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-rw-r--r--misc/sys/queue.h420
1 files changed, 52 insertions, 368 deletions
diff --git a/misc/sys/queue.h b/misc/sys/queue.h
index b0e6b38c19..5b6e2a0a23 100644
--- a/misc/sys/queue.h
+++ b/misc/sys/queue.h
@@ -10,7 +10,7 @@
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
- * 3. Neither the name of the University nor the names of its contributors
+ * 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
@@ -26,46 +26,29 @@
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
- * @(#)queue.h 8.5 (Berkeley) 8/20/94
+ * @(#)queue.h 8.3 (Berkeley) 12/13/93
*/
-#ifndef _SYS_QUEUE_H_
-#define _SYS_QUEUE_H_
+#ifndef _SYS_QUEUE_H
+#define _SYS_QUEUE_H 1
/*
- * This file defines five types of data structures: singly-linked lists,
- * lists, simple queues, tail queues, and circular queues.
- *
- * A singly-linked list is headed by a single forward pointer. The
- * elements are singly linked for minimum space and pointer manipulation
- * overhead at the expense of O(n) removal for arbitrary elements. New
- * elements can be added to the list after an existing element or at the
- * head of the list. Elements being removed from the head of the list
- * should use the explicit macro for this purpose for optimum
- * efficiency. A singly-linked list may only be traversed in the forward
- * direction. Singly-linked lists are ideal for applications with large
- * datasets and few or no removals or for implementing a LIFO queue.
+ * This file defines three types of data structures: lists, tail queues,
+ * and circular queues.
*
* A list is headed by a single forward pointer (or an array of forward
* pointers for a hash table header). The elements are doubly linked
* so that an arbitrary element can be removed without a need to
- * traverse the list. New elements can be added to the list before
- * or after an existing element or at the head of the list. A list
- * may only be traversed in the forward direction.
- *
- * A simple queue is headed by a pair of pointers, one the head of the
- * list and the other to the tail of the list. The elements are singly
- * linked to save space, so elements can only be removed from the
- * head of the list. New elements can be added to the list after
- * an existing element, at the head of the list, or at the end of the
- * list. A simple queue may only be traversed in the forward direction.
+ * traverse the list. New elements can be added to the list after
+ * an existing element or at the head of the list. A list may only be
+ * traversed in the forward direction.
*
* A tail queue is headed by a pair of pointers, one to the head of the
* list and the other to the tail of the list. The elements are doubly
* linked so that an arbitrary element can be removed without a need to
- * traverse the list. New elements can be added to the list before or
- * after an existing element, at the head of the list, or at the end of
- * the list. A tail queue may be traversed in either direction.
+ * traverse the list. New elements can be added to the list after
+ * an existing element, at the head of the list, or at the end of the
+ * list. A tail queue may only be traversed in the forward direction.
*
* A circle queue is headed by a pair of pointers, one to the head of the
* list and the other to the tail of the list. The elements are doubly
@@ -81,15 +64,12 @@
/*
* List definitions.
*/
-#define LIST_HEAD(name, type) \
+#define LIST_HEAD(name, type) \
struct name { \
struct type *lh_first; /* first element */ \
}
-#define LIST_HEAD_INITIALIZER(head) \
- { NULL }
-
-#define LIST_ENTRY(type) \
+#define LIST_ENTRY(type) \
struct { \
struct type *le_next; /* next element */ \
struct type **le_prev; /* address of previous next element */ \
@@ -98,307 +78,73 @@ struct { \
/*
* List functions.
