+Ring Peek API
+-------------
+
+For ring with serialized producer/consumer (HTS sync mode) it is possible
+to split public enqueue/dequeue API into two phases:
+
+* enqueue/dequeue start
+
+* enqueue/dequeue finish
+
+That allows user to inspect objects in the ring without removing them
+from it (aka MT safe peek) and reserve space for the objects in the ring
+before actual enqueue.
+Note that this API is available only for two sync modes:
+
+* Single Producer/Single Consumer (SP/SC)
+
+* Multi-producer/Multi-consumer with Head/Tail Sync (HTS)
+
+It is a user responsibility to create/init ring with appropriate sync modes
+selected. As an example of usage:
+
+.. code-block:: c
+
+ /* read 1 elem from the ring: */
+ uint32_t n = rte_ring_dequeue_bulk_start(ring, &obj, 1, NULL);
+ if (n != 0) {
+ /* examine object */
+ if (object_examine(obj) == KEEP)
+ /* decided to keep it in the ring. */
+ rte_ring_dequeue_finish(ring, 0);
+ else
+ /* decided to remove it from the ring. */
+ rte_ring_dequeue_finish(ring, n);
+ }
+
+Note that between ``_start_`` and ``_finish_`` none other thread can proceed
+with enqueue(/dequeue) operation till ``_finish_`` completes.
+
+Ring Peek Zero Copy API
+-----------------------
+
+Along with the advantages of the peek APIs, zero copy APIs provide the ability
+to copy the data to the ring memory directly without the need for temporary
+storage (for ex: array of mbufs on the stack).
+
+These APIs make it possible to split public enqueue/dequeue API into 3 phases:
+
+* enqueue/dequeue start
+
+* copy data to/from the ring
+
+* enqueue/dequeue finish
+
+Note that this API is available only for two sync modes:
+
+* Single Producer/Single Consumer (SP/SC)
+
+* Multi-producer/Multi-consumer with Head/Tail Sync (HTS)
+
+It is a user responsibility to create/init ring with appropriate sync modes.
+Following is an example of usage:
+
+.. code-block:: c
+
+ /* Reserve space on the ring */
+ n = rte_ring_enqueue_zc_burst_start(r, 32, &zcd, NULL);
+ /* Pkt I/O core polls packets from the NIC */
+ if (n != 0) {
+ nb_rx = rte_eth_rx_burst(portid, queueid, zcd->ptr1, zcd->n1);
+ if (nb_rx == zcd->n1 && n != zcd->n1)
+ nb_rx += rte_eth_rx_burst(portid, queueid, zcd->ptr2,
+ n - zcd->n1);
+ /* Provide packets to the packet processing cores */
+ rte_ring_enqueue_zc_finish(r, nb_rx);
+ }
+
+Note that between ``_start_`` and ``_finish_`` no other thread can proceed
+with enqueue(/dequeue) operation till ``_finish_`` completes.
+