PING: RFR: 8232594: Make the output of the JFR command duration more user friendly

[Erik Gahlin]

Looks good!

I will sponsor this.

Erik

On 2019-11-26 15:44, Chihiro Ito wrote:
> Hi,
>
> Could you review this, please?
>
> Regards,
> Chihiro
>
> 2019年11月17日(日) 1:49 Chihiro Ito <chiroito107 at gmail.com 
> <mailto:chiroito107 at gmail.com>>:
>
>     Hi Erik,
>
>     Could you please review this?
>
>     JBS : https://bugs.openjdk.java.net/browse/JDK-8232594
>     Webrev : http://cr.openjdk.java.net/~cito/JDK-8232594/webrev.01/
>
>     I improved this based on your idea and test case.
>
>     The test was passed test-tier1 and jdk/jdk/jfr.
>
>     Regards,
>     Chihiro
>
>
>     2019年11月11日(月) 23:57 Chihiro Ito <chiroito107 at gmail.com
>     <mailto:chiroito107 at gmail.com>>:
>
>         Hi Erik,
>
>         Thank you for giving the idea and implementing unit tests.
>         This is good for me.
>
>         I will improve according to this idea.
>
>         Regards,
>         Chihiro
>
>         2019年11月8日(金) 2:39 Erik Gahlin <erik.gahlin at oracle.com
>         <mailto:erik.gahlin at oracle.com>>:
>
>             Hi Chihiro,
>
>             Markus and I discussed what would be a suitable format and
>             this is what we came up with:
>
>             - A duration of 0 is displayed as "0 s"
>             - A duration less than 1 second is displayed in ms with 3
>             significant digits.
>             - A duration between 1 second and 60 seconds is displayed
>             in s with three significant units
>             - A duration of 60 second or more uses a combination of
>             two units, for example "1 m 30 s" or "3 h 30 m"
>             - The maxmim unit is a day.
>
>             I wrote a unit tests that you can use. Hopefully it is
>             correct.
>
>             http://cr.openjdk.java.net/~egahlin/8232594/
>
>             Thanks
>             Erik
>
>             On 2019-10-31 15:47, Chihiro Ito wrote:
>
>>             Hi Erik,
>>
>>             I can't imagine one event lasting more than a day.
>>             Therefore, I think the number of days is unnecessary.
>>             I also think we don't need duration as detailed as ns.
>>
>>             So how about using 0.001 ms to hours?
>>
>>             Also, it would be difficult to see all the units displayed.
>>             About rounding, how about using up to 3 units?
>>
>>             For example:
>>             27 h 34 m 56 s
>>             34 m 56 s 789 ms
>>             56 s 789.012 ms
>>             789.012 ms
>>
>>             Regards,
>>             Chihiro
>>
>>
>>             2019年10月30日(水) 2:57 Erik Gahlin <erik.gahlin at oracle.com
>>             <mailto:erik.gahlin at oracle.com>>:
>>
>>                 Hi Chihiro,
>>
>>                 I don't think 1 day is a good representation of for
>>                 example 27 hours.
>>                 The precision is too low.  I also think numbers
>>                 should be rounded up
>>                 where applicable.
>>
>>                 When a duration is short, it is often convenient to
>>                 use ms (with some
>>                 fractions) instead of microseconds. It makes it
>>                 easier to compare
>>                 values. This is especially true if you are looking at
>>                 multiple values
>>                 and want to compare them, for example GC pause time.
>>
>>                 It is probably a good idea to first decide how values
>>                 should be
>>                 formatted before attempting an implementation.
>>
>>                 Erik
>>
>>                 > Hi,
>>                 >
>>                 > I tried to implement this to output an accurate
>>                 time duration.
>>                 > Could you review this, please?
>>                 >
>>                 > Is a rounded duration better than an exact duration?
>>                 >
>>                 > JBS https://bugs.openjdk.java.net/browse/JDK-8232594
>>                 > webrev
>>                 http://cr.openjdk.java.net/~cito/JDK-8232594/webrev.00/
>>                 >
>>                 > Regards,
>>                 > Chihiro
>>