/*-
* BSD LICENSE
- *
- * Copyright(c) 2010-2012 Intel Corporation. All rights reserved.
+ *
+ * Copyright(c) 2010-2017 Intel Corporation. All rights reserved.
* All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
* are met:
- *
- * * Redistributions of source code must retain the above copyright
+ *
+ * * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
- * * Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in
- * the documentation and/or other materials provided with the
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
* distribution.
- * * Neither the name of Intel Corporation nor the names of its
- * contributors may be used to endorse or promote products derived
+ * * Neither the name of Intel Corporation nor the names of its
+ * contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- * version: DPDK.L.1.2.3-3
*/
/*
extern "C" {
#endif
+#include <stdio.h>
#include <stdint.h>
#include <sys/queue.h>
#include <errno.h>
#include <rte_lcore.h>
#include <rte_atomic.h>
#include <rte_branch_prediction.h>
+#include <rte_memzone.h>
+#include <rte_pause.h>
+#define RTE_TAILQ_RING_NAME "RTE_RING"
-#ifdef RTE_LIBRTE_RING_DEBUG
-/**
- * A structure that stores the ring statistics (per-lcore).
- */
-struct rte_ring_debug_stats {
- uint64_t enq_success_bulk; /**< Successful enqueues number. */
- uint64_t enq_success_objs; /**< Objects successfully enqueued. */
- uint64_t enq_quota_bulk; /**< Successful enqueues above watermark. */
- uint64_t enq_quota_objs; /**< Objects enqueued above watermark. */
- uint64_t enq_fail_bulk; /**< Failed enqueues number. */
- uint64_t enq_fail_objs; /**< Objects that failed to be enqueued. */
- uint64_t deq_success_bulk; /**< Successful dequeues number. */
- uint64_t deq_success_objs; /**< Objects successfully dequeued. */
- uint64_t deq_fail_bulk; /**< Failed dequeues number. */
- uint64_t deq_fail_objs; /**< Objects that failed to be dequeued. */
-} __rte_cache_aligned;
+enum rte_ring_queue_behavior {
+ RTE_RING_QUEUE_FIXED = 0, /* Enq/Deq a fixed number of items from a ring */
+ RTE_RING_QUEUE_VARIABLE /* Enq/Deq as many items as possible from ring */
+};
+
+#define RTE_RING_MZ_PREFIX "RG_"
+/**< 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
-#define RTE_RING_NAMESIZE 32 /**< The maximum length of a ring name. */
+/* structure to hold a pair of head/tail values and other metadata */
+struct rte_ring_headtail {
+ volatile uint32_t head; /**< Prod/consumer head. */
+ volatile uint32_t tail; /**< Prod/consumer tail. */
+ uint32_t single; /**< True if single prod/cons */
+};
/**
* An RTE ring structure.
* a problem.
*/
struct rte_ring {
- TAILQ_ENTRY(rte_ring) next; /**< Next in list. */
-
- char name[RTE_RING_NAMESIZE]; /**< Name of the ring. */
- int flags; /**< Flags supplied at creation. */
+ /*
+ * Note: this field kept the RTE_MEMZONE_NAMESIZE size due to ABI
+ * compatibility requirements, it could be changed to RTE_RING_NAMESIZE
+ * next time the ABI changes
+ */
+ char name[RTE_MEMZONE_NAMESIZE] __rte_cache_aligned; /**< Name of the ring. */
+ int flags; /**< Flags supplied at creation. */
+ const struct rte_memzone *memzone;
+ /**< Memzone, if any, containing the rte_ring */
+ uint32_t size; /**< Size of ring. */
+ uint32_t mask; /**< Mask (size-1) of ring. */
+ uint32_t capacity; /**< Usable size of ring */
/** Ring producer status. */
- struct prod {
- volatile uint32_t bulk_default; /**< Default bulk count. */
- uint32_t watermark; /**< Maximum items before EDQUOT. */
- uint32_t sp_enqueue; /**< True, if single producer. */
- uint32_t size; /**< Size of ring. */
- uint32_t mask; /**< Mask (size-1) of ring. */
- volatile uint32_t head; /**< Producer head. */
- volatile uint32_t tail; /**< Producer tail. */
- } prod __rte_cache_aligned;
+ struct rte_ring_headtail prod __rte_aligned(PROD_ALIGN);
/** Ring consumer status. */
- struct cons {
- volatile uint32_t bulk_default; /**< Default bulk count. */
- uint32_t sc_dequeue; /**< True, if single consumer. */
- uint32_t size; /**< Size of the ring. */
- uint32_t mask; /**< Mask (size-1) of ring. */
- volatile uint32_t head; /**< Consumer head. */
- volatile uint32_t tail; /**< Consumer tail. */
- } cons __rte_cache_aligned;
-
-
-#ifdef RTE_LIBRTE_RING_DEBUG
- struct rte_ring_debug_stats stats[RTE_MAX_LCORE];
-#endif
-
- void * volatile ring[0] \
- __rte_cache_aligned; /**< Memory space of ring starts here. */
+ struct rte_ring_headtail cons __rte_aligned(CONS_ALIGN);
};
#define RING_F_SP_ENQ 0x0001 /**< The default enqueue is "single-producer". */
#define RING_F_SC_DEQ 0x0002 /**< The default dequeue is "single-consumer". */
+/**
+ * Ring is to hold exactly requested number of entries.
+ * Without this flag set, the ring size requested must be a power of 2, and the
+ * usable space will be that size - 1. With the flag, the requested size will
+ * be rounded up to the next power of two, but the usable space will be exactly
+ * that requested. Worst case, if a power-of-2 size is requested, half the
+ * ring space will be wasted.
