Re: [boost] [stopwatches] About reducing the scope of the library

Subject: Re: [boost] [stopwatches] About reducing the scope of the library
From: Vicente J. Botet Escriba (vicente.botet_at_[hidden])
Date: 2011-09-10 11:06:56

Le 10/09/11 10:02, Gordon Woodhull a écrit :
>
> On Sep 9, 2011, at 3:10 PM, "Vicente J. Botet Escriba"<vicente.botet_at_[hidden]>  wrote:
>
>> Le 08/09/11 04:30, Gordon Woodhull a écrit :
>>> On Sep 7, 2011, at 5:35 PM, "Vicente J. Botet Escriba"<vicente.botet_at_[hidden]>   wrote:
>>>
>>>> Do you think that it is worth proposing an addition to Boost.Chrono that provides only stopwatches (without reporting)?
>>> It would be really nice to have a replacement for Boost.Timer ASAP. Perhaps it would make sense to introduce something simple as a Chrono example, and then decide how to expand it into a library later?
>> I don't know what  do you consider a simple example.
> Oops, I meant: yes please make stopwatches a sublibrary of chrono and then see if it needs to set off on its own.
Yes, this is a good idea.
> All I want is a replacement for boost::timer, for writing benchmarks.  I never used the progress_timer so I don't know about the reporting side of Boost.Timer, never wanted it.  I want a simple class that keeps track of elapsed time so I don't have to even do one subtraction.
>
> In one quick pass of the Stopwatches documentation, I can't find anything that doesn't do automatic reporting.  I figure there must be a class in there that looks a lot like boost::timer or the one in Chrono's "key is struck" example, which is what your original question must be proposing.
I guess this is due to the fact I used everytime the reporting 
facilities. The equivalent of the timer class is stopwatch. Here follows 
un example

using  namespace  boost::chrono;
using  namespace  boost::stopwatches;

int  f1(long  j)  {
     stopwatch||  <mailbox:///Users/viboes/Library/Thunderbird/Profiles/7k7xdbkm.default/Mail/pop.orange.fr/Sent?number=319244&part=1.2.2&filename=stopwatches.html><system_clock>  sw;

     for  (  long  i  =  0;  i  <  j;  ++i  )
         std::sqrt(  123.456L  );   // burn some time

     return  milliseconds(sw.elapsed()).count();  // retun the number of milliseconds
}

elapsed() returns the elapsed time since the stopwatch was created.

Does this respond to your expectations?
> I find Boost.Timer kind of buggy.  It was reporting CPU time on Linux, so I couldn't benchmark a parallelized program.  I feel it has other problems.  I thought Chrono was supposed to replace it, but it's still a little verbose for this very simple task.
>
My first proposal of Boost.Chrono included Stopwatches, but some on this 
list sugested that i would be better to split the library :(

If no body is agains I will move Boost.Stopwatches to the namespace 
boost::chrono, remove the reporting facilities, and find a date for a 
review.

Best,
Vicente