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* BSD LICENSE
*
* 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
* 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_config.h>
#include <rte_memory.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"
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
/* 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.
*
* 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 {
/*
* 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 rte_ring_headtail prod __rte_aligned(PROD_ALIGN);
/** Ring consumer status. */
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
/**
* 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
* - 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);
/**
* De-allocate all memory used by the ring.
*
* @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.
*/
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 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();
ht->tail = new_val;
}
/**
* @internal This function updates the producer head for enqueue
*
* @param r
* 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
* 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_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)
{
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;
}
/**
* @internal Enqueue several objects on 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 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 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
* - Actual number of objects dequeued.
* If behavior == RTE_RING_QUEUE_FIXED, this will be 0 or n only.
*/
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;
}
/**
* @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.
*/
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).
*
* 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
* The number of objects enqueued, either 0 or n
*/
static __rte_always_inline unsigned int
rte_ring_mp_enqueue_bulk(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_FIXED,
__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
* The number of objects enqueued, either 0 or n
*/
static __rte_always_inline unsigned int
rte_ring_sp_enqueue_bulk(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_FIXED,
__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
* The number of objects enqueued, either 0 or n
*/
static __rte_always_inline unsigned int
rte_ring_enqueue_bulk(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_FIXED,
r->prod.single, free_space);
}
/**
* 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.
* - -ENOBUFS: Not enough room in the ring to enqueue; no object is enqueued.
*/
static __rte_always_inline int
rte_ring_mp_enqueue(struct rte_ring *r, void *obj)
{
return rte_ring_mp_enqueue_bulk(r, &obj, 1, NULL) ? 0 : -ENOBUFS;
}
/**
* 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.
* - -ENOBUFS: Not enough room in the ring to enqueue; no object is enqueued.
*/
static __rte_always_inline int
rte_ring_sp_enqueue(struct rte_ring *r, void *obj)
{
return rte_ring_sp_enqueue_bulk(r, &obj, 1, NULL) ? 0 : -ENOBUFS;
}
/**
* 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.
* - -ENOBUFS: Not enough room in the ring to enqueue; no object is enqueued.
*/
static __rte_always_inline int
rte_ring_enqueue(struct rte_ring *r, void *obj)
{
return rte_ring_enqueue_bulk(r, &obj, 1, NULL) ? 0 : -ENOBUFS;
}
/**
* 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.
* @param available
* If non-NULL, returns the number of remaining ring entries after the
* dequeue has finished.
* @return
* The number of objects dequeued, either 0 or 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)
{
return __rte_ring_do_dequeue(r, obj_table, n, RTE_RING_QUEUE_FIXED,
__IS_MC, available);
}
/**
* 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.
* @param available
* If non-NULL, returns the number of remaining ring entries after the
* dequeue has finished.
* @return
* The number of objects dequeued, either 0 or 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)
{
return __rte_ring_do_dequeue(r, obj_table, n, RTE_RING_QUEUE_FIXED,
__IS_SC, available);
}
/**
* 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.
* @param available
* If non-NULL, returns the number of remaining ring entries after the
* dequeue has finished.
* @return
* The number of objects dequeued, either 0 or n
*/
static __rte_always_inline unsigned int
rte_ring_dequeue_bulk(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_FIXED,
r->cons.single, available);
}
/**
* 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 __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, NULL) ? 0 : -ENOENT;
}
/**
* 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 __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, NULL) ? 0 : -ENOENT;
}
/**
* 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 __rte_always_inline int
rte_ring_dequeue(struct rte_ring *r, void **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);
}
/**
* 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)
{
return rte_ring_free_count(r) == 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)
{
return rte_ring_count(r) == 0;
}
/**
* Return the size of the ring.
*
* @param r
* A pointer to the ring structure.
* @return
* 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 int
rte_ring_get_size(const struct rte_ring *r)
{
return r->size;
}
/**
* Return the number of elements which can be stored in the ring.
*
* @param r
* A pointer to the ring structure.
* @return
* The usable size of the ring.
*/
static inline unsigned int
rte_ring_get_capacity(const struct rte_ring *r)
{
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(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.
* @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
#endif /* _RTE_RING_H_ */
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