From: Søren Sandmann Pedersen <s...@redhat.com> This commit adds some new inline functions to maintain a doubly linked list.
The way to use them is to embed a pixman_link_t into the structures that should be linked, and use a pixman_list_t as the head of the list. The new functions are pixman_list_init (pixman_list_t *list); pixman_list_prepend (pixman_list_t *list, pixman_link_t *link); pixman_list_move_to_front (pixman_list_t *list, pixman_link_t *link); There are also new macros: OFFSET_OF(type, member) CONTAINER_OF(type, member, data); that can be used to get from a pointer to a member to the containing structure. --- pixman/pixman-compiler.h | 12 ++++++++++++ pixman/pixman-private.h | 44 ++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 56 insertions(+) diff --git a/pixman/pixman-compiler.h b/pixman/pixman-compiler.h index ffd5172..9bdbc6e 100644 --- a/pixman/pixman-compiler.h +++ b/pixman/pixman-compiler.h @@ -89,6 +89,18 @@ # define PIXMAN_EXPORT #endif +/* member offsets */ +#if defined(__GNUC__) && __GNUC__ >= 4 +# define OFFSET_OF(type, member) \ + ((unsigned long)__builtin_offsetof(type, member)) +#else +# define OFFSET_OF(type, member) \ + ((unsigned long)(&(((type *)0)->member)) +#endif + +#define CONTAINER_OF(type, member, data) \ + ((type *)(((uint8_t *)data) - OFFSET_OF(type, member))) + /* TLS */ #if defined(PIXMAN_NO_TLS) diff --git a/pixman/pixman-private.h b/pixman/pixman-private.h index f4ca632..b5dcc14 100644 --- a/pixman/pixman-private.h +++ b/pixman/pixman-private.h @@ -736,6 +736,50 @@ pixman_bool_t pixman_region16_copy_from_region32 (pixman_region16_t *dst, pixman_region32_t *src); +/* Doubly linked lists */ +typedef struct pixman_link_t pixman_link_t; +struct pixman_link_t +{ + pixman_link_t *next; + pixman_link_t *prev; +}; + +typedef struct pixman_list_t pixman_list_t; +struct pixman_list_t +{ + pixman_link_t *head; + pixman_link_t *tail; +}; + +static force_inline void +pixman_list_init (pixman_list_t *list) +{ + list->head = (pixman_link_t *)list; + list->tail = (pixman_link_t *)list; +} + +static force_inline void +pixman_list_prepend (pixman_list_t *list, pixman_link_t *link) +{ + link->next = list->head; + link->prev = (pixman_link_t *)list; + list->head->prev = link; + list->head = link; +} + +static force_inline void +pixman_list_unlink (pixman_link_t *link) +{ + link->prev->next = link->next; + link->next->prev = link->prev; +} + +static force_inline void +pixman_list_move_to_front (pixman_list_t *list, pixman_link_t *link) +{ + pixman_list_unlink (link); + pixman_list_prepend (list, link); +} /* Misc macros */ -- 1.7.10.2 _______________________________________________ Pixman mailing list Pixman@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/pixman