Hi Yasumasa, I tried jhsdb with a simple HelloWorld (with -Xcomp) and did not see any exception. Your app does anything else ?
Thanks, Sharath -----Original Message----- From: Yasumasa Suenaga [mailto:[email protected]] Sent: Friday, December 01, 2017 7:26 PM To: [email protected] Subject: RFR: 8192897: NPE occurs on clhsdb jstack Hi all, I saw NPE when I run jstack on clhsdb as below: ---------------- hsdb> jstack Deadlock Detection: No deadlocks found. "NonBlockingInputStreamThread" #27 daemon prio=5 tid=0x00007f0924674000 nid=0xf429 in Object.wait() [0x00007f08cf6fd000] java.lang.Thread.State: WAITING (on object monitor) JavaThread state: _thread_blocked - java.lang.Object.wait(long) @bci=0 (Compiled frame; information may be imprecise) - waiting on <no object reference available> Error occurred during stack walking: java.lang.NullPointerException at jdk.hotspot.agent/sun.jvm.hotspot.runtime.CompiledVFrame.getMonitors(CompiledVFrame.java:131) at jdk.hotspot.agent/sun.jvm.hotspot.runtime.JavaVFrame.printLockInfo(JavaVFrame.java:125) at jdk.hotspot.agent/sun.jvm.hotspot.tools.StackTrace.run(StackTrace.java:114) at jdk.hotspot.agent/sun.jvm.hotspot.CommandProcessor$26.doit(CommandProcessor.java:1073) at jdk.hotspot.agent/sun.jvm.hotspot.CommandProcessor.executeCommand(CommandProcessor.java:1964) at jdk.hotspot.agent/sun.jvm.hotspot.CommandProcessor.executeCommand(CommandProcessor.java:1934) at jdk.hotspot.agent/sun.jvm.hotspot.CommandProcessor.run(CommandProcessor.java:1814) at jdk.hotspot.agent/sun.jvm.hotspot.CLHSDB.run(CLHSDB.java:99) at jdk.hotspot.agent/sun.jvm.hotspot.CLHSDB.main(CLHSDB.java:40) at jdk.hotspot.agent/sun.jvm.hotspot.SALauncher.runCLHSDB(SALauncher.java:191) at jdk.hotspot.agent/sun.jvm.hotspot.SALauncher.main(SALauncher.java:439) ---------------- It is caused by CompiledVFrame#getScope() returns null. We should consider it at CompiledVFrame#getMonitors(). I uploaded a webrev. Could you review it? I checked this change with hotspot/jtreg/serviceability/sa on Linux x64. http://cr.openjdk.java.net/~ysuenaga/JDK-8192897/webrev.00/ We can reproduce this issue when we run the app with -Xcomp option. So I changed ClhsdbJstack.java to run with it. I cannot access mach5 and JPRT. So I need sponsor. Thanks, Yasumasa