+ */
+#define RING_F_EXACT_SZ 0x0004
+#define RTE_RING_SZ_MASK (0x7fffffffU) /**< Ring size mask */
+
+/* @internal defines for passing to the enqueue dequeue worker functions */
+#define __IS_SP 1
+#define __IS_MP 0
+#define __IS_SC 1
+#define __IS_MC 0
/**
- * When debug is enabled, store ring statistics.
+ * Calculate the memory size needed for a ring
+ *
+ * This function returns the number of bytes needed for a ring, given
+ * the number of elements in it. This value is the sum of the size of
+ * the structure rte_ring and the size of the memory needed by the
+ * objects pointers. The value is aligned to a cache line size.
+ *
+ * @param count
+ * The number of elements in the ring (must be a power of 2).
+ * @return
+ * - The memory size needed for the ring on success.
+ * - -EINVAL if count is not a power of 2.
+ */
+ssize_t rte_ring_get_memsize(unsigned count);
+
+/**
+ * Initialize a ring structure.
+ *
+ * Initialize a ring structure in memory pointed by "r". The size of the
+ * memory area must be large enough to store the ring structure and the
+ * object table. It is advised to use rte_ring_get_memsize() to get the
+ * appropriate size.
+ *
+ * The ring size is set to *count*, which must be a power of two. Water
+ * marking is disabled by default. The real usable ring size is
+ * *count-1* instead of *count* to differentiate a free ring from an
+ * empty ring.
+ *
+ * The ring is not added in RTE_TAILQ_RING global list. Indeed, the
+ * memory given by the caller may not be shareable among dpdk
+ * processes.
+ *
* @param r
- * A pointer to the ring.
+ * The pointer to the ring structure followed by the objects table.
* @param name
- * The name of the statistics field to increment in the ring.
- * @param n
- * The number to add to the object-oriented statistics.
- */
-#ifdef RTE_LIBRTE_RING_DEBUG
-#define __RING_STAT_ADD(r, name, n) do { \
- unsigned __lcore_id = rte_lcore_id(); \
- r->stats[__lcore_id].name##_objs += n; \
- r->stats[__lcore_id].name##_bulk += 1; \
- } while(0)
-#else
-#define __RING_STAT_ADD(r, name, n) do {} while(0)
-#endif
+ * The name of the ring.
+ * @param count
+ * The number of elements in the ring (must be a power of 2).
+ * @param flags
+ * An OR of the following:
+ * - RING_F_SP_ENQ: If this flag is set, the default behavior when
+ * using ``rte_ring_enqueue()`` or ``rte_ring_enqueue_bulk()``
+ * is "single-producer". Otherwise, it is "multi-producers".
+ * - RING_F_SC_DEQ: If this flag is set, the default behavior when
+ * using ``rte_ring_dequeue()`` or ``rte_ring_dequeue_bulk()``
+ * is "single-consumer". Otherwise, it is "multi-consumers".
+ * @return
+ * 0 on success, or a negative value on error.
+ */
+int rte_ring_init(struct rte_ring *r, const char *name, unsigned count,
+ unsigned flags);
/**
* Create a new ring named *name* in memory.
*
- * This function uses ``memzone_reserve()`` to allocate memory. Its size is
- * set to *count*, which must be a power of two. Water marking is
- * disabled by default. The default bulk count is initialized to 1.
- * Note that the real usable ring size is *count-1* instead of
- * *count*.
+ * This function uses ``memzone_reserve()`` to allocate memory. Then it
+ * calls rte_ring_init() to initialize an empty ring.
+ *
+ * The new ring size is set to *count*, which must be a power of
+ * two. Water marking is disabled by default. The real usable ring size
+ * is *count-1* instead of *count* to differentiate a free ring from an
+ * empty ring.
+ *
+ * The ring is added in RTE_TAILQ_RING list.
*
* @param name
* The name of the ring.
* rte_errno set appropriately. Possible errno values include:
* - E_RTE_NO_CONFIG - function could not get pointer to rte_config structure
* - E_RTE_SECONDARY - function was called from a secondary process instance
- * - E_RTE_NO_TAILQ - no tailq list could be got for the ring list
* - EINVAL - count provided is not a power of 2
* - ENOSPC - the maximum number of memzones has already been allocated
* - EEXIST - a memzone with the same name already exists
*/
struct rte_ring *rte_ring_create(const char *name, unsigned count,
int socket_id, unsigned flags);
-
/**
- * Set the default bulk count for enqueue/dequeue.
+ * De-allocate all memory used by the ring.
*
- * The parameter *count* is the default number of bulk elements to
- * get/put when using ``rte_ring_*_{en,de}queue_bulk()``. It must be
- * greater than 0 and less than half of the ring size.
+ * @param r
+ * Ring to free
+ */
+void rte_ring_free(struct rte_ring *r);
+
+/**
+ * Dump the status of the ring to a file.
*
+ * @param f
+ * A pointer to a file for output
* @param r
* A pointer to the ring structure.
- * @param count
- * A new water mark value.
- * @return
- * - 0: Success; default_bulk_count changed.
- * - -EINVAL: Invalid count value.
*/
-static inline int
-rte_ring_set_bulk_count(struct rte_ring *r, unsigned count)
+void rte_ring_dump(FILE *f, const struct rte_ring *r);
+
+/* the actual enqueue of pointers on the ring.
