On Thu, Aug 02, 2018 at 10:39:20AM +0100, Lionel Landwerlin wrote:
> Signed-off-by: Lionel Landwerlin <lionel.g.landwer...@intel.com>
> ---
> src/util/rb_tree.h | 36 ++++++++++++++++++++++++++++++++++++
> 1 file changed, 36 insertions(+)
>
> diff --git a/src/util/rb_tree.h b/src/util/rb_tree.h
> index c77e9255ea2..df1a4197b8a 100644
> --- a/src/util/rb_tree.h
> +++ b/src/util/rb_tree.h
> @@ -243,6 +243,24 @@ struct rb_node *rb_node_prev(struct rb_node *node);
> &node->field != NULL; \
> node = rb_node_data(type, rb_node_next(&node->field), field))
>
> +/** Iterate over the nodes in the tree, allowing the current node to be freed
> + *
> + * \param type The type of the containing data structure
> + *
> + * \param node The variable name for current node in the iteration;
> + * this will be declared as a pointer to \p type
> + *
> + * \param T The red-black tree
> + *
> + * \param field The rb_node field in containing data structure
> + */
> +#define rb_tree_foreach_safe(type, node, T, field) \
> + for (type *node = rb_node_data(type, rb_tree_first(T), field), \
> + *_next = (&node->field != NULL) ? rb_node_data(type,
> rb_node_next(&node->field), field) : node; \
> + &node->field != NULL; \
> + node = _next, \
> + _next = (&_next->field != NULL) ? rb_node_data(type,
> rb_node_next(&_next->field), field) : _next)
> +
This looks nice. I'm thinking if maybe a simple helper would make things
easier to read, like:
#define _next_if_available(node, type, field) \
(&node->field != NULL) ? rb_node_data(type, rb_node_next(&node->field),
field) : node
Wouldn't help to simplify things, but up to you in the end.
> /** Iterate over the nodes in the tree in reverse
> *
> * \param type The type of the containing data structure
> @@ -259,6 +277,24 @@ struct rb_node *rb_node_prev(struct rb_node *node);
> &node->field != NULL; \
> node = rb_node_data(type, rb_node_prev(&node->field), field))
>
> +/** Iterate over the nodes in the tree in reverse, allowing the current node
> to be freed
> + *
> + * \param type The type of the containing data structure
> + *
> + * \param node The variable name for current node in the iteration;
> + * this will be declared as a pointer to \p type
> + *
> + * \param T The red-black tree
> + *
> + * \param field The rb_node field in containing data structure
> + */
> +#define rb_tree_foreach_rev_safe(type, node, T, field) \
> + for (type *node = rb_node_data(type, rb_tree_last(T), field), \
> + *_prev = rb_node_prev(&node->field) ? rb_node_data(type,
> rb_node_prev(&node->field), field) : NULL; \
> + &node->field != NULL; \
> + node = _prev, \
> + _prev = (prev && rb_node_prev(&_prev->field)) ?
> rb_node_data(type, rb_node_prev(&_prev->field), field) : NULL)
^^^^
I can't really find where this "prev" came from, but I also don't see
any warning when building it.
Also, same comment about the helper could apply here I guess, but this
"prev" is making things confusing to me.
> +
> /** Validate a red-black tree
> *
> * This function walks the tree and validates that this is a valid red-
> --
> 2.18.0
>
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