RFR: JDK-8199729 - Usage Logger open sourcing

[Kevin Walls]

Hi -

I think the history of post_vm_init_hook_enabled was from the 
hotspot-express idea that the JVM and the runtime environment could be 
separate.  We could release a new JVM and slot it into an existing 
JDK/JRE...  In practice, the commented future optimisation never 
happened, but they've been in unison for years now and the VM has always 
tried to run PostVMInitHook, specifically ignoring any problems such as 
the class not existing in an open build.

Duplication inside PostVMInitHook.java was to avoid loading additional 
classes in every JVM everywhere unless they were likely to have the 
logger configured.

(I've seen Sharath's deferral message, but thought I'd mention this 
historical point...)

Thanks!
Kevin


On 31/05/2018 03:44, David Holmes wrote:
> Hi Sharath,
>
> I second Bernd's comments about removing all the ORCL_ prefixes.
>
> I'm unclear how this utility is managed. I expect it to be opt-in but 
> I see:
>
>     // Advertise presence of PostVMInitHook:
>     // future optimization: detect if this is enabled.
>     info->post_vm_init_hook_enabled = 1;
>
> in src/java.base/share/native/libjava/jdk_util.c, which suggests it is 
> in fact always going to be run (at least to the point where it looks 
> for the config file).
>
> Thanks,
> David
>
>
> On 31/05/2018 1:50 AM, Sharath Ballal wrote:
>> Hello,
>>
>> Requesting reviews for Usage Logger open sourcing (earlier known as 
>> Usage Tracker).
>>
>> ID: https://bugs.openjdk.java.net/browse/JDK-8199729
>>
>> Webrev: http://cr.openjdk.java.net/~sballal/8199729/webrev.00/
>>
>> Mach5 run has been successful for Usage Logger tests and hs-tier1, 
>> hs-tier2.
>>
>> Thanks,
>>
>> Sharath
>>