We already update the count field as the last step of these functions,
so returning the current count is very cheap. Callers that care about
the count become a bit more efficient, as they avoid extra
non-inlineable function call.
Signed-off-by: Jarno Rajahalme <jrajaha...@nicira.com>
---
lib/cmap.c | 25 ++++++++-----------------
lib/cmap.h | 24 +++++++++++++++++++-----
2 files changed, 27 insertions(+), 22 deletions(-)
diff --git a/lib/cmap.c b/lib/cmap.c
index db2b4a4..50eccbf 100644
--- a/lib/cmap.c
+++ b/lib/cmap.c
@@ -655,7 +655,7 @@ cmap_try_insert(struct cmap_impl *impl, struct cmap_node
*node, uint32_t hash)
* that 'cmap' cannot change concurrently (from another thread). If duplicates
* are undesirable, the caller must have already verified that 'cmap' does not
* contain a duplicate of 'node'. */
-void
+size_t
cmap_insert(struct cmap *cmap, struct cmap_node *node, uint32_t hash)
{
struct cmap_impl *impl = cmap_get_impl(cmap);
@@ -669,7 +669,7 @@ cmap_insert(struct cmap *cmap, struct cmap_node *node,
uint32_t hash)
while (OVS_UNLIKELY(!cmap_try_insert(impl, node, hash))) {
impl = cmap_rehash(cmap, impl->mask);
}
- impl->n++;
+ return ++impl->n;
}
static bool
@@ -705,20 +705,6 @@ cmap_replace__(struct cmap_impl *impl, struct cmap_node
*node,
}
}
-/* Removes 'node' from 'cmap'. The caller must ensure that 'cmap' cannot
- * change concurrently (from another thread).
- *
- * 'node' must not be destroyed or modified or inserted back into 'cmap' or
- * into any other concurrent hash map while any other thread might be accessing
- * it. One correct way to do this is to free it from an RCU callback with
- * ovsrcu_postpone(). */
-void
-cmap_remove(struct cmap *cmap, struct cmap_node *node, uint32_t hash)
-{
- cmap_replace(cmap, node, NULL, hash);
- cmap_get_impl(cmap)->n--;
-}
-
/* Replaces 'old_node' in 'cmap' with 'new_node'. The caller must
* ensure that 'cmap' cannot change concurrently (from another thread).
*
@@ -726,7 +712,7 @@ cmap_remove(struct cmap *cmap, struct cmap_node *node,
uint32_t hash)
* into any other concurrent hash map while any other thread might be accessing
* it. One correct way to do this is to free it from an RCU callback with
* ovsrcu_postpone(). */
-void
+size_t
cmap_replace(struct cmap *cmap, struct cmap_node *old_node,
struct cmap_node *new_node, uint32_t hash)
{
@@ -738,6 +724,11 @@ cmap_replace(struct cmap *cmap, struct cmap_node *old_node,
ok = cmap_replace__(impl, old_node, new_node, hash, h1)
|| cmap_replace__(impl, old_node, new_node, hash, h2);
ovs_assert(ok);
+
+ if (!new_node) {
+ impl->n--;
+ }
+ return impl->n;
}
static bool
diff --git a/lib/cmap.h b/lib/cmap.h
index 793202d..5fc7ead 100644
--- a/lib/cmap.h
+++ b/lib/cmap.h
@@ -87,11 +87,12 @@ void cmap_destroy(struct cmap *);
size_t cmap_count(const struct cmap *);
bool cmap_is_empty(const struct cmap *);
-/* Insertion and deletion. */
-void cmap_insert(struct cmap *, struct cmap_node *, uint32_t hash);
-void cmap_remove(struct cmap *, struct cmap_node *, uint32_t hash);
-void cmap_replace(struct cmap *, struct cmap_node *old_node,
- struct cmap_node *new_node, uint32_t hash);
+/* Insertion and deletion. Return the current count after the operation. */
+size_t cmap_insert(struct cmap *, struct cmap_node *, uint32_t hash);
+static inline size_t cmap_remove(struct cmap *, struct cmap_node *,
+ uint32_t hash);
+size_t cmap_replace(struct cmap *, struct cmap_node *old_node,
+ struct cmap_node *new_node, uint32_t hash);
/* Search.
*
@@ -225,4 +226,17 @@ cmap_first(const struct cmap *cmap)
return cmap_next_position(cmap, &pos);
}
+/* Removes 'node' from 'cmap'. The caller must ensure that 'cmap' cannot
+ * change concurrently (from another thread).
+ *
+ * 'node' must not be destroyed or modified or inserted back into 'cmap' or
+ * into any other concurrent hash map while any other thread might be accessing
+ * it. One correct way to do this is to free it from an RCU callback with
+ * ovsrcu_postpone(). */
+static inline size_t
+cmap_remove(struct cmap *cmap, struct cmap_node *node, uint32_t hash)
+{
+ return cmap_replace(cmap, node, NULL, hash);
+}
+
#endif /* cmap.h */
--
1.7.10.4
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