Author: lstewart
Date: Tue Jun 18 02:57:56 2013
New Revision: 251887
URL: http://svnweb.freebsd.org/changeset/base/251887
Log:
Add new FOREACH_FROM variants of the queue(3) FOREACH macros which can
optionally start the traversal from a previously found element by passing the
element in as "var". Passing a NULL "var" retains the same semantics as the
regular FOREACH macros.
Kudos to phk for suggesting the "FROM" suffix instead of my original proposal.
Reviewed by: jhb (previous version), rpaulo
MFC after: 1 week
Modified:
head/share/man/man3/queue.3
head/sys/sys/queue.h
Modified: head/share/man/man3/queue.3
==============================================================================
--- head/share/man/man3/queue.3 Tue Jun 18 02:53:45 2013 (r251886)
+++ head/share/man/man3/queue.3 Tue Jun 18 02:57:56 2013 (r251887)
@@ -32,7 +32,7 @@
.\" @(#)queue.3 8.2 (Berkeley) 1/24/94
.\" $FreeBSD$
.\"
-.Dd Sep 12, 2012
+.Dd June 17, 2013
.Dt QUEUE 3
.Os
.Sh NAME
@@ -40,7 +40,9 @@
.Nm SLIST_ENTRY ,
.Nm SLIST_FIRST ,
.Nm SLIST_FOREACH ,
+.Nm SLIST_FOREACH_FROM ,
.Nm SLIST_FOREACH_SAFE ,
+.Nm SLIST_FOREACH_FROM_SAFE ,
.Nm SLIST_HEAD ,
.Nm SLIST_HEAD_INITIALIZER ,
.Nm SLIST_INIT ,
@@ -56,7 +58,9 @@
.Nm STAILQ_ENTRY ,
.Nm STAILQ_FIRST ,
.Nm STAILQ_FOREACH ,
+.Nm STAILQ_FOREACH_FROM ,
.Nm STAILQ_FOREACH_SAFE ,
+.Nm STAILQ_FOREACH_FROM_SAFE ,
.Nm STAILQ_HEAD ,
.Nm STAILQ_HEAD_INITIALIZER ,
.Nm STAILQ_INIT ,
@@ -73,7 +77,9 @@
.Nm LIST_ENTRY ,
.Nm LIST_FIRST ,
.Nm LIST_FOREACH ,
+.Nm LIST_FOREACH_FROM ,
.Nm LIST_FOREACH_SAFE ,
+.Nm LIST_FOREACH_FROM_SAFE ,
.Nm LIST_HEAD ,
.Nm LIST_HEAD_INITIALIZER ,
.Nm LIST_INIT ,
@@ -89,9 +95,13 @@
.Nm TAILQ_ENTRY ,
.Nm TAILQ_FIRST ,
.Nm TAILQ_FOREACH ,
+.Nm TAILQ_FOREACH_FROM ,
.Nm TAILQ_FOREACH_SAFE ,
+.Nm TAILQ_FOREACH_FROM_SAFE ,
.Nm TAILQ_FOREACH_REVERSE ,
+.Nm TAILQ_FOREACH_REVERSE_FROM ,
.Nm TAILQ_FOREACH_REVERSE_SAFE ,
+.Nm TAILQ_FOREACH_REVERSE_FROM_SAFE ,
.Nm TAILQ_HEAD ,
.Nm TAILQ_HEAD_INITIALIZER ,
.Nm TAILQ_INIT ,
@@ -113,7 +123,9 @@ lists and tail queues
.Fn SLIST_ENTRY "TYPE"
.Fn SLIST_FIRST "SLIST_HEAD *head"
.Fn SLIST_FOREACH "TYPE *var" "SLIST_HEAD *head" "SLIST_ENTRY NAME"
+.Fn SLIST_FOREACH_FROM "TYPE *var" "SLIST_HEAD *head" "SLIST_ENTRY NAME"
.Fn SLIST_FOREACH_SAFE "TYPE *var" "SLIST_HEAD *head" "SLIST_ENTRY NAME" "TYPE
