NetNews Offline 2/NetNews Offline Volume 2.iso/news/comp/lang/c-part1/7911

Internet Message Format | 1996-08-05 | 2.0 KB

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From: Lawrence Kirby <[e-mail]>
Newsgroups: comp.lang.c
Subject: Re: timimng an event in milli seconds.
Date: Thu, 29 Feb 96 14:18:08 GMT
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In article <[e-mail]>
           [e-mail] "Kazimir Kylheku" writes:

>>       I am interested in _milli seconds_ can anybody help me? I am also
>>intersted in doing the same on the unix workstations at the university .

You can time things down to the granularity of the system clock which is
usually around 1/100sec in Unix. However you can't do it using standard C
functions.

>There is a _standard_ function called clock(), you know... it gives a time in
>clock ticks, which you can divide by the clock tick period, given by
>CLOCKS_PER_SECOND. Don't forget to #include <time.h>.

That's CLOCKS_PER_SEC.
>
>BTW, I think that this is normally measured in virtual process time, not real
>time.

Yes, which means that on a multitasking system it is no good if you want
to measure real time.

>I doubt that you can get a more accurate timer without referring to
>something like gettimeofday(), which is a UNIX thing, not a standard function.
>gettimeofday() gives you a struct timeval, which contains seconds and
>milliseconds.
>
>I know that it is available on PC's, since the requestor side of a
>communication protocol of mine was recently ported to Windows/Winsock, and this
>code uses gettimeofday() to measure round-trip times.

It tends to be supplied in socket libraries so was probably a part of
Winsock rather than Windows.

--
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Lawrence Kirby | [e-mail]
Wilts, England | [e-mail]
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