list: add singly-linked list and singly-linked tail list
RFC 1/1 list: add singly-linked list and singly-linked tail list
add singly-linked list and singly-linked tail list.
these two lists are also used widely in the kernel as doubly-linked list, so I am trying to add some APIs for these two lists to eliminate the duplicate code.
----
include/linux/list.h | 186 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 186 insertions(+)
include/linux/list.h +186 -0
@@ -706,4 +706,190 @@ static inline void hlist_move_list(struct hlist_head *old, ({ tpos =hlist_entry (pos,typeof (*tpos), member);1 ;}); \ pos = n) +/* singly-linked list */ + +struct slist_head { +struct slist_head *next; +}; + +#define slist_entry (ptr, type, member) \ + container_of(ptr, type, member) + +#define SLIST_HEAD_INIT { .next = NULL } +#define SLIST_HEAD (name) struct slist_head name = SLIST_HEAD_INIT + +static inline void INIT_SLIST_HEAD (struct slist_head *h) +{ + h->next =NULL ; +} + +static inline bool slist_empty (struct slist_head *h) +{ +return h->next ==NULL ; +} + +static inline void slist_push (struct slist_head *n,struct slist_head *h) +{ + n->next = h->next; + h->next = n; +} + +static inline struct slist_head *slist_pop (struct slist_head *h) +{ +struct slist_head *n; + + n = h->next; +if (n) + h->next = n->next; + +return n; +} + +static inline struct slist_head *slist_pop_init (struct slist_head *h) +{ +struct slist_head *n =slist_pop (h); + +if (n) +INIT_SLIST_HEAD (n); + +return n; +} + +static inline void __slist_splice (struct slist_head *first, +struct slist_head *to) +{ +struct slist_head **ptail; + +for (ptail = &to->next; *ptail; ptail = &(*ptail)->next) + ; + *ptail = first; +} + +static inline void slist_splice_init (struct slist_head *from, +struct slist_head *to) +{ + +if (from->next !=NULL ) { +__slist_splice (from->next, to); +INIT_SLIST_HEAD (from); + } +} + +#define slist_for_each (pos, head) \ + for (pos = (head)->next; pos && ({ prefetch(pos->next); 1; }); \ + pos = pos->next) + +#define slist_for_each_entry (tpos, pos, head, member) \ + for (pos = (head)->next; \ + pos && ({ prefetch(pos->next); 1; }) && \ + ({ tpos = slist_entry(pos, typeof(*tpos), member); 1; }); \ + pos = pos->next) + +#define slist_del (pos, n, ppos) \ + do { \ + *ppos = pos->next; \ + n = container_of(ppos, struct slist_head, next); \ + } while (0) + +#define slist_for_each_safe (pos, n, ppos, head) \ + for (ppos = &(head)->next; (n = pos = *ppos); ppos = &n->next) + +#define slist_for_each_entry_safe (tpos, pos, n, ppos, head, member) \ + for (ppos = &(head)->next; \ + (n = pos = *ppos) && \ + ({ tpos = slist_entry(pos, typeof(*tpos), member); 1; }); \ + ppos = &n->next) + +/* singly-linked tail list */ + +struct tlist_head { +struct slist_head *next; +struct slist_head **ptail; +}; + +#define TLIST_HEAD_INIT (name) { .next = NULL, .ptail = &(name).next } +#define TLIST_HEAD (name) struct tlist_head name = TLIST_HEAD_INIT(name) + +static inline void INIT_TLIST_HEAD (struct tlist_head *h) +{ + h->next =NULL ; + h->ptail = &h->next; +} + +static inline bool tlist_empty (struct tlist_head *h) +{ +return h->next ==NULL ; +} + +static inline void tlist_append (struct slist_head *n,struct tlist_head *h) +{ + *(h->ptail) = n; + h->ptail = &n->next; +} + +static inline void tlist_push (struct slist_head *n,struct tlist_head *h) +{ + n->next = h->next; + h->next = n; +if (h->ptail == &h->next) + h->ptail = &n->next; +} + +static inline struct slist_head *tlist_pop (struct tlist_head *h) +{ +struct slist_head *n = h->next; + +if (n) { + h->next = n->next; +if (n->next ==NULL ) + h->ptail = &h->next; + } + +return n; +} + +static inline struct slist_head *tlist_pop_init (struct tlist_head *h) +{ +struct slist_head *n =tlist_pop (h); + +if (n) +INIT_SLIST_HEAD (n); + +return n; +} + +static inline void tlist_splice_init (struct tlist_head *from, +struct tlist_head *to) +{ +if (!tlist_empty (from)) { + *(to->ptail) = from->next; + to->ptail = from->ptail; +INIT_TLIST_HEAD (from); + } +} + +static inline void tlist_splice_to_slist_init (struct tlist_head *from, +struct slist_head *to) +{ +if (!tlist_empty (from)) { +__slist_splice (from->next, to); +INIT_TLIST_HEAD (from); + } +} + +#define tlist_for_each slist_for_each + +#define tlist_for_each_entry slist_for_each_entry + +#define tlist_for_each_safe slist_for_each_safe + +#define tlist_for_each_entry_safe slist_for_each_entry_safe + +#define tlist_del (pos, n, ppos, head) \ + do { \ + slist_del(pos, n, ppos); \ + if (pos->next == NULL) \ + (head)->ptail = ppos; \ + } while (0) +#endif
Quoted 4 lines · Changli Gao
add singly-linked list and singly-linked tail list.
