RFR: 8217450: Add PackageEntry::locked_lookup_only

[David Holmes]

Hi Claes,

On 22/01/2019 2:18 am, Claes Redestad wrote:
> Hi,
> 
> adding a PackageEntry::locked_lookup_only for use from places where
> we know we hold the Module_lock avoids a small chunk of work during
> startup.
> 
> Bug:    https://bugs.openjdk.java.net/browse/JDK-8217450
> Webrev: http://cr.openjdk.java.net/~redestad/8217450/open.00/

Looks good. Please update copyright years.

One minor suggestions:

src/hotspot/share/classfile/packageEntry.hpp

The new method seems out of order where it is declared. I think it would 
be better to follow lookup_only with locked_lookup_only and also clarify 
the locking e.g.

     // Only lookup Package within loader's package entry table.
+   // This will acquire the Module_lock.
     PackageEntry* lookup_only(Symbol* Package);
+
+   // Only lookup Package within loader's package entry table.
+   // This assumes the Module_lock is already held.
+   PackageEntry* locked_lookup_only(Symbol* Package);

Thanks,
David


> Testing: tier1-3 (ongoing, complete on most platforms)
> 
> Thanks!
> 
> /Claes
>