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Groups > comp.arch.embedded > #31243

Re: newlib and time()

From Don Y <blockedofcourse@foo.invalid>
Newsgroups comp.arch.embedded
Subject Re: newlib and time()
Date 2022-09-30 11:42 -0700
Organization A noiseless patient Spider
Message-ID <th7da7$12qsd$1@dont-email.me> (permalink)
References <th62c5$ufge$1@dont-email.me> <th64eh$uo0n$1@dont-email.me> <th6cu8$ufgd$1@dont-email.me>

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On 9/30/2022 2:29 AM, pozz wrote:
> Another bonus is when you have NTP, that returns seconds in UTC, so you can set 
> your counter with the exact number retrived by NTP.

No.  You always have to ensure that time keeps flowing in one direction.

So, time either "doesn't exist" before your initial sync with the
time server (what if the server isn't available when you want to
do that?) *or* you have to look at your current notion of "now"
and ensure that the "real" value of now, when obtained from the
time server, is always in the future relative to your notion.

[Note that NTP slaves don't blindly assume the current time is
as reported but *slew* to the new value, over some interval.]

This also ignores the possibility of computations with relative
*intervals* being inconsistent with these spontaneous "resets".

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newlib and time() pozz <pozzugno@gmail.com> - 2022-09-30 08:29 +0200
  Re: newlib and time() David Brown <david.brown@hesbynett.no> - 2022-09-30 09:04 +0200
    Re: newlib and time() pozz <pozzugno@gmail.com> - 2022-09-30 11:29 +0200
      Re: newlib and time() Clifford Heath <no_spam@please.net> - 2022-09-30 21:51 +1000
        Re: newlib and time() pozz <pozzugno@gmail.com> - 2022-09-30 15:32 +0200
          Re: newlib and time() Richard Damon <Richard@Damon-Family.org> - 2022-09-30 09:48 -0400
            Re: newlib and time() Clifford Heath <no_spam@please.net> - 2022-10-01 08:43 +1000
        Re: newlib and time() Don Y <blockedofcourse@foo.invalid> - 2022-09-30 11:55 -0700
          Re: newlib and time() Clifford Heath <no_spam@please.net> - 2022-10-01 08:48 +1000
            Re: newlib and time() Don Y <blockedofcourse@foo.invalid> - 2022-09-30 16:11 -0700
      Re: newlib and time() David Brown <david.brown@hesbynett.no> - 2022-09-30 14:38 +0200
      Re: newlib and time() Don Y <blockedofcourse@foo.invalid> - 2022-09-30 11:42 -0700
        Re: newlib and time() pozz <pozzugno@gmail.com> - 2022-10-03 00:09 +0200
          Re: newlib and time() Don Y <blockedofcourse@foo.invalid> - 2022-10-02 19:02 -0700
            Re: newlib and time() pozz <pozzugno@gmail.com> - 2022-12-30 17:08 +0100
              Re: newlib and time() Don Y <blockedofcourse@foo.invalid> - 2022-12-30 17:35 -0700
                Re: newlib and time() pozz <pozzugno@gmail.com> - 2023-01-04 17:09 +0100
                Re: newlib and time() Don Y <blockedofcourse@foo.invalid> - 2023-01-04 12:19 -0700
                Re: newlib and time() George Neuner <gneuner2@comcast.net> - 2023-01-04 20:12 -0500
                Re: newlib and time() Don Y <blockedofcourse@foo.invalid> - 2023-01-04 19:40 -0700
          Re: newlib and time() Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2022-10-03 10:20 +0300
  Re: newlib and time() Clifford Heath <no_spam@please.net> - 2022-09-30 17:12 +1000
  Re: newlib and time() Theo <theom+news@chiark.greenend.org.uk> - 2022-09-30 14:06 +0100

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