byte[] classfileBuffer) throws IllegalClassFormatException { transformCount++; if (transformCount % 100 == 0) System.out.println("transformCount:" + transformCount); return null; } } Then I created this transformer and repeatedly invoke inst.retransformClasses(), as depicted below: public class LoggingAgent { public static void premain(String agentArgs, Instrumentation inst) throws Exception { LoggingTransformer t = new LoggingTransformer(); inst.addTransformer(t, true); Class demoClass = Class.forName("Tester"); while (true) { inst.retransformClasses(demoClass); } } } The command I used to run the application with my Java agent is : java -XX:+TraceClassLoading -XX:+TraceClassUnloading -XX:MetaspaceSize=12m -XX:MaxMetaspaceSize=12m -javaagent:../lib/loggingagent.jar MyDemoMain Note I set metaspace to 12m just to make it fail in a shorter time. The result is that, after about 5600 times of invocation of inst.retransformClasses() which triggers LoggingTransformer.transform(), the JVM crashes with below error: Exception in thread "main" java.lang.reflect.InvocationTargetException at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke( at sun.reflect.DelegatingMethodAccessorImpl.invoke( at java.lang.reflect.Method.invoke( at sun.instrument.InstrumentationImpl.loadClassAndStartAgent( at sun.instrument.InstrumentationImpl.loadClassAndCallPremain( Caused by: java.lang.OutOfMemoryError at sun.instrument.InstrumentationImpl.retransformClasses0(Native Method) at sun.instrument.InstrumentationImpl.retransformClasses( at LoggingAgent.premain( ... 6 more Since I enabled classloading and class unloading logs, I do see messages 'Loaded Tester from __VM_RedefineClasses__]' appearing in the log output, but I can't find any unloading messages related. THE PROBLEM WAS REPRODUCIBLE WITH -Xint FLAG: Yes THE PROBLEM WAS REPRODUCIBLE WITH -server FLAG: Yes STEPS TO FOLLOW TO REPRODUCE THE PROBLEM : 1. Write a couple of Agent classes as mentioned above; 2. Write a manifest file as below: Premain-Class: LoggingAgent Agent-Class: LoggingAgent Can-Redefine-Classes: true Can-Retransform-Classes: true 3. Make sure you call inst.retransformClasses() releatedly from within the agent's premain method 4. package your agent classes with manifest file and produces a jar file 5. Write a simple class MyDemoMain which has a main() method which just sleeps forever. 6. Once the number of invocation of inst.retransformClasses() is high enough, you will see JVM complains. EXPECTED VERSUS ACTUAL BEHAVIOR : 1. JVM should garbage collect the old class definitions when a class is transformed; 2. Such that JVM should not run out of memory if the same class is being redfined again and again; 3. We shall see class unloading logs from enabling -XX:+TraceClassUnloading option when running the program. REPRODUCIBILITY : This bug can be reproduced always.

    JDK Bug System | 8 months ago | Webbug Group

    Root Cause Analysis

    1. java.lang.OutOfMemoryError

      No message provided

      at sun.instrument.InstrumentationImpl.retransformClasses0()
    2. Java RT
      1. sun.instrument.InstrumentationImpl.retransformClasses0(Native Method)
      2. sun.instrument.InstrumentationImpl.retransformClasses(
      2 frames
    3. Unknown
      1. LoggingAgent.premain(
      1 frame
    4. Java RT
      1. sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
      2. sun.reflect.NativeMethodAccessorImpl.invoke(
      3. sun.reflect.DelegatingMethodAccessorImpl.invoke(
      4. java.lang.reflect.Method.invoke(
      5. sun.instrument.InstrumentationImpl.loadClassAndStartAgent(
      6. sun.instrument.InstrumentationImpl.loadClassAndCallPremain(
      6 frames