From: Paul Eggert <eggert@cs.ucla.edu>
To: Florian Weimer <fweimer@redhat.com>
Cc: Adhemerval Zanella Netto <adhemerval.zanella@linaro.org>,
libc-alpha@sourceware.org, Bruno Haible <bruno@clisp.org>
Subject: Re: [PATCH] time: Use CLOCK_REALTIME for time (BZ #30200)
Date: Wed, 8 Mar 2023 15:08:48 -0800 [thread overview]
Message-ID: <7f7c23db-15ce-c0bf-67b8-a11fab836c1a@cs.ucla.edu> (raw)
In-Reply-To: <874jqvty7w.fsf@oldenburg.str.redhat.com>
On 3/8/23 00:59, Florian Weimer wrote:
> Even if the same underlying clock is used, rounding may cause interface
> which use different precision for the fractional seconds part to report
> different integral seconds. The standard does not require rounding
> towards minus infinity.
Actually, POSIX does require rounding timestamps towards minus infinity
for file timestamps, in its spec for utimensat. This requirement was put
in because some implementations played fast and loose with these
timestamps, with some rounding up and some rounding down, and this
confusion caused more trouble than it was worth.
Perhaps it would help if POSIX had a similar requirement for the 'time'
function, as my impression from this discussion is that the confusion
with 'time' being out-of-sync with CLOCK_REALTIME is also more trouble
than it's worth.
Anyway, thanks for clarifying what Glibc does.
next prev parent reply other threads:[~2023-03-08 23:08 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-06 16:03 Adhemerval Zanella
2023-03-07 11:11 ` Florian Weimer
2023-03-07 11:45 ` Adhemerval Zanella Netto
2023-03-07 11:51 ` Florian Weimer
2023-03-07 11:57 ` Adhemerval Zanella Netto
2023-03-07 12:07 ` Florian Weimer
2023-03-08 5:51 ` Paul Eggert
2023-03-08 8:59 ` Florian Weimer
2023-03-08 23:08 ` Paul Eggert [this message]
2023-03-08 16:23 ` Bruno Haible
2023-03-08 16:57 ` Adhemerval Zanella Netto
2023-03-08 17:09 ` Florian Weimer
2023-03-08 17:46 ` Adhemerval Zanella Netto
2023-03-08 17:44 ` Bruno Haible
2023-03-08 17:50 ` Adhemerval Zanella Netto
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