[PATCH] Enable configuration of the MONOTONIC_CLOCK when cross-compiling.

[Mark Kettenis]

> Date: Wed, 19 May 2010 09:12:59 -0700
> From: David James <davidjames at google.com>
> 
> On Wed, May 19, 2010 at 8:47 AM, Adam Jackson <ajax at nwnk.net> wrote:
> > On Tue, 2010-05-18 at 15:17 -0700, David James wrote:
> >> When xorg-xserver is being cross-compiled, there is currently no way
> >> for us to detect whether the monotonic clock is available on the
> >> target system. Currently, in this situation, we default to not use the
> >> monotonic clock. One problem with this situation is that the user will
> >> be treated as idle when the date is updated.
> >>
> >> To fix this situation, this patch creates a new variable called
> >> xorg_cv_MONOTONIC_CLOCK. If packagers who cross-compile setup this
> >> variable appropriately, then we can enable usage of the
> >> MONOTONIC_CLOCK when cross-compiling.
> >
> > This requires editing the configure cache?  That's a little non-obvious.
> > I think the liboil-style compile check is probably fine.
> 
> The liboil-style compile check is fine? Great! This makes my patch
> simpler, and saves everybody the trouble of specifying options or
> environment variables. Please take a look at the updated patch
> (monotonic-clock-patch-v2.txt).

OpenBSD has a working CLOCK_MONOTONIC implementation, but doesn't define
_POSIX_MONOTONIC_CLOCK.  So I'm afraid this approach doesn't work.