Hi, The time is measured using the clock() POSIX function, which measures the elapsed CPU-time of the process that calls it. Calling usleep does not put the process into a busy-loop (and thus incurring CPU-time), it just delays the scheduling of that process. Compare the reported runtime with running your program using the time wrapper command to see the wall-clock time, user time, and kernel time.
If the program is busy (i.e., not calling functions such as usleep) and is running on an otherwise unloaded machine, wall-clock time and CPU-time will be roughly equal. Cheers, Mikael On Tue, Feb 24, 2009 at 5:23 PM, David Przybilla <[email protected]> wrote: > I made a small testing sample, I made a simple propagator and some variables > subscribing to it. > Inside the propagate method there is a usleep line, which is supposed to > delay the execution for some seconds. > When I run the example, the delay is there, however when stats are shown, > they say the example`s runtime was 0ms. > what does "runtime" measure? am I doing anything wrong? > Also, Im making performance comparisons between some programs on Gecode old > versions and between the same ones on Gecode 2.1.1, > I wonder whether I should measure the time on my own or just use the > runtime thrown by gecode`s stats > > Thank you in advance! > > _______________________________________________ > Gecode users mailing list > [email protected] > https://www.gecode.org/mailman/listinfo/gecode-users > > -- Mikael Zayenz Lagerkvist, http://www.ict.kth.se/~zayenz/ _______________________________________________ Gecode users mailing list [email protected] https://www.gecode.org/mailman/listinfo/gecode-users
