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Groups > comp.lang.c++ > #87246
| From | Keith Thompson <Keith.S.Thompson+u@gmail.com> |
|---|---|
| Newsgroups | comp.lang.c, comp.lang.c++ |
| Subject | Re: what is the best way to get microseconds of time on Windows in C or C++ ? |
| Date | 2022-11-04 15:05 -0700 |
| Organization | None to speak of |
| Message-ID | <8735ayml3k.fsf@nosuchdomain.example.com> (permalink) |
| References | <tk1p0t$1iv03$1@dont-email.me> <tk2fch$13ej$1@gioia.aioe.org> <tk3oto$1va6e$1@dont-email.me> |
Cross-posted to 2 groups.
Lynn McGuire <lynnmcguire5@gmail.com> writes:
> On 11/4/2022 2:35 AM, Juha Nieminen wrote:
>> In comp.lang.c++ Lynn McGuire <lynnmcguire5@gmail.com> wrote:
>>> What is the best way to get microseconds of time on Windows in C or C++
>> It's a bit unclear whether you mean "time in microseconds units" or
>> "time
>> at the microseconds resolution".
>> Because the latter may not be even possible (portable or not). Just
>> because
>> some time function returns time "in microseconds" that doesn't mean that it
>> uses microsecond resolution (in other words, the value it returns may well
>> change at longer intervals than every microsecond; probably *significantly*
>> longer intervals).
>> It is possible to get some kind of timing at the CPU clock cycle
>> interval
>> (in most modern CPUs, at least), which is about as accurate as you can
>> possibly get, but I don't know if there are eg. some system functions that
>> will return elapsed clock cycles converted into the equivalent amount of
>> microseconds.
>
> Get time at the microseconds resolution. My calculation engine
> creates a bunch of temporary files and I use the time to create unique
> names for those temporary files. Seconds should be good enough for
> uniqueness but I like adding microseconds as a guarantee. Something
> like
> uniquac1.out.009.20181972.20220912
An alternative is to keep a counter, incremented for each generated file
name, and append it to the file name, perhaps resetting to 0 when the
seconds count advances. If your only requirement is uniqueness, that
should be good enough.
Digression: I remember an implementation of gettimeofday() that did
something like that (on SunOS, maybe?). The system clock had a
resolution of 0.01 second, so the value of tv_usec on successive calls
might be:
420000
420001
420002
430000
430001
430002
...
I don't remember whether the implicit counter was per-process or
system-wide.
--
Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com
Working, but not speaking, for XCOM Labs
void Void(void) { Void(); } /* The recursive call of the void */
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what is the best way to get microseconds of time on Windows in C or C++ ? Lynn McGuire <lynnmcguire5@gmail.com> - 2022-11-03 20:14 -0500
Re: what is the best way to get microseconds of time on Windows in C or C++ ? Lynn McGuire <lynnmcguire5@gmail.com> - 2022-11-04 00:06 -0500
Re: what is the best way to get microseconds of time on Windows in C or C++ ? Christian Gollwitzer <auriocus@gmx.de> - 2022-11-04 08:03 +0100
Re: what is the best way to get microseconds of time on Windows in C or C++ ? Lynn McGuire <lynnmcguire5@gmail.com> - 2022-11-04 14:32 -0500
Re: what is the best way to get microseconds of time on Windows in C or C++ ? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2022-11-04 09:07 -0700
Re: what is the best way to get microseconds of time on Windows in C or C++ ? Lynn McGuire <lynnmcguire5@gmail.com> - 2022-11-04 14:33 -0500
Re: what is the best way to get microseconds of time on Windows in C or C++ ? Opus <ifonly@youknew.org> - 2022-11-06 20:53 +0100
Re: what is the best way to get microseconds of time on Windows in C or C++ ? Michael S <already5chosen@yahoo.com> - 2022-11-06 14:30 -0800
Re: what is the best way to get microseconds of time on Windows in C or C++ ? "Alf P. Steinbach" <alf.p.steinbach@gmail.com> - 2022-11-07 07:48 +0100
Re: what is the best way to get microseconds of time on Windows in C or C++ ? Michael S <already5chosen@yahoo.com> - 2022-11-07 04:11 -0800
