I have been attempting to get the call stack from AS 7.1.0.CR1-SNAPSHOT (built on December 8, 2011), on the compare method of the inner class String$CaseInsensitiveComparator.compare(String, String). This method is the number one consumer of CPU in my profiling, and I want to see who is calling it.

I created the following script:

RULE String Inner Class CaseInsensitiveComparator call stack
CLASS java.lang.String$CaseInsensitiveComparator
METHOD compare
AT EXIT
IF TRUE
DO traceStack("*** Called compare(" + $1 + ") in thread " + Thread.currentThread().getName() + "\n", 20)
ENDRULE

I have the following command line options from standalone.conf:

JAVA_OPTS="-Xms11264m -Xmx11264m -XX:+UseLargePages -XX:+UseCompressedOops -XX:+UseParallelOldGC -Djava.net.preferIPv4Stack=true -Dorg.jboss.resolver.warning=true -Dsun.rmi.dgc.client.gcInterval=3600000 -Dsun.rmi.dgc.server.gcInterval=3600000 -Dorg.apache.coyote.http11.HttpProtocol.MAX_KEEP_ALIVE_REQUESTS=-1 -javaagent:${BYTEMAN_HOME}/lib/byteman.jar=script:${BYTEMAN_HOME}/CaseInsensitiveCompareCallStack.btm,boot:${BYTEMAN_HOME}/lib/byteman.jar -Dorg.jboss.byteman.transform.all"

I actually received the first call stack output on boot of the application server, as follows:

• • • Called compare(originalType) in thread main
      java.lang.String$CaseInsensitiveComparator.compare(String.java:1240)
      java.lang.String$CaseInsensitiveComparator.compare(String.java:1220)
      java.util.TreeMap.put(TreeMap.java:547)
      javax.management.ImmutableDescriptor.makeMap(ImmutableDescriptor.java:166)
      javax.management.ImmutableDescriptor.<init>(ImmutableDescriptor.java:73)
      com.sun.jmx.mbeanserver.MXBeanIntrospector.typeDescriptor(MXBeanIntrospector.java:296)
      com.sun.jmx.mbeanserver.MXBeanIntrospector.getMBeanAttributeInfo(MXBeanIntrospector.java:159)
      com.sun.jmx.mbeanserver.MXBeanIntrospector.getMBeanAttributeInfo(MXBeanIntrospector.java:51)
      com.sun.jmx.mbeanserver.MBeanIntrospector$MBeanInfoMaker.visitAttribute(MBeanIntrospector.java:311)
      com.sun.jmx.mbeanserver.MBeanAnalyzer.visit(MBeanAnalyzer.java:70)
      com.sun.jmx.mbeanserver.MBeanIntrospector.makeInterfaceMBeanInfo(MBeanIntrospector.java:207)
      com.sun.jmx.mbeanserver.MBeanIntrospector.getPerInterface(MBeanIntrospector.java:182)
      com.sun.jmx.mbeanserver.MBeanSupport.<init>(MBeanSupport.java:136)
      com.sun.jmx.mbeanserver.MXBeanSupport.<init>(MXBeanSupport.java:66)
      javax.management.StandardMBean.construct(StandardMBean.java:177)
      javax.management.StandardMBean.<init>(StandardMBean.java:270)
      sun.management.ManagementFactory.addMXBean(ManagementFactory.java:267)
      sun.management.ManagementFactory.createPlatformMBeanServer(ManagementFactory.java:322)
      java.lang.management.ManagementFactory.getPlatformMBeanServer(ManagementFactory.java:521)
      org.jboss.modules.Main.main(Main.java:292)

But right after that I get the following null pointer exception:

Exception in thread "main" java.lang.IllegalArgumentException: javax.management.NotCompliantMBeanException: java.lang.management.ClassLoadingMXBean: null
at javax.management.StandardMBean.<init>(StandardMBean.java:272)
at sun.management.ManagementFactory.addMXBean(ManagementFactory.java:267)
at sun.management.ManagementFactory.createPlatformMBeanServer(ManagementFactory.java:322)
at java.lang.management.ManagementFactory.getPlatformMBeanServer(ManagementFactory.java:521)
at org.jboss.modules.Main.main(Main.java:292)
Caused by: javax.management.NotCompliantMBeanException: java.lang.management.ClassLoadingMXBean: null
at com.sun.jmx.mbeanserver.Introspector.throwException(Introspector.java:419)
at com.sun.jmx.mbeanserver.MBeanIntrospector.getPerInterface(MBeanIntrospector.java:189)
at com.sun.jmx.mbeanserver.MBeanSupport.<init>(MBeanSupport.java:136)
at com.sun.jmx.mbeanserver.MXBeanSupport.<init>(MXBeanSupport.java:66)
at javax.management.StandardMBean.construct(StandardMBean.java:177)
at javax.management.StandardMBean.<init>(StandardMBean.java:270)
... 4 more
Caused by: java.lang.NullPointerException
at org.jboss.byteman.rule.Rule.installParameters(Rule.java:595)
at org.jboss.byteman.rule.Rule.typeCheck(Rule.java:519)
at org.jboss.byteman.rule.Rule.ensureTypeCheckedCompiled(Rule.java:449)
at org.jboss.byteman.rule.Rule.execute(Rule.java:670)
at org.jboss.byteman.rule.Rule.execute(Rule.java:651)
at java.lang.String$CaseInsensitiveComparator.compare(String.java:1220)
at java.util.TreeMap.put(TreeMap.java:547)
at javax.management.ImmutableDescriptor.makeMap(ImmutableDescriptor.java:166)
at javax.management.ImmutableDescriptor.<init>(ImmutableDescriptor.java:73)
at com.sun.jmx.mbeanserver.MXBeanIntrospector.typeDescriptor(MXBeanIntrospector.java:296)
at com.sun.jmx.mbeanserver.MXBeanIntrospector.getMBeanAttributeInfo(MXBeanIntrospector.java:159)
at com.sun.jmx.mbeanserver.MXBeanIntrospector.getMBeanAttributeInfo(MXBeanIntrospector.java:51)
at com.sun.jmx.mbeanserver.MBeanIntrospector$MBeanInfoMaker.visitAttribute(MBeanIntrospector.java:311)
at com.sun.jmx.mbeanserver.MBeanAnalyzer.visit(MBeanAnalyzer.java:70)
at com.sun.jmx.mbeanserver.MBeanIntrospector.makeInterfaceMBeanInfo(MBeanIntrospector.java:207)
at com.sun.jmx.mbeanserver.MBeanIntrospector.getPerInterface(MBeanIntrospector.java:182)
... 8 more