RFR: 8219718: ZGC: Make nmethod entry barriers and nmethod::is_unloading use ZNMethodDataOops

[Erik Osterlund]

Hi Per,

Thanks for the review!

/Erik

> On 26 Feb 2019, at 22:07, Per Liden <per.liden at oracle.com> wrote:
> 
> Looks good!
> 
> /Per
> 
>> On 02/26/2019 01:23 PM, Erik Österlund wrote:
>> Hi,
>> Accessing ZNMethodDataOops outside of concurrent code cache iteration used to be unsafe. It is now safe. Therefore, we should utilize this in the nmethod entry barriers and nmethod::is_unloading.
>> Webrev:
>> http://cr.openjdk.java.net/~eosterlund/8219718/webrev.00/
>> Bug:
>> https://bugs.openjdk.java.net/browse/JDK-8219718
>> Thanks,
>> /Erik