RFR 8226690: SIGSEGV in MetadataOnStackClosure::do_metadata

[coleen.phillimore at oracle.com]

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