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

[Lois Foltan]

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?

Thanks,
Lois