Re: An argument against (the liberal use of) references

From	Juha Nieminen <nospam@thanks.invalid>
Newsgroups	comp.lang.c++
Subject	Re: An argument against (the liberal use of) references
Date	2022-12-06 11:36 +0000
Organization	Aioe.org NNTP Server
Message-ID	<tmn9fl$1kpl$1@gioia.aioe.org> (permalink)
References	(3 earlier) <tll502$ce5l$1@dont-email.me> <tll88a$13vs$1@gioia.aioe.org> <tm7gjh$2hau4$1@dont-email.me> <tm9iig$1can$1@gioia.aioe.org> <tm9khr$2oi11$3@dont-email.me>

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Paavo Helde <eesnimi@osa.pri.ee> wrote:
> When tracking down this bug, I monitored all refcounter changes for a 
> particular single smartpointer during the program run (ca 10 min). There 
> were 591848 increments and decrements, from which 1526 came from the 
> problematic (parallelized) part. It looks like a pessimization to slow 
> down 99.75% of accesses when only 0.25% would actually benefit from this.

There's place for micro-optimization and there's place to do the
Right Thing (TM) instead.

In the vast, vast majority of situations micro-optimization will have
little to no effect on the program. It's only when you have number
crunching code that does something billions of times per second that
micro-optimization may start having some discernible effect. Those
situations tend to be very rare and far-in-between. And when you do
have such situations you can make faster versions of things for that
alone.

Micro-optimization is extra useless if it's surrounded by, and thus
swamped by code that's a lot slower than it. Even when micro-optimizing
you should start with the worst offenders, not the smallest things.

(By "micro-optimization" I'm referring to things that do not change
the computational complexity of something and only makes that something
some clock cycles faster.)

So unless your smart pointer is being copied and assigned around
millions of times per second in tight number-crunching loops, you can
safely ignore any lost clock cycles by making the reference counter
thread-safe.

(If you actually need to copy and assign smart pointers around
millions of times per second in a tight number-crunching inner
loop, perhaps create a specialized version of the pointer for
that particular purpose...)