Re: what is the best way to get microseconds of time on Windows in C or C++ ? "Alf P. Steinbach" <alf.p.steinbach@gmail.com> - 2022-11-08 18:30 +0100
Re: what is the best way to get microseconds of time on Windows in C or C++ ? Michael S <already5chosen@yahoo.com> - 2022-11-08 15:37 -0800
Re: what is the best way to get microseconds of time on Windows in C or C++ ? Öö Tiib <ootiib@hot.ee> - 2022-11-09 06:14 -0800
Re: what is the best way to get microseconds of time on Windows in C or C++ ? Michael S <already5chosen@yahoo.com> - 2022-11-12 16:21 -0800
Re: what is the best way to get microseconds of time on Windows in C or C++ ? Juha Nieminen <nospam@thanks.invalid> - 2022-11-04 07:35 +0000
Re: what is the best way to get microseconds of time on Windows in C or C++ ? Lynn McGuire <lynnmcguire5@gmail.com> - 2022-11-04 14:24 -0500
Re: what is the best way to get microseconds of time on Windows in C or C++ ? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2022-11-04 19:50 +0000
Re: what is the best way to get microseconds of time on Windows in C or C++ ? Lynn McGuire <lynnmcguire5@gmail.com> - 2022-11-04 15:16 -0500
Re: what is the best way to get microseconds of time on Windows in C or C++ ? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2022-11-04 15:05 -0700
Re: what is the best way to get microseconds of time on Windows in C or C++ ? Lynn McGuire <lynnmcguire5@gmail.com> - 2022-11-04 17:35 -0500
Re: what is the best way to get microseconds of time on Windows in C or C++ ? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2022-11-04 15:56 -0700
Re: what is the best way to get microseconds of time on Windows in C or C++ ? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2022-11-04 16:15 -0700
Re: what is the best way to get microseconds of time on Windows in C or C++ ? Michael S <already5chosen@yahoo.com> - 2022-11-06 14:41 -0800
Re: what is the best way to get microseconds of time on Windows in C or C++ ? scott@slp53.sl.home (Scott Lurndal) - 2022-11-07 14:39 +0000
Re: what is the best way to get microseconds of time on Windows in C or C++ ? Michael S <already5chosen@yahoo.com> - 2022-11-07 11:03 -0800
Re: what is the best way to get microseconds of time on Windows in C or C++ ? Lynn McGuire <lynnmcguire5@gmail.com> - 2022-11-07 23:26 -0600
Re: what is the best way to get microseconds of time on Windows in C or C++ ? Öö Tiib <ootiib@hot.ee> - 2022-11-04 01:23 -0700
Re: what is the best way to get microseconds of time on Windows in C or C++ ? Juha Nieminen <nospam@thanks.invalid> - 2022-11-07 07:20 +0000
Re: what is the best way to get microseconds of time on Windows in C or C++ ? Öö Tiib <ootiib@hot.ee> - 2022-11-07 07:11 -0800
Re: what is the best way to get microseconds of time on Windows in C or C++ ? Michael S <already5chosen@yahoo.com> - 2022-11-04 03:12 -0700
Re: what is the best way to get microseconds of time on Windows in C or C++ ? Lynn McGuire <lynnmcguire5@gmail.com> - 2022-11-04 14:35 -0500
Re: what is the best way to get microseconds of time on Windows in C or C++ ? scott@slp53.sl.home (Scott Lurndal) - 2022-11-04 13:44 +0000
Re: what is the best way to get microseconds of time on Windows in C or C++ ? Lynn McGuire <lynnmcguire5@gmail.com> - 2022-11-04 14:34 -0500
Re: what is the best way to get microseconds of time on Windows in C or C++ ? Lynn McGuire <lynnmcguire5@gmail.com> - 2022-11-14 16:58 -0600
Re: what is the best way to get microseconds of time on Windows in C or C++ ? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2022-11-14 17:36 -0800
Re: what is the best way to get microseconds of time on Windows in C or C++ ? Lynn McGuire <lynnmcguire5@gmail.com> - 2022-11-15 17:26 -0600
Re: what is the best way to get microseconds of time on Windows in C or C++ ? Andreas <nospam@gmx.de> - 2022-11-16 13:15 +0100
Re: what is the best way to get microseconds of time on Windows in C or C++ ? Bonita Montero <Bonita.Montero@gmail.com> - 2022-11-04 20:49 +0100
Re: what is the best way to get microseconds of time on Windows in C or C++ ? Manu Raju <MR@invalid.invalid> - 2022-11-20 21:30 +0000
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