Re: [Boost-users] [signals] thread-safe post-disconnect() cleanup

From: Frank Mori Hess (frank.hess_at_[hidden])
Date: 2007-02-23 10:29:08

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On Friday 23 February 2007 09:53 am, you wrote:
> On Friday 23 February 2007 09:24 am, Peter Dimov wrote:
> >
> > Have you actually run a test and observed a 50x slowdown? You can use
> > libs/smart_ptr/test/shared_ptr_timing_test.cpp.
>
> I get:
>
> fhess_at_humidor:~/cvs/boost/libs/smart_ptr/test$ g++ -Wall -O3
> shared_ptr_timing_test.cpp
> fhess_at_humidor:~/cvs/boost/libs/smart_ptr/test$ ./a.out
> 0.22
> fhess_at_humidor:~/cvs/boost/libs/smart_ptr/test$ g++ -Wall -O3
> shared_ptr_timing_test.cpp -pthread
> fhess_at_humidor:~/cvs/boost/libs/smart_ptr/test$ ./a.out
> 1.87
>
> With boost 1.32,
> $ gcc --version
> gcc (GCC) 3.3.5 (Debian 1:3.3.5-13)
> on a 3.2GHz pentium d.
>

For further comparison, I modified the test to use an ordinary int* instead 
of a shared_ptr<int>, and got:

g++ -Wall -O3 raw_ptr_timing_test.cpp
fhess_at_humidor:~/cvs/boost/libs/smart_ptr/test$ ./a.out
0.08

So it's about x3 slower using shared_ptr without -pthread, and about x20 
slower using shared_ptr with -pthread.

- -- 
Frank
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