*/
-#define LIST_INIT(head) do { \
+#define LIST_INIT(head) { \
(head)->lh_first = NULL; \
-} while (/*CONSTCOND*/0)
+}
-#define LIST_INSERT_AFTER(listelm, elm, field) do { \
+#define LIST_INSERT_AFTER(listelm, elm, field) { \
if (((elm)->field.le_next = (listelm)->field.le_next) != NULL) \
(listelm)->field.le_next->field.le_prev = \
&(elm)->field.le_next; \
(listelm)->field.le_next = (elm); \
(elm)->field.le_prev = &(listelm)->field.le_next; \
-} while (/*CONSTCOND*/0)
-
-#define LIST_INSERT_BEFORE(listelm, elm, field) do { \
- (elm)->field.le_prev = (listelm)->field.le_prev; \
- (elm)->field.le_next = (listelm); \
- *(listelm)->field.le_prev = (elm); \
- (listelm)->field.le_prev = &(elm)->field.le_next; \
-} while (/*CONSTCOND*/0)
+}
-#define LIST_INSERT_HEAD(head, elm, field) do { \
+#define LIST_INSERT_HEAD(head, elm, field) { \
if (((elm)->field.le_next = (head)->lh_first) != NULL) \
(head)->lh_first->field.le_prev = &(elm)->field.le_next;\
(head)->lh_first = (elm); \
(elm)->field.le_prev = &(head)->lh_first; \
-} while (/*CONSTCOND*/0)
+}
-#define LIST_REMOVE(elm, field) do { \
+#define LIST_REMOVE(elm, field) { \
if ((elm)->field.le_next != NULL) \
(elm)->field.le_next->field.le_prev = \
(elm)->field.le_prev; \
*(elm)->field.le_prev = (elm)->field.le_next; \
-} while (/*CONSTCOND*/0)
-
-#define LIST_FOREACH(var, head, field) \
- for ((var) = ((head)->lh_first); \
- (var); \
- (var) = ((var)->field.le_next))
-
-/*
- * List access methods.
- */
-#define LIST_EMPTY(head) ((head)->lh_first == NULL)
-#define LIST_FIRST(head) ((head)->lh_first)
-#define LIST_NEXT(elm, field) ((elm)->field.le_next)
-
-
-/*
- * Singly-linked List definitions.
- */
-#define SLIST_HEAD(name, type) \
-struct name { \
- struct type *slh_first; /* first element */ \
-}
-
-#define SLIST_HEAD_INITIALIZER(head) \
- { NULL }
-
-#define SLIST_ENTRY(type) \
-struct { \
- struct type *sle_next; /* next element */ \
-}
-
-/*
- * Singly-linked List functions.
- */
-#define SLIST_INIT(head) do { \
- (head)->slh_first = NULL; \
-} while (/*CONSTCOND*/0)
-
-#define SLIST_INSERT_AFTER(slistelm, elm, field) do { \
- (elm)->field.sle_next = (slistelm)->field.sle_next; \
- (slistelm)->field.sle_next = (elm); \
-} while (/*CONSTCOND*/0)
-
-#define SLIST_INSERT_HEAD(head, elm, field) do { \
- (elm)->field.sle_next = (head)->slh_first; \
- (head)->slh_first = (elm); \
-} while (/*CONSTCOND*/0)
-
-#define SLIST_REMOVE_HEAD(head, field) do { \
- (head)->slh_first = (head)->slh_first->field.sle_next; \
-} while (/*CONSTCOND*/0)
-
-#define SLIST_REMOVE(head, elm, type, field) do { \
- if ((head)->slh_first == (elm)) { \
- SLIST_REMOVE_HEAD((head), field); \
- } \
- else { \
- struct type *curelm = (head)->slh_first; \
- while(curelm->field.sle_next != (elm)) \
- curelm = curelm->field.sle_next; \
- curelm->field.sle_next = \
- curelm->field.sle_next->field.sle_next; \
- } \
-} while (/*CONSTCOND*/0)
-
-#define SLIST_FOREACH(var, head, field) \
- for((var) = (head)->slh_first; (var); (var) = (var)->field.sle_next)
-
-/*
- * Singly-linked List access methods.
- */
-#define SLIST_EMPTY(head) ((head)->slh_first == NULL)
-#define SLIST_FIRST(head) ((head)->slh_first)
-#define SLIST_NEXT(elm, field) ((elm)->field.sle_next)
-
-
-/*
- * Singly-linked Tail queue declarations.
