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35 * Derived from FreeBSD's bufring.h
37 **************************************************************************
39 * Copyright (c) 2007-2009 Kip Macy kmacy@freebsd.org
40 * All rights reserved.
42 * Redistribution and use in source and binary forms, with or without
43 * modification, are permitted provided that the following conditions are met:
45 * 1. Redistributions of source code must retain the above copyright notice,
46 * this list of conditions and the following disclaimer.
48 * 2. The name of Kip Macy nor the names of other
49 * contributors may be used to endorse or promote products derived from
50 * this software without specific prior written permission.
52 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
53 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
54 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
55 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
56 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
57 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
58 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
59 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
60 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
61 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
62 * POSSIBILITY OF SUCH DAMAGE.
64 ***************************************************************************/
73 * The Ring Manager is a fixed-size queue, implemented as a table of
74 * pointers. Head and tail pointers are modified atomically, allowing
75 * concurrent access to it. It has the following features:
77 * - FIFO (First In First Out)
78 * - Maximum size is fixed; the pointers are stored in a table.
79 * - Lockless implementation.
80 * - Multi- or single-consumer dequeue.
81 * - Multi- or single-producer enqueue.
85 * Note: the ring implementation is not preemptable. A lcore must not
86 * be interrupted by another task that uses the same ring.
96 #include <sys/queue.h>
98 #include <rte_common.h>
99 #include <rte_config.h>
100 #include <rte_memory.h>
101 #include <rte_lcore.h>
102 #include <rte_atomic.h>
103 #include <rte_branch_prediction.h>
104 #include <rte_memzone.h>
105 #include <rte_pause.h>
107 #define RTE_TAILQ_RING_NAME "RTE_RING"
109 enum rte_ring_queue_behavior {
110 RTE_RING_QUEUE_FIXED = 0, /* Enq/Deq a fixed number of items from a ring */
111 RTE_RING_QUEUE_VARIABLE /* Enq/Deq as many items as possible from ring */
114 #define RTE_RING_MZ_PREFIX "RG_"
115 /**< The maximum length of a ring name. */
116 #define RTE_RING_NAMESIZE (RTE_MEMZONE_NAMESIZE - \
117 sizeof(RTE_RING_MZ_PREFIX) + 1)
119 struct rte_memzone; /* forward declaration, so as not to require memzone.h */
121 #if RTE_CACHE_LINE_SIZE < 128
122 #define PROD_ALIGN (RTE_CACHE_LINE_SIZE * 2)
123 #define CONS_ALIGN (RTE_CACHE_LINE_SIZE * 2)
125 #define PROD_ALIGN RTE_CACHE_LINE_SIZE
126 #define CONS_ALIGN RTE_CACHE_LINE_SIZE
129 /* structure to hold a pair of head/tail values and other metadata */
130 struct rte_ring_headtail {
131 volatile uint32_t head; /**< Prod/consumer head. */
132 volatile uint32_t tail; /**< Prod/consumer tail. */
133 uint32_t single; /**< True if single prod/cons */
137 * An RTE ring structure.
139 * The producer and the consumer have a head and a tail index. The particularity
140 * of these index is that they are not between 0 and size(ring). These indexes
141 * are between 0 and 2^32, and we mask their value when we access the ring[]
142 * field. Thanks to this assumption, we can do subtractions between 2 index
143 * values in a modulo-32bit base: that's why the overflow of the indexes is not
148 * Note: this field kept the RTE_MEMZONE_NAMESIZE size due to ABI
149 * compatibility requirements, it could be changed to RTE_RING_NAMESIZE
150 * next time the ABI changes
152 char name[RTE_MEMZONE_NAMESIZE] __rte_cache_aligned; /**< Name of the ring. */
153 int flags; /**< Flags supplied at creation. */
154 const struct rte_memzone *memzone;
155 /**< Memzone, if any, containing the rte_ring */
156 uint32_t size; /**< Size of ring. */
157 uint32_t mask; /**< Mask (size-1) of ring. */
158 uint32_t capacity; /**< Usable size of ring */
160 /** Ring producer status. */
161 struct rte_ring_headtail prod __rte_aligned(PROD_ALIGN);
163 /** Ring consumer status. */
164 struct rte_ring_headtail cons __rte_aligned(CONS_ALIGN);
167 #define RING_F_SP_ENQ 0x0001 /**< The default enqueue is "single-producer". */
168 #define RING_F_SC_DEQ 0x0002 /**< The default dequeue is "single-consumer". */
170 * Ring is to hold exactly requested number of entries.
