Re: [boost] Low-level precision timer proposal

From: Gennaro Prota (gennaro_prota_at_[hidden])
Date: 2006-07-14 08:36:24

On Fri, 14 Jul 2006 09:58:40 +0200, "Philippe Vaucher"
<philippe.vaucher_at_[hidden]> wrote:

>> I guess the whole component has to go through a fast track review, at
>> least
>
>
>Hum, ok.

I restate that this was just a guess on my part. The point is, I'm
under the impression this has grown a bit beyond the (arbitrary) limit
under which we consider additions as sort of "patches" which can go
into the code without discussion.

>At a first glance there are a couple of points which perplex me, for
>> instance the auto_start/manual_start option.
>
>
>Well it thought it was pretty obvious, if you want the timer to start
>immediatly when it is created of if you want to manually start it with
>tmr.start().

Yes, I understood what the effect was :) I just wasn't sure it was a
good design choice, as the manual_start mode leaves to the user's
responsibility to correctly couple start/stop calls.

>To be honest I just took the draft design that was on the wiki
>and on vault (from Jeff iirc).
>
>Also, wouldn't an std::clock() based Clock be worth having anyway?
>
>
>Why not, will try to add one.

If you give me a day or two I can try and cleanup the code I already
have. I guess we could "merge" the two solutions in some way.

>AFAICS, only a Win32 Clock is provided.
>
>
>No no no, this new timer class is meant to be used along with
>boost::posix_time::microsec_clock or boost::posix_time::second_clock.

Ok :)

>It would also be useful to make a quick comparison with an
>> implementation based on GetProcessTimes(), if this hasn't already been
>> discussed.
>
>
>This wasn't discussed but I think it's mainly because this api never seems
>to be used for timing stuffs, it's usually GetTickCount(),
>QueryPerformanceCounter() or timeGetTime().
>IIRC, boost::posix_time:microsec_clock uses GetSystemTime()...
>
>Anyway, I'll try to do a clock() based timer and give a go at
>GetProcessTimes().

My code, like Beman's, is based on GetProcessTimes(), because that
isn't affect by other running processes. AFAIK, the only particular
advantage of GetTickCount() among Windows-specific options is that it
is available everywhere, including Windows CE, IIRC.

>I'll propose the whole for a fast track review once I'm done with the
>documentation and everything, so you think I'd not care about where this
>timer class should be now (date_time or timer) and let the review decide it
>?

Yes, that was my idea.

--
[ Gennaro Prota, C++ developer for hire ]
[    resume:  available on request      ]