[8u40] RFR 6642881: Improve performance of Class.getClassLoader()

[Leela Mohan]

I think, change in the file unsafe.cpp is incorrect. (
http://cr.openjdk.java.net/~coleenp/6642881_8u40_hotspot/ )

Below function is accessing naked oops when thread has transitioned to
"native":

*+ static jobject get_class_loader(JNIEnv* env, jclass cls) {**+   if
(java_lang_Class::is_primitive(JNIHandles::resolve_non_null(cls)))
{**+     return NULL;**+   }**+   Klass* k =
java_lang_Class::as_Klass(JNIHandles::resolve_non_null(cls));**+   oop
loader = k->class_loader();**+   return JNIHandles::make_local(env,
loader);**+ }*


- Leela

On Mon, Sep 8, 2014 at 7:05 PM, Coleen Phillimore <
coleen.phillimore at oracle.com> wrote:

>
> Thanks, Mandy!
>
> Coleen
>
>
> On 9/8/14, 6:59 PM, Mandy Chung wrote:
>
>> Thumbs up.
>>
>> Mandy
>>
>> On 9/5/2014 12:55 PM, Coleen Phillimore wrote:
>>
>>> Summary: Add classLoader to java/lang/Class instance for fast access
>>>
>>> This is a backport request for 8u40.   This change has been in the jdk9
>>> code for 3 months without any problems.
>>>
>>> The JDK changes hg imported cleanly.  The Hotspot change needed a hand
>>> merge for create_mirror call in klass.cpp.
>>>
>>> http://cr.openjdk.java.net/~coleenp/6642881_8u40_jdk/
>>> http://cr.openjdk.java.net/~coleenp/6642881_8u40_hotspot/
>>>
>>> bug link https://bugs.openjdk.java.net/browse/JDK-6642881
>>>
>>> Ran jdk_core jtreg tests in jdk with both jdk/hotspot changes. Also ran
>>> jck java_lang tests with only the hotspot change.  The hotspot change can
>>> be tested separately from the jdk change (but not the other way around).
>>>
>>> Thanks,
>>> Coleen
>>>
>>
>>
>