/*-
* BSD LICENSE
*
* Copyright(c) 2010-2014 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
* are met:
*
* * 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
* distribution.
* * 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
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/*
* Derived from FreeBSD's bufring.h
*
**************************************************************************
*
* Copyright (c) 2007-2009 Kip Macy kmacy@freebsd.org
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* 2. The name of Kip Macy nor the names of other
* 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 OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
***************************************************************************/
#ifndef _RTE_RING_H_
#define _RTE_RING_H_
/**
* @file
* RTE Ring
*
* The Ring Manager is a fixed-size queue, implemented as a table of
* pointers. Head and tail pointers are modified atomically, allowing
* concurrent access to it. It has the following features:
*
* - FIFO (First In First Out)
* - Maximum size is fixed; the pointers are stored in a table.
* - Lockless implementation.
* - Multi- or single-consumer dequeue.
* - Multi- or single-producer enqueue.
* - 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.
*
*/
#ifdef __cplusplus
extern "C" {
#endif
#include <stdio.h>
#include <stdint.h>
#include <sys/queue.h>
#include <errno.h>
#include <rte_common.h>
#include <rte_memory.h>
#include <rte_lcore.h>
#include <rte_atomic.h>
#include <rte_branch_prediction.h>
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 a possible from 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;
#endif
#define RTE_RING_NAMESIZE 32 /**< The maximum length of a ring name. */
#define RTE_RING_MZ_PREFIX "RG_"
/**
* An RTE ring structure.
*
* The producer and the consumer have a head and a tail index. The particularity
* of these index is that they are not between 0 and size(ring). These indexes
* are between 0 and 2^32, and we mask their value when we access the ring[]
* field. Thanks to this assumption, we can do subtractions between 2 index
* values in a modulo-32bit base: that's why the overflow of the indexes is not
* a problem.
*/
struct rte_ring {
char name[RTE_RING_NAMESIZE]; /**< Name of the ring. */
int flags; /**< Flags supplied at creation. */
/** Ring producer status. */
struct prod {
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;
/** Ring consumer status. */
struct cons {
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. */
#ifdef RTE_RING_SPLIT_PROD_CONS
} cons __rte_cache_aligned;
#else
} cons;
#endif
#ifdef RTE_LIBRTE_RING_DEBUG
struct rte_ring_debug_stats stats[RTE_MAX_LCORE];
#endif
void * ring[0] __rte_cache_aligned; /**< Memory space of ring starts here.
* not volatile so need to be careful
* about compiler re-ordering */
};
#define RING_F_SP_ENQ 0x0001 /**< The default enqueue is "single-producer". */
#define RING_F_SC_DEQ 0x0002 /**< The default dequeue is "single-consumer". */
#define RTE_RING_QUOT_EXCEED (1 << 31) /**< Quota exceed for burst ops */
#define RTE_RING_SZ_MASK (unsigned)(0x0fffffff) /**< Ring size mask */
/**
* @internal When debug is enabled, store ring statistics.
* @param r
* A pointer to the ring.
* @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
/**
* 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
* The pointer to the ring structure followed by the objects table.
* @param name
* 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. 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.
* @param count
* The size of the ring (must be a power of 2).
* @param socket_id
* The *socket_id* argument is the socket identifier in case of
* NUMA. The value can be *SOCKET_ID_ANY* if there is no NUMA
* constraint for the reserved zone.
* @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
* On success, the pointer to the new allocated ring. NULL on error with
* 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
* - ENOMEM - no appropriate memory area found in which to create memzone
*/
struct rte_ring *rte_ring_create(const char *name, unsigned count,
int socket_id, unsigned flags);
/**
* 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.
*
* This function can be called at any time (not necessarily at
* initialization).
*
* @param r
* A pointer to the ring structure.
* @param count
* The new water mark value.
* @return
* - 0: Success; water mark changed.
* - -EINVAL: Invalid water mark value.
*/
int rte_ring_set_water_mark(struct rte_ring *r, unsigned count);
/**
* Dump the status of the ring to the console.
*
* @param f
* A pointer to a file for output
* @param r
* A pointer to the ring structure.