+ * Placed here since identical code needed in both
+ * single and multi producer enqueue functions */
+#define ENQUEUE_PTRS(r, ring_start, prod_head, obj_table, n, obj_type) do { \
+ unsigned int i; \
+ const uint32_t size = (r)->size; \
+ uint32_t idx = prod_head & (r)->mask; \
+ obj_type *ring = (obj_type *)ring_start; \
+ if (likely(idx + n < size)) { \
+ for (i = 0; i < (n & ((~(unsigned)0x3))); i+=4, idx+=4) { \
+ ring[idx] = obj_table[i]; \
+ ring[idx+1] = obj_table[i+1]; \
+ ring[idx+2] = obj_table[i+2]; \
+ ring[idx+3] = obj_table[i+3]; \
+ } \
+ switch (n & 0x3) { \
+ case 3: \
+ ring[idx++] = obj_table[i++]; /* fallthrough */ \
+ case 2: \
+ ring[idx++] = obj_table[i++]; /* fallthrough */ \
+ case 1: \
+ ring[idx++] = obj_table[i++]; \
+ } \
+ } else { \
+ for (i = 0; idx < size; i++, idx++)\
+ ring[idx] = obj_table[i]; \
+ for (idx = 0; i < n; i++, idx++) \
+ ring[idx] = obj_table[i]; \
+ } \
+} while (0)
+
+/* the actual copy of pointers on the ring to obj_table.
+ * Placed here since identical code needed in both
+ * single and multi consumer dequeue functions */
+#define DEQUEUE_PTRS(r, ring_start, cons_head, obj_table, n, obj_type) do { \
+ unsigned int i; \
+ uint32_t idx = cons_head & (r)->mask; \
+ const uint32_t size = (r)->size; \
+ obj_type *ring = (obj_type *)ring_start; \
+ if (likely(idx + n < size)) { \
+ for (i = 0; i < (n & (~(unsigned)0x3)); i+=4, idx+=4) {\
+ obj_table[i] = ring[idx]; \
+ obj_table[i+1] = ring[idx+1]; \
+ obj_table[i+2] = ring[idx+2]; \
+ obj_table[i+3] = ring[idx+3]; \
+ } \
+ switch (n & 0x3) { \
+ case 3: \
+ obj_table[i++] = ring[idx++]; /* fallthrough */ \
+ case 2: \
+ obj_table[i++] = ring[idx++]; /* fallthrough */ \
+ case 1: \
+ obj_table[i++] = ring[idx++]; \
+ } \
+ } else { \
+ for (i = 0; idx < size; i++, idx++) \
+ obj_table[i] = ring[idx]; \
+ for (idx = 0; i < n; i++, idx++) \
+ obj_table[i] = ring[idx]; \
+ } \
+} while (0)
+
+static __rte_always_inline void
+update_tail(struct rte_ring_headtail *ht, uint32_t old_val, uint32_t new_val,
+ uint32_t single)
{
- if (unlikely(count == 0 || count >= r->prod.size))
- return -EINVAL;
+ /*
+ * If there are other enqueues/dequeues in progress that preceded us,
+ * we need to wait for them to complete
+ */
+ if (!single)
+ while (unlikely(ht->tail != old_val))
+ rte_pause();
- r->prod.bulk_default = r->cons.bulk_default = count;
- return 0;
+ ht->tail = new_val;
}
/**
- * Get the default bulk count for enqueue/dequeue.
+ * @internal This function updates the producer head for enqueue
*
* @param r
- * A pointer to the ring structure.
+ * A pointer to the ring structure
+ * @param is_sp
+ * Indicates whether multi-producer path is needed or not
+ * @param n
+ * The number of elements we will want to enqueue, i.e. how far should the
+ * head be moved
+ * @param behavior
+ * RTE_RING_QUEUE_FIXED: Enqueue a fixed number of items from a ring
+ * RTE_RING_QUEUE_VARIABLE: Enqueue as many items as possible from ring
+ * @param old_head
+ * Returns head value as it was before the move, i.e. where enqueue starts
+ * @param new_head
+ * Returns the current/new head value i.e. where enqueue finishes
+ * @param free_entries
+ * Returns the amount of free space in the ring BEFORE head was moved
* @return
- * The default bulk count for enqueue/dequeue.
+ * Actual number of objects enqueued.
+ * If behavior == RTE_RING_QUEUE_FIXED, this will be 0 or n only.
*/
-static inline unsigned
-rte_ring_get_bulk_count(struct rte_ring *r)
+static __rte_always_inline unsigned int
+__rte_ring_move_prod_head(struct rte_ring *r, int is_sp,
+ unsigned int n, enum rte_ring_queue_behavior behavior,
+ uint32_t *old_head, uint32_t *new_head,
+ uint32_t *free_entries)
{
- return r->prod.bulk_default;
+ const uint32_t capacity = r->capacity;
+ unsigned int max = n;
+ int success;
+
+ do {
+ /* Reset n to the initial burst count */
+ n = max;
+
+ *old_head = r->prod.head;
+
+ /* add rmb barrier to avoid load/load reorder in weak
+ * memory model. It is noop on x86
+ */
+ rte_smp_rmb();
+
+ const uint32_t cons_tail = r->cons.tail;
+ /*
+ * The subtraction is done between two unsigned 32bits value
+ * (the result is always modulo 32 bits even if we have
+ * *old_head > cons_tail). So 'free_entries' is always between 0
+ * and capacity (which is < size).
+ */
+ *free_entries = (capacity + cons_tail - *old_head);
+
+ /* check that we have enough room in ring */
+ if (unlikely(n > *free_entries))
+ n = (behavior == RTE_RING_QUEUE_FIXED) ?
+ 0 : *free_entries;
+
+ if (n == 0)
+ return 0;
+
+ *new_head = *old_head + n;
+ if (is_sp)
+ r->prod.head = *new_head, success = 1;
+ else
+ success = rte_atomic32_cmpset(&r->prod.head,
+ *old_head, *new_head);
+ } while (unlikely(success == 0));
+ return n;
}
/**
- * Change the high water mark.
- *
- * If *count* is 0, water marking is disabled. Otherwise, it is set to the
- * *count* value. The *count* value must be greater than 0 and less
- * than the ring size.
+ * @internal Enqueue several objects on the ring
*
- * This function can be called at any time (not necessarilly at
- * initialization).
+ * @param r
+ * A pointer to the ring structure.
+ * @param obj_table
+ * A pointer to a table of void * pointers (objects).