these two lists are also used widely in the kernel as doubly-linked list, so I am trying to add some APIs for these two lists to eliminate the duplicate code.
What callsites do you have in mind?
Quoted 9 lines
Signed-off-by Changli Gao <[email protected]>----
include/linux/list.h | 186 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 186 insertions(+)include/linux/list.h +0
-0
include/linux/list.h static inline void hlist_move_list(struct hlist_head *old, · line 713
Quoted 8 lines
include/linux/list.h +5
-0@@ -706,4 +706,190 @@ static inline void hlist_move_list(struct hlist_head *old, ({ tpos =hlist_entry (pos,typeof (*tpos), member);1 ;}); \ pos = n) +/* singly-linked list */ + +struct slist_head { +struct slist_head *next; +};
I would rather call that a stack and change the prefix:
struct stack_top {
struct stack_top *next;
}And have helpers named like stack_push(), stack_pop(), etc...
Quoted 85 lines
include/linux/list.h +85
-0+ +#define slist_entry (ptr, type, member) \ + container_of(ptr, type, member) + +#define SLIST_HEAD_INIT { .next = NULL } +#define SLIST_HEAD (name) struct slist_head name = SLIST_HEAD_INIT + +static inline void INIT_SLIST_HEAD (struct slist_head *h) +{ + h->next =NULL ; +} + +static inline bool slist_empty (struct slist_head *h) +{ +return h->next ==NULL ; +} + +static inline void slist_push (struct slist_head *n,struct slist_head *h) +{ + n->next = h->next; + h->next = n; +} + +static inline struct slist_head *slist_pop (struct slist_head *h) +{ +struct slist_head *n; + + n = h->next; +if (n) + h->next = n->next; + +return n; +} + +static inline struct slist_head *slist_pop_init (struct slist_head *h) +{ +struct slist_head *n =slist_pop (h); + +if (n) +INIT_SLIST_HEAD (n); + +return n; +} + +static inline void __slist_splice (struct slist_head *first, +struct slist_head *to) +{ +struct slist_head **ptail; + +for (ptail = &to->next; *ptail; ptail = &(*ptail)->next) + ; + *ptail = first; +} + +static inline void slist_splice_init (struct slist_head *from, +struct slist_head *to) +{ + +if (from->next !=NULL ) { +__slist_splice (from->next, to); +INIT_SLIST_HEAD (from); + } +} + +#define slist_for_each (pos, head) \ + for (pos = (head)->next; pos && ({ prefetch(pos->next); 1; }); \ + pos = pos->next) + +#define slist_for_each_entry (tpos, pos, head, member) \ + for (pos = (head)->next; \ + pos && ({ prefetch(pos->next); 1; }) && \ + ({ tpos = slist_entry(pos, typeof(*tpos), member); 1; }); \ + pos = pos->next) + +#define slist_del (pos, n, ppos) \ + do { \ + *ppos = pos->next; \ + n = container_of(ppos, struct slist_head, next); \ + } while (0) + +#define slist_for_each_safe (pos, n, ppos, head) \ + for (ppos = &(head)->next; (n = pos = *ppos); ppos = &n->next) + +#define slist_for_each_entry_safe (tpos, pos, n, ppos, head, member) \ + for (ppos = &(head)->next; \
include/linux/list.h static inline void hlist_move_list(struct hlist_head *old, · line 808
Quoted 10 lines
include/linux/list.h +10
-0+ (n = pos = *ppos) && \ + ({ tpos =slist_entry (pos,typeof (*tpos), member);1 ; }); \ + ppos = &n->next) + +/* singly-linked tail list */ + +struct tlist_head { +struct slist_head *next; +struct slist_head **ptail; +};
Well. It's like list_head with a lowered memory footprint but the loss of beeing able to insert elements in the middle.
Why not, but it depends on which callsites waiting to be converted you have in mind.
Thanks.