RFR: 8194759: Support caching class mirror objects

[Jiangli Zhou]

Hi Ioi,

>> 
>>> 
>>> 
>>> 2.
>>> 
>>> For has_signer_and_not_archived -- I think it's still not clear that this function applies only during dumping.
>>> 
>>> How about always setting this flag (during run time and dump time), then it can be renamed simply as "has_signers()". This function would work both at run time and dump time (although there may not be a use case for this function during normal run time …).
>> 
>> Let’s keep has_signer_and_not_archived as is until there are other use case for it.
> 
> OK, how about renaming it to "is_signed_when_dumping"? Then it's clear from the name that the function won't return true at runtime even when the class is signed.

Thanks for thinking through this. It might be a bit odd to add “dumping” in the name explicitly just for this particular function as all our existing ‘dump time only’ functions do not follow the same naming convention. Your suggestion does remind me that we need an assert(DumpSharedSpaces, “dump time only”) in this function to make sure it is only called at CDS dump time. I will add the assert.

Thanks!

Jiangli