RFR (XS): 8214523: Fix nmethod asserts for concurrent nmethod unloading

[Erik Österlund]

Hi Coleen,

Thanks for the review.

/Erik

On 2018-11-30 16:49, coleen.phillimore at oracle.com wrote:
> 
> This looks good to me.
> Coleen
> 
> On 11/30/18 10:46 AM, Erik Österlund wrote:
>> By popular demand, I decided to CC hotspot-dev. And Coleen.
>>
>> /Erik
>>
>> On 2018-11-30 11:29, Erik Österlund wrote:
>>> Hi,
>>>
>>> There are some asserts in nmethod.cpp that do not play well with 
>>> concurrent nmethod unloading. This patch adjusts said asserts and 
>>> makes nmethod::maybe_invalidate_installed_code() return early if the 
>>> nmethod is not JVMCI compiled, to dodge JVMCI requirements on 
>>> locking, that is far from supported right now anyway for concurrent 
>>> unloading.
>>>
>>> Bug:
>>> https://bugs.openjdk.java.net/browse/JDK-8214523
>>>
>>> Webrev:
>>> http://cr.openjdk.java.net/~eosterlund/8214523/webrev.00/
>>>
>>> Thanks,
>>> /Erik
>