RFR 8213150: Add verification for locking by VMThread

[Robbin Ehn]

Hi Coleen,

First, a side note, I notice that we forgot to change, e.g.:
Monitor::_safepoint_check_never to Mutex::_safepoint_check_never in some places.

> 
> I'm going to work on the issues with 'special' locks as part of : 
> https://bugs.openjdk.java.net/browse/JDK-8184732 next, but the rewriting (below) 
> removed these two uses of this ranking check.

Ok

> 
>>
>> do_safepoint_check is checked four times (once via not_allowed), can you 
>> please re-write this method, or better yet remove the bool input.
>> The bool is hardcoded so can you just create two methods, with one helper 
>> method for the common checks. (yes there will be more code, but readable :) )
> 
> This is a good suggestion.  I've rewritten it to be a lot clearer, and am 
> retesting it now with tier1 (all Oracle platforms) and tier2,3 linux-x64-debug.
> 
> incremental webrev at 
> http://cr.openjdk.java.net/~coleenp/2019/8213150.02.incr/webrev
> full webrev at http://cr.openjdk.java.net/~coleenp/2019/8213150.02/webrev

Thanks!

/Robbin

> 
> Thanks,
> Coleen
> 
>>
>> Thanks, Robbin
>>
>> On 9/20/19 11:36 PM, coleen.phillimore at oracle.com wrote:
>>> Summary: extend verification for all locking not just VMOperations, and fix 
>>> CLDG lock to not be taken by VM thread.
>>>
>>> See bug comments for more details about this change.
>>>
>>> Tested with tier1 all Oracle platforms, tier2-8 linux-x64-debug.
>>>
>>> open webrev at http://cr.openjdk.java.net/~coleenp/2019/8213150.01/webrev
>>> bug link https://bugs.openjdk.java.net/browse/JDK-8213150
>>>
>>> Thanks,
>>> Coleen
>