ring: support configurable element size

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

diff --git a/lib/librte_ring/rte_ring.h b/lib/librte_ring/rte_ring.h
index 253cdc9..18fc5d8 100644 (file)
--- a/lib/librte_ring/rte_ring.h
+++ b/lib/librte_ring/rte_ring.h
@@ -26,8 +26,9 @@
  * - Bulk dequeue.
  * - Bulk enqueue.
  *
- * Note: the ring implementation is not preemptable. A lcore must not
- * be interrupted by another task that uses the same ring.
+ * Note: the ring implementation is not preemptible. Refer to Programmer's
+ * guide/Environment Abstraction Layer/Multiple pthread/Known Issues/rte_ring
+ * for more information.
  *
  */
 
@@ -56,20 +57,10 @@ enum rte_ring_queue_behavior {
 };
 
 #define RTE_RING_MZ_PREFIX "RG_"
-/**< The maximum length of a ring name. */
+/** The maximum length of a ring name. */
 #define RTE_RING_NAMESIZE (RTE_MEMZONE_NAMESIZE - \
                           sizeof(RTE_RING_MZ_PREFIX) + 1)
 
-struct rte_memzone; /* forward declaration, so as not to require memzone.h */
-
-#if RTE_CACHE_LINE_SIZE < 128
-#define PROD_ALIGN (RTE_CACHE_LINE_SIZE * 2)
-#define CONS_ALIGN (RTE_CACHE_LINE_SIZE * 2)
-#else
-#define PROD_ALIGN RTE_CACHE_LINE_SIZE
-#define CONS_ALIGN RTE_CACHE_LINE_SIZE
-#endif
-
 /* structure to hold a pair of head/tail values and other metadata */
 struct rte_ring_headtail {
        volatile uint32_t head;  /**< Prod/consumer head. */
@@ -101,11 +92,15 @@ struct rte_ring {
        uint32_t mask;           /**< Mask (size-1) of ring. */
        uint32_t capacity;       /**< Usable size of ring */
 
+       char pad0 __rte_cache_aligned; /**< empty cache line */
+
        /** Ring producer status. */
-       struct rte_ring_headtail prod __rte_aligned(PROD_ALIGN);
+       struct rte_ring_headtail prod __rte_cache_aligned;
+       char pad1 __rte_cache_aligned; /**< empty cache line */
 
        /** Ring consumer status. */
-       struct rte_ring_headtail cons __rte_aligned(CONS_ALIGN);
+       struct rte_ring_headtail cons __rte_cache_aligned;
+       char pad2 __rte_cache_aligned; /**< empty cache line */
 };
 
 #define RING_F_SP_ENQ 0x0001 /**< The default enqueue is "single-producer". */
@@ -221,6 +216,7 @@ int rte_ring_init(struct rte_ring *r, const char *name, unsigned count,
  */
 struct rte_ring *rte_ring_create(const char *name, unsigned count,
                                 int socket_id, unsigned flags);
+
 /**
  * De-allocate all memory used by the ring.
  *
@@ -305,12 +301,12 @@ void rte_ring_dump(FILE *f, const struct rte_ring *r);
  * (powerpc/arm).
  * There are 2 choices for the users
  * 1.use rmb() memory barrier
- * 2.use one-direcion load_acquire/store_release barrier,defined by
- * CONFIG_RTE_RING_USE_C11_MEM_MODEL=y
+ * 2.use one-direction load_acquire/store_release barrier,defined by
+ * CONFIG_RTE_USE_C11_MEM_MODEL=y
  * It depends on performance test results.
  * By default, move common functions to rte_ring_generic.h
  */
-#ifdef RTE_RING_USE_C11_MEM_MODEL
+#ifdef RTE_USE_C11_MEM_MODEL
 #include "rte_ring_c11_mem.h"
 #else
 #include "rte_ring_generic.h"
@@ -339,7 +335,7 @@ void rte_ring_dump(FILE *f, const struct rte_ring *r);
 static __rte_always_inline unsigned int
 __rte_ring_do_enqueue(struct rte_ring *r, void * const *obj_table,
                 unsigned int n, enum rte_ring_queue_behavior behavior,
-                int is_sp, unsigned int *free_space)
+                unsigned int is_sp, unsigned int *free_space)
 {
        uint32_t prod_head, prod_next;
        uint32_t free_entries;
@@ -381,12 +377,12 @@ end:
 static __rte_always_inline unsigned int
 __rte_ring_do_dequeue(struct rte_ring *r, void **obj_table,
                 unsigned int n, enum rte_ring_queue_behavior behavior,
-                int is_sc, unsigned int *available)
+                unsigned int is_sc, unsigned int *available)
 {
        uint32_t cons_head, cons_next;
        uint32_t entries;
 
-       n = __rte_ring_move_cons_head(r, is_sc, n, behavior,
+       n = __rte_ring_move_cons_head(r, (int)is_sc, n, behavior,
                        &cons_head, &cons_next, &entries);
        if (n == 0)
                goto end;
@@ -673,6 +669,23 @@ rte_ring_dequeue(struct rte_ring *r, void **obj_p)
        return rte_ring_dequeue_bulk(r, obj_p, 1, NULL) ? 0 : -ENOENT;
 }
 
+/**
+ * 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.
+ */
+__rte_experimental
+void
+rte_ring_reset(struct rte_ring *r);
+
 /**
  * Return the number of entries in a ring.
  *