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authorPierre Riteau <Pierre.Riteau@irisa.fr>2009-11-30 18:21:20 +0100
committerAnthony Liguori <aliguori@us.ibm.com>2009-12-03 10:48:52 -0600
commitc616bbe1fd17ee633f2e8c4f96423399a85ca4a4 (patch)
treeca45725d0662e483faf5678b2565629594cfc637 /qemu-queue.h
parentblock migration: Drop dead code (diff)
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Import a simple queue implementation from NetBSD
Signed-off-by: Pierre Riteau <Pierre.Riteau@irisa.fr> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Diffstat (limited to 'qemu-queue.h')
-rw-r--r--qemu-queue.h109
1 files changed, 105 insertions, 4 deletions
diff --git a/qemu-queue.h b/qemu-queue.h
index 8877efd7b..1d077458c 100644
--- a/qemu-queue.h
+++ b/qemu-queue.h
@@ -1,8 +1,9 @@
-/* $NetBSD: queue.h,v 1.45.14.1 2007/07/18 20:13:24 liamjfoy Exp $ */
+/* $NetBSD: queue.h,v 1.52 2009/04/20 09:56:08 mschuett Exp $ */
/*
* Qemu version: Copy from netbsd, removed debug code, removed some of
- * the implementations. Left in lists, tail queues and circular queues.
+ * the implementations. Left in lists, simple queues, tail queues and
+ * circular queues.
*/
/*
@@ -40,8 +41,8 @@
#define QEMU_SYS_QUEUE_H_
/*
- * This file defines three types of data structures:
- * lists, tail queues, and circular queues.
+ * This file defines four types of data structures:
+ * lists, simple queues, 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
@@ -50,6 +51,13 @@
* 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.
+ *
* 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
@@ -140,6 +148,99 @@ struct { \
/*
+ * Simple queue definitions.
+ */
+#define QSIMPLEQ_HEAD(name, type) \
+struct name { \
+ struct type *sqh_first; /* first element */ \
+ struct type **sqh_last; /* addr of last next element */ \
+}
+
+#define QSIMPLEQ_HEAD_INITIALIZER(head) \
+ { NULL, &(head).sqh_first }
+
+#define QSIMPLEQ_ENTRY(type) \
+struct { \
+ struct type *sqe_next; /* next element */ \
+}
+
+/*
+ * Simple queue functions.
+ */
+#define QSIMPLEQ_INIT(head) do { \
+ (head)->sqh_first = NULL; \
+ (head)->sqh_last = &(head)->sqh_first; \
+} while (/*CONSTCOND*/0)
+
+#define QSIMPLEQ_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 QSIMPLEQ_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 QSIMPLEQ_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 QSIMPLEQ_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 QSIMPLEQ_REMOVE(head, elm, type, field) do { \
+ if ((head)->sqh_first == (elm)) { \
+ QSIMPLEQ_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 QSIMPLEQ_FOREACH(var, head, field) \
+ for ((var) = ((head)->sqh_first); \
+ (var); \
+ (var) = ((var)->field.sqe_next))
+
+#define QSIMPLEQ_FOREACH_SAFE(var, head, field, next) \
+ for ((var) = ((head)->sqh_first); \
+ (var) && ((next = ((var)->field.sqe_next)), 1); \
+ (var) = (next))
+
+#define QSIMPLEQ_CONCAT(head1, head2) do { \
+ if (!QSIMPLEQ_EMPTY((head2))) { \
+ *(head1)->sqh_last = (head2)->sqh_first; \
+ (head1)->sqh_last = (head2)->sqh_last; \
+ QSIMPLEQ_INIT((head2)); \
+ } \
+} while (/*CONSTCOND*/0)
+
+#define QSIMPLEQ_LAST(head, type, field) \
+ (QSIMPLEQ_EMPTY((head)) ? \
+ NULL : \
+ ((struct type *)(void *) \
+ ((char *)((head)->sqh_last) - offsetof(struct type, field))))
+
+/*
+ * Simple queue access methods.
+ */
+#define QSIMPLEQ_EMPTY(head) ((head)->sqh_first == NULL)
+#define QSIMPLEQ_FIRST(head) ((head)->sqh_first)
+#define QSIMPLEQ_NEXT(elm, field) ((elm)->field.sqe_next)
+
+
+/*
* Tail queue definitions.
*/
#define Q_TAILQ_HEAD(name, type, qual) \