ring: introduce RTS ring mode

[dpdk.git] / lib / librte_ring / rte_ring_core.h

diff --git a/lib/librte_ring/rte_ring_core.h b/lib/librte_ring/rte_ring_core.h
index d9cef76..bd21fa5 100644 (file)
--- a/lib/librte_ring/rte_ring_core.h
+++ b/lib/librte_ring/rte_ring_core.h
@@ -57,6 +57,9 @@ enum rte_ring_queue_behavior {
 enum rte_ring_sync_type {
        RTE_RING_SYNC_MT,     /**< multi-thread safe (default mode) */
        RTE_RING_SYNC_ST,     /**< single thread only */
+#ifdef ALLOW_EXPERIMENTAL_API
+       RTE_RING_SYNC_MT_RTS, /**< multi-thread relaxed tail sync */
+#endif
 };
 
 /**
@@ -76,6 +79,22 @@ struct rte_ring_headtail {
        };
 };
 
+union __rte_ring_rts_poscnt {
+       /** raw 8B value to read/write *cnt* and *pos* as one atomic op */
+       uint64_t raw __rte_aligned(8);
+       struct {
+               uint32_t cnt; /**< head/tail reference counter */
+               uint32_t pos; /**< head/tail position */
+       } val;
+};
+
+struct rte_ring_rts_headtail {
+       volatile union __rte_ring_rts_poscnt tail;
+       enum rte_ring_sync_type sync_type;  /**< sync type of prod/cons */
+       uint32_t htd_max;   /**< max allowed distance between head/tail */
+       volatile union __rte_ring_rts_poscnt head;
+};
+
 /**
  * An RTE ring structure.
  *
@@ -104,11 +123,21 @@ struct rte_ring {
        char pad0 __rte_cache_aligned; /**< empty cache line */
 
        /** Ring producer status. */
-       struct rte_ring_headtail prod __rte_cache_aligned;
+       RTE_STD_C11
+       union {
+               struct rte_ring_headtail prod;
+               struct rte_ring_rts_headtail rts_prod;
+       }  __rte_cache_aligned;
+
        char pad1 __rte_cache_aligned; /**< empty cache line */
 
        /** Ring consumer status. */
-       struct rte_ring_headtail cons __rte_cache_aligned;
+       RTE_STD_C11
+       union {
+               struct rte_ring_headtail cons;
+               struct rte_ring_rts_headtail rts_cons;
+       }  __rte_cache_aligned;
+
        char pad2 __rte_cache_aligned; /**< empty cache line */
 };
 
@@ -125,6 +154,9 @@ struct rte_ring {
 #define RING_F_EXACT_SZ 0x0004
 #define RTE_RING_SZ_MASK  (0x7fffffffU) /**< Ring size mask */
 
+#define RING_F_MP_RTS_ENQ 0x0008 /**< The default enqueue is "MP RTS". */
+#define RING_F_MC_RTS_DEQ 0x0010 /**< The default dequeue is "MC RTS". */
+
 #ifdef __cplusplus
 }
 #endif