Re: [Qemu-devel] [PATCH] qom: Make object_child_foreach safe for objects removal

[Hu Tao]

On Mon, Jul 14, 2014 at 12:41:08AM +1000, Alexey Kardashevskiy wrote:
> Current object_child_foreach() uses QTAILQ_FOREACH() to walk
> through children and that makes children removal from the callback
> impossible.
> 
> This makes object_child_foreach() use QTAILQ_FOREACH_SAFE().
> 
> Signed-off-by: Alexey Kardashevskiy <address@hidden>
> ---
> 
> The problem I am trying to solve is:
> there is a PHB with multiple DMA windows a.k.a. sPAPRTCETable's which are
> QOM children of PHB. One of RTAS functions is "reset" which is supposed to
> remove all windows (now just one) except the default one.
> 
> I could call QTAILQ_FOREACH_SAFE in sPAPR PHB code but 
> object_property_is_child()
> is static and we probably do not want to make it public.

Reviewed-by: Hu Tao <address@hidden>

But people tend to accept changes like this one together with the
patch(es) that need it.

Regards,
Hu

> 
> 
> ---
>  qom/object.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/qom/object.c b/qom/object.c
> index 0e8267b..4a814dc 100644
> --- a/qom/object.c
> +++ b/qom/object.c
> @@ -678,10 +678,10 @@ void object_class_foreach(void (*fn)(ObjectClass 
> *klass, void *opaque),
>  int object_child_foreach(Object *obj, int (*fn)(Object *child, void *opaque),
>                           void *opaque)
>  {
> -    ObjectProperty *prop;
> +    ObjectProperty *prop, *next;
>      int ret = 0;
>  
> -    QTAILQ_FOREACH(prop, &obj->properties, node) {
> +    QTAILQ_FOREACH_SAFE(prop, &obj->properties, node, next) {
>          if (object_property_is_child(prop)) {
>              ret = fn(prop->opaque, opaque);
>              if (ret != 0) {
> -- 
> 2.0.0
>