RFR 8153123 : Streamline StackWalker code

[Brent Christian]

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

-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
>>>>
>>>
>>
>