* Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:
> I'm a bit nervous about the 'active' role of (trace_)events, because of the
> way multiple callbacks can be registered. How would:
>
> err = event_x();
> if (err == -EACCESS) {
>
> be handled? [...]
The default behavior would be something obvious: to trigger all callbacks and
use the first non-zero return value.
> [...] Would we need a way to prioritize which call back gets the return
> value? One way I guess would be to add a check_event option, where you pass
> in an ENUM of the event you want:
>
> event_x();
> err = check_event_x(MYEVENT);
>
> If something registered itself as "MYEVENT" to event_x, then you get the
> return code of MYEVENT. If the MYEVENT was not registered, a -ENODEV or
> something could be returned. I'm sure we could even optimize it such a way if
> no active events have been registered to event_x, that check_event_x() will
> return -ENODEV without any branches.
I would keep it simple and extensible - that way we can complicate it when the
need arises! :)
Thanks,
Ingo
