RFR 6642881: Improve performance of Class.getClassLoader()

[Christian Thalinger]

+  template(classClassLoader_name,                      "classLoader")                                             \

This should be classLoader_name.

Otherwise this looks good.

On Jun 16, 2014, at 8:42 AM, Coleen Phillimore <coleen.phillimore at oracle.com> wrote:

> Summary: Add classLoader to java/lang/Class instance for fast access
> 
> In order to improve performance of Class.getClassLoader() in a way to allow the compilers to automatically optimize this call, I added the classLoader to the instance of java/lang/Class.  For microbenchmarks, this results in a 98% improvement, which was expected.  For Oracle internal applications, this results in a 10-12% improvement on solaris/sparc.   The increase in size of java/lang/Class can be offset by other changes (removing constant pool lock, or removing signers).
> 
> See bug link https://bugs.openjdk.java.net/browse/JDK-6642881 and associated linked bugs for more details.
> 
> open webrev at http://cr.openjdk.java.net/~coleenp/6642881_hotspot/
> open webrev at http://cr.openjdk.java.net/~coleenp/6642881_jdk/
> 
> There is both hotspot and jdk changes for this change.  The hotspot changes can work without the jdk changes (check for optional field), but not vice-versa.  I'll file another bug (and compatibility request) to remove JVM_GetClassLoader from hotspot.
> 
> Tested with jck lang, vm, api/java_lang tests with/without jdk change, nsk vm.quick.testlist and hotspot jtreg tests, and jprt.
> 
> Thanks,
> Coleen
> 
>