*temp_var"
+.Fn SLIST_FOREACH_FROM_SAFE "TYPE *var" "SLIST_HEAD *head" "SLIST_ENTRY NAME"
"TYPE *temp_var"
.Fn SLIST_HEAD "HEADNAME" "TYPE"
.Fn SLIST_HEAD_INITIALIZER "SLIST_HEAD head"
.Fn SLIST_INIT "SLIST_HEAD *head"
@@ -130,7 +142,9 @@ lists and tail queues
.Fn STAILQ_ENTRY "TYPE"
.Fn STAILQ_FIRST "STAILQ_HEAD *head"
.Fn STAILQ_FOREACH "TYPE *var" "STAILQ_HEAD *head" "STAILQ_ENTRY NAME"
+.Fn STAILQ_FOREACH_FROM "TYPE *var" "STAILQ_HEAD *head" "STAILQ_ENTRY NAME"
.Fn STAILQ_FOREACH_SAFE "TYPE *var" "STAILQ_HEAD *head" "STAILQ_ENTRY NAME"
"TYPE *temp_var"
+.Fn STAILQ_FOREACH_FROM_SAFE "TYPE *var" "STAILQ_HEAD *head" "STAILQ_ENTRY
NAME" "TYPE *temp_var"
.Fn STAILQ_HEAD "HEADNAME" "TYPE"
.Fn STAILQ_HEAD_INITIALIZER "STAILQ_HEAD head"
.Fn STAILQ_INIT "STAILQ_HEAD *head"
@@ -148,7 +162,9 @@ lists and tail queues
.Fn LIST_ENTRY "TYPE"
.Fn LIST_FIRST "LIST_HEAD *head"
.Fn LIST_FOREACH "TYPE *var" "LIST_HEAD *head" "LIST_ENTRY NAME"
+.Fn LIST_FOREACH_FROM "TYPE *var" "LIST_HEAD *head" "LIST_ENTRY NAME"
.Fn LIST_FOREACH_SAFE "TYPE *var" "LIST_HEAD *head" "LIST_ENTRY NAME" "TYPE
*temp_var"
+.Fn LIST_FOREACH_FROM_SAFE "TYPE *var" "LIST_HEAD *head" "LIST_ENTRY NAME"
"TYPE *temp_var"
.Fn LIST_HEAD "HEADNAME" "TYPE"
.Fn LIST_HEAD_INITIALIZER "LIST_HEAD head"
.Fn LIST_INIT "LIST_HEAD *head"
@@ -165,9 +181,13 @@ lists and tail queues
.Fn TAILQ_ENTRY "TYPE"
.Fn TAILQ_FIRST "TAILQ_HEAD *head"
.Fn TAILQ_FOREACH "TYPE *var" "TAILQ_HEAD *head" "TAILQ_ENTRY NAME"
+.Fn TAILQ_FOREACH_FROM "TYPE *var" "TAILQ_HEAD *head" "TAILQ_ENTRY NAME"
.Fn TAILQ_FOREACH_SAFE "TYPE *var" "TAILQ_HEAD *head" "TAILQ_ENTRY NAME" "TYPE
*temp_var"
+.Fn TAILQ_FOREACH_FROM_SAFE "TYPE *var" "TAILQ_HEAD *head" "TAILQ_ENTRY NAME"
"TYPE *temp_var"
.Fn TAILQ_FOREACH_REVERSE "TYPE *var" "TAILQ_HEAD *head" "HEADNAME"
"TAILQ_ENTRY NAME"
+.Fn TAILQ_FOREACH_REVERSE_FROM "TYPE *var" "TAILQ_HEAD *head" "HEADNAME"
"TAILQ_ENTRY NAME"
.Fn TAILQ_FOREACH_REVERSE_SAFE "TYPE *var" "TAILQ_HEAD *head" "HEADNAME"
"TAILQ_ENTRY NAME" "TYPE *temp_var"
+.Fn TAILQ_FOREACH_REVERSE_FROM_SAFE "TYPE *var" "TAILQ_HEAD *head" "HEADNAME"
"TAILQ_ENTRY NAME" "TYPE *temp_var"
.Fn TAILQ_HEAD "HEADNAME" "TYPE"
.Fn TAILQ_HEAD_INITIALIZER "TAILQ_HEAD head"
.Fn TAILQ_INIT "TAILQ_HEAD *head"
@@ -365,6 +385,19 @@ turn to
.Fa var .