+ * @param n
+ * The number of objects to add in the ring from the obj_table.
+ * @param behavior
+ * RTE_RING_QUEUE_FIXED: Enqueue a fixed number of items from a ring
+ * RTE_RING_QUEUE_VARIABLE: Enqueue as many items as possible from ring
+ * @param is_sp
+ * Indicates whether to use single producer or multi-producer head update
+ * @param free_space
+ * returns the amount of space after the enqueue operation has finished
+ * @return
+ * Actual number of objects enqueued.
+ * If behavior == RTE_RING_QUEUE_FIXED, this will be 0 or n only.
+ */
+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)
+{
+ uint32_t prod_head, prod_next;
+ uint32_t free_entries;
+
+ n = __rte_ring_move_prod_head(r, is_sp, n, behavior,
+ &prod_head, &prod_next, &free_entries);
+ if (n == 0)
+ goto end;
+
+ ENQUEUE_PTRS(r, &r[1], prod_head, obj_table, n, void *);
+ rte_smp_wmb();
+
+ update_tail(&r->prod, prod_head, prod_next, is_sp);
+end:
+ if (free_space != NULL)
+ *free_space = free_entries - n;
+ return n;
+}
+
+/**
+ * @internal This function updates the consumer head for dequeue
*
* @param r
- * A pointer to the ring structure.
- * @param count
- * The new water mark value.
+ * A pointer to the ring structure
+ * @param is_sc
+ * Indicates whether multi-consumer path is needed or not
+ * @param n
+ * The number of elements we will want to enqueue, i.e. how far should the
+ * head be moved
+ * @param behavior
+ * RTE_RING_QUEUE_FIXED: Dequeue a fixed number of items from a ring
+ * RTE_RING_QUEUE_VARIABLE: Dequeue as many items as possible from ring
+ * @param old_head
+ * Returns head value as it was before the move, i.e. where dequeue starts
+ * @param new_head
+ * Returns the current/new head value i.e. where dequeue finishes
+ * @param entries
+ * Returns the number of entries in the ring BEFORE head was moved
* @return
- * - 0: Success; water mark changed.
- * - -EINVAL: Invalid water mark value.
+ * - Actual number of objects dequeued.
+ * If behavior == RTE_RING_QUEUE_FIXED, this will be 0 or n only.
*/
-int rte_ring_set_water_mark(struct rte_ring *r, unsigned count);
+static __rte_always_inline unsigned int
+__rte_ring_move_cons_head(struct rte_ring *r, int is_sc,
+ unsigned int n, enum rte_ring_queue_behavior behavior,
+ uint32_t *old_head, uint32_t *new_head,
+ uint32_t *entries)
+{
+ unsigned int max = n;
+ int success;
+
+ /* move cons.head atomically */
+ do {
+ /* Restore n as it may change every loop */
+ n = max;
+
+ *old_head = r->cons.head;
+
+ /* add rmb barrier to avoid load/load reorder in weak
+ * memory model. It is noop on x86
+ */
+ rte_smp_rmb();
+
+ const uint32_t prod_tail = r->prod.tail;
+ /* The subtraction is done between two unsigned 32bits value
+ * (the result is always modulo 32 bits even if we have
+ * cons_head > prod_tail). So 'entries' is always between 0
+ * and size(ring)-1. */
+ *entries = (prod_tail - *old_head);
+
+ /* Set the actual entries for dequeue */
+ if (n > *entries)
+ n = (behavior == RTE_RING_QUEUE_FIXED) ? 0 : *entries;
+
+ if (unlikely(n == 0))
+ return 0;
+
+ *new_head = *old_head + n;
+ if (is_sc)
+ r->cons.head = *new_head, success = 1;
+ else
+ success = rte_atomic32_cmpset(&r->cons.head, *old_head,
+ *new_head);
+ } while (unlikely(success == 0));
+ return n;
+}
/**
- * Dump the status of the ring to the console.
+ * @internal Dequeue several objects from the ring
*
* @param r
* A pointer to the ring structure.
+ * @param obj_table
+ * A pointer to a table of void * pointers (objects).
+ * @param n
+ * The number of objects to pull from the ring.
+ * @param behavior
+ * RTE_RING_QUEUE_FIXED: Dequeue a fixed number of items from a ring
+ * RTE_RING_QUEUE_VARIABLE: Dequeue as many items as possible from ring
+ * @param is_sc
+ * Indicates whether to use single consumer or multi-consumer head update
+ * @param available
+ * returns the number of remaining ring entries after the dequeue has finished
+ * @return
+ * - Actual number of objects dequeued.
+ * If behavior == RTE_RING_QUEUE_FIXED, this will be 0 or n only.
*/
-void rte_ring_dump(const struct rte_ring *r);
+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)
+{
+ uint32_t cons_head, cons_next;
+ uint32_t entries;
+
+ n = __rte_ring_move_cons_head(r, is_sc, n, behavior,
+ &cons_head, &cons_next, &entries);
+ if (n == 0)
+ goto end;
+
+ DEQUEUE_PTRS(r, &r[1], cons_head, obj_table, n, void *);
+ rte_smp_rmb();
+
+ update_tail(&r->cons, cons_head, cons_next, is_sc);
+
+end:
+ if (available != NULL)
+ *available = entries - n;
+ return n;
+}
/**
* Enqueue several objects on the ring (multi-producers safe).
* @param obj_table
* A pointer to a table of void * pointers (objects).
* @param n
- * The number of objects to add in the ring from the obj_table. The
- * value must be strictly positive.
+ * The number of objects to add in the ring from the obj_table.
+ * @param free_space
+ * if non-NULL, returns the amount of space in the ring after the
+ * enqueue operation has finished.
* @return
- * - 0: Success; objects enqueue.
