Re: [Qemu-devel] Re: [RFC: 0/2] patch for QEMU HPET periodic timer emulation to alleviate time drift

[Avi Kivity <avi@redhat.com>]

On 02/07/2011 05:17 PM, Jan Kiszka wrote:
> On 2011-02-07 16:13, Avi Kivity wrote:
> >  On 02/07/2011 05:01 PM, Anthony Liguori wrote:
> >>
> >>  typedef struct PeriodicTimer PeriodicTimer;
> >>
> >>  /**
> >>   * @accumulated_ticks:  the number of unacknowledged ticks in total
> >>  since the creation of the timer
> >>   **/
> >
> >  Outdated comment even before the code is committed.  Will be hard to beat.
> >
> >>  typedef void (PeriodicTimerFunc)(void *opaque);
> >
> >  s/void *opaque/PeriodicTimer *timer/
> >
> >  Down with opaques!
>
> What else? DeviceState?

typedef void (PeriodicTimerFunc)(PeriodicTimer *timer);

the callback then uses container_of() to get whatever its internal data 
structure is from the embedded PeriodicTimer.

> >>
> >>  PeriodicTimer *periodic_timer_new(PeriodicTimerFunc *cb, void *opaque);
> >>
> >
> >  void periodic_timer_init(PeriodicTimer *timer, PeriodicTimerFunc *cb);
> >
> >  It is better to embed than to reference.
>
> Likely, though this diverges from exiting QEMUTimer.

That's the more modern style.  Saves allocations and dereferences, and 
is more type safe.

-- 
error compiling committee.c: too many arguments to function