On Fri, 11 Feb 2005 18:05:34 -0500, Preston A. Elder <prez@neuromancy.net> wrote:
I thought boost::timer (which the high_res_timer is modelled on) used wall clock values though. This makes sense, because if you're using the timer to say "X task to Y seconds", you hardly want to tell them how much CPU time it spent on it. It would look odd to use a timer that told the user X task took 20 seconds, when its been over a minute, it just got 20s CPU time.
No, boost::timer uses std::clock, which measures CPU cycles. For example: #include <boost/progress.hpp> #include <cstdlib> int main () { boost::progress_timer t; sleep (10); } Outputs "0.00 s" on my machine.
This is basically something that needs to be decided, though I suppose policies could take care of it (wall_clock or cpu_time for accumulation), but do you want to profile how long it took something to run, or how much time was spent doing it? As you say, they're subtly different things.
I agree that this should be user-selectable (and it is in Christopher's implementation). Having those two user-friendly timer names as you suggest is a good idea. -- Caleb Epstein caleb dot epstein at gmail dot com