RFR 8226690: SIGSEGV in MetadataOnStackClosure::do_metadata

[coleen.phillimore at oracle.com]

Thanks Gilles.
Coleen

On 9/26/19 5:53 AM, Gilles Duboscq wrote:
> The JVMCI changes look good.
>
> Thank you,
>  Gilles
>
> On 25/09/2019 21:53, coleen.phillimore at oracle.com wrote:
>> Thanks Gilles, I'll remove it from vmStructs_jvmci.cpp. So the jvmci 
>> code looks good?
>> thanks,
>> Coleen
>>
>> On 9/25/19 11:26 AM, Gilles Duboscq wrote:
>>> It looks to me like `_jvmti_redefinition_count` only needs to be 
>>> checked for consistency during code installation (which you do in 
>>> jvmciEnv & ciEnv).
>>> The compiler doesn't need to look at the value during the 
>>> compilation process so I don't think we need it in 
>>> `vmStructs_jvmci.cpp`.
>>>
>>>  Gilles
>>>
>>> On 25/09/2019 16:33, coleen.phillimore at oracle.com wrote:
>>>> Summary: Dont create nmethod if classes have been redefined since 
>>>> compilation start.
>>>>
>>>> The bug was caused by a new nmethod created with an old Method in 
>>>> the metadata section.  Added verification (which hit on windows) 
>>>> and NSV in the other place where the method can be replaced in the 
>>>> nmethod metadata section.
>>>>
>>>> There are some jvmci changes (to vmStructs_jvmci.cpp) that might be 
>>>> needed also in the graal compiler.
>>>>
>>>> Tested with tier1-6 and failing test 100 times.
>>>>
>>>> open webrev at 
>>>> http://cr.openjdk.java.net/~coleenp/2019/8226690.01/webrev
>>>> bug link https://bugs.openjdk.java.net/browse/JDK-8226690
>>>>
>>>> Thanks,
>>>> Coleen
>>