8u60 backport RFR (M) 8067662: "java.lang.NullPointerException: Method name is null" from StackTraceElement.<init>

[serguei.spitsyn at oracle.com]

Ok, thanks!
Serguei

On 4/7/15 9:59 AM, Daniel D. Daugherty wrote:
> I _think_ you're OK with a single (R)eviewer for a backport even
> when minor changes are required, but I can never remember all these
> rules for sure...
>
> Dan
>
>
> On 4/6/15 5:50 PM, serguei.spitsyn at oracle.com wrote:
>> Coleen and Dan,
>>
>> I'm asking you as the jdk  9 reviewers...
>>
>> Please, let me know if you have any chance and plans to review this.
>> Would it be enough to have just one (R) reviewer for a non-clean 
>> backport?
>>
>> Thanks,
>> Serguei
>>
>>
>>
>> On 4/2/15 5:03 PM, serguei.spitsyn at oracle.com wrote:
>>> Please, review the jdk 8u60 backport for:
>>>   https://bugs.openjdk.java.net/browse/JDK-8067662
>>>
>>> 8u60 hotspot webrev:
>>> http://cr.openjdk.java.net/~sspitsyn/webrevs/2015/hotspot/8067662-JVMTI-trace.8u60 
>>>
>>>
>>> 8u60 webrev for unit test update (the fix applies cleanly):
>>> http://cr.openjdk.java.net/~sspitsyn/webrevs/2015/jdk/8067662-JVMTI-trace-test.8u60 
>>>
>>>
>>>
>>>
>>> 9 hotspot webrev:
>>> http://cr.openjdk.java.net/~sspitsyn/webrevs/2015/hotspot/8067662-JVMTI-trace.2 
>>>
>>>
>>> 9 webrev for unit test update:
>>> http://cr.openjdk.java.net/~sspitsyn/webrevs/2015/jdk/8067662-JVMTI-trace-test.2 
>>>
>>>
>>>
>>> Summary:
>>>   The 9 fix can not be applied cleanly so that I have to rework the 
>>> fix a little bit.
>>>
>>>   An NPE is trown in a thread dumping via JMX when doing CPU 
>>> profiling in NetBeans Profiler and VisualVM.
>>>   The issue is that the methods and related klass versions are not 
>>> kept alive if a class redefinition
>>>   takes place between catching a Throwable and taking a thread dump.
>>>   It can result in loosing an obsolete method, and so, the 
>>> reconstruction of method name becomes impossible.
>>>   In such a case, the null reference is returned instead of a valid 
>>> method name.
>>>
>>>   The solution is to use current klass version and method orig_idnum 
>>> instead of ordinary method idnum
>>>   to find required method pointer. In the worst case when the 
>>> related klass version is gone
>>>   (was not included to or was removed from the previous_versions 
>>> linked list), a saved method name
>>>   CP index of the latest klass version can be used to restore the 
>>> method name.
>>>   The footprint extra overhead for this approach is u2 per stack frame.
>>>
>>> Testing in progress:
>>>   In progress: nsk redefine classes tests, JTREG java/lang/instrument
>>>
>>>
>>> Thanks,
>>> Serguei
>>>
>>
>>
>