bug#57346: undeclared identifier 'CLOCK_MONOTONIC'

bug#57346: undeclared identifier 'CLOCK_MONOTONIC'

[Glenn Morris]

Package: emacs
Version: 29.0.50

OS X Clang build failing for three weeks. Ref:
https://hydra.nixos.org/build/186116177
https://hydra.nixos.org/build/188132926

xterm.c:6659:3: warning: implicit declaration of function
'clock_gettime' is invalid in C99 [-Wimplicit-function-declaration]
  clock_gettime (CLOCK_MONOTONIC, &time);
  ^
xterm.c:6659:18: error: use of undeclared identifier 'CLOCK_MONOTONIC'
  clock_gettime (CLOCK_MONOTONIC, &time);

bug#57346: undeclared identifier 'CLOCK_MONOTONIC'

[Po Lu via Bug reports for GNU Emacs, the Swiss army knife of text editors]

Glenn Morris <rgm@gnu.org> writes:

> Package: emacs
> Version: 29.0.50
>
> OS X Clang build failing for three weeks. Ref:
> https://hydra.nixos.org/build/186116177
> https://hydra.nixos.org/build/188132926
>
> xterm.c:6659:3: warning: implicit declaration of function
> 'clock_gettime' is invalid in C99 [-Wimplicit-function-declaration]
>   clock_gettime (CLOCK_MONOTONIC, &time);
>   ^
> xterm.c:6659:18: error: use of undeclared identifier 'CLOCK_MONOTONIC'
>   clock_gettime (CLOCK_MONOTONIC, &time);

Right, the internet says OS X doesn't have clock_gettime.

Does gnulib provide it? Failing that, I'd rather just make vsync
conditional on clock_gettime being available, since the mechanism it
uses cannot possibly work on OS X.

bug#57346: undeclared identifier 'CLOCK_MONOTONIC'

[Eli Zaretskii]

> Cc: 57346@debbugs.gnu.org
> Date: Tue, 23 Aug 2022 08:48:29 +0800
> From:  Po Lu via "Bug reports for GNU Emacs,
>  the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>
> 
> Right, the internet says OS X doesn't have clock_gettime.
> 
> Does gnulib provide it?

Not AFAICT.

bug#57346: undeclared identifier 'CLOCK_MONOTONIC'

[Gerd Möllmann]

Po Lu <luangruo@yahoo.com> writes:

>
> Glenn Morris <rgm@gnu.org> writes:
>
>> Package: emacs
>> Version: 29.0.50
>>
>> OS X Clang build failing for three weeks. Ref:
>> https://hydra.nixos.org/build/186116177
>> https://hydra.nixos.org/build/188132926
>>
>> xterm.c:6659:3: warning: implicit declaration of function
>> 'clock_gettime' is invalid in C99 [-Wimplicit-function-declaration]
>>   clock_gettime (CLOCK_MONOTONIC, &time);
>>   ^
>> xterm.c:6659:18: error: use of undeclared identifier 'CLOCK_MONOTONIC'
>>   clock_gettime (CLOCK_MONOTONIC, &time);
>
> Right, the internet says OS X doesn't have clock_gettime.

I don't know what version Glenn is building (it just says x86_74-darwin,
AFAICT), so maybe this is not useful, so just in case...

On my system it says for 'man clock_gettime'

DESCRIPTION
...
     CLOCK_MONOTONIC    clock that increments monotonically, tracking the time since an arbitrary point, and will
                        continue to increment while the system is asleep.
...
HISTORY
     These functions first appeared in Mac OSX 10.12

bug#57346: undeclared identifier 'CLOCK_MONOTONIC'

[Po Lu via Bug reports for GNU Emacs, the Swiss army knife of text editors]

Gerd Möllmann <gerd.moellmann@gmail.com> writes:

> I don't know what version Glenn is building (it just says x86_74-darwin,
> AFAICT), so maybe this is not useful, so just in case...
>
> On my system it says for 'man clock_gettime'
>
> DESCRIPTION
> ...
>      CLOCK_MONOTONIC    clock that increments monotonically, tracking the time since an arbitrary point, and will
>                         continue to increment while the system is asleep.
> ...
> HISTORY
>      These functions first appeared in Mac OSX 10.12

So I guess OS X 10.12 is relatively new, and the information I saw is
out of date.  We support much older versions anyway, so if nobody has
any better ideas I will make the vsync support conditional on
clock_gettime.

bug#57346: undeclared identifier 'CLOCK_MONOTONIC'

[Gerd Möllmann]

Po Lu <luangruo@yahoo.com> writes:

> So I guess OS X 10.12 is relatively new, and the information I saw is
> out of date.  We support much older versions anyway

FWIW, 10.12 was released 2016, and doesn't get security updates since
November 30, 2019.  Not really advisable to use something like this.
Just saying...

bug#57346: undeclared identifier 'CLOCK_MONOTONIC'

[Lars Ingebrigtsen]

Po Lu <luangruo@yahoo.com> writes:

> So I guess OS X 10.12 is relatively new, and the information I saw is
> out of date.  We support much older versions anyway, so if nobody has
> any better ideas I will make the vsync support conditional on
> clock_gettime.

