Review request 8153912: StackFrame::getFileName and StackFrame::getLineNumber not needed

[Daniel Fuchs]

Hi Ralph,

On 14/03/2017 06:03, Ralph Goers wrote:
> I have fixed the test that located the caller’s Class object with
> StackWalker. It is now faster than Reflection.getCallerClass() was.
>
> I have also created a test to get the Caller’s StackTraceElement with
> StackWalker. It is now much, much faster than walking the Throwable was
> in Java 8, so that will be a definite incentive for Log4j to use it.

This is good news :-) Thanks for sharing it!

> Sorry for the misinformation on these but thanks for giving me help on
> improving the tests.

No problem! Thanks for taking the time to test this new API and
providing feedback. This is the only way we can improve!

best regards,

-- daniel

>
> Ralph
>
>> On Mar 13, 2017, at 3:38 PM, Mandy Chung <mandy.chung at oracle.com
>> <mailto:mandy.chung at oracle.com>> wrote:
>>
>> Hi Ralph,
>>
>> I have filed https://bugs.openjdk.java.net/browse/JDK-8176593 for
>> Throwable::getStackTrace performance regression.
>>
>>> On Mar 13, 2017, at 1:57 PM, Daniel Fuchs <daniel.fuchs at oracle.com
>>> <mailto:daniel.fuchs at oracle.com>> wrote:
>>>
>>> Hi Ralph,
>>>
>>> On 13/03/17 19:06, Ralph Goers wrote:
>>>> OK - I will do that when I fix the other bug.  But if you can
>>>> suggest some other way to bail out of the loop after I have found
>>>> the correct StackFrame that would help as well.
>>>>
>>>
>>> I'd suggest using filter + findFirst, possibly with a
>>> statefull Predicate<StackFrame> - depending on the logic
>>> needed to identify the frame you want to return.
>>>
>>>
>>> That's what we do in java.util.logging - where we walk
>>> until we find a logger implementation frame, and then
>>> continue walking until we find a frame that no longer
>>> belong to the logging infrastructure.
>>
>> As Daniel said, we suggest to walk the stack from the most recent
>> frame and stops when the logging implementation frames are skipped.
>>
>> This is where java.util.logging does its filtering that you can reference:
>> http://hg.openjdk.java.net/jdk9/jdk9/jdk/file/ddf8af0e536a/src/java.logging/share/classes/java/util/logging/LogRecord.java#l696
>>
>> Mandy
>