- * - -EDQUOT: Quota exceeded. The objects have been enqueued, but the
- * high water mark is exceeded.
- * - -ENOBUFS: Not enough room in the ring to enqueue, no object is enqueued.
+ * The number of objects enqueued, either 0 or n
*/
-static inline int
+static __rte_always_inline unsigned int
rte_ring_mp_enqueue_bulk(struct rte_ring *r, void * const *obj_table,
- unsigned n)
+ unsigned int n, unsigned int *free_space)
{
- uint32_t prod_head, prod_next;
- uint32_t cons_tail, free_entries;
- int success;
- unsigned i;
- uint32_t mask = r->prod.mask;
- int ret;
-
- /* move prod.head atomically */
- do {
- prod_head = r->prod.head;
- cons_tail = r->cons.tail;
- /* The subtraction is done between two unsigned 32bits value
- * (the result is always modulo 32 bits even if we have
- * prod_head > cons_tail). So 'free_entries' is always between 0
- * and size(ring)-1. */
- free_entries = (mask + cons_tail - prod_head);
-
- /* check that we have enough room in ring */
- if (unlikely(n > free_entries)) {
- __RING_STAT_ADD(r, enq_fail, n);
- return -ENOBUFS;
- }
-
- prod_next = prod_head + n;
- success = rte_atomic32_cmpset(&r->prod.head, prod_head,
- prod_next);
- } while (unlikely(success == 0));
-
- /* write entries in ring */
- for (i = 0; likely(i < n); i++)
- r->ring[(prod_head + i) & mask] = obj_table[i];
- rte_wmb();
-
- /* return -EDQUOT if we exceed the watermark */
- if (unlikely(((mask + 1) - free_entries + n) > r->prod.watermark)) {
- ret = -EDQUOT;
- __RING_STAT_ADD(r, enq_quota, n);
- }
- else {
- ret = 0;
- __RING_STAT_ADD(r, enq_success, n);
- }
-
- /*
- * If there are other enqueues in progress that preceeded us,
- * we need to wait for them to complete
- */
- while (unlikely(r->prod.tail != prod_head))
- rte_pause();
-
- r->prod.tail = prod_next;
- return ret;
+ return __rte_ring_do_enqueue(r, obj_table, n, RTE_RING_QUEUE_FIXED,
+ __IS_MP, free_space);
}
/**
* @param obj_table
* A pointer to a table of void * pointers (objects).
* @param n
- * The number of objects to add in the ring from the obj_table. The
- * value must be strictly positive.
+ * The number of objects to add in the ring from the obj_table.
+ * @param free_space
+ * if non-NULL, returns the amount of space in the ring after the
+ * enqueue operation has finished.
* @return
- * - 0: Success; objects enqueued.
- * - -EDQUOT: Quota exceeded. The objects have been enqueued, but the
- * high water mark is exceeded.
- * - -ENOBUFS: Not enough room in the ring to enqueue; no object is enqueued.
+ * The number of objects enqueued, either 0 or n
*/
-static inline int
+static __rte_always_inline unsigned int
rte_ring_sp_enqueue_bulk(struct rte_ring *r, void * const *obj_table,
- unsigned n)
+ unsigned int n, unsigned int *free_space)
{
- uint32_t prod_head, cons_tail;
- uint32_t prod_next, free_entries;
- unsigned i;
- uint32_t mask = r->prod.mask;
- int ret;
-
- prod_head = r->prod.head;
- cons_tail = r->cons.tail;
- /* The subtraction is done between two unsigned 32bits value
- * (the result is always modulo 32 bits even if we have
- * prod_head > cons_tail). So 'free_entries' is always between 0
- * and size(ring)-1. */
- free_entries = mask + cons_tail - prod_head;
-
- /* check that we have enough room in ring */
- if (unlikely(n > free_entries)) {
- __RING_STAT_ADD(r, enq_fail, n);
- return -ENOBUFS;
- }
-
- prod_next = prod_head + n;
- r->prod.head = prod_next;
-
- /* write entries in ring */
- for (i = 0; likely(i < n); i++)
- r->ring[(prod_head + i) & mask] = obj_table[i];
- rte_wmb();
-
- /* return -EDQUOT if we exceed the watermark */
- if (unlikely(((mask + 1) - free_entries + n) > r->prod.watermark)) {
- ret = -EDQUOT;
- __RING_STAT_ADD(r, enq_quota, n);
- }
- else {
- ret = 0;
- __RING_STAT_ADD(r, enq_success, n);
- }
-
- r->prod.tail = prod_next;
- return ret;
+ return __rte_ring_do_enqueue(r, obj_table, n, RTE_RING_QUEUE_FIXED,
+ __IS_SP, free_space);
}
/**
* A pointer to a table of void * pointers (objects).
* @param n
* The number of objects to add in the ring from the obj_table.
+ * @param free_space
+ * if non-NULL, returns the amount of space in the ring after the
+ * enqueue operation has finished.
* @return
- * - 0: Success; objects enqueued.
- * - -EDQUOT: Quota exceeded. The objects have been enqueued, but the
- * high water mark is exceeded.
- * - -ENOBUFS: Not enough room in the ring to enqueue; no object is enqueued.
+ * The number of objects enqueued, either 0 or n
*/
-static inline int
+static __rte_always_inline unsigned int
rte_ring_enqueue_bulk(struct rte_ring *r, void * const *obj_table,
- unsigned n)
+ unsigned int n, unsigned int *free_space)
{
- if (r->prod.sp_enqueue)
- return rte_ring_sp_enqueue_bulk(r, obj_table, n);
- else
- return rte_ring_mp_enqueue_bulk(r, obj_table, n);
+ return __rte_ring_do_enqueue(r, obj_table, n, RTE_RING_QUEUE_FIXED,
+ r->prod.single, free_space);
}
/**
* A pointer to the object to be added.
