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

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