*/
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() do { \
const uint32_t size = r->prod.size; \
uint32_t idx = prod_head & mask; \
if (likely(idx + n < size)) { \
for (i = 0; i < (n & ((~(unsigned)0x3))); i+=4, idx+=4) { \
r->ring[idx] = obj_table[i]; \
r->ring[idx+1] = obj_table[i+1]; \
r->ring[idx+2] = obj_table[i+2]; \
r->ring[idx+3] = obj_table[i+3]; \
} \
switch (n & 0x3) { \
case 3: r->ring[idx++] = obj_table[i++]; \
case 2: r->ring[idx++] = obj_table[i++]; \
case 1: r->ring[idx++] = obj_table[i++]; \
} \
} else { \
for (i = 0; idx < size; i++, idx++)\
r->ring[idx] = obj_table[i]; \
for (idx = 0; i < n; i++, idx++) \
r->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() do { \
uint32_t idx = cons_head & mask; \
const uint32_t size = r->cons.size; \
if (likely(idx + n < size)) { \
for (i = 0; i < (n & (~(unsigned)0x3)); i+=4, idx+=4) {\
obj_table[i] = r->ring[idx]; \
obj_table[i+1] = r->ring[idx+1]; \
obj_table[i+2] = r->ring[idx+2]; \
obj_table[i+3] = r->ring[idx+3]; \
} \
switch (n & 0x3) { \
case 3: obj_table[i++] = r->ring[idx++]; \
case 2: obj_table[i++] = r->ring[idx++]; \
case 1: obj_table[i++] = r->ring[idx++]; \
} \
} else { \
for (i = 0; idx < size; i++, idx++) \
obj_table[i] = r->ring[idx]; \
for (idx = 0; i < n; i++, idx++) \
obj_table[i] = r->ring[idx]; \
} \
} while (0)
/**
* @internal 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 behavior
* RTE_RING_QUEUE_FIXED: Enqueue a fixed number of items from a ring
* RTE_RING_QUEUE_VARIABLE: Enqueue as many items a possible from ring
* @return
* Depend on the behavior value
* if behavior = RTE_RING_QUEUE_FIXED
* - 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.
* if behavior = RTE_RING_QUEUE_VARIABLE
* - n: Actual number of objects enqueued.
*/
static inline int __attribute__((always_inline))
__rte_ring_mp_do_enqueue(struct rte_ring *r, void * const *obj_table,
unsigned n, enum rte_ring_queue_behavior behavior)
{
uint32_t prod_head, prod_next;
uint32_t cons_tail, free_entries;
const unsigned max = n;
int success;
unsigned i;
uint32_t mask = r->prod.mask;
int ret;
/* move prod.head atomically */
do {
/* Reset n to the initial burst count */
n = max;
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)) {
if (behavior == RTE_RING_QUEUE_FIXED) {
__RING_STAT_ADD(r, enq_fail, n);
return -ENOBUFS;
}
else {
/* No free entry available */
if (unlikely(free_entries == 0)) {
__RING_STAT_ADD(r, enq_fail, n);
return 0;
}
n = free_entries;
}
}
prod_next = prod_head + n;
success = rte_atomic32_cmpset(&r->prod.head, prod_head,
prod_next);
} while (unlikely(success == 0));
/* write entries in ring */
ENQUEUE_PTRS();
rte_compiler_barrier();
/* if we exceed the watermark */
if (unlikely(((mask + 1) - free_entries + n) > r->prod.watermark)) {
ret = (behavior == RTE_RING_QUEUE_FIXED) ? -EDQUOT :
(int)(n | RTE_RING_QUOT_EXCEED);
__RING_STAT_ADD(r, enq_quota, n);
}
else {
ret = (behavior == RTE_RING_QUEUE_FIXED) ? 0 : n;
__RING_STAT_ADD(r, enq_success, n);
}
/*
* If there are other enqueues in progress that preceded 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;
}
/**
* @internal 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 behavior
* RTE_RING_QUEUE_FIXED: Enqueue a fixed number of items from a ring
* RTE_RING_QUEUE_VARIABLE: Enqueue as many items a possible from ring
* @return
* Depend on the behavior value
* if behavior = RTE_RING_QUEUE_FIXED
* - 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.
