• Lynn Allan (17/17) Aug 28 2004
• Dave (9/26) Aug 29 2004 in
• Lynn Allan (20/37) Sep 23 2004 I did some further looking, and came across:

"Lynn Allan" <l.allan att.net> writes:

<alert comment="newbie">

I'm hoping to learn enough D to use for a freeware app that involves
low-level bit-twiddling. I'd like to sprinkle in calls to obtain "d_time" in
order to figure out how much elapsed time is used by different approaches.

As I looked over std.date, it seemed like the best choice was getUTCtime. Is
that correct? That routine just calls lower level o/s code, so would it be
better to use the o/s call directly? Or is that asking for portability
problems? Is there a simpler alternative to getUTCtime? A constructor
followed by getting an attribute?

Realistically, getUTCtime is probably fine and my question is pretty much a
"poster child" for "premature optimization is the root of most software
evil -- Knuth". I ask partly to understand D and phobos better.

d_time startTime = std.date.getUTCtime();
// Code to be timed goes here ...
d_time curTime = getUTCtime();
d_time elapsed = curTime - startTime;

</alert>

"Dave" <Dave_member pathlink.com> writes:

"Lynn Allan" <l.allan att.net> wrote in message
news:cgrhfn$112t$1 digitaldaemon.com...
 <alert comment="newbie">

 I'm hoping to learn enough D to use for a freeware app that involves
 low-level bit-twiddling. I'd like to sprinkle in calls to obtain "d_time"

in
 order to figure out how much elapsed time is used by different approaches.

 As I looked over std.date, it seemed like the best choice was getUTCtime.

Is
 that correct? That routine just calls lower level o/s code, so would it be
 better to use the o/s call directly? Or is that asking for portability
 problems? Is there a simpler alternative to getUTCtime? A constructor
 followed by getting an attribute?

 Realistically, getUTCtime is probably fine and my question is pretty much

a
 "poster child" for "premature optimization is the root of most software
 evil -- Knuth". I ask partly to understand D and phobos better.

 d_time startTime = std.date.getUTCtime();
 // Code to be timed goes here ...
 d_time curTime = getUTCtime();
 d_time elapsed = curTime - startTime;

 </alert>

So far that has worked fine on both Win32 and Linux for me. To get the time
in seconds, divide the difference by TicksPerSecond.

If you don't need precision greater than ~1ms, then it should work Ok for
you.

"Lynn Allan" <l_d_allan adelphia.net> writes:

I did some further looking, and came across:
std.perf.HighPerformanceCounter

#import std.stdio;
#import std.c.time;
#import std.perf;

#void main ()













"Lynn Allan" <l.allan att.net> wrote in message
news:cgrhfn$112t$1 digitaldaemon.com...
 <alert comment="newbie">

 I'm hoping to learn enough D to use for a freeware app that involves
 low-level bit-twiddling. I'd like to sprinkle in calls to obtain "d_time"

in
 order to figure out how much elapsed time is used by different approaches.

 As I looked over std.date, it seemed like the best choice was getUTCtime.

Is
 that correct? That routine just calls lower level o/s code, so would it be
 better to use the o/s call directly? Or is that asking for portability
 problems? Is there a simpler alternative to getUTCtime? A constructor
 followed by getting an attribute?

 Realistically, getUTCtime is probably fine and my question is pretty much

a
 "poster child" for "premature optimization is the root of most software
 evil -- Knuth". I ask partly to understand D and phobos better.

 d_time startTime = std.date.getUTCtime();
 // Code to be timed goes here ...
 d_time curTime = getUTCtime();
 d_time elapsed = curTime - startTime;

 </alert>