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| author | alfred <alfred@FreeBSD.org> | 2002-08-05 05:18:43 +0000 |
|---|---|---|
| committer | alfred <alfred@FreeBSD.org> | 2002-08-05 05:18:43 +0000 |
| commit | e7bcbc4dbfb3670fa4b840cd0b67ad74f0ab1239 (patch) | |
| tree | 639c54fc9eb48349a0f40ef525de62b2dddb589e /sys | |
| parent | 0a5393ffc8182ca70dacf0825f2e4e91bb10beb6 (diff) | |
| download | FreeBSD-src-e7bcbc4dbfb3670fa4b840cd0b67ad74f0ab1239.zip FreeBSD-src-e7bcbc4dbfb3670fa4b840cd0b67ad74f0ab1239.tar.gz | |
Add a macro for SLIST traversal 'SLIST_FOREACH_PREVPTR',
this macro keeps a pointer to the previous element's next
pointer to allow for search and O(1) removal.
Diffstat (limited to 'sys')
| -rw-r--r-- | sys/sys/queue.h | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/sys/sys/queue.h b/sys/sys/queue.h index a86fda0..63012d4 100644 --- a/sys/sys/queue.h +++ b/sys/sys/queue.h @@ -164,6 +164,11 @@ struct { \ (var); \ (var) = SLIST_NEXT((var), field)) +#define SLIST_FOREACH_PREVPTR(var, varp, head, field) \ + for ((varp) = &SLIST_FIRST((head)); \ + ((var) = *(varp)) != NULL; \ + (varp) = &SLIST_NEXT((var), field)) + #define SLIST_INIT(head) do { \ SLIST_FIRST((head)) = NULL; \ } while (0) |
