Re: [PATCH 1/7] qemu/queue: add some useful QLIST_ and QTAILQ_ macros

[Markus Armbruster <armbru@redhat.com>]

Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> writes:

> Add QLIST_FOREACH_FUNC_SAFE(), QTAILQ_FOREACH_FUNC_SAFE() and
> QTAILQ_POP_HEAD(), to be used in following commit.
>
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
> ---
>  include/qemu/queue.h | 14 ++++++++++++++
>  1 file changed, 14 insertions(+)
>
> diff --git a/include/qemu/queue.h b/include/qemu/queue.h
> index e029e7bf66..03e1fce85f 100644
> --- a/include/qemu/queue.h
> +++ b/include/qemu/queue.h
> @@ -173,6 +173,13 @@ struct {                                                                \
>                  (var) && ((next_var) = ((var)->field.le_next), 1);      \
>                  (var) = (next_var))
>  
> +#define QLIST_FOREACH_FUNC_SAFE(head, field, func) do {                 \
> +    typeof(*QLIST_FIRST(head)) *qffs_var, *qffs_next_var;               \
> +    QLIST_FOREACH_SAFE(qffs_var, (head), field, qffs_next_var) {        \
> +        (func)(qffs_var);                                               \
> +    }                                                                   \
> +} while (/*CONSTCOND*/0)
> +
>  /*
>   * List access methods.
>   */
> @@ -490,6 +497,13 @@ union {                                                                 \
>               (var) && ((prev_var) = QTAILQ_PREV(var, field), 1);        \
>               (var) = (prev_var))
>  
> +#define QTAILQ_FOREACH_FUNC_SAFE(head, field, func) do {                \
> +    typeof(*QTAILQ_FIRST(head)) *qffs_var, *qffs_next_var;              \
> +    QTAILQ_FOREACH_SAFE(qffs_var, (head), field, qffs_next_var) {       \
> +        (func)(qffs_var);                                               \
> +    }                                                                   \
> +} while (/*CONSTCOND*/0)
> +
>  /*
>   * Tail queue access methods.
>   */

I wonder whether these are worth having.  Can you show the difference
they make in the next patch?