[2/9] add unregister_displaychangelistener

Also change the way the gui_timer is initialized: each time a
displaychangelistener is registered or unregistered we'll check
whenever we need a timer (due to dpy_refresh callback being present)
and if so setup a timer, otherwise zap it.  This way the gui timer works
correctly with displaychangelisteners coming and going.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 console.h |   10 ++++++++++
 vl.c      |   31 +++++++++++++++++++++++--------
 2 files changed, 33 insertions(+), 8 deletions(-)

On Tue, 18 Sep 2012, Gerd Hoffmann wrote:
> Also change the way the gui_timer is initialized: each time a
> displaychangelistener is registered or unregistered we'll check
> whenever we need a timer (due to dpy_refresh callback being present)
> and if so setup a timer, otherwise zap it.  This way the gui timer works
> correctly with displaychangelisteners coming and going.
> 
> Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>


Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>

>  console.h |   10 ++++++++++
>  vl.c      |   31 +++++++++++++++++++++++--------
>  2 files changed, 33 insertions(+), 8 deletions(-)
> 
> diff --git a/console.h b/console.h
> index 646ad4b..48fef22 100644
> --- a/console.h
> +++ b/console.h
> @@ -229,9 +229,19 @@ static inline int is_buffer_shared(DisplaySurface *surface)
>              !(surface->flags & QEMU_REALPIXELS_FLAG));
>  }
>  
> +void gui_setup_refresh(DisplayState *ds);
> +
>  static inline void register_displaychangelistener(DisplayState *ds, DisplayChangeListener *dcl)
>  {
>      QLIST_INSERT_HEAD(&ds->listeners, dcl, next);
> +    gui_setup_refresh(ds);
> +}
> +
> +static inline void unregister_displaychangelistener(DisplayState *ds,
> +                                                    DisplayChangeListener *dcl)
> +{
> +    QLIST_REMOVE(dcl, next);
> +    gui_setup_refresh(ds);
>  }
>  
>  static inline void dpy_update(DisplayState *s, int x, int y, int w, int h)
> diff --git a/vl.c b/vl.c
> index 2a7c92a..fbb77fe 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -1288,6 +1288,29 @@ static void gui_update(void *opaque)
>      qemu_mod_timer(ds->gui_timer, interval + qemu_get_clock_ms(rt_clock));
>  }
>  
> +void gui_setup_refresh(DisplayState *ds)
> +{
> +    DisplayChangeListener *dcl;
> +    bool need_timer = false;
> +
> +    QLIST_FOREACH(dcl, &ds->listeners, next) {
> +        if (dcl->dpy_refresh != NULL) {
> +            need_timer = true;
> +            break;
> +        }
> +    }
> +
> +    if (need_timer && ds->gui_timer == NULL) {
> +        ds->gui_timer = qemu_new_timer_ms(rt_clock, gui_update, ds);
> +        qemu_mod_timer(ds->gui_timer, qemu_get_clock_ms(rt_clock));
> +    }
> +    if (!need_timer && ds->gui_timer != NULL) {
> +        qemu_del_timer(ds->gui_timer);
> +        qemu_free_timer(ds->gui_timer);
> +        ds->gui_timer = NULL;
> +    }
> +}
> +
>  struct vm_change_state_entry {
>      VMChangeStateHandler *cb;
>      void *opaque;
> @@ -2350,7 +2373,6 @@ int main(int argc, char **argv, char **envp)
>      const char *kernel_filename, *kernel_cmdline;
>      char boot_devices[33] = "cad"; /* default to HD->floppy->CD-ROM */
>      DisplayState *ds;
> -    DisplayChangeListener *dcl;
>      int cyls, heads, secs, translation;
>      QemuOpts *hda_opts = NULL, *opts, *machine_opts;
>      QemuOptsList *olist;
> @@ -3698,13 +3720,6 @@ int main(int argc, char **argv, char **envp)
>  
>      /* display setup */
>      dpy_resize(ds);
> -    QLIST_FOREACH(dcl, &ds->listeners, next) {
> -        if (dcl->dpy_refresh != NULL) {
> -            ds->gui_timer = qemu_new_timer_ms(rt_clock, gui_update, ds);
> -            qemu_mod_timer(ds->gui_timer, qemu_get_clock_ms(rt_clock));
> -            break;
> -        }
> -    }
>      text_consoles_set_display(ds);
>  
>      if (foreach_device_config(DEV_GDB, gdbserver_start) < 0) {
> -- 
> 1.7.1
> 
>