- */
-#define STAILQ_HEAD(name, type) \
-struct name { \
- struct type *stqh_first; /* first element */ \
- struct type **stqh_last; /* addr of last next element */ \
-}
-
-#define STAILQ_HEAD_INITIALIZER(head) \
- { NULL, &(head).stqh_first }
-
-#define STAILQ_ENTRY(type) \
-struct { \
- struct type *stqe_next; /* next element */ \
-}
-
-/*
- * Singly-linked Tail queue functions.
- */
-#define STAILQ_INIT(head) do { \
- (head)->stqh_first = NULL; \
- (head)->stqh_last = &(head)->stqh_first; \
-} while (/*CONSTCOND*/0)
-
-#define STAILQ_INSERT_HEAD(head, elm, field) do { \
- if (((elm)->field.stqe_next = (head)->stqh_first) == NULL) \
- (head)->stqh_last = &(elm)->field.stqe_next; \
- (head)->stqh_first = (elm); \
-} while (/*CONSTCOND*/0)
-
-#define STAILQ_INSERT_TAIL(head, elm, field) do { \
- (elm)->field.stqe_next = NULL; \
- *(head)->stqh_last = (elm); \
- (head)->stqh_last = &(elm)->field.stqe_next; \
-} while (/*CONSTCOND*/0)
-
-#define STAILQ_INSERT_AFTER(head, listelm, elm, field) do { \
- if (((elm)->field.stqe_next = (listelm)->field.stqe_next) == NULL)\
- (head)->stqh_last = &(elm)->field.stqe_next; \
- (listelm)->field.stqe_next = (elm); \
-} while (/*CONSTCOND*/0)
-
-#define STAILQ_REMOVE_HEAD(head, field) do { \
- if (((head)->stqh_first = (head)->stqh_first->field.stqe_next) == NULL) \
- (head)->stqh_last = &(head)->stqh_first; \
-} while (/*CONSTCOND*/0)
-
-#define STAILQ_REMOVE(head, elm, type, field) do { \
- if ((head)->stqh_first == (elm)) { \
- STAILQ_REMOVE_HEAD((head), field); \
- } else { \
- struct type *curelm = (head)->stqh_first; \
- while (curelm->field.stqe_next != (elm)) \
- curelm = curelm->field.stqe_next; \
- if ((curelm->field.stqe_next = \
- curelm->field.stqe_next->field.stqe_next) == NULL) \
- (head)->stqh_last = &(curelm)->field.stqe_next; \
- } \
-} while (/*CONSTCOND*/0)
-
-#define STAILQ_FOREACH(var, head, field) \
- for ((var) = ((head)->stqh_first); \
- (var); \
- (var) = ((var)->field.stqe_next))
-
-/*
- * Singly-linked Tail queue access methods.
- */
-#define STAILQ_EMPTY(head) ((head)->stqh_first == NULL)
-#define STAILQ_FIRST(head) ((head)->stqh_first)
-#define STAILQ_NEXT(elm, field) ((elm)->field.stqe_next)
-
-
-/*
- * Simple queue definitions.
- */
-#define SIMPLEQ_HEAD(name, type) \
-struct name { \
- struct type *sqh_first; /* first element */ \
- struct type **sqh_last; /* addr of last next element */ \
-}
-
-#define SIMPLEQ_HEAD_INITIALIZER(head) \
- { NULL, &(head).sqh_first }
-
-#define SIMPLEQ_ENTRY(type) \
-struct { \
- struct type *sqe_next; /* next element */ \
}
/*
- * Simple queue functions.