* @return
* - 0: Success; objects enqueued.
- * - -EDQUOT: Quota exceeded. The objects have been enqueued, but the
- * high water mark is exceeded.
* - -ENOBUFS: Not enough room in the ring to enqueue; no object is enqueued.
*/
-static inline int
+static __rte_always_inline int
rte_ring_mp_enqueue(struct rte_ring *r, void *obj)
{
- return rte_ring_mp_enqueue_bulk(r, &obj, 1);
+ return rte_ring_mp_enqueue_bulk(r, &obj, 1, NULL) ? 0 : -ENOBUFS;
}
/**
* A pointer to the object to be added.
* @return
* - 0: Success; objects enqueued.
- * - -EDQUOT: Quota exceeded. The objects have been enqueued, but the
- * high water mark is exceeded.
* - -ENOBUFS: Not enough room in the ring to enqueue; no object is enqueued.
*/
-static inline int
+static __rte_always_inline int
rte_ring_sp_enqueue(struct rte_ring *r, void *obj)
{
- return rte_ring_sp_enqueue_bulk(r, &obj, 1);
+ return rte_ring_sp_enqueue_bulk(r, &obj, 1, NULL) ? 0 : -ENOBUFS;
}
/**
* A pointer to the object to be added.
* @return
* - 0: Success; objects enqueued.
- * - -EDQUOT: Quota exceeded. The objects have been enqueued, but the
- * high water mark is exceeded.
* - -ENOBUFS: Not enough room in the ring to enqueue; no object is enqueued.
*/
-static inline int
+static __rte_always_inline int
rte_ring_enqueue(struct rte_ring *r, void *obj)
{
- if (r->prod.sp_enqueue)
- return rte_ring_sp_enqueue(r, obj);
- else
- return rte_ring_mp_enqueue(r, obj);
+ return rte_ring_enqueue_bulk(r, &obj, 1, NULL) ? 0 : -ENOBUFS;
}
/**
* @param obj_table
* A pointer to a table of void * pointers (objects) that will be filled.
* @param n
- * The number of objects to dequeue from the ring to the obj_table,
- * must be strictly positive
+ * The number of objects to dequeue from the ring to the obj_table.
+ * @param available
+ * If non-NULL, returns the number of remaining ring entries after the
+ * dequeue has finished.
* @return
- * - 0: Success; objects dequeued.
- * - -ENOENT: Not enough entries in the ring to dequeue; no object is
- * dequeued.
+ * The number of objects dequeued, either 0 or n
*/
-static inline int
-rte_ring_mc_dequeue_bulk(struct rte_ring *r, void **obj_table, unsigned n)
+static __rte_always_inline unsigned int
+rte_ring_mc_dequeue_bulk(struct rte_ring *r, void **obj_table,
+ unsigned int n, unsigned int *available)
{
- uint32_t cons_head, prod_tail;
- uint32_t cons_next, entries;
- int success;
- unsigned i;
- uint32_t mask = r->prod.mask;
-
- /* move cons.head atomically */
- do {
- cons_head = r->cons.head;
- prod_tail = r->prod.tail;
- /* The subtraction is done between two unsigned 32bits value
- * (the result is always modulo 32 bits even if we have
- * cons_head > prod_tail). So 'entries' is always between 0
- * and size(ring)-1. */
- entries = (prod_tail - cons_head);
-
- /* check that we have enough entries in ring */
- if (unlikely(n > entries)) {
- __RING_STAT_ADD(r, deq_fail, n);
- return -ENOENT;
- }
-
- cons_next = cons_head + n;
- success = rte_atomic32_cmpset(&r->cons.head, cons_head,
- cons_next);
- } while (unlikely(success == 0));
-
- /* copy in table */
- rte_rmb();
- for (i = 0; likely(i < n); i++) {
- obj_table[i] = r->ring[(cons_head + i) & mask];
- }
-
- /*
- * If there are other dequeues in progress that preceeded us,
- * we need to wait for them to complete
- */
- while (unlikely(r->cons.tail != cons_head))
- rte_pause();
-
- __RING_STAT_ADD(r, deq_success, n);
- r->cons.tail = cons_next;
- return 0;
+ return __rte_ring_do_dequeue(r, obj_table, n, RTE_RING_QUEUE_FIXED,
+ __IS_MC, available);
}
/**
* @param n
* The number of objects to dequeue from the ring to the obj_table,
* must be strictly positive.
+ * @param available
+ * If non-NULL, returns the number of remaining ring entries after the
+ * dequeue has finished.
* @return
- * - 0: Success; objects dequeued.
- * - -ENOENT: Not enough entries in the ring to dequeue; no object is
- * dequeued.
+ * The number of objects dequeued, either 0 or n
*/
-static inline int
-rte_ring_sc_dequeue_bulk(struct rte_ring *r, void **obj_table, unsigned n)
+static __rte_always_inline unsigned int
+rte_ring_sc_dequeue_bulk(struct rte_ring *r, void **obj_table,
+ unsigned int n, unsigned int *available)
{
- uint32_t cons_head, prod_tail;
- uint32_t cons_next, entries;
- unsigned i;
- uint32_t mask = r->prod.mask;
-
- cons_head = r->cons.head;
- prod_tail = r->prod.tail;
- /* The subtraction is done between two unsigned 32bits value
- * (the result is always modulo 32 bits even if we have
- * cons_head > prod_tail). So 'entries' is always between 0
- * and size(ring)-1. */
- entries = prod_tail - cons_head;
-
- /* check that we have enough entries in ring */
- if (unlikely(n > entries)) {
- __RING_STAT_ADD(r, deq_fail, n);
- return -ENOENT;
- }
-
- cons_next = cons_head + n;
- r->cons.head = cons_next;
-
- /* copy in table */
- rte_rmb();
- for (i = 0; likely(i < n); i++) {
- obj_table[i] = r->ring[(cons_head + i) & mask];
- }
-
- __RING_STAT_ADD(r, deq_success, n);
- r->cons.tail = cons_next;
- return 0;
+ return __rte_ring_do_dequeue(r, obj_table, n, RTE_RING_QUEUE_FIXED,
+ __IS_SC, available);
}
/**
* A pointer to a table of void * pointers (objects) that will be filled.
