diff options
| author | Kenneth Graunke <[email protected]> | 2010-07-08 13:06:22 -0700 |
|---|---|---|
| committer | Ian Romanick <[email protected]> | 2010-07-09 09:46:07 -0700 |
| commit | f3290e950cd78a423d380b7e0a7aa18eb7718e27 (patch) | |
| tree | 9f134837e59bc40d35c9202805134596627519df | |
| parent | dfd30ca6a95a7d95835dad78ffe1fba4d1f4ef69 (diff) | |
glsl2: Add foreach_list_safe which works even when mutating the list.
In particular, with foreach_list_safe, one can remove and free the current
node without crashes; if new nodes are added after the current node,
they will be properly visited as well.
Signed-off-by: Ian Romanick <[email protected]>
| -rw-r--r-- | src/glsl/list.h | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/src/glsl/list.h b/src/glsl/list.h index b5a413dc511..48502fb4c8c 100644 --- a/src/glsl/list.h +++ b/src/glsl/list.h @@ -421,6 +421,20 @@ struct exec_list { #endif }; +/** + * This version is safe even if the current node is removed. If you insert + * new nodes before the current node, they will be processed next. + * + * \note + * The extra test for \c __node being \c NULL is required because after the + * iteration \c __prev coupld be the last node in the list. The loop increment + * then causes \c __prev to point to the sentinal and \c __node to be \c NULL. + */ +#define foreach_list_safe(__node, __list) \ + for (exec_node * __prev = (exec_node *) (__list), * __node = (__list)->head \ + ; __node != NULL && (__node)->next != NULL \ + ; __prev = (__prev)->next, __node = (__prev)->next) + #define foreach_list(__node, __list) \ for (exec_node * __node = (__list)->head \ ; (__node)->next != NULL \ |