Sounds good.  But I wonder what the OS X version nixos is using, anyway?
I had a look at the log file, and it says:

Configured for 'x86_64-apple-darwin17.7.0'.

But I don't know what that is.

bug#57346: undeclared identifier 'CLOCK_MONOTONIC'

[Gregory Heytings]

>> Right, the internet says OS X doesn't have clock_gettime.
>>
>> Does gnulib provide it?
>
> Not AFAICT.
>

It should be easy to emulate it with what Mac OS X/macOS provides, 
however:

int
clock_gettime (clockid_t ignored /* assuming CLOCK_MONOTONIC */,
                struct timespec *tp)
{
   clock_serv_t cs;
   mach_timespec_t mts;
   kern_return_t ret;
   host_get_clock_service (mach_host_self (), SYSTEM_CLOCK, &cs);
   ret = clock_get_time (cs, &mts);
   mach_port_deallocate(mach_task_self (), cs);
   if (ret) return ret;
   tp->tv_sec = mts.tv_sec;
   tp->tv_nsec = mts.tv_nsec;
}

bug#57346: undeclared identifier 'CLOCK_MONOTONIC'

[Po Lu via Bug reports for GNU Emacs, the Swiss army knife of text editors]

Gregory Heytings <gregory@heytings.org> writes:

> It should be easy to emulate it with what Mac OS X/macOS provides,
> however:

In that case I'd rather remove the code entirely.  vsync in the X port
can't work on Macintosh X servers anyway (or over a network connection),
and the use of CLOCK_MONOTONIC makes no sense, since the X sample server
will use its internal clock if clock_gettime is not available.

bug#57346: undeclared identifier 'CLOCK_MONOTONIC'

[Po Lu via Bug reports for GNU Emacs, the Swiss army knife of text editors]

Lars Ingebrigtsen <larsi@gnus.org> writes:

> Po Lu <luangruo@yahoo.com> writes:
>
>> So I guess OS X 10.12 is relatively new, and the information I saw is
>> out of date.  We support much older versions anyway, so if nobody has
>> any better ideas I will make the vsync support conditional on
>> clock_gettime.
>
> Sounds good.  But I wonder what the OS X version nixos is using, anyway?
> I had a look at the log file, and it says:

Now done.  Please let me know once problem is also resolved on the nixos
build bot, I will close this bug.

> Configured for 'x86_64-apple-darwin17.7.0'.
>
> But I don't know what that is.

Unfortunately I don't know either.

bug#57346: undeclared identifier 'CLOCK_MONOTONIC'

[Gregory Heytings]

>
> Configured for 'x86_64-apple-darwin17.7.0'.
>
> But I don't know what that is.
>

See https://github.com/apple/darwin-xnu.

Darwin is the roughly speaking the kernel of all Apple operating systems 
(macOS, iOS, ...).  More precisely, XNU is the kernel of Darwin, and 
Darwin is the core operating system on which Apple operating systems are 
based.  Darwin 17.7.0 is the basis of macOS 10.13.6.

bug#57346: undeclared identifier 'CLOCK_MONOTONIC'

[Howard Melman]

Gregory Heytings <gregory@heytings.org> writes:

>> Configured for 'x86_64-apple-darwin17.7.0'.
>>
>> But I don't know what that is.
>>
>
> See https://github.com/apple/darwin-xnu.
>
> Darwin is the roughly speaking the kernel of all Apple operating
> systems (macOS, iOS, ...).  More precisely, XNU is the kernel of
> Darwin, and Darwin is the core operating system on which Apple
> operating systems are based.  Darwin 17.7.0 is the basis of macOS
> 10.13.6.

Nice mapping of versions here:
https://en.wikipedia.org/wiki/Darwin_(operating_system)#Darwin_16_%E2%80%93_19;_OS_X_rebranded_into_macOS

-- 

Howard

bug#57346: undeclared identifier 'CLOCK_MONOTONIC'

[Lars Ingebrigtsen]

Po Lu <luangruo@yahoo.com> writes:

> Now done.  Please let me know once problem is also resolved on the nixos
> build bot, I will close this bug.

Hm...  looks like that job is failing, but due to an internal Hydra
error?

 [31;1merror:[0m cannot connect to ‘[35;1mroot@e461fe17.packethost.net[0m’: [35;1mroot@e461fe17.packethost.net: Permission denied (publickey).[

  https://hydra.nixos.org/eval/1777547

Perhaps they'll have Hydra tomorrow so that we can see whether your fix
did the trick.  :-/

bug#57346: undeclared identifier 'CLOCK_MONOTONIC'

[Lars Ingebrigtsen]

Lars Ingebrigtsen <larsi@gnus.org> writes:

> Hm...  looks like that job is failing, but due to an internal Hydra
> error?

And hydra hasn't been running these tests for a week now, so it sounds
like it's semi-permanently wedged.  So I'm closing this bug report.  If
the problem still exists, please respond to the debbugs address and
we'll reopen.