[dpdk-stable] [PATCH v7 1/2] ring: add reset API to flush the ring when not in use

[Gavin Hu]

Currently, the flush is done by dequeuing the ring in a while loop. It is
much simpler to flush the queue by resetting the head and tail indices.

Fixes: af75078fece3 ("first public release")
Cc: stable at dpdk.org

Signed-off-by: Gavin Hu <gavin.hu at arm.com>
Reviewed-by: Ruifeng Wang <ruifeng.wang at arm.com>
Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli at arm.com>
---
 lib/librte_ring/rte_ring.h           | 20 ++++++++++++++++++++
 lib/librte_ring/rte_ring_version.map |  7 +++++++
 2 files changed, 27 insertions(+)

diff --git a/lib/librte_ring/rte_ring.h b/lib/librte_ring/rte_ring.h
index af5444a..2830300 100644
--- a/lib/librte_ring/rte_ring.h
+++ b/lib/librte_ring/rte_ring.h
@@ -671,6 +671,26 @@ rte_ring_dequeue(struct rte_ring *r, void **obj_p)
 }
 
 /**
+ * Flush a ring.
+ *
+ * This function flush all the elements in a ring
+ *
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * @warning
+ * Make sure the ring is not in use while calling this function.
+ *
+ * @param r
+ *   A pointer to the ring structure.
+ */
+static inline void __rte_experimental
+rte_ring_reset(struct rte_ring *r)
+{
+	r->prod.head = r->cons.head = 0;
+	r->prod.tail = r->cons.tail = 0;
+}
+
+/**
  * Return the number of entries in a ring.
  *
  * @param r
diff --git a/lib/librte_ring/rte_ring_version.map b/lib/librte_ring/rte_ring_version.map
index d935efd..581d9ca 100644
--- a/lib/librte_ring/rte_ring_version.map
+++ b/lib/librte_ring/rte_ring_version.map
@@ -17,3 +17,10 @@ DPDK_2.2 {
 	rte_ring_free;
 
 } DPDK_2.0;
+
+EXPERIMENTAL {
+    global:
+
+	rte_ring_reset;
+
+};
-- 
2.7.4