171 * Without this flag set, the ring size requested must be a power of 2, and the
172 * usable space will be that size - 1. With the flag, the requested size will
173 * be rounded up to the next power of two, but the usable space will be exactly
174 * that requested. Worst case, if a power-of-2 size is requested, half the
175 * ring space will be wasted.
177 #define RING_F_EXACT_SZ 0x0004
178 #define RTE_RING_SZ_MASK (0x7fffffffU) /**< Ring size mask */
180 /* @internal defines for passing to the enqueue dequeue worker functions */
187 * Calculate the memory size needed for a ring
189 * This function returns the number of bytes needed for a ring, given
190 * the number of elements in it. This value is the sum of the size of
191 * the structure rte_ring and the size of the memory needed by the
192 * objects pointers. The value is aligned to a cache line size.
195 * The number of elements in the ring (must be a power of 2).
197 * - The memory size needed for the ring on success.
198 * - -EINVAL if count is not a power of 2.
200 ssize_t rte_ring_get_memsize(unsigned count);
203 * Initialize a ring structure.
205 * Initialize a ring structure in memory pointed by "r". The size of the
206 * memory area must be large enough to store the ring structure and the
207 * object table. It is advised to use rte_ring_get_memsize() to get the
210 * The ring size is set to *count*, which must be a power of two. Water
211 * marking is disabled by default. The real usable ring size is
212 * *count-1* instead of *count* to differentiate a free ring from an
215 * The ring is not added in RTE_TAILQ_RING global list. Indeed, the
216 * memory given by the caller may not be shareable among dpdk
220 * The pointer to the ring structure followed by the objects table.
222 * The name of the ring.
224 * The number of elements in the ring (must be a power of 2).
226 * An OR of the following:
227 * - RING_F_SP_ENQ: If this flag is set, the default behavior when
228 * using ``rte_ring_enqueue()`` or ``rte_ring_enqueue_bulk()``
229 * is "single-producer". Otherwise, it is "multi-producers".
230 * - RING_F_SC_DEQ: If this flag is set, the default behavior when
231 * using ``rte_ring_dequeue()`` or ``rte_ring_dequeue_bulk()``
232 * is "single-consumer". Otherwise, it is "multi-consumers".
234 * 0 on success, or a negative value on error.
236 int rte_ring_init(struct rte_ring *r, const char *name, unsigned count,
240 * Create a new ring named *name* in memory.
242 * This function uses ``memzone_reserve()`` to allocate memory. Then it
243 * calls rte_ring_init() to initialize an empty ring.
245 * The new ring size is set to *count*, which must be a power of
246 * two. Water marking is disabled by default. The real usable ring size
247 * is *count-1* instead of *count* to differentiate a free ring from an
250 * The ring is added in RTE_TAILQ_RING list.
253 * The name of the ring.
255 * The size of the ring (must be a power of 2).
257 * The *socket_id* argument is the socket identifier in case of
258 * NUMA. The value can be *SOCKET_ID_ANY* if there is no NUMA
259 * constraint for the reserved zone.
261 * An OR of the following:
262 * - RING_F_SP_ENQ: If this flag is set, the default behavior when
263 * using ``rte_ring_enqueue()`` or ``rte_ring_enqueue_bulk()``
264 * is "single-producer". Otherwise, it is "multi-producers".
265 * - RING_F_SC_DEQ: If this flag is set, the default behavior when
266 * using ``rte_ring_dequeue()`` or ``rte_ring_dequeue_bulk()``
267 * is "single-consumer". Otherwise, it is "multi-consumers".
269 * On success, the pointer to the new allocated ring. NULL on error with
270 * rte_errno set appropriately. Possible errno values include:
271 * - E_RTE_NO_CONFIG - function could not get pointer to rte_config structure
272 * - E_RTE_SECONDARY - function was called from a secondary process instance
273 * - EINVAL - count provided is not a power of 2
274 * - ENOSPC - the maximum number of memzones has already been allocated
275 * - EEXIST - a memzone with the same name already exists
276 * - ENOMEM - no appropriate memory area found in which to create memzone
278 struct rte_ring *rte_ring_create(const char *name, unsigned count,
279 int socket_id, unsigned flags);
281 * De-allocate all memory used by the ring.
