RFR: JDK-8145788: JVM crashes with -XX:+EnableTracing

[David Holmes]

On 19/12/2015 1:50 AM, Yasumasa Suenaga wrote:
> Hi all,
> 
> I encountered JVM crash when I passed -XX:+EnableTracing.
> 
>   I checked core image, it crashed in EventBooleanFlagChanged::writeEvent()
>   which is called by Arguments::apply_ergo() because thread had not been
>   initialized. (JVM seems to log changing GC algorithm to G1.)

This seems like a logic error to me - something is trying to happen too
early during VM initialization. We need to look at exactly what we are
trying to do here, not just work around the crash.

David
-----

>   writeEvent() uses ResourceMark. Default constructor of ResourceMark uses
>   ResourceArea in current thread. So ResourceMark in writeEvent() should
>   pass valid ResourceArea.
> 
> I think this issue is in traceEventClasses.xsl .
> However, my environment (GCC 5.3.1 on Fedora23) cannot build it because
> -Werror=maybe-uninitialized was occurred.
> So I also fixed them together.
> 
> I've uploaded webrev. Could you review it?
>    http://cr.openjdk.java.net/~ysuenaga/JDK-8145788/webrev.00/
> 
> I'm jdk9 committer, however I cannot access JPRT.
> So I need a sponsor.
> 
> 
> Thanks,
> 
> Yasumasa
>