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Re: A question about synchronized threads

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byhesed wrote:
> I thought that synchronizing entire methods would be wasteful.

Why?

> Also, although two methods need to be synchronized,
> if two methods are totally unrelated to each other,
> then it would be too bad, isn't it?\

We cannot tell without an SSCCE.
http://sscce.org/

Please provide one.

Also, if two methods are "totally unrelated to each other" then you don't need 
any synchronization at all.  They shouldn't even be in the same class, perhaps 
not even in the same application.

> The rate of using CPU resources will be too low.
> That is why I though it is ineffectual.

How do you know?  Please explain your measurement methodology for performance. 
  What was the metric of performance, what value did it have, and how much of 
overall application performance was it, percentagewise?

Make sure that you measure under conditions similar to anticipated real-life 
loads, and compare proposed "optimizations" to your baseline under the same 
conditions.

Especially with concurrent programming, it is a terrible, terrible mistake to 
imagine that you will "optimize" something when you don't have any objective 
data.  Much more likely, you will "optimize" by getting wrong answers in half 
the time of correct ones.

The single best, most effective way to optimize concurrent code is not to 
share data.  The second-best way is to make shared-data immutable (read-only).

You should do ABSOLUTELY NOTHING about or with concurrent programming until 
you've read at least one of the two books people have recommended to you, and 
understand it.

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

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A question about synchronized threads byhesed <byhesed@gmail.com> - 2011-04-29 08:35 -0700
  Re: A question about synchronized threads Lew <noone@lewscanon.com> - 2011-04-29 11:53 -0400
    Re: A question about synchronized threads byhesed <byhesed@gmail.com> - 2011-04-29 09:12 -0700
      Re: A question about synchronized threads Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-04-29 21:01 -0400
        Re: A question about synchronized threads byhesed <byhesed@gmail.com> - 2011-04-29 18:43 -0700
  Re: A question about synchronized threads Daniele Futtorovic <da.futt.news@laposte-dot-net.invalid> - 2011-04-29 17:58 +0200
    Re: A question about synchronized threads byhesed <byhesed@gmail.com> - 2011-04-29 09:09 -0700
      Re: A question about synchronized threads markspace <-@.> - 2011-04-29 11:11 -0700
        Re: A question about synchronized threads Daniele Futtorovic <da.futt.news@laposte-dot-net.invalid> - 2011-04-29 20:19 +0200
          Re: A question about synchronized threads markspace <-@.> - 2011-04-29 15:21 -0700
          Re: A question about synchronized threads Patricia Shanahan <pats@acm.org> - 2011-04-29 21:10 -0700
  Re: A question about synchronized threads dagon@dagon.net (Dagon) - 2011-04-29 15:55 -0700
    Re: A question about synchronized threads Alice <quaxx1108@example.com> - 2011-04-29 20:08 -0400
    Re: A question about synchronized threads markspace <-@.> - 2011-04-29 19:07 -0700
    Re: A question about synchronized threads byhesed <byhesed@gmail.com> - 2011-04-29 18:49 -0700
      Re: A question about synchronized threads Lew <noone@lewscanon.com> - 2011-05-03 18:57 -0400
        Re: A question about synchronized threads Deeyana <d.awlberg@hotmail.invalid> - 2011-05-04 00:17 +0000
          Re: A question about synchronized threads Lew <noone@lewscanon.com> - 2011-05-04 12:45 -0400
            Re: A question about synchronized threads Deeyana <d.awlberg@hotmail.invalid> - 2011-05-04 19:59 +0000

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