'netflow_count' and the existence of actual netflow objects is not
tightly synchronized, so we can use the relaxed atomic_count for it.
Signed-off-by: Jarno Rajahalme <jrajaha...@nicira.com>
---
ofproto/netflow.c | 19 ++++++++-----------
1 file changed, 8 insertions(+), 11 deletions(-)
diff --git a/ofproto/netflow.c b/ofproto/netflow.c
index b3678ca..5915441 100644
--- a/ofproto/netflow.c
+++ b/ofproto/netflow.c
@@ -79,7 +79,7 @@ struct netflow_flow {
};
static struct ovs_mutex mutex = OVS_MUTEX_INITIALIZER;
-static atomic_uint netflow_count = ATOMIC_VAR_INIT(0);
+static atomic_count netflow_count = ATOMIC_COUNT_INIT(0);
static struct netflow_flow *netflow_flow_lookup(const struct netflow *,
const struct flow *)
@@ -381,7 +381,6 @@ struct netflow *
netflow_create(void)
{
struct netflow *nf = xzalloc(sizeof *nf);
- int junk;
nf->engine_type = 0;
nf->engine_id = 0;
@@ -392,7 +391,7 @@ netflow_create(void)
hmap_init(&nf->flows);
ovs_refcount_init(&nf->ref_cnt);
ofpbuf_init(&nf->packet, 1500);
- atomic_add(&netflow_count, 1, &junk);
+ atomic_count_inc(&netflow_count);
return nf;
}
@@ -410,23 +409,21 @@ void
netflow_unref(struct netflow *nf)
{
if (nf && ovs_refcount_unref_relaxed(&nf->ref_cnt) == 1) {
- int orig;
-
- atomic_sub(&netflow_count, 1, &orig);
+ atomic_count_dec(&netflow_count);
collectors_destroy(nf->collectors);
ofpbuf_uninit(&nf->packet);
free(nf);
}
}
-/* Returns true if there exist any netflow objects, false otherwise. */
+/* Returns true if there exist any netflow objects, false otherwise.
+ * Callers can cope with transient false positives, i.e., there is no tight
+ * synchronization with the count and the actual existence of netflow objects.
+ */
bool
netflow_exists(void)
{
- int n;
-
- atomic_read(&netflow_count, &n);
- return n > 0;
+ return atomic_count_get(&netflow_count) > 0;
}
/* Helpers. */
--
1.7.10.4
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