Groups > comp.lang.java.programmer > #5743

Re: Why "lock" functionality is introduced for all the objects?

From	Lew <noone@lewscanon.com>
Newsgroups	comp.lang.java.programmer
Subject	Re: Why "lock" functionality is introduced for all the objects?
Date	2011-06-28 14:40 -0400
Organization	albasani.net
Message-ID	<iud777$rag$1@news.albasani.net> (permalink)
References	<d0bb9e06-16f0-4282-a37e-47e9ca9630ec@r2g2000vbj.googlegroups.com> <lock-20110628193208@ram.dialup.fu-berlin.de>

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On 06/28/2011 01:33 PM, Stefan Ram wrote:
> Alex J<vstrength@gmail.com>  writes:
>> What do you think of it?
>
>    I do not think, but use a web search engine and find:
>
> http://c2.com/cgi/wiki?JavaObjectOverheadIsRidiculous

Refers to Java 1.2.2.  Things have changed significantly since then, including 
the loss of a word from object pointers.

> http://www.trevorpounds.com/blog/?p=351
>
>    . And here is a rationale given for why every object has a lock:
>
> http://forums.oracle.com/forums/thread.jspa?threadID=1140765
>
>    , that is, so that one can use »synchronized« on object
>    methods (which stands for »synchronized( this )«).

It is evident that Java's design introduces overhead.  Duh.  But it's not the 
wild claim of 100% overhead.  That's just stupid.

How much that overhead is in practice depends on HotSpot and what idioms would 
be needed to replace the lost feature of inbuilt synchronization.

Given that Java's design does introduce a cost, the question remains - for 
what benefit?  We give up some memory - did we save on developer cost?  Did we 
save on runtime crashes?  Did HotSpot optimize away the unused cruft?

We need to know the real numbers.  How much does Java's design cost an actual 
program, and what would it have cost that program to have lacked that design 
feature?

People are throwing around terms like "bloated" but only focusing on half the 
cost-benefit analysis, picking numbers out of their butts, and exaggerating 
those numbers to boot.  That can only lead to suboptimal decisions.

-- 
Lew
Honi soit qui mal y pense.
http://upload.wikimedia.org/wikipedia/commons/c/cf/Friz.jpg

