d/freebsd-dev
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Introduce REMOVE_NEXT() macro's for SLIST and STAILQ.

Browse Source 
Even though single linked lists allow items to be removed at constant time
(when the previous element is known), the queue macro's don't allow this.
Implement new REMOVE_NEXT() macro's. Because the REMOVE() macro's also
contain the same code, make it call REMOVE_NEXT().

The OpenBSD version of SLIST_REMOVE_NEXT() needs a reference to the list
head, even though it is unused. We'd better mimic this. The STAILQ version
also needs a reference to the list. This means the prototypes of both
macro's are the same.

Approved by:	philip (mentor)
PR:		kern/121117
This commit is contained in:
Ed Schouten 2008-05-22 14:40:03 +00:00
parent 55eff7704c
commit e2fd72de44
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=179210
3 changed files with 36 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
share/man/man3/Makefile
View File

@ -63,6 +63,7 @@ MLINKS+= queue.3 LIST_EMPTY.3 \
queue.3 SLIST_NEXT.3 \
queue.3 SLIST_REMOVE.3 \
queue.3 SLIST_REMOVE_HEAD.3 \
queue.3 SLIST_REMOVE_NEXT.3 \
queue.3 STAILQ_CONCAT.3 \
queue.3 STAILQ_EMPTY.3 \
queue.3 STAILQ_ENTRY.3 \
@ -79,6 +80,7 @@ MLINKS+= queue.3 LIST_EMPTY.3 \
queue.3 STAILQ_NEXT.3 \
queue.3 STAILQ_REMOVE.3 \
queue.3 STAILQ_REMOVE_HEAD.3 \
queue.3 STAILQ_REMOVE_NEXT.3 \
queue.3 TAILQ_CONCAT.3 \
queue.3 TAILQ_EMPTY.3 \
queue.3 TAILQ_ENTRY.3 \

20
share/man/man3/queue.3
View File

@ -48,6 +48,7 @@
.Nm SLIST_INSERT_HEAD ,
.Nm SLIST_NEXT ,
.Nm SLIST_REMOVE_HEAD ,
.Nm SLIST_REMOVE_NEXT ,
.Nm SLIST_REMOVE ,
.Nm STAILQ_CONCAT ,
.Nm STAILQ_EMPTY ,
@ -64,6 +65,7 @@
.Nm STAILQ_LAST ,
.Nm STAILQ_NEXT ,
.Nm STAILQ_REMOVE_HEAD ,
.Nm STAILQ_REMOVE_NEXT ,
.Nm STAILQ_REMOVE ,
.Nm LIST_EMPTY ,
.Nm LIST_ENTRY ,
@ -114,6 +116,7 @@ lists and tail queues
.Fn SLIST_INSERT_HEAD "SLIST_HEAD *head" "TYPE *elm" "SLIST_ENTRY NAME"
.Fn SLIST_NEXT "TYPE *elm" "SLIST_ENTRY NAME"
.Fn SLIST_REMOVE_HEAD "SLIST_HEAD *head" "SLIST_ENTRY NAME"
.Fn SLIST_REMOVE_NEXT "SLIST_HEAD *head" "TYPE *elm" "SLIST_ENTRY NAME"
.Fn SLIST_REMOVE "SLIST_HEAD *head" "TYPE *elm" "TYPE" "SLIST_ENTRY NAME"
.\"
.Fn STAILQ_CONCAT "STAILQ_HEAD *head1" "STAILQ_HEAD *head2"
@ -131,6 +134,7 @@ lists and tail queues
.Fn STAILQ_LAST "STAILQ_HEAD *head" "TYPE" "STAILQ_ENTRY NAME"
.Fn STAILQ_NEXT "TYPE *elm" "STAILQ_ENTRY NAME"
.Fn STAILQ_REMOVE_HEAD "STAILQ_HEAD *head" "STAILQ_ENTRY NAME"
.Fn STAILQ_REMOVE_NEXT "STAILQ_HEAD *head" "TYPE *elm" "STAILQ_ENTRY NAME"
.Fn STAILQ_REMOVE "STAILQ_HEAD *head" "TYPE *elm" "TYPE" "STAILQ_ENTRY NAME"
.\"
.Fn LIST_EMPTY "LIST_HEAD *head"
@ -387,6 +391,14 @@ this macro instead of the generic
macro.
.Pp
The macro
.Nm SLIST_REMOVE_NEXT
removes the element after
.Fa elm
from the list. Unlike
.Fa SLIST_REMOVE ,
this macro does not traverse the entire list.
.Pp
The macro
.Nm SLIST_REMOVE
removes the element
.Fa elm
@ -561,6 +573,14 @@ use this macro explicitly rather than the generic
macro.
.Pp
The macro
.Nm STAILQ_REMOVE_NEXT
removes the element after
.Fa elm
from the tail queue. Unlike
.Fa STAILQ_REMOVE ,
this macro does not traverse the entire tail queue.
.Pp
The macro
.Nm STAILQ_REMOVE
removes the element
.Fa elm

19
sys/sys/queue.h
View File

@ -97,6 +97,7 @@
* _INSERT_TAIL - - + +
* _CONCAT - - + +
* _REMOVE_HEAD + - + -
* _REMOVE_NEXT + - + -
* _REMOVE + + + +
*
*/
@ -195,12 +196,16 @@ struct { \
struct type *curelm = SLIST_FIRST((head)); \
while (SLIST_NEXT(curelm, field) != (elm)) \
curelm = SLIST_NEXT(curelm, field); \
SLIST_NEXT(curelm, field) = \
SLIST_NEXT(SLIST_NEXT(curelm, field), field); \
SLIST_REMOVE_NEXT(head, curelm, field); \
} \
TRASHIT((elm)->field.sle_next); \
} while (0)
#define SLIST_REMOVE_NEXT(head, elm, field) do { \
SLIST_NEXT(elm, field) = \
SLIST_NEXT(SLIST_NEXT(elm, field), field); \
} while (0)
#define SLIST_REMOVE_HEAD(head, field) do { \
SLIST_FIRST((head)) = SLIST_NEXT(SLIST_FIRST((head)), field); \
} while (0)
@ -287,9 +292,7 @@ struct { \
struct type *curelm = STAILQ_FIRST((head)); \
while (STAILQ_NEXT(curelm, field) != (elm)) \
curelm = STAILQ_NEXT(curelm, field); \
if ((STAILQ_NEXT(curelm, field) = \
STAILQ_NEXT(STAILQ_NEXT(curelm, field), field)) == NULL)\
(head)->stqh_last = &STAILQ_NEXT((curelm), field);\
STAILQ_REMOVE_NEXT(head, curelm, field); \
} \
TRASHIT((elm)->field.stqe_next); \
} while (0)
@ -300,6 +303,12 @@ struct { \
(head)->stqh_last = &STAILQ_FIRST((head)); \
} while (0)
#define STAILQ_REMOVE_NEXT(head, elm, field) do { \
if ((STAILQ_NEXT(elm, field) = \
STAILQ_NEXT(STAILQ_NEXT(elm, field), field)) == NULL) \
(head)->stqh_last = &STAILQ_NEXT((elm), field); \
} while (0)
/*
* List declarations.
*/