* @param n
* The number of objects to dequeue from the ring to the obj_table.
+ * @param available
+ * If non-NULL, returns the number of remaining ring entries after the
+ * dequeue has finished.
* @return
- * - 0: Success; objects dequeued.
- * - -ENOENT: Not enough entries in the ring to dequeue, no object is
- * dequeued.
+ * The number of objects dequeued, either 0 or n
*/
-static inline int
-rte_ring_dequeue_bulk(struct rte_ring *r, void **obj_table, unsigned n)
+static __rte_always_inline unsigned int
+rte_ring_dequeue_bulk(struct rte_ring *r, void **obj_table, unsigned int n,
+ unsigned int *available)
{
- if (r->cons.sc_dequeue)
- return rte_ring_sc_dequeue_bulk(r, obj_table, n);
- else
- return rte_ring_mc_dequeue_bulk(r, obj_table, n);
+ return __rte_ring_do_dequeue(r, obj_table, n, RTE_RING_QUEUE_FIXED,
+ r->cons.single, available);
}
/**
* - -ENOENT: Not enough entries in the ring to dequeue; no object is
* dequeued.
*/
-static inline int
+static __rte_always_inline int
rte_ring_mc_dequeue(struct rte_ring *r, void **obj_p)
{
- return rte_ring_mc_dequeue_bulk(r, obj_p, 1);
+ return rte_ring_mc_dequeue_bulk(r, obj_p, 1, NULL) ? 0 : -ENOENT;
}
/**
* - -ENOENT: Not enough entries in the ring to dequeue, no object is
* dequeued.
*/
-static inline int
+static __rte_always_inline int
rte_ring_sc_dequeue(struct rte_ring *r, void **obj_p)
{
- return rte_ring_sc_dequeue_bulk(r, obj_p, 1);
+ return rte_ring_sc_dequeue_bulk(r, obj_p, 1, NULL) ? 0 : -ENOENT;
}
/**
* - -ENOENT: Not enough entries in the ring to dequeue, no object is
* dequeued.
*/
-static inline int
+static __rte_always_inline int
rte_ring_dequeue(struct rte_ring *r, void **obj_p)
{
- if (r->cons.sc_dequeue)
- return rte_ring_sc_dequeue(r, obj_p);
- else
- return rte_ring_mc_dequeue(r, obj_p);
+ return rte_ring_dequeue_bulk(r, obj_p, 1, NULL) ? 0 : -ENOENT;
+}
+
+/**
+ * Return the number of entries in a ring.
+ *
+ * @param r
+ * A pointer to the ring structure.
+ * @return
+ * The number of entries in the ring.
+ */
+static inline unsigned
+rte_ring_count(const struct rte_ring *r)
+{
+ uint32_t prod_tail = r->prod.tail;
+ uint32_t cons_tail = r->cons.tail;
+ uint32_t count = (prod_tail - cons_tail) & r->mask;
+ return (count > r->capacity) ? r->capacity : count;
+}
+
+/**
+ * Return the number of free entries in a ring.
+ *
+ * @param r
+ * A pointer to the ring structure.
+ * @return
+ * The number of free entries in the ring.
+ */
+static inline unsigned
+rte_ring_free_count(const struct rte_ring *r)
+{
+ return r->capacity - rte_ring_count(r);
}
/**
static inline int
rte_ring_full(const struct rte_ring *r)
{
- uint32_t prod_tail = r->prod.tail;
- uint32_t cons_tail = r->cons.tail;
- return (((cons_tail - prod_tail - 1) & r->prod.mask) == 0);
+ return rte_ring_free_count(r) == 0;
}
/**
static inline int
rte_ring_empty(const struct rte_ring *r)
{
- uint32_t prod_tail = r->prod.tail;
- uint32_t cons_tail = r->cons.tail;
- return !!(cons_tail == prod_tail);
+ return rte_ring_count(r) == 0;
}
/**
- * Return the number of entries in a ring.
+ * Return the size of the ring.
*
* @param r
* A pointer to the ring structure.
* @return
- * The number of entries in the ring.
+ * The size of the data store used by the ring.
+ * NOTE: this is not the same as the usable space in the ring. To query that
+ * use ``rte_ring_get_capacity()``.
*/
-static inline unsigned
-rte_ring_count(const struct rte_ring *r)
+static inline unsigned int
+rte_ring_get_size(const struct rte_ring *r)
{
- uint32_t prod_tail = r->prod.tail;
- uint32_t cons_tail = r->cons.tail;
- return ((prod_tail - cons_tail) & r->prod.mask);
+ return r->size;
}
/**
- * Return the number of free entries in a ring.
+ * Return the number of elements which can be stored in the ring.
*
* @param r
* A pointer to the ring structure.
* @return
- * The number of free entries in the ring.
+ * The usable size of the ring.
*/
-static inline unsigned
-rte_ring_free_count(const struct rte_ring *r)
+static inline unsigned int
+rte_ring_get_capacity(const struct rte_ring *r)
{
- uint32_t prod_tail = r->prod.tail;
- uint32_t cons_tail = r->cons.tail;
- return ((cons_tail - prod_tail - 1) & r->prod.mask);
+ return r->capacity;
}
/**
* Dump the status of all rings on the console
+ *
+ * @param f
+ * A pointer to a file for output
*/
-void rte_ring_list_dump(void);
+void rte_ring_list_dump(FILE *f);
/**
* Search a ring from its name
*/
struct rte_ring *rte_ring_lookup(const char *name);
+/**
+ * Enqueue several objects on the ring (multi-producers safe).