- */
-#define SIMPLEQ_INIT(head) do { \
- (head)->sqh_first = NULL; \
- (head)->sqh_last = &(head)->sqh_first; \
-} while (/*CONSTCOND*/0)
-
-#define SIMPLEQ_INSERT_HEAD(head, elm, field) do { \
- if (((elm)->field.sqe_next = (head)->sqh_first) == NULL) \
- (head)->sqh_last = &(elm)->field.sqe_next; \
- (head)->sqh_first = (elm); \
-} while (/*CONSTCOND*/0)
-
-#define SIMPLEQ_INSERT_TAIL(head, elm, field) do { \
- (elm)->field.sqe_next = NULL; \
- *(head)->sqh_last = (elm); \
- (head)->sqh_last = &(elm)->field.sqe_next; \
-} while (/*CONSTCOND*/0)
-
-#define SIMPLEQ_INSERT_AFTER(head, listelm, elm, field) do { \
- if (((elm)->field.sqe_next = (listelm)->field.sqe_next) == NULL)\
- (head)->sqh_last = &(elm)->field.sqe_next; \
- (listelm)->field.sqe_next = (elm); \
-} while (/*CONSTCOND*/0)
-
-#define SIMPLEQ_REMOVE_HEAD(head, field) do { \
- if (((head)->sqh_first = (head)->sqh_first->field.sqe_next) == NULL) \
- (head)->sqh_last = &(head)->sqh_first; \
-} while (/*CONSTCOND*/0)
-
-#define SIMPLEQ_REMOVE(head, elm, type, field) do { \
- if ((head)->sqh_first == (elm)) { \
- SIMPLEQ_REMOVE_HEAD((head), field); \
- } else { \
- struct type *curelm = (head)->sqh_first; \
- while (curelm->field.sqe_next != (elm)) \
- curelm = curelm->field.sqe_next; \
- if ((curelm->field.sqe_next = \
- curelm->field.sqe_next->field.sqe_next) == NULL) \
- (head)->sqh_last = &(curelm)->field.sqe_next; \
- } \
-} while (/*CONSTCOND*/0)
-
-#define SIMPLEQ_FOREACH(var, head, field) \
- for ((var) = ((head)->sqh_first); \
- (var); \
- (var) = ((var)->field.sqe_next))
-
-/*
- * Simple queue access methods.
- */
-#define SIMPLEQ_EMPTY(head) ((head)->sqh_first == NULL)
-#define SIMPLEQ_FIRST(head) ((head)->sqh_first)
-#define SIMPLEQ_NEXT(elm, field) ((elm)->field.sqe_next)
-
-
-/*
* Tail queue definitions.
*/
-#define _TAILQ_HEAD(name, type, qual) \
+#define TAILQ_HEAD(name, type) \
struct name { \
- qual type *tqh_first; /* first element */ \
- qual type *qual *tqh_last; /* addr of last next element */ \
+ struct type *tqh_first; /* first element */ \
+ struct type **tqh_last; /* addr of last next element */ \
}
-#define TAILQ_HEAD(name, type) _TAILQ_HEAD(name, struct type,)
-
-#define TAILQ_HEAD_INITIALIZER(head) \
- { NULL, &(head).tqh_first }
-#define _TAILQ_ENTRY(type, qual) \
+#define TAILQ_ENTRY(type) \
struct { \
- qual type *tqe_next; /* next element */ \
- qual type *qual *tqe_prev; /* address of previous next element */\
+ struct type *tqe_next; /* next element */ \
+ struct type **tqe_prev; /* address of previous next element */ \
}
-#define TAILQ_ENTRY(type) _TAILQ_ENTRY(struct type,)
/*
* Tail queue functions.
