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Groups > comp.lang.java.programmer > #8835

Re: Getter performance

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On 10/15/2011 5:36 PM, Arne Vajhøj wrote:
> On 10/15/2011 5:03 PM, Aéris wrote:
>> I work on an application where performances are important.
>>
>> To optimize it, I thought a direct access to a variable (foo.bar) would
>> be more efficient than a getter call (foo.getBar()).
>
> Wrong approach. Write nice clean code. If it is fast enough then
> fine. If not then measure where the bottleneck is. It seems highly
> unlikely to be in getters.
>
>> I thought by avoiding the call to a method and all that goes with it
>> (context switching, stacking, return value…), I can save time, but this
>> code sample prove the contrary :
>> http://pastebin.com/bP1nqxce
>> Direct variable access : 1041 ms
>> Getter call : 556 ms
>>
>> The difference is even more important if I don't modify the variable
>> value (lines 29 and 36 commented) :
>> Direct variable access : 95 ms
>> Getter call : 4 ms
>>
>> How can we explain this not obvious huge difference ( 50 and 95% ) ?
>
> First thing would be to run a lot more than 100000 times. Such
> small intervals will be very random on a multi tasking OS.

With 1000000 and -server I get:

1763
1608

which is rather close.

Arne

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Getter performance Aéris <aeris@imirhil.fr> - 2011-10-15 23:03 +0200
  Re: Getter performance Arne Vajhøj <arne@vajhoej.dk> - 2011-10-15 17:36 -0400
    Re: Getter performance Arne Vajhøj <arne@vajhoej.dk> - 2011-10-15 17:42 -0400
      Re: Getter performance BGB <cr88192@hotmail.com> - 2011-10-15 15:00 -0700
        Re: Getter performance markspace <-@.> - 2011-10-15 15:20 -0700
          Re: Getter performance David Lamb <dalamb@cs.queensu.ca> - 2011-10-20 12:45 -0400
            Re: Getter performance Roedy Green <see_website@mindprod.com.invalid> - 2011-10-21 14:27 -0700
              Re: Getter performance Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2011-10-21 18:57 -0700
                Re: Getter performance Patricia Shanahan <pats@acm.org> - 2011-10-22 07:27 +0100
                Re: Getter performance Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2011-10-22 09:57 -0300
              Re: Getter performance Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-10-21 22:12 -0400
                Re: Getter performance BGB <cr88192@hotmail.com> - 2011-11-13 10:14 -0700
                Re: Getter performance Lew <lewbloch@gmail.com> - 2011-11-13 11:00 -0800
              Re: Getter performance Arne Vajhøj <arne@vajhoej.dk> - 2011-11-06 16:09 -0500
    Re: Getter performance Aéris <aeris@imirhil.fr> - 2011-10-15 23:59 +0200
      Re: Getter performance Arne Vajhøj <arne@vajhoej.dk> - 2011-10-15 19:44 -0400
        Re: Getter performance Aéris <aeris@imirhil.fr> - 2011-10-16 13:14 +0200
          Re: Getter performance Lars Enderin <lars.enderin@telia.com> - 2011-10-16 16:28 +0200
  Re: Getter performance Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-10-16 09:47 -0400
  Re: Getter performance Jaap Droogers <JaapDroogers@unusable.meel.homelinux.net> - 2011-10-16 22:12 +0200
    Re: Getter performance BGB <cr88192@hotmail.com> - 2011-10-16 13:58 -0700
    Re: Getter performance David Lamb <dalamb@cs.queensu.ca> - 2011-10-20 12:51 -0400
      Re: Getter performance Paul Cager <paul.cager@googlemail.com> - 2011-10-21 08:49 -0700
  Re: Getter performance Roedy Green <see_website@mindprod.com.invalid> - 2011-10-21 08:02 -0700
  Re: Getter performance Wanja Gayk <brixomatic@yahoo.com> - 2011-10-22 21:11 +0200

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