* if behavior = RTE_RING_QUEUE_VARIABLE
* - n: Actual number of objects enqueued.
*/
static inline int __attribute__((always_inline))
__rte_ring_sp_do_enqueue(struct rte_ring *r, void * const *obj_table,
unsigned n, enum rte_ring_queue_behavior behavior)
{
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)) {
if (behavior == RTE_RING_QUEUE_FIXED) {
__RING_STAT_ADD(r, enq_fail, n);
return -ENOBUFS;
}
else {
/* No free entry available */
if (unlikely(free_entries == 0)) {
__RING_STAT_ADD(r, enq_fail, n);
return 0;
}
n = free_entries;
}
}
prod_next = prod_head + n;
r->prod.head = prod_next;
/* write entries in ring */
ENQUEUE_PTRS();
rte_compiler_barrier();
/* if we exceed the watermark */
if (unlikely(((mask + 1) - free_entries + n) > r->prod.watermark)) {
ret = (behavior == RTE_RING_QUEUE_FIXED) ? -EDQUOT :
(int)(n | RTE_RING_QUOT_EXCEED);
__RING_STAT_ADD(r, enq_quota, n);
}
else {
ret = (behavior == RTE_RING_QUEUE_FIXED) ? 0 : n;
__RING_STAT_ADD(r, enq_success, n);
}
r->prod.tail = prod_next;
return ret;
}
/**
* @internal 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 behavior
* RTE_RING_QUEUE_FIXED: Dequeue a fixed number of items from a ring
* RTE_RING_QUEUE_VARIABLE: Dequeue as many items a possible from ring
* @return
* Depend on the behavior value
* if behavior = RTE_RING_QUEUE_FIXED
* - 0: Success; objects dequeued.
* - -ENOENT: Not enough entries in the ring to dequeue; no object is
* dequeued.
* if behavior = RTE_RING_QUEUE_VARIABLE
* - n: Actual number of objects dequeued.
*/
static inline int __attribute__((always_inline))
__rte_ring_mc_do_dequeue(struct rte_ring *r, void **obj_table,
unsigned n, enum rte_ring_queue_behavior behavior)
{
uint32_t cons_head, prod_tail;
uint32_t cons_next, entries;
const unsigned max = n;
int success;
unsigned i;
uint32_t mask = r->prod.mask;
/* move cons.head atomically */
do {
/* Restore n as it may change every loop */
n = max;
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);
/* Set the actual entries for dequeue */
if (n > entries) {
if (behavior == RTE_RING_QUEUE_FIXED) {
__RING_STAT_ADD(r, deq_fail, n);
return -ENOENT;
}
else {
if (unlikely(entries == 0)){
__RING_STAT_ADD(r, deq_fail, n);
return 0;
}
n = entries;
}
}
cons_next = cons_head + n;
success = rte_atomic32_cmpset(&r->cons.head, cons_head,
cons_next);
} while (unlikely(success == 0));
/* copy in table */
DEQUEUE_PTRS();
rte_compiler_barrier();
/*
* If there are other dequeues in progress that preceded 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 behavior == RTE_RING_QUEUE_FIXED ? 0 : n;
}
/**
* @internal 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 behavior
* RTE_RING_QUEUE_FIXED: Dequeue a fixed number of items from a ring
* RTE_RING_QUEUE_VARIABLE: Dequeue as many items a possible from ring
* @return
* Depend on the behavior value
* if behavior = RTE_RING_QUEUE_FIXED
* - 0: Success; objects dequeued.
* - -ENOENT: Not enough entries in the ring to dequeue; no object is
* dequeued.
* if behavior = RTE_RING_QUEUE_VARIABLE
* - n: Actual number of objects dequeued.
*/
static inline int __attribute__((always_inline))
__rte_ring_sc_do_dequeue(struct rte_ring *r, void **obj_table,
unsigned n, enum rte_ring_queue_behavior behavior)
{
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;
if (n > entries) {
if (behavior == RTE_RING_QUEUE_FIXED) {
__RING_STAT_ADD(r, deq_fail, n);
return -ENOENT;
}
else {
if (unlikely(entries == 0)){
__RING_STAT_ADD(r, deq_fail, n);
return 0;
}
n = entries;
}
}
cons_next = cons_head + n;
r->cons.head = cons_next;
/* copy in table */
DEQUEUE_PTRS();
rte_compiler_barrier();
__RING_STAT_ADD(r, deq_success, n);
r->cons.tail = cons_next;
return behavior == RTE_RING_QUEUE_FIXED ? 0 : n;
}
/**
* 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.
