Yasumasa, 1. It's better to change JSnap code to produce meaningful error message instead of NPE.
2. We should check that no other consumer of perf counters rely on the fact it's NULL after call to destroy(). I'm not sure that this part of the fix is not dangerous. -Dmitry On 2016-03-29 15:02, Yasumasa Suenaga wrote: > PING: Could you review it? > > > Yasumasa > > > On 2016/03/22 21:24, Yasumasa Suenaga wrote: >> PING: Could you review it? >> >> Yasumasa >> >> 2016/03/14 23:39 "Yasumasa Suenaga" <yasue...@gmail.com >> <mailto:yasue...@gmail.com>>: >> >> Hi all, >> >> When I use `jhsdb jsnap` to get PerfCounter from core images, I >> encountered NPE: >> ------------- >> Exception in thread "main" java.lang.NullPointerException >> at sun.jvm.hotspot.tools.JSnap.run(JSnap.java:45) >> at sun.jvm.hotspot.tools.Tool.startInternal(Tool.java:260) >> at sun.jvm.hotspot.tools.Tool.start(Tool.java:223) >> at sun.jvm.hotspot.tools.Tool.execute(Tool.java:118) >> at sun.jvm.hotspot.tools.JSnap.main(JSnap.java:67) >> at sun.jvm.hotspot.SALauncher.runJSNAP(SALauncher.java:352) >> at sun.jvm.hotspot.SALauncher.main(SALauncher.java:404) >> ------------- >> >> PerfMemory::destroy() clears all members which are used in JSnap. >> Thus NPE is occurred. >> >> I uploaded webrev for this issue. >> Could you review it? >> >> http://cr.openjdk.java.net/~ysuenaga/JDK-8151815/webrev.00/ >> >> I cannot access JPRT. >> So I need a Sponsor. >> >> >> Thanks, >> >> Yasumasa >> -- Dmitry Samersoff Oracle Java development team, Saint Petersburg, Russia * I would love to change the world, but they won't give me the source code.
