RFR 8153123 : Streamline StackWalker code

[Coleen Phillimore]

On 4/5/16 7:48 PM, Brent Christian wrote:
> Thanks, Coleen.  Coordinating method/function names on "to stack trace 
> element" is a fine thing.  I've done so in the updated webrev, and 
> also implemented Claes's suggestion.
>
> http://cr.openjdk.java.net/~bchristi/8153123/webrev.01/index.html

Thank you for making this change.  It looks good!  I've reviewed this.

Coleen

>
> -Brent
> On 04/05/2016 11:25 AM, Coleen Phillimore wrote:
>>
>> A correction below.
>>
>> On 4/5/16 1:29 PM, Coleen Phillimore wrote:
>>>
>>> Also meant to include core-libs-dev in the email.
>>> Thanks,
>>> Coleen
>>>
>>> On 4/5/16 1:27 PM, Coleen Phillimore wrote:
>>>>
>>>> Hi, I've reviewed the hotspot changes and some of the jdk changes.
>>>> This looks really good.
>>>>
>>>> One comment about the jvm function names:
>>>>
>>>> I think FillInStackTraceElement is too close of a name to
>>>> Throwable::fill_in_stack_trace().
>>>>
>>>> -JVM_ENTRY(void, JVM_SetMethodInfo(JNIEnv *env, jobject frame))
>>>> +JVM_ENTRY(void, JVM_FillInStackTraceElement(JNIEnv *env, jobject
>>>> frame, jobject stack))
>>>>    JVMWrapper("JVM_SetMethodInfo");
>>>> - Handle stackFrame(THREAD, JNIHandles::resolve(frame));
>>>> - java_lang_StackFrameInfo::fill_methodInfo(stackFrame, THREAD);
>>>> + Handle stack_frame_info(THREAD, JNIHandles::resolve(frame));
>>>> + Handle stack_trace_element(THREAD, JNIHandles::resolve(stack));
>>>> + java_lang_StackFrameInfo::fill_methodInfo(stack_frame_info,
>>>> stack_trace_element, THREAD); JVM_END
>>>>
>>>>
>>>> And the function is called fill_methodInfo in the javaClasses 
>>>> function.
>>>>
>>>> I think the JVM and the java_lang_StackFrameInfo function names
>>>> should be closer.
>>>>
>>>> I wonder if the name JVM_ToStackFrameElement() and
>>>> java_lang_StackFrameInfo::to_stack_frame_element() would be better
>>>> and then it'd match the Java name.
>>>>
>>
>> I meant JVM_ToStackTraceElement() and
>> java_lang_StackFrameInfo::to_stack_trace_element(), since it's producing
>> a StackTraceElement.
>>
>> thanks,
>> Coleen
>>>> Thanks!
>>>> Coleen
>>>>
>>>> On 4/4/16 9:29 PM, Mandy Chung wrote:
>>>>>> On Apr 4, 2016, at 4:45 PM, Brent Christian
>>>>>> <brent.christian at oracle.com> wrote:
>>>>>>
>>>>>> Hi,
>>>>>>
>>>>>> I'd like to check in some footprint and code reduction changes to
>>>>>> the java.lang.StackWalker implementation.
>>>>>>
>>>>>> Webrev:
>>>>>> http://cr.openjdk.java.net/~bchristi/8153123/webrev.00/
>>>>>> Bug:
>>>>>> https://bugs.openjdk.java.net/browse/JDK-8153123
>>>>>>
>>>>> This looks good to me.
>>>>>
>>>>> One thing to mention is that this patch is a follow-up work from the
>>>>> investigation on what it takes to enable Throwable to use
>>>>> StackWalker (JDK-8141239). The current built-in VM backtrace is very
>>>>> compact and performant.  We have identified and prototypes the
>>>>> performance improvements if Throwable backtrace is generated using
>>>>> stack walker.  There are some performance gaps that we agree to
>>>>> defer JDK-8141239 to a future release and improve the footprint
>>>>> performance and GC throughput concerns when MemberNames are stored
>>>>> in the throwable backtrace.
>>>>>
>>>>> Mandy
>>>>>
>>>>
>>>
>>
>