Review Request for JMC-6467

[Henrik Dafgård]

Hi Alex,

Thanks for finding this, the issue seems to be that I mis-typed the type
string for Jdk.ShenandoahRegionStateChange as
Jdk.ShenandoahRegionTypeChange. Fixing that solved the NPEs.

Updated Webrev: http://cr.openjdk.java.net/~hdafgard/JMC-6467/webrev.1/

Cheers,
Henrik Dafgård


On Mon, 29 Jul 2019 at 18:03, Alex Macdonald <almacdon at redhat.com> wrote:

> Hi Henrik,
>
> On Thu, Jul 25, 2019 at 1:37 PM Henrik Dafgård <hdafgard at gmail.com> wrote:
>
>> Hi all,
>>
>> Please review this request for generalizing the G1 Heap Layout page. The
>> pages.xml file that contains the new default color values could use one or
>> two suggestions for Shenandoah events, if anyone has particular
>> suggestions
>> for default color values there.
>>
>
> I've applied the patch and tried to open the Heap Layout page, however I'm
> running into a NPE when G1Page.createRegionList() [0] is adding items to
> "allRegions".
>
> For type jdk.ShenandoahHeapRegionInformation, the "typeAccessor" variable
> [1] is coming back null, which ultimately causes an NPE when trying to to
> retrieve a value from it [2]. Taking a bit of a deeper look there seems to
> be a mismatch between the structure of REGION_STATE and what I'm observing
> in the list of accessors. G1Constants is looking for (state, Type(text)),
> however the actual value of the key involving state is (state,
> Linear(number)). To quickly test I was able to retrieve a value using
> attr("state", "State", NUMBER), however this doesn't match the return type
> of customAccessor().
>
> I only have one shenandoah jfr file that I've been using, if you aren't
> experiencing this exception would you be able to provide a basic jfr file
> for verifying the behaviour?
>
> [0]
> http://hg.openjdk.java.net/jmc/jmc/file/91a803e741ac/application/org.openjdk.jmc.flightrecorder.ext.g1/src/main/java/org/openjdk/jmc/flightrecorder/ext/g1/G1Page.java#l442
> [1]
> http://hg.openjdk.java.net/jmc/jmc/file/91a803e741ac/application/org.openjdk.jmc.flightrecorder.ext.g1/src/main/java/org/openjdk/jmc/flightrecorder/ext/g1/G1Page.java#l453
> [2]
> http://hg.openjdk.java.net/jmc/jmc/file/91a803e741ac/application/org.openjdk.jmc.flightrecorder.ext.g1/src/main/java/org/openjdk/jmc/flightrecorder/ext/g1/G1Page.java#l458
>
>
>> JIRA: https://bugs.openjdk.java.net/browse/JMC-6467
>> Webrev: http://cr.openjdk.java.net/~hdafgard/JMC-6467/webrev.0/
>>
>>
>> Cheers,
>> Henrik Dafgård
>>
>
> Cheers,
>
> Alex
>