Re: [Qemu-devel] [RFC] [PATCHv8 11/30] aio / timers: Add a notify callback to QEMUTimerList

[Paolo Bonzini <pbonzini@redhat.com>]

Il 08/08/2013 23:42, Alex Bligh ha scritto:
> Add a notify pointer to QEMUTimerList so it knows what to notify
> on a timer change.

If we do the "two AioContexts" trick, this can simply be a back-pointer
to the AioContext.

Paolo

> Signed-off-by: Alex Bligh <alex@alex.org.uk>
> ---
>  async.c              |    7 ++++++-
>  include/qemu/timer.h |   35 ++++++++++++++++++++++++++++++++---
>  qemu-timer.c         |   24 ++++++++++++++++++++++--
>  3 files changed, 60 insertions(+), 6 deletions(-)
> 
> diff --git a/async.c b/async.c
> index 99fb5a8..2051921 100644
> --- a/async.c
> +++ b/async.c
> @@ -234,6 +234,11 @@ void aio_notify(AioContext *ctx)
>      event_notifier_set(&ctx->notifier);
>  }
>  
> +static void aio_timerlist_notify(void *opaque)
> +{
> +    aio_notify(opaque);
> +}
> +
>  AioContext *aio_context_new(void)
>  {
>      AioContext *ctx;
> @@ -245,7 +250,7 @@ AioContext *aio_context_new(void)
>      aio_set_event_notifier(ctx, &ctx->notifier, 
>                             (EventNotifierHandler *)
>                             event_notifier_test_and_clear, NULL);
> -    timerlistgroup_init(ctx->tlg);
> +    timerlistgroup_init(ctx->tlg, aio_timerlist_notify, ctx);
>  
>      return ctx;
>  }
> diff --git a/include/qemu/timer.h b/include/qemu/timer.h
> index 3b46f60..07e6d9e 100644
> --- a/include/qemu/timer.h
> +++ b/include/qemu/timer.h
> @@ -54,6 +54,7 @@ typedef struct QEMUClock QEMUClock;
>  typedef struct QEMUTimerList QEMUTimerList;
>  typedef QEMUTimerList *QEMUTimerListGroup[QEMU_CLOCK_MAX];
>  typedef void QEMUTimerCB(void *opaque);
> +typedef void QEMUTimerListNotifyCB(void *opaque);
>  
>  extern QEMUTimerListGroup main_loop_tlg;
>  extern QEMUClock *qemu_clocks[QEMU_CLOCK_MAX];
> @@ -213,13 +214,41 @@ QEMUClock *timerlist_get_clock(QEMUTimerList *timer_list);
>  bool timerlist_run_timers(QEMUTimerList *timer_list);
>  
>  /**
> + * timerlist_set_notify_cb:
> + * @timer_list: the timer list to use
> + * @cb: the callback to call on notification
> + * @opaque: the opaque pointer to pass to the callback
> + *
> + * Set the notify callback for a timer list. The notifier
> + * callback is called when the clock is reenabled or a timer
> + * on the list is modified.
> + */
> +void timerlist_set_notify_cb(QEMUTimerList *timer_list,
> +                             QEMUTimerListNotifyCB *cb, void *opaque);
> +
> +/**
> + * timerlist_notify:
> + * @timer_list: the timer list to use
> + *
> + * call the notifier callback associated with the timer list.
> + */
> +void timerlist_notify(QEMUTimerList *timer_list);
> +
> +/**
>   * timerlistgroup_init:
>   * @tlg: the timer list group
> + * @cb: the callback to call when a notify is required
> + * @opaque: the opaque pointer to be passed to the callback.
>   *
>   * Initialise a timer list group. This must already be
> - * allocated in memory and zeroed.
> - */
> -void timerlistgroup_init(QEMUTimerListGroup tlg);
> + * allocated in memory and zeroed. The notifier callback is
> + * called whenever a clock in the timer list group is
> + * reenabled or whenever a timer associated with any timer
> + * list is modified. If @cb is specified as null, qemu_notify()
> + * is used instead.
> + */
> +void timerlistgroup_init(QEMUTimerListGroup tlg,
> +                         QEMUTimerListNotifyCB *cb, void *opaque);
>  
>  /**
>   * timerlistgroup_deinit:
> diff --git a/qemu-timer.c b/qemu-timer.c
> index e151d24..14cb433 100644
> --- a/qemu-timer.c
> +++ b/qemu-timer.c
> @@ -73,6 +73,8 @@ struct QEMUTimerList {
>      QEMUClock *clock;
>      QEMUTimer *active_timers;
>      QLIST_ENTRY(QEMUTimerList) list;
> +    QEMUTimerListNotifyCB *notify_cb;
> +    void *notify_opaque;
>  };
>  
>  struct QEMUTimer {
> @@ -394,6 +396,22 @@ QEMUTimerList *qemu_clock_get_main_loop_timerlist(QEMUClock *clock)
>      return clock->main_loop_timerlist;
>  }
>  
> +void timerlist_set_notify_cb(QEMUTimerList *timer_list,
> +                             QEMUTimerListNotifyCB *cb, void *opaque)
> +{
> +    timer_list->notify_cb = cb;
> +    timer_list->notify_opaque = opaque;
> +}
> +
> +void timerlist_notify(QEMUTimerList *timer_list)
> +{
> +    if (timer_list->notify_cb) {
> +        timer_list->notify_cb(timer_list->notify_opaque);
> +    } else {
> +        qemu_notify_event();
> +    }
> +}
> +
>  /* Transition function to convert a nanosecond timeout to ms
>   * This is used where a system does not support ppoll
>   */
> @@ -518,7 +536,7 @@ void qemu_mod_timer_ns(QEMUTimer *ts, int64_t expire_time)
>          /* Interrupt execution to force deadline recalculation.  */
>          qemu_clock_warp(ts->timer_list->clock);
>          if (use_icount) {
> -            qemu_notify_event();
> +            timerlist_notify(ts->timer_list);
>          }
>      }
>  }
> @@ -576,11 +594,13 @@ bool qemu_run_timers(QEMUClock *clock)
>      return timerlist_run_timers(clock->main_loop_timerlist);
>  }
>  
> -void timerlistgroup_init(QEMUTimerListGroup tlg)
> +void timerlistgroup_init(QEMUTimerListGroup tlg,
> +                         QEMUTimerListNotifyCB *cb, void *opaque)
>  {
>      QEMUClockType type;
>      for (type = 0; type < QEMU_CLOCK_MAX; type++) {
>          tlg[type] = timerlist_new(type);
> +        timerlist_set_notify_cb(tlg[type], cb, opaque);
>      }
>  }
>  
>