[Boost-users] progress_timer, incorrect timing

From: __PPS__ (i-love-spam_at_[hidden])
Date: 2005-11-19 22:12:30

I got strange results with boost::progress_timer - it shows timings like 
1.45s whereas it took about 15 sec. to complete a routine.

It used to work ok, but I have no idea why it just doesn't work anymore!
I use freebsd 4.11 and clocks_per_sec is defined 128.
sysconf(_SC_CLK_TCK) also returns 128, but clock counter is not correct 
completely.

I wrote simple test class, to see what's wrong:

struct Timer {
        clock_t t;
        time_t tt;
        Timer() : t(clock()), tt(time(0)){}
        ~Timer(){
                std::cout <<
                "Elapsed interval: " <<
                (static_cast<double>(clock() -t))/CLOCKS_PER_SEC <<
                "s " << (time(0)-tt) << "s\n" ;
        }
};

this is the output:
Elapsed interval: 1.52344s 33s
1.52 s <- output by boost::progress_timer.

so, you may see that measured time is completely wrong. I rewrote it 
with microtime(...) and it works correctly now.

any ideas what's wrong, why clock() doesn't work anymore? Wouldn't that 
be a good idea to use microtime for unices?

thanks