Groups > comp.lang.java.programmer > #8294

Re: Bulk Array Element Allocation, is it faster?

From	Jan Burse <janburse@fastmail.fm>
Newsgroups	comp.lang.java.programmer
Subject	Re: Bulk Array Element Allocation, is it faster?
Date	2011-09-25 16:11 +0200
Organization	albasani.net
Message-ID	<j5ncqi$1hv$1@news.albasani.net> (permalink)
References	(1 earlier) <Ypydnd8C3rt7G-PTnZ2dnUVZ_iydnZ2d@earthlink.com> <9e8fplF19bU1@mid.individual.net> <j5n3qv$dbo$1@news.albasani.net> <9e8kdhF6lmU1@mid.individual.net> <j5ncco$hl$1@news.albasani.net>

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Jan Burse schrieb:
> Currently I am planning to change the loop
> to something like that:
>
>      Bla[] bla = new Bla[n];
>      for (int i=0; i<n; i++) {
>          bla[i] = createBla();
>      }
>
> So that the JIT has less information on what
> the loop is about, and to do some new
> measurements. To be fair I would also use
> createBla() in the lazy scenario. Lets see
> what happens.

Maybe there is a bug somewhere else in the
application that leads to the performance loss.
There are also points in the application where
some of the bla elements are forcefully set
to null so as to release Bla objects:

      ...
      bla[j] = null;
      ...

I am not sure whether these releases work
the same in the bulk and the lazy version of
the code. Need to check first.

So measurements have already shown that the
release gives some gain, measurements where
16000 ms vs. 9600 ms. The release condition
is more complicated than the lazy new
condition, but the overhead is compensated
the overall gain.

Lets see.

Best Regards

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Thread

Bulk Array Element Allocation, is it faster? Jan Burse <janburse@fastmail.fm> - 2011-09-25 03:17 +0200
  Re: Bulk Array Element Allocation, is it faster? Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-09-24 21:37 -0400
    Re: Bulk Array Element Allocation, is it faster? Jan Burse <janburse@fastmail.fm> - 2011-09-25 10:39 +0200
  Re: Bulk Array Element Allocation, is it faster? Patricia Shanahan <pats@acm.org> - 2011-09-24 18:41 -0700
    Re: Bulk Array Element Allocation, is it faster? Robert Klemme <shortcutter@googlemail.com> - 2011-09-25 12:57 +0200
      Re: Bulk Array Element Allocation, is it faster? Jan Burse <janburse@fastmail.fm> - 2011-09-25 13:38 +0200
        Re: Bulk Array Element Allocation, is it faster? Robert Klemme <shortcutter@googlemail.com> - 2011-09-25 14:16 +0200
          Re: Bulk Array Element Allocation, is it faster? Jan Burse <janburse@fastmail.fm> - 2011-09-25 16:04 +0200
            Re: Bulk Array Element Allocation, is it faster? Jan Burse <janburse@fastmail.fm> - 2011-09-25 16:11 +0200
              Re: Bulk Array Element Allocation, is it faster? Patricia Shanahan <pats@acm.org> - 2011-09-25 09:30 -0700
            Re: Bulk Array Element Allocation, is it faster? Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-09-25 10:59 -0400
              Re: Bulk Array Element Allocation, is it faster? Jan Burse <janburse@fastmail.fm> - 2011-09-25 17:14 +0200
                Re: Bulk Array Element Allocation, is it faster? Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-09-25 15:26 +0000
                Re: Bulk Array Element Allocation, is it faster? Lew <lewbloch@gmail.com> - 2011-09-25 11:02 -0700
                Re: Bulk Array Element Allocation, is it faster? Jan Burse <janburse@fastmail.fm> - 2011-09-25 20:19 +0200
                Re: Bulk Array Element Allocation, is it faster? Jan Burse <janburse@fastmail.fm> - 2011-09-25 20:21 +0200
                Re: Bulk Array Element Allocation, is it faster? Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-09-25 17:48 -0400
                Re: Bulk Array Element Allocation, is it faster? Jan Burse <janburse@fastmail.fm> - 2011-09-26 00:10 +0200
  Re: Bulk Array Element Allocation, is it faster? Roedy Green <see_website@mindprod.com.invalid> - 2011-09-24 19:05 -0700
    Re: Bulk Array Element Allocation, is it faster? Lew <lewbloch@gmail.com> - 2011-09-24 23:22 -0700
      Re: Bulk Array Element Allocation, is it faster? Roedy Green <see_website@mindprod.com.invalid> - 2011-09-25 00:23 -0700
        Re: Bulk Array Element Allocation, is it faster? Lew <lewbloch@gmail.com> - 2011-09-25 11:17 -0700
        Re: Bulk Array Element Allocation, is it faster? Joshua Cranmer <Pidgeot18@verizon.invalid> - 2011-09-25 14:00 -0500
    Re: Bulk Array Element Allocation, is it faster? Jan Burse <janburse@fastmail.fm> - 2011-09-25 10:47 +0200
      Re: Bulk Array Element Allocation, is it faster? Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-09-25 08:07 -0400
        Re: Bulk Array Element Allocation, is it faster? Jan Burse <janburse@fastmail.fm> - 2011-09-25 19:21 +0200
          Re: Bulk Array Element Allocation, is it faster? Jan Burse <janburse@fastmail.fm> - 2011-09-25 19:41 +0200
          Re: Bulk Array Element Allocation, is it faster? Lew <lewbloch@gmail.com> - 2011-09-25 11:28 -0700
            Re: Bulk Array Element Allocation, is it faster? Jan Burse <janburse@fastmail.fm> - 2011-09-25 21:25 +0200
              Re: Bulk Array Element Allocation, is it faster? Jan Burse <janburse@fastmail.fm> - 2011-09-25 23:50 +0200
              Re: Bulk Array Element Allocation, is it faster? Lew <lewbloch@gmail.com> - 2011-09-25 15:43 -0700
                Re: Bulk Array Element Allocation, is it faster? Jan Burse <janburse@fastmail.fm> - 2011-09-26 01:06 +0200
                Re: Bulk Array Element Allocation, is it faster? Jan Burse <janburse@fastmail.fm> - 2011-09-26 01:21 +0200
                Re: Bulk Array Element Allocation, is it faster? Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-09-26 06:00 +0000
                Re: Bulk Array Element Allocation, is it faster? Jan Burse <janburse@fastmail.fm> - 2011-09-26 14:52 +0200
                Re: Bulk Array Element Allocation, is it faster? Jan Burse <janburse@fastmail.fm> - 2011-09-26 15:02 +0200

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