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Re: sht static guard locks

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jacobnavia wrote:
> Le 27/08/2015 20:11, fir a écrit :
>> Im not sure if this is a problem of c++
>> only or it appleies to c, too
>>
>> Sometimes (usually?) when using static entities
>> in functions the compiler puts special code which
>> contains a lock acquire and release
>>
>
> This is because C++ changed yet again the language underneath your feet.
>
>> Thisd bloats the executable yet also slows down the code.. Im not quite sure
>> 1)how serious this problem is?
>
> If you do not care about performance (as many C++ people do) it doesn't
> matter. If you are very interested in performance this is a serious problem.

If you take the trouble to look (but that would spoil a good rant, 
wouldn't it?) you would see that static variable initialisation that is 
legal in C (from a constant) is treated the same in C++ as C.  The 
compiler inserts guards where a race condition could occur.

>> 2) in which cases it do apply?
>
> in ALL cases where you have the bad idea to compile your code as C++
> instead of compiling it as C, where you wouldn't have any of those problems.

If it is seeing guards, the code couldn't be compiled as C.

-- 
Ian Collins

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sht static guard locks fir <profesor.fir@gmail.com> - 2015-08-27 11:11 -0700
  Re: sht static guard locks jacobnavia <jacob@jacob.remcomp.fr> - 2015-08-27 23:15 +0200
    Re: sht static guard locks Ian Collins <ian-news@hotmail.com> - 2015-08-28 09:51 +1200
      Re: sht static guard locks Les Cargill <lcargill99@comcast.com> - 2015-08-27 18:06 -0500
        Re: sht static guard locks David Brown <david.brown@hesbynett.no> - 2015-08-28 10:14 +0200
          Re: sht static guard locks Les Cargill <lcargill99@comcast.com> - 2015-08-28 21:30 -0500
            Re: sht static guard locks fir <profesor.fir@gmail.com> - 2015-08-29 00:46 -0700
              Re: sht static guard locks fir <profesor.fir@gmail.com> - 2015-08-29 01:39 -0700
                Re: sht static guard locks fir <profesor.fir@gmail.com> - 2015-08-29 03:09 -0700
                Re: sht static guard locks David Brown <david.brown@hesbynett.no> - 2015-08-29 12:43 +0200
              Re: sht static guard locks fir <profesor.fir@gmail.com> - 2015-08-29 03:20 -0700
              Re: sht static guard locks fir <profesor.fir@gmail.com> - 2015-08-29 04:28 -0700
            Re: sht static guard locks David Brown <david.brown@hesbynett.no> - 2015-08-29 12:38 +0200
    Re: sht static guard locks Ian Collins <ian-news@hotmail.com> - 2015-08-28 11:02 +1200
      Re: sht static guard locks Gareth Owen <gwowen@gmail.com> - 2015-08-31 18:15 +0100

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