[Nestmates] RFR (S): Dynamic nestmate update

[Lois Foltan]

On 10/29/2018 2:37 AM, David Holmes wrote:

> webrev: http://cr.openjdk.java.net/~dholmes/dynamic-nestmates/webrev/
>
> This fleshes out Mandy's initial implementation with additional error 
> checking on the VM side to match the defineClass API, and with an 
> additional VM test.
>
> Thanks,
> David
Hi David,

I have a couple of concerns about this approach longer term for setting 
the nest host post return from either 
SystemDictionary::resolve_from_stream or SystemDictionary::parse_stream 
within jvm_lookup_define_class().

- for a findable class as soon as that class is added to the 
SystemDictionary, is there any concern that another thread could request 
that class and access it before its nest host is legitimately set?  
Would it be better to pass nest host down into ClassFileParser so it is 
known at the point the InstanceKlass is created?

- At the time class file nest members attributes are parsed and the nest 
host setting within the byte stream matches the nest host used when 
jvm_lookup_define_class() is invoked, than in my opinion an error should 
not result.

- Finally, should the setting of nest_host be known at the point class 
file load hook is processed?

Thanks,
Lois