RFR(S): 8170672: Event-based tracing to support classloader instances

[Markus Gronlund]

Hi Lois,

Many thanks for taking a look at this - unfortunately i did submit the changeset before I saw your input, sorry about that.

Good point about also checking for the empty string.

I just filed https://bugs.openjdk.java.net/browse/JDK-8170847 so i will incorporate your feedback there.

Thanks again
Markus

-----Original Message-----
From: Lois Foltan 
Sent: den 6 december 2016 23:02
To: Markus Gronlund
Cc: hotspot-runtime-dev; serviceability-dev at openjdk.java.net
Subject: Re: RFR(S): 8170672: Event-based tracing to support classloader instances


On 12/5/2016 6:33 PM, Markus Gronlund wrote:
> Greetings,
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>   
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> Kindly asking for reviews for the following changeset:
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>   
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> Bug/Enh: https://bugs.openjdk.java.net/browse/JDK-8170672
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> Webrev: http://cr.openjdk.java.net/~mgronlun/8170672/webrev01/
>
> (this work is covered by an FC exception)

Hi Markus,

Looks good.  One comment:

src/share/vm/trace/traceStream.hpp
- line #121 - you might want to check not only if the class_loader_name_oop is NULL but also for the empty string?  Much like the code does in runtime/SharedRuntime.cpp class_loader_and_module_name()?

Thanks,
Lois

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> Summary:
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> Event-based tracing previously had little information about class loaders; a class loader was essentially treated no different than from a regular class (type information only).
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> With JDK9, supported has been added to java.lang.ClassLoader to associate a name with an individual class loader instance.
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>   
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> This changeset will allow the name information of individual class loader instances to be provided by the event-based tracing framework.
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> Aux info:
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> Some folding of the numerous macros completed as well.
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> Thanks in advance
> Markus
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>