RFR(S) 8210864 Reduce the use of metaspaceShared.hpp

[Ioi Lam]

On 9/18/18 10:19 AM, Lois Foltan wrote:
> On 9/18/2018 1:03 PM, Ioi Lam wrote:
>
>> https://bugs.openjdk.java.net/browse/JDK-8210864
>> http://cr.openjdk.java.net/~iklam/jdk12/8210864-reduce-metaspaceShared-hpp-include.v01/ 
>>
>>
>> I really hate it whenever I edit metaspaceShared.hpp I have to
>> rebuild almost every source file in HotSpot. That's due to this
>> usage in the popular header file oop.inline.hpp:
>>
>>     void oopDesc::forward_to(oop p) {
>>       ...
>>       assert(!MetaspaceShared::is_archive_object(oop(this)) &&
>>              !MetaspaceShared::is_archive_object(p),
>>              "forwarding archive object");
>>
>>
>> The fix is to change the call to oopDesc::is_archive_object() which is
>> defined out-of-line.
>>
>> With this change, the number of dependent .o files reduced from 500+ to
>> 45.
>>
>> I added metaspaceShared.inline.hpp so oopDesc::forward_to should be
>> as fast as before, and all other callers of 
>> MetaspaceShared::is_archive_object
>> should be a little faster (probably not measurable).
>>
>> I also removed a few unnecessary includes of metaspaceShared.hpp
>>
>> Thanks
>> - Ioi
> Looks good.  One minor comment:
>
> Within src/share/memory/metaspaceShared.inline.hpp, can the method 
> is_archive_object be placed in PRODUCT conditional code like it is in 
> src/share/oops/oopsDesc.cpp?
>
Hi Lois,

Thanks for the review.

I couldn't exclude MetaspaceShared::is_archive_object from product 
builds because it's used in the method initialize_static_field in 
javaClasses.cpp.

Thanks
- Ioi

> Thanks,
> Lois