.Pp
The macro
+.Nm SLIST_FOREACH_FROM
+behaves identically to
+.Nm SLIST_FOREACH
+when
+.Fa var
+is NULL, else it treats
+.Fa var
+as a previously found SLIST element and begins the loop at
+.Fa var
+instead of the first element in the SLIST referenced by
+.Fa head .
+.Pp
+The macro
.Nm SLIST_FOREACH_SAFE
traverses the list referenced by
.Fa head
@@ -379,6 +412,19 @@ as well as free it from within the loop
traversal.
.Pp
The macro
+.Nm SLIST_FOREACH_FROM_SAFE
+behaves identically to
+.Nm SLIST_FOREACH_SAFE
+when
+.Fa var
+is NULL, else it treats
+.Fa var
+as a previously found SLIST element and begins the loop at
+.Fa var
+instead of the first element in the SLIST referenced by
+.Fa head .
+.Pp
+The macro
.Nm SLIST_INIT
initializes the list referenced by
.Fa head .
@@ -545,6 +591,19 @@ in turn to
.Fa var .
.Pp
The macro
+.Nm STAILQ_FOREACH_FROM
+behaves identically to
+.Nm STAILQ_FOREACH
+when
+.Fa var
+is NULL, else it treats
+.Fa var
+as a previously found STAILQ element and begins the loop at
+.Fa var
+instead of the first element in the STAILQ referenced by
+.Fa head .
+.Pp
+The macro
.Nm STAILQ_FOREACH_SAFE
traverses the tail queue referenced by
.Fa head
@@ -559,6 +618,19 @@ as well as free it from within the loop
traversal.
.Pp
The macro
+.Nm STAILQ_FOREACH_FROM_SAFE
+behaves identically to
+.Nm STAILQ_FOREACH_SAFE
+when
+.Fa var
+is NULL, else it treats
+.Fa var
+as a previously found STAILQ element and begins the loop at
+.Fa var
+instead of the first element in the STAILQ referenced by
+.Fa head .
+.Pp
+The macro
.Nm STAILQ_INIT
initializes the tail queue referenced by
.Fa head .
@@ -735,6 +807,19 @@ in the forward direction, assigning each
.Fa var .
.Pp
The macro
+.Nm LIST_FOREACH_FROM
+behaves identically to
+.Nm LIST_FOREACH
+when
+.Fa var
+is NULL, else it treats
+.Fa var
+as a previously found LIST element and begins the loop at
+.Fa var
+instead of the first element in the LIST referenced by
+.Fa head .
+.Pp
+The macro
.Nm LIST_FOREACH_SAFE
traverses the list referenced by
.Fa head
@@ -748,6 +833,19 @@ as well as free it from within the loop
traversal.
.Pp
The macro
+.Nm LIST_FOREACH_FROM_SAFE
+behaves identically to
+.Nm LIST_FOREACH_SAFE
+when
+.Fa var
+is NULL, else it treats
+.Fa var
+as a previously found LIST element and begins the loop at
+.Fa var
+instead of the first element in the LIST referenced by
+.Fa head .
+.Pp
+The macro
.Nm LIST_INIT
initializes the list referenced by
.Fa head .
@@ -920,12 +1018,38 @@ is set to
if the loop completes normally, or if there were no elements.