*/
-#define TAILQ_INIT(head) do { \
+#define TAILQ_INIT(head) { \
(head)->tqh_first = NULL; \
(head)->tqh_last = &(head)->tqh_first; \
-} while (/*CONSTCOND*/0)
+}
-#define TAILQ_INSERT_HEAD(head, elm, field) do { \
+#define TAILQ_INSERT_HEAD(head, elm, field) { \
if (((elm)->field.tqe_next = (head)->tqh_first) != NULL) \
- (head)->tqh_first->field.tqe_prev = \
+ (elm)->field.tqe_next->field.tqe_prev = \
&(elm)->field.tqe_next; \
else \
(head)->tqh_last = &(elm)->field.tqe_next; \
(head)->tqh_first = (elm); \
(elm)->field.tqe_prev = &(head)->tqh_first; \
-} while (/*CONSTCOND*/0)
+}
-#define TAILQ_INSERT_TAIL(head, elm, field) do { \
+#define TAILQ_INSERT_TAIL(head, elm, field) { \
(elm)->field.tqe_next = NULL; \
(elm)->field.tqe_prev = (head)->tqh_last; \
*(head)->tqh_last = (elm); \
(head)->tqh_last = &(elm)->field.tqe_next; \
-} while (/*CONSTCOND*/0)
+}
-#define TAILQ_INSERT_AFTER(head, listelm, elm, field) do { \
+#define TAILQ_INSERT_AFTER(head, listelm, elm, field) { \
if (((elm)->field.tqe_next = (listelm)->field.tqe_next) != NULL)\
(elm)->field.tqe_next->field.tqe_prev = \
&(elm)->field.tqe_next; \
@@ -406,60 +152,27 @@ struct { \
(head)->tqh_last = &(elm)->field.tqe_next; \
(listelm)->field.tqe_next = (elm); \
(elm)->field.tqe_prev = &(listelm)->field.tqe_next; \
-} while (/*CONSTCOND*/0)
-
-#define TAILQ_INSERT_BEFORE(listelm, elm, field) do { \
- (elm)->field.tqe_prev = (listelm)->field.tqe_prev; \
- (elm)->field.tqe_next = (listelm); \
- *(listelm)->field.tqe_prev = (elm); \
- (listelm)->field.tqe_prev = &(elm)->field.tqe_next; \
-} while (/*CONSTCOND*/0)
+}
-#define TAILQ_REMOVE(head, elm, field) do { \
+#define TAILQ_REMOVE(head, elm, field) { \
if (((elm)->field.tqe_next) != NULL) \
(elm)->field.tqe_next->field.tqe_prev = \
(elm)->field.tqe_prev; \
else \
(head)->tqh_last = (elm)->field.tqe_prev; \
*(elm)->field.tqe_prev = (elm)->field.tqe_next; \
-} while (/*CONSTCOND*/0)
-
-#define TAILQ_FOREACH(var, head, field) \
- for ((var) = ((head)->tqh_first); \
- (var); \
- (var) = ((var)->field.tqe_next))
-
-#define TAILQ_FOREACH_REVERSE(var, head, headname, field) \
- for ((var) = (*(((struct headname *)((head)->tqh_last))->tqh_last)); \
- (var); \
- (var) = (*(((struct headname *)((var)->field.tqe_prev))->tqh_last)))
-
-/*
- * Tail queue access methods.
- */
-#define TAILQ_EMPTY(head) ((head)->tqh_first == NULL)
-#define TAILQ_FIRST(head) ((head)->tqh_first)
-#define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next)
-
-#define TAILQ_LAST(head, headname) \
- (*(((struct headname *)((head)->tqh_last))->tqh_last))
-#define TAILQ_PREV(elm, headname, field) \
- (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last))
-
+}
/*
* Circular queue definitions.
*/
-#define CIRCLEQ_HEAD(name, type) \
+#define CIRCLEQ_HEAD(name, type) \
struct name { \
struct type *cqh_first; /* first element */ \
struct type *cqh_last; /* last element */ \
}
-#define CIRCLEQ_HEAD_INITIALIZER(head) \
- { (void *)&head, (void *)&head }
-
-#define CIRCLEQ_ENTRY(type) \
+#define CIRCLEQ_ENTRY(type) \
struct { \
struct type *cqe_next; /* next element */ \
struct type *cqe_prev; /* previous element */ \
@@ -468,12 +181,12 @@ struct { \
/*
* Circular queue functions.