* @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.
*/
static inline int __attribute__((always_inline))
rte_ring_mp_enqueue_bulk(struct rte_ring *r, void * const *obj_table,
unsigned n)
{
return __rte_ring_mp_do_enqueue(r, obj_table, n, RTE_RING_QUEUE_FIXED);
}
/**
* 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.
* @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 __attribute__((always_inline))
rte_ring_sp_enqueue_bulk(struct rte_ring *r, void * const *obj_table,
unsigned n)
{
return __rte_ring_sp_do_enqueue(r, obj_table, n, RTE_RING_QUEUE_FIXED);
}
/**
* 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.
* @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 __attribute__((always_inline))
rte_ring_enqueue_bulk(struct rte_ring *r, void * const *obj_table,
unsigned n)
{
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);
}
/**
* Enqueue one object on a 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
* 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 __attribute__((always_inline))
rte_ring_mp_enqueue(struct rte_ring *r, void *obj)
{
return rte_ring_mp_enqueue_bulk(r, &obj, 1);
}
/**
* Enqueue one object on a ring (NOT multi-producers safe).
*
* @param r
* A pointer to the ring structure.
* @param obj
* 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 __attribute__((always_inline))
rte_ring_sp_enqueue(struct rte_ring *r, void *obj)
{
return rte_ring_sp_enqueue_bulk(r, &obj, 1);
}
/**
* Enqueue one object on a ring.
*
* This function calls the multi-producer or the single-producer
* 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
* 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 __attribute__((always_inline))
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);
}
/**
* Dequeue several objects from a ring (multi-consumers safe).
*
* 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.
* @return
* - 0: Success; objects dequeued.
* - -ENOENT: Not enough entries in the ring to dequeue; no object is
* dequeued.
*/
static inline int __attribute__((always_inline))
rte_ring_mc_dequeue_bulk(struct rte_ring *r, void **obj_table, unsigned n)
{
return __rte_ring_mc_do_dequeue(r, obj_table, n, RTE_RING_QUEUE_FIXED);
}
/**
* Dequeue several objects from a ring (NOT multi-consumers safe).
*
* @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,
* must be strictly positive.
* @return
* - 0: Success; objects dequeued.
* - -ENOENT: Not enough entries in the ring to dequeue; no object is
* dequeued.
*/
static inline int __attribute__((always_inline))
rte_ring_sc_dequeue_bulk(struct rte_ring *r, void **obj_table, unsigned n)
{
return __rte_ring_sc_do_dequeue(r, obj_table, n, RTE_RING_QUEUE_FIXED);
}
/**
* Dequeue several objects from a ring.
*
* 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.
* @return
* - 0: Success; objects dequeued.
* - -ENOENT: Not enough entries in the ring to dequeue, no object is
* dequeued.
*/
static inline int __attribute__((always_inline))
rte_ring_dequeue_bulk(struct rte_ring *r, void **obj_table, unsigned n)
{
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);
}
/**
* Dequeue one object from a ring (multi-consumers safe).
*
* This function uses a "compare and set" instruction to move the
* consumer index atomically.
*
* @param r
* A pointer to the ring structure.
* @param obj_p
* A pointer to a void * pointer (object) that will be filled.
* @return
* - 0: Success; objects dequeued.
* - -ENOENT: Not enough entries in the ring to dequeue; no object is
* dequeued.
*/
static inline int __attribute__((always_inline))
rte_ring_mc_dequeue(struct rte_ring *r, void **obj_p)
{
return rte_ring_mc_dequeue_bulk(r, obj_p, 1);
}
/**
* Dequeue one object from a ring (NOT multi-consumers safe).
*
* @param r
* A pointer to the ring structure.
* @param obj_p
* A pointer to a void * pointer (object) that will be filled.
