JEP 232 RFR: JDK-8065942 and JDK-8056179

[Weijun Wang]

Hi Sean

Everything is fine, some comments:

FilePermission (also in SocketPermission, PropertyPermission, 
ServicePermission):

     int oldMask = ((FilePermission)existingVal).getMask();
     int newMask = ((FilePermission)newVal).getMask();
     if (oldMask != newMask) {
         int effective = oldMask | newMask;
         if (effective != oldMask) {
             return new FilePermission(fp.getName(), effective);
         }
     }
     return existingVal;

Is it worth checking "if (effective == newMask)"? Then you can return 
newVal without creating a new FilePermission object.

SocketPermission:

     JDK-431064? There should be 7 digits.

UnresolvedPermissionCollection:

     The use of CopyOnWriteArrayList is cool, but add(up) right after an 
empty one is created seems like an unnecessary copy-on-write. Maybe we 
can file an RFE on CopyOnWriteArrayList itself?

The newly added tests are great, but are they already covered by JCK or 
shall we contribute them to JCK?

Thanks
Max


On 06/04/2015 04:38 AM, Sean Mullan wrote:
> This is the third and fourth in a series of fixes for JEP 232 (Improve
> Secure Application Performance) [1].
>
> webrev:
> http://cr.openjdk.java.net/~mullan/webrevs/8065942-8056179/webrev.00/
> bugs: https://bugs.openjdk.java.net/browse/JDK-8065942 and
> https://bugs.openjdk.java.net/browse/JDK-8056179
>
> This fix changes the Permissions and PermissionCollection subclasses to
> use concurrent collections, which significantly reduces contention when
> multiple threads are performing security checks. The bugs needed to be
> fixed together, because removing the synchronized blocks in Permissions
> revealed that several of the underlying PermissionCollection
> implementations were not thread-safe.
>
> Several new unit tests were also added to test basic functionality of
> these classes.
>
> With these fixes, the throughput of the Permissions.implies method
> improves from approximately 6x to 10x when more than one thread is
> running. Each of the bugs contains a performance chart with more details.
>
> Thanks,
> Sean
>
> [1] http://openjdk.java.net/jeps/232