*/
-#define CIRCLEQ_INIT(head) do { \
+#define CIRCLEQ_INIT(head) { \
(head)->cqh_first = (void *)(head); \
(head)->cqh_last = (void *)(head); \
-} while (/*CONSTCOND*/0)
+}
-#define CIRCLEQ_INSERT_AFTER(head, listelm, elm, field) do { \
+#define CIRCLEQ_INSERT_AFTER(head, listelm, elm, field) { \
(elm)->field.cqe_next = (listelm)->field.cqe_next; \
(elm)->field.cqe_prev = (listelm); \
if ((listelm)->field.cqe_next == (void *)(head)) \
@@ -481,9 +194,9 @@ struct { \
else \
(listelm)->field.cqe_next->field.cqe_prev = (elm); \
(listelm)->field.cqe_next = (elm); \
-} while (/*CONSTCOND*/0)
+}
-#define CIRCLEQ_INSERT_BEFORE(head, listelm, elm, field) do { \
+#define CIRCLEQ_INSERT_BEFORE(head, listelm, elm, field) { \
(elm)->field.cqe_next = (listelm); \
(elm)->field.cqe_prev = (listelm)->field.cqe_prev; \
if ((listelm)->field.cqe_prev == (void *)(head)) \
@@ -491,9 +204,9 @@ struct { \
else \
(listelm)->field.cqe_prev->field.cqe_next = (elm); \
(listelm)->field.cqe_prev = (elm); \
-} while (/*CONSTCOND*/0)
+}
-#define CIRCLEQ_INSERT_HEAD(head, elm, field) do { \
+#define CIRCLEQ_INSERT_HEAD(head, elm, field) { \
(elm)->field.cqe_next = (head)->cqh_first; \
(elm)->field.cqe_prev = (void *)(head); \
if ((head)->cqh_last == (void *)(head)) \
@@ -501,9 +214,9 @@ struct { \
else \
(head)->cqh_first->field.cqe_prev = (elm); \
(head)->cqh_first = (elm); \
-} while (/*CONSTCOND*/0)
+}
-#define CIRCLEQ_INSERT_TAIL(head, elm, field) do { \
+#define CIRCLEQ_INSERT_TAIL(head, elm, field) { \
(elm)->field.cqe_next = (void *)(head); \
(elm)->field.cqe_prev = (head)->cqh_last; \
if ((head)->cqh_first == (void *)(head)) \
@@ -511,9 +224,9 @@ struct { \
else \
(head)->cqh_last->field.cqe_next = (elm); \
(head)->cqh_last = (elm); \
-} while (/*CONSTCOND*/0)
+}
-#define CIRCLEQ_REMOVE(head, elm, field) do { \
+#define CIRCLEQ_REMOVE(head, elm, field) { \
if ((elm)->field.cqe_next == (void *)(head)) \
(head)->cqh_last = (elm)->field.cqe_prev; \
else \
@@ -524,34 +237,5 @@ struct { \
else \
(elm)->field.cqe_prev->field.cqe_next = \
(elm)->field.cqe_next; \
-} while (/*CONSTCOND*/0)
-
-#define CIRCLEQ_FOREACH(var, head, field) \
- for ((var) = ((head)->cqh_first); \
- (var) != (const void *)(head); \
- (var) = ((var)->field.cqe_next))
-
-#define CIRCLEQ_FOREACH_REVERSE(var, head, field) \
- for ((var) = ((head)->cqh_last); \
- (var) != (const void *)(head); \
- (var) = ((var)->field.cqe_prev))
-
-/*
- * Circular queue access methods.
- */
-#define CIRCLEQ_EMPTY(head) ((head)->cqh_first == (void *)(head))
-#define CIRCLEQ_FIRST(head) ((head)->cqh_first)
-#define CIRCLEQ_LAST(head) ((head)->cqh_last)
-#define CIRCLEQ_NEXT(elm, field) ((elm)->field.cqe_next)
-#define CIRCLEQ_PREV(elm, field) ((elm)->field.cqe_prev)
-
-#define CIRCLEQ_LOOP_NEXT(head, elm, field) \
- (((elm)->field.cqe_next == (void *)(head)) \
- ? ((head)->cqh_first) \
- : (elm->field.cqe_next))
-#define CIRCLEQ_LOOP_PREV(head, elm, field) \
- (((elm)->field.cqe_prev == (void *)(head)) \
- ? ((head)->cqh_last) \
- : (elm->field.cqe_prev))
-
+}
#endif /* sys/queue.h */