Hi David, Patrick,
re explicit StringBuilders
I did try that but the overheads of calling the PrintStreamOrWriter are
minimally about the same ( for a StringWriter that I use for the test) but this
will clearly depend on the writer that you are using. In my config the end
result was slower than what I presented
I did also consider batching multiple lines together but this requires the
Throwable to take control of the line endings rather than delegating it to the
streams, event though this is a cut across the concerns, but it was slower than
what I presented
I also tried making PrintStreamOrWriter extend AbstractStringBuffer and writing
to it directly, and then flushing, but again this did not achieve any better
results
The majority of the CPu reduction comes from removing the creation of implicit
StringBuilders and their resizing
Patrick - this is why you idea doesn't really provide the answer, there is
still a StringBuilder created for each line of stack trace printed, and
probably a resize as the line is probably > 16 chars, as well as 2 writes for
each line
regards
Mike
>________________________________
>From: David Holmes <david.hol...@oracle.com>
>To: Patrick Reinhart <patr...@reini.net>
>Cc: mike.ske...@talk21.com; "core-libs-dev@openjdk.java.net"
><core-libs-dev@openjdk.java.net>
>Sent: Tuesday, 11 October 2011, 11:16
>Subject: Re: Patch to Throwable and StackTraceElement (reduced CPU usage)
>
>Hi Patrick,
>
>
>On 11/10/2011 3:39 PM, Patrick Reinhart wrote:
>>
>> In my opinion, this could be even written in this ways:
>>
>> for (StackTraceElement traceElement : trace)
>> s.append("\tat ").println(traceElement);
>
>I think you are confusing your streams and your StringBuilders - s is a
>stream.
>
>David
>
>
>>
>> and Similarly for:
>>
>> for (int i = 0; i <= m; i++)
>> s.append(prefix).append("\tat ").println(trace[i]);
>>
>> and the change would be only on one line ;-)
>>
>> Cheers,
>>
>> Patrick "Reini" Reinhart
>>
>>
>>
>> Am 11.10.11 01:12, schrieb David Holmes:
>>> Hi Mike,
>>>
>>> I have one question. In part the existing code tends to use a single
>>> println with multiple string concatenations. Your changes optimize the
>>> string operations by using explicit, rather than implicit
>>> StringBuilders. Did you consider instead/aso using multiple print
>>> statmements top avoid the need for doing the concatenation in the
>>> first place? Eg:
>>>
>>> for (StackTraceElement traceElement : trace)
>>> s.println("\tat " + traceElement);
>>>
>>> becomes
>>>
>>> for (StackTraceElement traceElement : trace) {
>>> s.print("\tat ");
>>> s.println(traceElement);
>>> }
>>>
>>> Similarly for:
>>>
>>> for (int i = 0; i <= m; i++)
>>> s.println(prefix + "\tat " + trace[i]);
>>>
>>>
>>> Cheers,
>>> David Holmes
>>>
>>> On 11/10/2011 8:30 AM, Mike Skells wrote:
>>>> Hi All,
>>>> Last attempt - hopefully
>>>>
>>>> with all 3 files, a patch, test case and results. The patch and
>>>> results are text format to avoid the filters on this list
>>>>
>>>> Hopefully you are not all to irritated with this posting to review it
>>>> :-)
>>>>
>>>> Regards
>>>> Mike
>>>>
>>>>
>>>>> ________________________________
>>>>> From: Mike Skells<mike.ske...@talk21.com>
>>>>> To: Core-Libs-Dev<core-libs-dev@openjdk.java.net>
>>>>> Sent: Monday, 10 October 2011, 22:39
>>>>> Subject: Re: Patch to Throwable and StackTraceElement (reduced CPU
>>>>> usage)
>>>>>
>>>>> Hi All,
>>>>> Trying to request a review again with different file types
>>>>>
>>>>> hopefully it will get through the filter
>>>>>
>>>>> Regards
>>>>> Mike
>>>>>
>>>>>
>>>>>
>>>>>> ________________________________
>>>>>> From: Mike Skells<mike.ske...@talk21.com>
>>>>>> To: Mike Skells<mike.ske...@talk21.com>; Alan
>>>>>> Bateman<alan.bate...@oracle.com>
>>>>>> Cc: Core-Libs-Dev<core-libs-dev@openjdk.java.net>
>>>>>> Sent: Monday, 10 October 2011, 9:17
>>>>>> Subject: Re: Patch to Throwable and StackTraceElement (reduced CPU
>>>>>> usage)
>>>>>>
>>>>>>
>>>>>> The patch (.patch) and results (.xlsx) seem to be filtered out.
>>>>>> What is the best format to submit files to avoid list filtering
>>>>>> attachments?
>>>>>>
>>>>>>
>>>>>>
>>>>>>> ________________________________
>>>>>>> From: Mike Skells<mike.ske...@talk21.com>
>>>>>>> To: Alan Bateman<alan.bate...@oracle.com>
>>>>>>> Cc: Core-Libs-Dev<core-libs-dev@openjdk.java.net>
>>>>>>> Sent: Monday, 10 October 2011, 8:53
>>>>>>> Subject: Re: Patch to Throwable and StackTraceElement (reduced CPU
>>>>>>> usage)
>>>>>>>
>>>>>>> Doh,
>>>>>>> This time with the patches, test code, and CPU usage stats attached
>>>>>>>
>>>>>>> Regard
>>>>>>>
>>>>>>> Mike
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>> ________________________________
>>>>>>>> From: Alan Bateman<alan.bate...@oracle.com>
>>>>>>>> To: mike.ske...@talk21.com
>>>>>>>> Cc: Core-Libs-Dev<core-libs-dev@openjdk.java.net>
>>>>>>>> Sent: Monday, 10 October 2011, 0:15
>>>>>>>> Subject: Re: Patch to Throwable and StackTraceElement (reduced
>>>>>>>> CPU usage)
>>>>>>>>
>>>>>>>> mike.ske...@talk21.com wrote:
>>>>>>>>> :
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> I include the patch, a micro-benchmark and the results of the
>>>>>>>>> micro-benchmark which show an improvement of 80% throughput (ie
>>>>>>>>> it is almost twice as fast)
>>>>>>>>>
>>>>>>>> Mike - I don't think there is a patch attached to your mail.
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>>
>>
>
>
>
