What's the meaning of XSyncAlarmNotify ?

Fernando Carrijo fcarrijo.lists at gmail.com
Sat Dec 4 07:55:56 PST 2010

Hi Danny,

danny <tornadory at 163.com> wrote:

> Could you explain about the XSyncAlarmNotify? What's function it provides?
> Which situation could it be sent by X server?

It seems to me XSyncAlarmNotify is an event type, not a request type. And as
such, it is delivered from server to clients, not the other way around. Thus,
whenever a triggering condition of a previously registered alarm occurs, the
interested client will be notified with a XSyncAlarmNotify event.

With respect to your first email: yes, a XSync enabled server keeps info about
its idle time but, from the top of my head, I don't remember which piece of the
protocol you can use to query it.

Anyway, the fact is: the implementation of the XSync Extension, both client-
and server-side, is kind of easy to understand. Reading the code won't be hard,
after you grasp the main concepts introduced in the specifications. Give them
a try!

> And why sometimes the xevent->type is not right? (if the event_base = 96 ,
> then sometimes the xevent->type always be 98 but not 97)

"Sometimes" before "always" sounds pretty confusing to me. :)

I'm not sure about it.

More information about the xorg-devel mailing list