RFR: 8210321: Create NO_KEEPALIVE CLD holder accessor

[Erik Österlund]

Hi Coleen,

I specifically need this one for reading the holder without marking it, 
so that my GC code can subsequently mark it with either finalizable or 
strong marking, depending on whether we are marking the subgraph 
reachable from finalizers, or from strong roots concurrently. The 
klass_holder() accessor applies strong load barriers (as it is not 
AS_NO_KEEPALIVE).

Thanks,
/Erik

On 2018-09-04 14:29, coleen.phillimore at oracle.com wrote:
>
>
> On 9/4/18 8:02 AM, coleen.phillimore at oracle.com wrote:
>>
>> I thought the ClassLoaderData::is_alive() function would do this for 
>> you?
>
> Or can you call this new function from is_alive()?
> thanks
> Coleen
>
>> thanks,
>> Coleen
>>
>> On 9/3/18 10:38 AM, Erik Österlund wrote:
>>> Hi,
>>>
>>> In order to perform concurrent class unloading, ZGC needs a way to 
>>> peek the holder without keeping it alive.
>>>
>>> Webrev:
>>> http://cr.openjdk.java.net/~eosterlund/8210321/webrev.00/
>>>
>>> Bug:
>>> https://bugs.openjdk.java.net/browse/JDK-8210321
>>>
>>> Thanks,
>>> /Erik
>>
>