.Pp
The macro
+.Nm TAILQ_FOREACH_FROM
+behaves identically to
+.Nm TAILQ_FOREACH
+when
+.Fa var
+is NULL, else it treats
+.Fa var
+as a previously found TAILQ element and begins the loop at
+.Fa var
+instead of the first element in the TAILQ referenced by
+.Fa head .
+.Pp
+The macro
.Nm TAILQ_FOREACH_REVERSE
traverses the tail queue referenced by
.Fa head
in the reverse direction, assigning each element in turn to
.Fa var .
.Pp
+The macro
+.Nm TAILQ_FOREACH_REVERSE_FROM
+behaves identically to
+.Nm TAILQ_FOREACH_REVERSE
+when
+.Fa var
+is NULL, else it treats
+.Fa var
+as a previously found TAILQ element and begins the reverse loop at
+.Fa var
+instead of the last element in the TAILQ referenced by
+.Fa head .
+.Pp
The macros
.Nm TAILQ_FOREACH_SAFE
and
@@ -945,6 +1069,32 @@ as well as free it from within the loop
traversal.
.Pp
The macro
+.Nm TAILQ_FOREACH_FROM_SAFE
+behaves identically to
+.Nm TAILQ_FOREACH_SAFE
+when
+.Fa var
+is NULL, else it treats
+.Fa var
+as a previously found TAILQ element and begins the loop at
+.Fa var
+instead of the first element in the TAILQ referenced by
+.Fa head .
+.Pp
+The macro
+.Nm TAILQ_FOREACH_REVERSE_FROM_SAFE
+behaves identically to
+.Nm TAILQ_FOREACH_REVERSE_SAFE
+when
+.Fa var
+is NULL, else it treats
+.Fa var
+as a previously found TAILQ element and begins the reverse loop at
+.Fa var
+instead of the last element in the TAILQ referenced by
+.Fa head .
+.Pp
+The macro
.Nm TAILQ_INIT
initializes the tail queue referenced by
.Fa head .
Modified: head/sys/sys/queue.h
==============================================================================
--- head/sys/sys/queue.h Tue Jun 18 02:53:45 2013 (r251886)
+++ head/sys/sys/queue.h Tue Jun 18 02:57:56 2013 (r251887)
@@ -88,9 +88,13 @@
* _PREV - + - +
* _LAST - - + +
* _FOREACH + + + +
+ * _FOREACH_FROM + + + +
* _FOREACH_SAFE + + + +
+ * _FOREACH_FROM_SAFE + + + +
* _FOREACH_REVERSE - - - +
+ * _FOREACH_REVERSE_FROM - - - +
* _FOREACH_REVERSE_SAFE - - - +
+ * _FOREACH_REVERSE_FROM_SAFE - - - +
* _INSERT_HEAD + + + +
* _INSERT_BEFORE - + - +
* _INSERT_AFTER + + + +
@@ -167,11 +171,21 @@ struct {
\
(var); \
(var) = SLIST_NEXT((var), field))
+#define SLIST_FOREACH_FROM(var, head, field)
\
+ for ((var) = ((var) ? (var) : SLIST_FIRST((head))); \
+ (var); \
+ (var) = SLIST_NEXT((var), field))
+
#define SLIST_FOREACH_SAFE(var, head, field, tvar)
\
for ((var) = SLIST_FIRST((head)); \
(var) && ((tvar) = SLIST_NEXT((var), field), 1); \
(var) = (tvar))
+#define SLIST_FOREACH_FROM_SAFE(var, head, field, tvar)
\
+ for ((var) = ((var) ? (var) : SLIST_FIRST((head))); \
+ (var) && ((tvar) = SLIST_NEXT((var), field), 1); \
+ (var) = (tvar))
+
#define SLIST_FOREACH_PREVPTR(var, varp, head, field)
\
for ((varp) = &SLIST_FIRST((head)); \
((var) = *(varp)) != NULL; \
@@ -259,12 +273,21 @@ struct {
