Re: [Boost-users] [timer] incorrect time ?

From: Ruediger Berlich (ruediger.berlich_at_[hidden])
Date: 2007-07-05 06:22:45

Hi again,

apologies - probably my last posting was a stupid one. I had
interpreted "The timer library supplies a timer class for measuring elapsed
time" in such a way that the library can be used to measure a given amount
of real time. However, the library internally uses the clock() call,
which "returns an approximation of processor time used by the program". As
I have just used usleep calls to simulate activity, the timer always
returned 0. I will use the date_time library now instead, as my application
spends a lot of time being idle.

Thanks and Best Regards,
Ruediger

Ruediger Berlich wrote:

> Hi there,
> the following program
> 
> /****************************************************/
> 
> #include <iostream>
> #include <boost/timer.hpp>
> 
> using namespace std;
> 
> boost::timer t;
> 
> main()
> {
>     t.restart();
>     for(int i=0; i<5; i++){
>         usleep(500000);
>         cout << t.elapsed() << endl
>              << t.elapsed_min() << endl
>              << t.elapsed_max() << endl;
>     }
> }
> 
> /****************************************************/
> 
> gives five times the following output, in 0.5 s intervals:
> 
> 0
> 1e-06
> 9.22337e+12
> 
> I have tried the timer_test.cpp application (from
> http://www.boost.org/libs/timer/index.html). Most of it seems to be
> working, but the first messages also say:
> 
> timer::elapased_min() reports 1e-06 seconds
> timer::elapased_max() reports 9.22337e+12 seconds,
> which is 2.56205e+09 hours
> 
> After this the output seems to be fine.
> 
> 
> So something clearly is wrong. Any ideas ?
> 
> This is on an OpenSuSE 10.2 system with a Boost 1.34.0 (with added ASIO
> support, 0.38rc3). g++ is 4.1.2 .
> 
> Thanks and Best Regards,
> Ruediger