Re: [sleepy.penguin] [PATCH] Add support for Mac OS X

[Eric Wong <normalperson@yhbt.net>]

Lin Jen-Shin <godfat@godfat.org> wrote:
> Since Mac OS X does not support clock_gettime, we need to wrap
> around clock_gettime to make kqueue work on Mac OS X.
> 
> epoll.c does not need this wrapper as it's only on Linux,
> but I guess it's fine to use the wrapper as well. Maybe
> someday *BSD could also support epoll in someway?

I can accept something along these lines if it only uses
generic/portable calls instead of system-specific code/ifdefs.

This way it can be easier to test/review and reusable to other platforms
which may not have proper clock_gettime

> @@ -0,0 +1,17 @@
> +#ifdef __MACH__

Use have_func() checks instead.

Actually, clogger already has a fallback for clock_gettime which works
for all platforms (but is less "correct")

	git clone git://bogomips.org/clogger.git

You can probably just copy code from that.

I can't accept using interfaces which only work on rare/non-Free systems.

> +void clock_gettime_mach(struct timespec *now){
> +	clock_serv_t cclock;
> +	mach_timespec_t mts;
> +	host_get_clock_service(mach_host_self(), CALENDAR_CLOCK, &cclock);
> +	clock_get_time(cclock, &mts);
> +	mach_port_deallocate(mach_task_self(), cclock);
> +	now->tv_sec = mts.tv_sec;
> +	now->tv_nsec = mts.tv_nsec;

clogger just uses gettimeofday(), but that's usually good enough.

Also, Ruby trunk recently got Process.clock_gettime; so someday we can
just fall back to rb_funcall.

Anyways thanks for bringing this to my attention.  If you want, please
send me a patch based on what's in clogger (and that fallback in clogger
is probably buggy, too, so an extra set of eyes would be appreciated :)