Steven D'Aprano schreef:
> On Fri, 24 Feb 2006 10:11:18 +0100, Magnus Lycka wrote:
>
>> Steven D'Aprano wrote:
>>> It looks like the time function under Linux at least is very slow.
>> Perhaps you should try doing the same thing in C.
>> Then you can see whether the problem is in the
>> wrapper or in the system call.
>
> Good idea.
>
> Now, has anyone got a copy of "Learning C for Dummies" I can borrow?
>
> *chagrined smile*
First, for reference, the Python version on the machine I used for
testing (Debian 3.1, P4 3GHz):
timer1: 0.36007809639
timer2: 3.18800234795
On Windows the difference is much less.
C (compiled with gcc 3.3.5 without optimizations) (see below for the code):
timer1: 0.000603
timer2: 2.624557
I think it looks like the problem is in the system call.
C code:
#include <stdio.h>
#include <sys/time.h>
#include <time.h>
void func(void)
{
}
double gettime()
{
struct timeval tv;
gettimeofday(&tv, NULL);
return tv.tv_sec + tv.tv_usec/1e6;
}
double timer1(void)
{
double t0, t1;
int i;
t0 = gettime();
for (i = 0; i < 100000; ++i)
{
func();
}
t1 = gettime();
return t1 - t0;
}
double timer2(void)
{
int i;
double t = 0.0;
double t0, t1;
for (i = 0; i < 1000000; ++i)
{
t0 = gettime();
func();
t1 = gettime();
t += t1 - t0;
}
return t;
}
int main(void)
{
printf("timer1: %lf\n", timer1());
printf("timer2: %lf\n", timer2());
return 0;
}
--
If I have been able to see further, it was only because I stood
on the shoulders of giants. -- Isaac Newton
Roel Schroeven
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