+ *
+ * This function uses a "compare and set" instruction to move the
+ * producer index atomically.
+ *
+ * @param r
+ * A pointer to the ring structure.
+ * @param obj_table
+ * A pointer to a table of void * pointers (objects).
+ * @param n
+ * The number of objects to add in the ring from the obj_table.
+ * @param free_space
+ * if non-NULL, returns the amount of space in the ring after the
+ * enqueue operation has finished.
+ * @return
+ * - n: Actual number of objects enqueued.
+ */
+static __rte_always_inline unsigned
+rte_ring_mp_enqueue_burst(struct rte_ring *r, void * const *obj_table,
+ unsigned int n, unsigned int *free_space)
+{
+ return __rte_ring_do_enqueue(r, obj_table, n,
+ RTE_RING_QUEUE_VARIABLE, __IS_MP, free_space);
+}
+
+/**
+ * Enqueue several objects on a ring (NOT multi-producers safe).
+ *
+ * @param r
+ * A pointer to the ring structure.
+ * @param obj_table
+ * A pointer to a table of void * pointers (objects).
+ * @param n
+ * The number of objects to add in the ring from the obj_table.
+ * @param free_space
+ * if non-NULL, returns the amount of space in the ring after the
+ * enqueue operation has finished.
+ * @return
+ * - n: Actual number of objects enqueued.
+ */
+static __rte_always_inline unsigned
+rte_ring_sp_enqueue_burst(struct rte_ring *r, void * const *obj_table,
+ unsigned int n, unsigned int *free_space)
+{
+ return __rte_ring_do_enqueue(r, obj_table, n,
+ RTE_RING_QUEUE_VARIABLE, __IS_SP, free_space);
+}
+
+/**
+ * Enqueue several objects on a ring.
+ *
+ * This function calls the multi-producer or the single-producer
+ * version depending on the default behavior that was specified at
+ * ring creation time (see flags).
+ *
+ * @param r
+ * A pointer to the ring structure.
+ * @param obj_table
+ * A pointer to a table of void * pointers (objects).
+ * @param n
+ * The number of objects to add in the ring from the obj_table.
+ * @param free_space
+ * if non-NULL, returns the amount of space in the ring after the
+ * enqueue operation has finished.
+ * @return
+ * - n: Actual number of objects enqueued.
+ */
+static __rte_always_inline unsigned
+rte_ring_enqueue_burst(struct rte_ring *r, void * const *obj_table,
+ unsigned int n, unsigned int *free_space)
+{
+ return __rte_ring_do_enqueue(r, obj_table, n, RTE_RING_QUEUE_VARIABLE,
+ r->prod.single, free_space);
+}
+
+/**
+ * Dequeue several objects from a ring (multi-consumers safe). When the request
+ * objects are more than the available objects, only dequeue the actual number
+ * of objects
+ *
+ * This function uses a "compare and set" instruction to move the
+ * consumer index atomically.
+ *
+ * @param r
+ * A pointer to the ring structure.
+ * @param obj_table
+ * A pointer to a table of void * pointers (objects) that will be filled.
+ * @param n
+ * The number of objects to dequeue from the ring to the obj_table.
+ * @param available
+ * If non-NULL, returns the number of remaining ring entries after the
+ * dequeue has finished.
+ * @return
+ * - n: Actual number of objects dequeued, 0 if ring is empty
+ */
+static __rte_always_inline unsigned
+rte_ring_mc_dequeue_burst(struct rte_ring *r, void **obj_table,
+ unsigned int n, unsigned int *available)
+{
+ return __rte_ring_do_dequeue(r, obj_table, n,
+ RTE_RING_QUEUE_VARIABLE, __IS_MC, available);
+}
+
+/**
+ * Dequeue several objects from a ring (NOT multi-consumers safe).When the
+ * request objects are more than the available objects, only dequeue the
+ * actual number of objects
+ *
+ * @param r
+ * A pointer to the ring structure.
+ * @param obj_table
+ * A pointer to a table of void * pointers (objects) that will be filled.
+ * @param n
+ * The number of objects to dequeue from the ring to the obj_table.
+ * @param available
+ * If non-NULL, returns the number of remaining ring entries after the
+ * dequeue has finished.
+ * @return
+ * - n: Actual number of objects dequeued, 0 if ring is empty
+ */
+static __rte_always_inline unsigned
+rte_ring_sc_dequeue_burst(struct rte_ring *r, void **obj_table,
+ unsigned int n, unsigned int *available)
+{
+ return __rte_ring_do_dequeue(r, obj_table, n,
+ RTE_RING_QUEUE_VARIABLE, __IS_SC, available);
+}
+
+/**
+ * Dequeue multiple objects from a ring up to a maximum number.
+ *
+ * This function calls the multi-consumers or the single-consumer
+ * version, depending on the default behaviour that was specified at
+ * ring creation time (see flags).
+ *
+ * @param r
+ * A pointer to the ring structure.
+ * @param obj_table
+ * A pointer to a table of void * pointers (objects) that will be filled.
+ * @param n
+ * The number of objects to dequeue from the ring to the obj_table.
+ * @param available
+ * If non-NULL, returns the number of remaining ring entries after the
+ * dequeue has finished.
+ * @return
+ * - Number of objects dequeued
+ */
+static __rte_always_inline unsigned
+rte_ring_dequeue_burst(struct rte_ring *r, void **obj_table,
+ unsigned int n, unsigned int *available)
+{
+ return __rte_ring_do_dequeue(r, obj_table, n,
+ RTE_RING_QUEUE_VARIABLE,
+ r->cons.single, available);
+}
+
#ifdef __cplusplus
}
#endif
git.droids-corp.org / dpdk.git / blobdiff