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Why "lock" functionality is introduced for all the objects? Alex J <vstrength@gmail.com> - 2011-06-28 02:29 -0700
  Re: Why "lock" functionality is introduced for all the objects? Lew <noone@lewscanon.com> - 2011-06-28 07:33 -0400
    OT "sic" (was Re: Why "lock" functionality is introduced for all the objects? blmblm@myrealbox.com <blmblm.myrealbox@gmail.com> - 2011-06-28 15:56 +0000
      Re: OT "sic" (was Re: Why "lock" functionality is introduced for all the objects? Lew <noone@lewscanon.com> - 2011-06-28 12:19 -0400
    Re: Why "lock" functionality is introduced for all the objects? Michal Kleczek <kleku75@gmail.com> - 2011-06-28 18:41 +0200
      Re: Why "lock" functionality is introduced for all the objects? Lew <noone@lewscanon.com> - 2011-06-28 13:10 -0400
        Re: Why "lock" functionality is introduced for all the objects? Michal Kleczek <kleku75@gmail.com> - 2011-06-28 19:53 +0200
          Re: Why "lock" functionality is introduced for all the objects? Lew <noone@lewscanon.com> - 2011-06-28 14:13 -0400
            Re: Why "lock" functionality is introduced for all the objects? supercalifragilisticexpialadiamaticonormalizeringelimatisticantations <supercalifragilisticexpialadiamaticonormalizeringelimatisticantations@averylongandannoyingdomainname.com> - 2011-06-28 14:23 -0400
              Re: Why "lock" functionality is introduced for all the objects? Lew <noone@lewscanon.com> - 2011-06-28 14:33 -0400
                Re: Why "lock" functionality is introduced for all the objects? supercalifragilisticexpialadiamaticonormalizeringelimatisticantations <supercalifragilisticexpialadiamaticonormalizeringelimatisticantations@averylongandannoyingdomainname.com> - 2011-06-28 14:52 -0400
                Re: Why "lock" functionality is introduced for all the objects? Lew <noone@lewscanon.com> - 2011-06-28 16:20 -0400
                Re: Why "lock" functionality is introduced for all the objects? supercalifragilisticexpialadiamaticonormalizeringelimatisticantations <supercalifragilisticexpialadiamaticonormalizeringelimatisticantations@averylongandannoyingdomainname.com> - 2011-06-29 00:53 -0400
                Re: Why "lock" functionality is introduced for all the objects? Lew <noone@lewscanon.com> - 2011-06-29 01:04 -0400
                Re: Why "lock" functionality is introduced for all the objects? supercalifragilisticexpialadiamaticonormalizeringelimatisticantations <supercalifragilisticexpialadiamaticonormalizeringelimatisticantations@averylongandannoyingdomainname.com> - 2011-06-29 01:43 -0400
              Re: Why "lock" functionality is introduced for all the objects? Patricia Shanahan <pats@acm.org> - 2011-06-28 11:42 -0700
                Re: Why "lock" functionality is introduced for all the objects? supercalifragilisticexpialadiamaticonormalizeringelimatisticantations <supercalifragilisticexpialadiamaticonormalizeringelimatisticantations@averylongandannoyingdomainname.com> - 2011-06-28 14:54 -0400
                Re: Why "lock" functionality is introduced for all the objects? Patricia Shanahan <pats@acm.org> - 2011-06-28 12:34 -0700
                Re: Why "lock" functionality is introduced for all the objects? markspace <-@.> - 2011-06-28 13:20 -0700
                Re: Why "lock" functionality is introduced for all the objects? Patricia Shanahan <pats@acm.org> - 2011-06-28 13:44 -0700
                Re: Why "lock" functionality is introduced for all the objects? supercalifragilisticexpialadiamaticonormalizeringelimatisticantations <supercalifragilisticexpialadiamaticonormalizeringelimatisticantations@averylongandannoyingdomainname.com> - 2011-06-29 01:05 -0400
                Re: Why "lock" functionality is introduced for all the objects? Lew <noone@lewscanon.com> - 2011-06-28 16:21 -0400
                Re: Why "lock" functionality is introduced for all the objects? supercalifragilisticexpialadiamaticonormalizeringelimatisticantations <supercalifragilisticexpialadiamaticonormalizeringelimatisticantations@averylongandannoyingdomainname.com> - 2011-06-29 01:06 -0400
