Re: [PATCH 2/2] posix clocks: introduce a sysfs presence.

Richard Cochran
2010-09-10T09:31:35Z

On Fri, Sep 10, 2010 at 12:00:08AM +0100, Alan Cox wrote:
> Also we have existing time sources that don't follow the poxix clock
> model - I can open /dev/rtc and I can open the hpet and so on.
>
> I like /sys/class/time* *but* you need to be able to open the sysfs
> device and apply operations to it in order for it to work when your closk
> can be dynamically created and destroyed and to get a sane Unix API.
>
> To start with try applying permissions to clock sources via the POSIX
> API. That is something that will be required for some applications.
>
> I need to be able to open sys/clock/foo/something and get a meaningful
> handle. Sure it's quite likely the operations it supports are related to
> the POSIX timer ops.

Do you mean this:

id = read(/sys/clock/foo/lock); /* clock is busy, cannot be removed */
...
clock_gettime(id, ts);
...
write(/sys/clock/foo/release, id); /* all done with clock */

I am not sure what you are describing. Can you give an example, like
pseudocode or something?

Thanks,
Richard