On 2011-02-07 16:01, Anthony Liguori wrote: > On 02/07/2011 08:57 AM, Jan Kiszka wrote: >> There should rather be a special vmstate struct for PeriodicTimer, just >> like we already have for normal timers. >> > > Agreed. > >>> It's convenient because then if we lose ticks in the PeriodicTimer >>> layer, the devices have instance access to that info. When you do a >>> read() from timerfd, it returns the number of coalesced events. That's >>> the interface I had in my mind. >>> >>> We could just add a getter for PeriodicTimer and it would serve the same >>> purpose. >>> >> I'm still not sure what the device model is supposed to do with that >> information. I think at could remain private to the PeriodicTimer >> implementation (unless we want to dump some stats or such). >> > > Yeah, I've been thinking about it too and I think I agree with you. > > So here's the new proposal: > > typedef struct PeriodicTimer PeriodicTimer; > > /** > * @accumulated_ticks: the number of unacknowledged ticks in total > since the creation of the timer > **/ > typedef void (PeriodicTimerFunc)(void *opaque); Or just use QEMUTimerCB directly. BTW, QEMUPeriodicTimer* would probably be more consistent with the existing naming scheme. > > PeriodicTimer *periodic_timer_new(PeriodicTimerFunc *cb, void *opaque); > > void periodic_timer_mod(PeriodicTimer *timer, int64_t interval, TimeUnit > unit); > > /** > * @policy: the drift catch-up policy > * DRIFT_COMP_FAST, deliver next tick as soon as any > tick is acknowledged if accumulated_ticks > 1 > * DRIFT_COMP_NONE, do not change interval regardless of > accumulated ticks > * DRIFT_COMP_GRADUAL, shorten interval by half until > accumulated_ticks <= 1 > */ > void periodic_timer_set_policy(PeriodicTimer *timer, > DriftCompensationPolicy policy); > > /** > * @ticks: number of ticks to acknowledge that are currently outstanding. > **/ > void periodic_timer_ack(PeriodicTimer *timer, int ticks); > > int periodic_timer_get_accumulated_ticks(PeriodicTimer *timer); > Looks like a plan. Jan -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