Thread

An argument *against* (the liberal use of) references Juha Nieminen <nospam@thanks.invalid> - 2022-11-22 09:52 +0000
  Re: An argument *against* (the liberal use of) references "Fred. Zwarts" <F.Zwarts@KVI.nl> - 2022-11-22 11:23 +0100
  Re: An argument *against* (the liberal use of) references Paavo Helde <eesnimi@osa.pri.ee> - 2022-11-22 13:27 +0200
    Re: An argument *against* (the liberal use of) references Juha Nieminen <nospam@thanks.invalid> - 2022-11-23 06:52 +0000
      Re: An argument *against* (the liberal use of) references "Alf P. Steinbach" <alf.p.steinbach@gmail.com> - 2022-11-23 13:51 +0100
        Re: An argument *against* (the liberal use of) references Juha Nieminen <nospam@thanks.invalid> - 2022-11-23 13:46 +0000
          Re: An argument *against* (the liberal use of) references Paavo Helde <eesnimi@osa.pri.ee> - 2022-11-30 13:59 +0200
            Re: An argument *against* (the liberal use of) references Juha Nieminen <nospam@thanks.invalid> - 2022-12-01 06:45 +0000
              Re: An argument *against* (the liberal use of) references Paavo Helde <eesnimi@osa.pri.ee> - 2022-12-01 09:19 +0200
                Re: An argument *against* (the liberal use of) references Stuart Redmann <DerTopper@web.de> - 2022-12-01 14:06 +0100
                Re: An argument *against* (the liberal use of) references Paavo Helde <eesnimi@osa.pri.ee> - 2022-12-01 16:45 +0200
                Re: An argument *against* (the liberal use of) references scott@slp53.sl.home (Scott Lurndal) - 2022-12-01 16:02 +0000
                Re: An argument *against* (the liberal use of) references Paavo Helde <eesnimi@osa.pri.ee> - 2022-12-01 20:21 +0200
                Re: An argument *against* (the liberal use of) references scott@slp53.sl.home (Scott Lurndal) - 2022-12-01 19:09 +0000
                Re: An argument *against* (the liberal use of) references Michael S <already5chosen@yahoo.com> - 2022-12-02 05:53 -0800
                Re: An argument *against* (the liberal use of) references scott@slp53.sl.home (Scott Lurndal) - 2022-12-02 14:36 +0000
                Re: An argument *against* (the liberal use of) references "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2022-12-02 12:29 -0800
                Re: An argument *against* (the liberal use of) references scott@slp53.sl.home (Scott Lurndal) - 2022-12-02 20:55 +0000
                Re: An argument *against* (the liberal use of) references "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2022-12-02 12:58 -0800
                Re: An argument *against* (the liberal use of) references scott@slp53.sl.home (Scott Lurndal) - 2022-12-02 21:18 +0000
                Re: An argument *against* (the liberal use of) references "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2022-12-02 14:16 -0800
                Re: An argument *against* (the liberal use of) references Branimir Maksimovic <branimir.maksimovic@icloud.com> - 2022-12-02 21:09 +0000
                Re: An argument *against* (the liberal use of) references "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2022-12-02 13:22 -0800
                Re: An argument *against* (the liberal use of) references Branimir Maksimovic <branimir.maksimovic@icloud.com> - 2022-12-02 21:36 +0000
                Re: An argument *against* (the liberal use of) references "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2022-12-02 14:13 -0800
                Re: An argument *against* (the liberal use of) references Paavo Helde <eesnimi@osa.pri.ee> - 2022-12-02 18:33 +0200
                Re: An argument *against* (the liberal use of) references Michael S <already5chosen@yahoo.com> - 2022-12-01 11:59 -0800
                Re: An argument *against* (the liberal use of) references Paavo Helde <eesnimi@osa.pri.ee> - 2022-12-01 23:53 +0200
                Re: An argument *against* (the liberal use of) references Michael S <already5chosen@yahoo.com> - 2022-12-02 04:11 -0800
                Re: An argument *against* (the liberal use of) references "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2022-12-01 12:21 -0800
                Re: An argument *against* (the liberal use of) references Juha Nieminen <nospam@thanks.invalid> - 2022-12-06 11:36 +0000
                Re: An argument *against* (the liberal use of) references "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2022-12-06 12:26 -0800
                Re: An argument *against* (the liberal use of) references scott@slp53.sl.home (Scott Lurndal) - 2022-12-06 20:39 +0000
                Re: An argument *against* (the liberal use of) references Paavo Helde <eesnimi@osa.pri.ee> - 2022-12-06 23:53 +0200
                Re: An argument *against* (the liberal use of) references "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2022-12-06 13:59 -0800
                Re: An argument *against* (the liberal use of) references scott@slp53.sl.home (Scott Lurndal) - 2022-12-06 22:04 +0000
                Re: An argument *against* (the liberal use of) references Öö Tiib <ootiib@hot.ee> - 2022-12-06 21:38 -0800
                Re: An argument *against* (the liberal use of) references scott@slp53.sl.home (Scott Lurndal) - 2022-12-07 15:22 +0000
                Re: An argument *against* (the liberal use of) references Paavo Helde <eesnimi@osa.pri.ee> - 2022-12-07 18:37 +0200
                Re: An argument *against* (the liberal use of) references "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2022-12-06 14:01 -0800
                Re: An argument *against* (the liberal use of) references Juha Nieminen <nospam@thanks.invalid> - 2022-12-07 09:05 +0000
                Re: An argument *against* (the liberal use of) references "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2022-12-07 12:48 -0800
                Re: An argument *against* (the liberal use of) references "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2022-12-07 12:50 -0800
                Re: An argument *against* (the liberal use of) references Juha Nieminen <nospam@thanks.invalid> - 2022-12-08 07:52 +0000
                Re: An argument *against* (the liberal use of) references Tim Rentsch <tr.17687@z991.linuxsc.com> - 2022-12-08 05:50 -0800
                Re: An argument *against* (the liberal use of) references Michael S <already5chosen@yahoo.com> - 2022-12-08 13:30 -0800
                Re: An argument *against* (the liberal use of) references Tim Rentsch <tr.17687@z991.linuxsc.com> - 2022-12-09 12:50 -0800
                Re: An argument *against* (the liberal use of) references David Brown <david.brown@hesbynett.no> - 2022-12-11 12:18 +0100
                Re: An argument *against* (the liberal use of) references Paavo Helde <eesnimi@osa.pri.ee> - 2022-12-08 13:38 +0200
                Re: An argument *against* (the liberal use of) references "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2022-12-08 16:45 -0800
                Re: An argument *against* (the liberal use of) references Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2022-12-09 04:35 -0800
  Re: An argument *against* (the liberal use of) references Bonita Montero <Bonita.Montero@gmail.com> - 2022-11-22 15:36 +0100
  Re: An argument *against* (the liberal use of) references Chris Vine <chris@cvine--nospam--.freeserve.co.uk> - 2022-11-22 15:21 +0000
  Re: An argument *against* (the liberal use of) references Richard Damon <Richard@Damon-Family.org> - 2022-11-22 10:48 -0500
    Re: An argument *against* (the liberal use of) references "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2022-11-22 13:18 -0800
  Re: An argument *against* (the liberal use of) references El Jo <giorgio.zoppi@gmail.com> - 2022-11-22 13:41 -0800
    Re: An argument *against* (the liberal use of) references "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2022-11-22 13:51 -0800
  Re: An argument *against* (the liberal use of) references Bonita Montero <Bonita.Montero@gmail.com> - 2022-11-23 20:08 +0100

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