                Re: Why "lock" functionality is introduced for all the objects? BGB <cr88192@hotmail.com> - 2011-06-28 14:30 -0700
          Re: Why "lock" functionality is introduced for all the objects? Robert Klemme <shortcutter@googlemail.com> - 2011-06-29 18:56 +0200
      Re: Why "lock" functionality is introduced for all the objects? BGB <cr88192@hotmail.com> - 2011-06-28 13:43 -0700
        Re: Why "lock" functionality is introduced for all the objects? Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-06-28 20:43 -0400
          Re: Why "lock" functionality is introduced for all the objects? BGB <cr88192@hotmail.com> - 2011-06-28 21:14 -0700
        Re: Why "lock" functionality is introduced for all the objects? supercalifragilisticexpialadiamaticonormalizeringelimatisticantations <supercalifragilisticexpialadiamaticonormalizeringelimatisticantations@averylongandannoyingdomainname.com> - 2011-06-29 01:12 -0400
          Re: Why "lock" functionality is introduced for all the objects? Joshua Maurice <joshuamaurice@gmail.com> - 2011-07-01 18:28 -0700
            Re: Why "lock" functionality is introduced for all the objects? supercalifragilisticexpialadiamaticonormalizeringelimatisticantations <supercalifragilisticexpialadiamaticonormalizeringelimatisticantations@averylongandannoyingdomainname.com> - 2011-07-02 00:19 -0400
          Re: Why "lock" functionality is introduced for all the objects? Joshua Cranmer <Pidgeot18@verizon.invalid> - 2011-07-01 19:05 -0700
            Re: Why "lock" functionality is introduced for all the objects? supercalifragilisticexpialadiamaticonormalizeringelimatisticantations <supercalifragilisticexpialadiamaticonormalizeringelimatisticantations@averylongandannoyingdomainname.com> - 2011-07-02 00:26 -0400
            Re: Why "lock" functionality is introduced for all the objects? BGB <cr88192@hotmail.com> - 2011-07-04 09:39 -0700
              Re: Why "lock" functionality is introduced for all the objects? supercalifragilisticexpialadiamaticonormalizeringelimatisticantations <supercalifragilisticexpialadiamaticonormalizeringelimatisticantations@averylongandannoyingdomainname.com> - 2011-07-05 02:11 -0400
    Re: Why "lock" functionality is introduced for all the objects? Alex J <vstrength@gmail.com> - 2011-07-05 16:56 -0700
      Re: Why "lock" functionality is introduced for all the objects? "John B. Matthews" <nospam@nospam.invalid> - 2011-07-06 00:57 -0400
      Re: Why "lock" functionality is introduced for all the objects? supercalifragilisticexpialadiamaticonormalizeringelimatisticantations <supercalifragilisticexpialadiamaticonormalizeringelimatisticantations@averylongandannoyingdomainname.com> - 2011-07-06 05:55 -0400
  Re: Why "lock" functionality is introduced for all the objects? Lew <noone@lewscanon.com> - 2011-06-28 14:40 -0400
  Re: Why "lock" functionality is introduced for all the objects? Robert Klemme <shortcutter@googlemail.com> - 2011-06-29 19:15 +0200
  Re: Why "lock" functionality is introduced for all the objects? Tom Anderson <twic@urchin.earth.li> - 2011-06-30 23:04 +0100
    Re: Why "lock" functionality is introduced for all the objects? KitKat <kitkat_11697@gmail.example.com> - 2011-06-30 18:29 -0400
      Re: Why "lock" functionality is introduced for all the objects? Patricia Shanahan <pats@acm.org> - 2011-06-30 17:05 -0700
        Re: Why "lock" functionality is introduced for all the objects? KitKat <kitkat_11697@gmail.example.com> - 2011-06-30 20:17 -0400
          Re: Why "lock" functionality is introduced for all the objects? Tom Anderson <twic@urchin.earth.li> - 2011-07-01 21:22 +0100
      Re: Why "lock" functionality is introduced for all the objects? Tom Anderson <twic@urchin.earth.li> - 2011-07-01 21:40 +0100
        Re: Why "lock" functionality is introduced for all the objects? KitKat <kitkat_11697@gmail.example.com> - 2011-07-01 18:08 -0400
          Re: Why "lock" functionality is introduced for all the objects? BGB <cr88192@hotmail.com> - 2011-07-05 12:15 -0700
            Re: Why "lock" functionality is introduced for all the objects? KitKat <kitkat_11697@gmail.example.com> - 2011-07-05 15:30 -0400