\
(var); \
(var) = STAILQ_NEXT((var), field))
+#define STAILQ_FOREACH_FROM(var, head, field)
\
+ for ((var) = ((var) ? (var) : STAILQ_FIRST((head))); \
+ (var); \
+ (var) = STAILQ_NEXT((var), field))
#define STAILQ_FOREACH_SAFE(var, head, field, tvar)
\
for ((var) = STAILQ_FIRST((head)); \
(var) && ((tvar) = STAILQ_NEXT((var), field), 1); \
(var) = (tvar))
+#define STAILQ_FOREACH_FROM_SAFE(var, head, field, tvar)
\
+ for ((var) = ((var) ? (var) : STAILQ_FIRST((head))); \
+ (var) && ((tvar) = STAILQ_NEXT((var), field), 1); \
+ (var) = (tvar))
+
#define STAILQ_INIT(head) do {
\
STAILQ_FIRST((head)) = NULL; \
(head)->stqh_last = &STAILQ_FIRST((head)); \
@@ -389,11 +412,21 @@ struct {
\
(var); \
(var) = LIST_NEXT((var), field))
+#define LIST_FOREACH_FROM(var, head, field)
\
+ for ((var) = ((var) ? (var) : LIST_FIRST((head))); \
+ (var); \
+ (var) = LIST_NEXT((var), field))
+
#define LIST_FOREACH_SAFE(var, head, field, tvar)
\
for ((var) = LIST_FIRST((head)); \
(var) && ((tvar) = LIST_NEXT((var), field), 1); \
(var) = (tvar))
+#define LIST_FOREACH_FROM_SAFE(var, head, field, tvar)
\
+ for ((var) = ((var) ? (var) : LIST_FIRST((head))); \
+ (var) && ((tvar) = LIST_NEXT((var), field), 1); \
+ (var) = (tvar))
+
#define LIST_INIT(head) do {
\
LIST_FIRST((head)) = NULL; \
} while (0)
@@ -526,21 +559,41 @@ struct {
\
(var); \
(var) = TAILQ_NEXT((var), field))
+#define TAILQ_FOREACH_FROM(var, head, field)
\
+ for ((var) = ((var) ? (var) : TAILQ_FIRST((head))); \
+ (var); \
+ (var) = TAILQ_NEXT((var), field))
+
#define TAILQ_FOREACH_SAFE(var, head, field, tvar)
\
for ((var) = TAILQ_FIRST((head)); \
(var) && ((tvar) = TAILQ_NEXT((var), field), 1); \
(var) = (tvar))
+#define TAILQ_FOREACH_FROM_SAFE(var, head, field, tvar)
\
+ for ((var) = ((var) ? (var) : TAILQ_FIRST((head))); \
+ (var) && ((tvar) = TAILQ_NEXT((var), field), 1); \
+ (var) = (tvar))
+
#define TAILQ_FOREACH_REVERSE(var, head, headname, field)
\
for ((var) = TAILQ_LAST((head), headname); \
(var); \
(var) = TAILQ_PREV((var), headname, field))
+#define TAILQ_FOREACH_REVERSE_FROM(var, head, headname, field)
\
+ for ((var) = ((var) ? (var) : TAILQ_LAST((head), headname)); \
+ (var); \
+ (var) = TAILQ_PREV((var), headname, field))
+
#define TAILQ_FOREACH_REVERSE_SAFE(var, head, headname, field, tvar)
\
for ((var) = TAILQ_LAST((head), headname); \
(var) && ((tvar) = TAILQ_PREV((var), headname, field), 1); \
(var) = (tvar))
+#define TAILQ_FOREACH_REVERSE_FROM_SAFE(var, head, headname, field,
tvar) \
+ for ((var) = ((var) ? (var) : TAILQ_LAST((head), headname)); \
+ (var) && ((tvar) = TAILQ_PREV((var), headname, field), 1); \
+ (var) = (tvar))
+
#define TAILQ_INIT(head) do {
\
TAILQ_FIRST((head)) = NULL; \
(head)->tqh_last = &TAILQ_FIRST((head)); \
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