* @return
* - 0: Success; objects dequeued.
* - -ENOENT: Not enough entries in the ring to dequeue, no object is
* dequeued.
*/
static inline int __attribute__((always_inline))
rte_ring_sc_dequeue(struct rte_ring *r, void **obj_p)
{
return rte_ring_sc_dequeue_bulk(r, obj_p, 1);
}
/**
* Dequeue one object from a ring.
*
* 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_p
* A pointer to a void * pointer (object) that will be filled.
* @return
* - 0: Success, objects dequeued.
* - -ENOENT: Not enough entries in the ring to dequeue, no object is
* dequeued.
*/
static inline int __attribute__((always_inline))
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);
}
/**
* Test if a ring is full.
*
* @param r
* A pointer to the ring structure.
* @return
* - 1: The ring is full.
* - 0: The ring is not full.
*/
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);
}
/**
* Test if a ring is empty.
*
* @param r
* A pointer to the ring structure.
* @return
* - 1: The ring is empty.
* - 0: The ring is not empty.
*/
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 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;
return ((prod_tail - cons_tail) & r->prod.mask);
}
/**
* 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)
{
uint32_t prod_tail = r->prod.tail;
uint32_t cons_tail = r->cons.tail;
return ((cons_tail - prod_tail - 1) & r->prod.mask);
}
/**
* Dump the status of all rings on the console
*
* @param f
* A pointer to a file for output
*/
void rte_ring_list_dump(FILE *f);
/**
* Search a ring from its name
*
* @param name
* The name of the ring.
* @return
* The pointer to the ring matching the name, or NULL if not found,
* with rte_errno set appropriately. Possible rte_errno values include:
* - ENOENT - required entry not available to return.
*/
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.
* @return
* - n: Actual number of objects enqueued.
*/
static inline unsigned __attribute__((always_inline))
rte_ring_mp_enqueue_burst(struct rte_ring *r, void * const *obj_table,
unsigned n)
{
return __rte_ring_mp_do_enqueue(r, obj_table, n, RTE_RING_QUEUE_VARIABLE);
}
/**
* 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.
* @return
* - n: Actual number of objects enqueued.
*/
static inline unsigned __attribute__((always_inline))
rte_ring_sp_enqueue_burst(struct rte_ring *r, void * const *obj_table,
unsigned n)
{
return __rte_ring_sp_do_enqueue(r, obj_table, n, RTE_RING_QUEUE_VARIABLE);
}
/**
* 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.
* @return
* - n: Actual number of objects enqueued.
*/
static inline unsigned __attribute__((always_inline))
rte_ring_enqueue_burst(struct rte_ring *r, void * const *obj_table,
unsigned n)
{
if (r->prod.sp_enqueue)
return rte_ring_sp_enqueue_burst(r, obj_table, n);
else
return rte_ring_mp_enqueue_burst(r, obj_table, n);
}
/**
* 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.
* @return
* - n: Actual number of objects dequeued, 0 if ring is empty
*/
static inline unsigned __attribute__((always_inline))
rte_ring_mc_dequeue_burst(struct rte_ring *r, void **obj_table, unsigned n)
{
return __rte_ring_mc_do_dequeue(r, obj_table, n, RTE_RING_QUEUE_VARIABLE);
}
/**
* 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.
* @return
* - n: Actual number of objects dequeued, 0 if ring is empty
*/
static inline unsigned __attribute__((always_inline))
rte_ring_sc_dequeue_burst(struct rte_ring *r, void **obj_table, unsigned n)
{
return __rte_ring_sc_do_dequeue(r, obj_table, n, RTE_RING_QUEUE_VARIABLE);
}
/**
* 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.
* @return
* - Number of objects dequeued
*/
static inline unsigned __attribute__((always_inline))
rte_ring_dequeue_burst(struct rte_ring *r, void **obj_table, unsigned n)
{
if (r->cons.sc_dequeue)
return rte_ring_sc_dequeue_burst(r, obj_table, n);
else
return rte_ring_mc_dequeue_burst(r, obj_table, n);
}
#ifdef __cplusplus
}
#endif
#endif /* _RTE_RING_H_ */