              Re: Why "lock" functionality is introduced for all the objects? blmblm@myrealbox.com <blmblm.myrealbox@gmail.com> - 2011-07-05 21:10 +0000
                Re: Why "lock" functionality is introduced for all the objects? BGB <cr88192@hotmail.com> - 2011-07-05 22:08 -0700
                Re: Why "lock" functionality is introduced for all the objects? KitKat <kitkat_11697@gmail.example.com> - 2011-07-06 05:57 -0400
                Re: Why "lock" functionality is introduced for all the objects? blmblm@myrealbox.com <blmblm.myrealbox@gmail.com> - 2011-07-06 17:07 +0000
                Re: Why "lock" functionality is introduced for all the objects? Steve Erwin <trollHunter@Usenet.4.usenetizens.org.invalid> - 2011-07-07 04:08 +1000
                Re: Why "lock" functionality is introduced for all the objects? blmblm@myrealbox.com <blmblm.myrealbox@gmail.com> - 2011-07-06 19:09 +0000
                Re: Why "lock" functionality is introduced for all the objects? Steve Erwin <trollHunter@Usenet.4.usenetizens.org.invalid> - 2011-07-07 09:26 +1000
                Re: Why "lock" functionality is introduced for all the objects? KitKat <kitkat_11697@gmail.example.com> - 2011-07-06 20:25 -0400
                Re: Why "lock" functionality is introduced for all the objects? blmblm@myrealbox.com <blmblm.myrealbox@gmail.com> - 2011-07-07 19:37 +0000
                Re: Why "lock" functionality is introduced for all the objects? blmblm@myrealbox.com <blmblm.myrealbox@gmail.com> - 2011-07-07 19:35 +0000
                Re: Why "lock" functionality is introduced for all the objects? Steve Erwin <trollHunter@Usenet.4.usenetizens.org.invalid> - 2011-07-07 14:34 -0700
                OT names/nyms/etc. (was Re: Why "lock" functionality is introduced for all the objects?) blmblm@myrealbox.com <blmblm.myrealbox@gmail.com> - 2011-07-08 17:19 +0000
                Re: OT names/nyms/etc. (was Re: Why "lock" functionality is introduced for all the objects?) Steve Erwin <trollHunter@Usenet.4.usenetizens.org.invalid> - 2011-07-09 05:41 +1000
                Re: OT names/nyms/etc. (was Re: Why "lock" functionality is introduced for all the objects?) blmblm@myrealbox.com <blmblm.myrealbox@gmail.com> - 2011-07-08 19:58 +0000
                Re: OT names/nyms/etc. (was Re: Why "lock" functionality is introduced for all the objects?) lewbloch <lewbloch@gmail.com> - 2011-07-08 13:45 -0700
                Re: OT names/nyms/etc. (was Re: Why "lock" functionality is introduced for all the objects?) Steve Erwin <trollHunter@Usenet.4.usenetizens.org.invalid> - 2011-07-10 01:50 -0400
                Re: OT names/nyms/etc. (was Re: Why "lock" functionality is introduced for all the objects?) blmblm@myrealbox.com <blmblm.myrealbox@gmail.com> - 2011-07-10 19:15 +0000
                Re: OT names/nyms/etc. (was Re: Why "lock" functionality is introduced for all the objects?) KitKat <kitkat_11697@gmail.example.com> - 2011-07-10 18:38 -0400
                Re: OT names/nyms/etc. (was Re: Why "lock" functionality is introduced for all the objects?) KitKat <kitkat_11697@gmail.example.com> - 2011-07-09 00:29 -0400
                Re: Why "lock" functionality is introduced for all the objects? KitKat <kitkat_11697@gmail.example.com> - 2011-07-09 00:26 -0400
                Re: Why "lock" functionality is introduced for all the objects? KitKat <kitkat_11697@gmail.example.com> - 2011-07-06 20:05 -0400
                Re: Why "lock" functionality is introduced for all the objects? Steve Erwin <trollHunter@Usenet.4.usenetizens.org.invalid> - 2011-07-07 10:24 +1000
                Re: Why "lock" functionality is introduced for all the objects? KitKat <kitkat_11697@gmail.example.com> - 2011-07-06 21:52 -0400
                Re: Why "lock" functionality is introduced for all the objects? Steve Erwin <trollHunter@Usenet.4.usenetizens.org.invalid> - 2011-07-07 12:43 +1000
                Re: Why "lock" functionality is introduced for all the objects? KitKat <kitkat_11697@gmail.example.com> - 2011-07-06 23:00 -0400

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