From: Max Nikulin <manikulin@gmail.com>
To: Eli Zaretskii <eliz@gnu.org>
Cc: eggert@cs.ucla.edu, bug-gnulib@gnu.org, 54764@debbugs.gnu.org
Subject: bug#54764: encode-time: make DST and TIMEZONE fields of the list argument optional ones
Date: Fri, 22 Apr 2022 00:23:01 +0700 [thread overview]
Message-ID: <f3b9dc57-fcfe-526e-1e55-97ea587f8802@gmail.com> (raw)
In-Reply-To: <83levyqvhp.fsf@gnu.org>
On 21/04/2022 22:58, Eli Zaretskii wrote:
>> Date: Thu, 21 Apr 2022 22:30:21 +0700
>> From: Max Nikulin
>>
>> Eli Zaretskii, Wed, 20 Apr 2022 22:30:21
>>> I see the time samples change in jumps of 15 msec. Which is expected
>>> on MS-Windows, given the scheduler time tick,
>>
>> Why do you expect such value?
>
> It is a well-known fact that the system timer tick happens 64 times a
> second on MS-Windows.
You may notice similar coarse scheduler timer on Linux as well. General
purpose PC nowadays may have higher scheduler frequency, but I saw a
case when usleep(1) caused 20ms pause while there was no problem to get
higher precision form system clock.
>> Clock resolution generally has a little common with timers.
>
> I agree, but that's something you should tell/ask Paul, not myself.
It may be deeper, e.g. additional call during initialization or extra
privileges may be required.
>> I have no experience with windows-specific code, but quick search gives
>> GetSystemTimePreciseAsFileTime that should provide timestamps with fine
>> granularity
>> https://docs.microsoft.com/en-us/windows/win32/api/sysinfoapi/nf-sysinfoapi-getsystemtimepreciseasfiletime
>
> That API exists only since Windows 8.
I suspect that it means just that MS does not support anything prior to
Windows 8 any more. XP is mentioned in connection to this function:
https://www.lochan.org/2005/keith-cl/useful/win32time.html
Writing about possible intentional hiding of high precision clock I was
assuming latest windows versions, I believe, even Windows 8 is too old
for such modern tricks.
> More importantly the Gnulib
> implementation of current_timespec doesn't use it.
Even if it is not used yet, is it intentional design decision or just an
issue that should be fixed? I am unsure what function
clock_gettime/timespec_get/gettimeofday is actually used on windows
platform and how it is implemented.
It seems, only coarse clock is currently available in Emacs on Windows
due to usage of current_timespec. Are there any known problem with 16ms
resolution?
next prev parent reply other threads:[~2022-04-21 17:23 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-07 12:37 bug#54764: encode-time: make DST and TIMEZONE fields of the list argument optional ones Max Nikulin
2022-04-09 7:52 ` Paul Eggert
[not found] ` <149de00f-115b-5367-414f-c7700ef8966b@cs.ucla.edu>
2022-04-09 11:36 ` Max Nikulin
2022-04-13 14:40 ` Max Nikulin
2022-04-13 18:35 ` Paul Eggert
2022-04-14 13:19 ` Max Nikulin
[not found] ` <4a23f3a4-fe8f-d396-49d8-10034803be63@gmail.com>
2022-04-14 22:46 ` Paul Eggert
[not found] ` <52fb10fb-892a-f273-3be8-28793f27e204@cs.ucla.edu>
2022-04-15 2:14 ` Tim Cross
2022-04-15 17:23 ` Max Nikulin
[not found] ` <5cd820d4-ae67-43d4-9e63-c284d51ff1e4@gmail.com>
2022-04-16 19:23 ` Paul Eggert
2022-04-19 2:02 ` Paul Eggert
2022-04-19 5:50 ` Eli Zaretskii
[not found] ` <83tuapvcxs.fsf@gnu.org>
2022-04-19 22:22 ` Paul Eggert
2022-04-20 7:23 ` Eli Zaretskii
[not found] ` <83fsm8tdzl.fsf@gnu.org>
2022-04-20 18:19 ` Paul Eggert
2022-04-20 18:41 ` Eli Zaretskii
2022-04-20 19:01 ` Paul Eggert
[not found] ` <4e41671c-fae8-61c4-845c-4c7ba4317e88@cs.ucla.edu>
2022-04-20 19:14 ` Eli Zaretskii
[not found] ` <83fsm7sh2s.fsf@gnu.org>
2022-04-20 19:23 ` Paul Eggert
[not found] ` <e4cc58ca-51f9-395e-05f5-5f06cb9d439d@cs.ucla.edu>
2022-04-20 19:30 ` Eli Zaretskii
2022-04-21 0:11 ` Paul Eggert
[not found] ` <33fb24fb-282b-cc13-a597-e7b63f19982d@cs.ucla.edu>
2022-04-21 6:44 ` Eli Zaretskii
[not found] ` <83y1zzq6kd.fsf@gnu.org>
2022-04-21 15:30 ` Max Nikulin
2022-04-21 15:58 ` Eli Zaretskii
2022-04-21 17:23 ` Max Nikulin [this message]
2022-04-21 18:46 ` Eli Zaretskii
2022-04-21 23:56 ` Paul Eggert
[not found] ` <aa2bc0a0-1bec-37ff-919d-c20fcdfdab68@cs.ucla.edu>
2022-04-22 5:01 ` Eli Zaretskii
2022-04-23 14:35 ` Bernhard Voelker
2022-04-20 15:07 ` Max Nikulin
[not found] ` <25d90a4b-f47d-01b4-2bfe-9951e97fe676@gmail.com>
2022-04-20 18:29 ` Paul Eggert
2022-04-25 15:30 ` Max Nikulin
2022-04-25 15:37 ` Paul Eggert
[not found] ` <4bd57f21-0660-fce0-d796-08c534402340@cs.ucla.edu>
2022-04-25 19:49 ` Paul Eggert
2022-04-30 11:22 ` Max Nikulin
2022-05-01 2:32 ` Paul Eggert
2022-05-01 17:15 ` Max Nikulin
[not found] ` <507cc0a2-d2d9-4283-7cc2-0da3c6510ac8@cs.ucla.edu>
2022-04-21 16:59 ` Max Nikulin
2022-04-13 15:12 ` Max Nikulin
2022-04-16 16:26 ` Max Nikulin
[not found] ` <2d57e59b-f971-483b-ad65-e0c5ff7883e8@gmail.com>
2022-04-17 1:58 ` Paul Eggert
[not found] ` <3624beb8-71fd-924e-a065-74d0034ed351@cs.ucla.edu>
2022-04-20 16:56 ` Max Nikulin
2022-04-20 19:17 ` Paul Eggert
[not found] ` <handler.54764.D54764.165091617725815.notifdone@debbugs.gnu.org>
2022-04-25 21:16 ` Glenn Morris
2022-04-26 1:18 ` Paul Eggert
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