286 void rte_ring_free(struct rte_ring *r);
289 * Dump the status of the ring to a file.
292 * A pointer to a file for output
294 * A pointer to the ring structure.
296 void rte_ring_dump(FILE *f, const struct rte_ring *r);
298 /* the actual enqueue of pointers on the ring.
299 * Placed here since identical code needed in both
300 * single and multi producer enqueue functions */
301 #define ENQUEUE_PTRS(r, ring_start, prod_head, obj_table, n, obj_type) do { \
303 const uint32_t size = (r)->size; \
304 uint32_t idx = prod_head & (r)->mask; \
305 obj_type *ring = (obj_type *)ring_start; \
306 if (likely(idx + n < size)) { \
307 for (i = 0; i < (n & ((~(unsigned)0x3))); i+=4, idx+=4) { \
308 ring[idx] = obj_table[i]; \
309 ring[idx+1] = obj_table[i+1]; \
310 ring[idx+2] = obj_table[i+2]; \
311 ring[idx+3] = obj_table[i+3]; \
315 ring[idx++] = obj_table[i++]; /* fallthrough */ \
317 ring[idx++] = obj_table[i++]; /* fallthrough */ \
319 ring[idx++] = obj_table[i++]; \
322 for (i = 0; idx < size; i++, idx++)\
323 ring[idx] = obj_table[i]; \
324 for (idx = 0; i < n; i++, idx++) \
325 ring[idx] = obj_table[i]; \
329 /* the actual copy of pointers on the ring to obj_table.
330 * Placed here since identical code needed in both
331 * single and multi consumer dequeue functions */
332 #define DEQUEUE_PTRS(r, ring_start, cons_head, obj_table, n, obj_type) do { \
334 uint32_t idx = cons_head & (r)->mask; \
335 const uint32_t size = (r)->size; \
336 obj_type *ring = (obj_type *)ring_start; \
337 if (likely(idx + n < size)) { \
338 for (i = 0; i < (n & (~(unsigned)0x3)); i+=4, idx+=4) {\
339 obj_table[i] = ring[idx]; \
340 obj_table[i+1] = ring[idx+1]; \
341 obj_table[i+2] = ring[idx+2]; \
342 obj_table[i+3] = ring[idx+3]; \
346 obj_table[i++] = ring[idx++]; /* fallthrough */ \
348 obj_table[i++] = ring[idx++]; /* fallthrough */ \
350 obj_table[i++] = ring[idx++]; \
353 for (i = 0; idx < size; i++, idx++) \
354 obj_table[i] = ring[idx]; \
355 for (idx = 0; i < n; i++, idx++) \
356 obj_table[i] = ring[idx]; \
360 /* Move common functions to generic file */
361 #include "rte_ring_generic.h"
364 * @internal Enqueue several objects on the ring
367 * A pointer to the ring structure.
369 * A pointer to a table of void * pointers (objects).
371 * The number of objects to add in the ring from the obj_table.
373 * RTE_RING_QUEUE_FIXED: Enqueue a fixed number of items from a ring
374 * RTE_RING_QUEUE_VARIABLE: Enqueue as many items as possible from ring
376 * Indicates whether to use single producer or multi-producer head update
378 * returns the amount of space after the enqueue operation has finished
380 * Actual number of objects enqueued.
381 * If behavior == RTE_RING_QUEUE_FIXED, this will be 0 or n only.
383 static __rte_always_inline unsigned int
384 __rte_ring_do_enqueue(struct rte_ring *r, void * const *obj_table,
385 unsigned int n, enum rte_ring_queue_behavior behavior,
386 int is_sp, unsigned int *free_space)
388 uint32_t prod_head, prod_next;
389 uint32_t free_entries;
391 n = __rte_ring_move_prod_head(r, is_sp, n, behavior,
392 &prod_head, &prod_next, &free_entries);
396 ENQUEUE_PTRS(r, &r[1], prod_head, obj_table, n, void *);
398 update_tail(&r->prod, prod_head, prod_next, is_sp, 1);
400 if (free_space != NULL)
401 *free_space = free_entries - n;
406 * @internal Dequeue several objects from the ring
409 * A pointer to the ring structure.
411 * A pointer to a table of void * pointers (objects).
413 * The number of objects to pull from the ring.
415 * RTE_RING_QUEUE_FIXED: Dequeue a fixed number of items from a ring
416 * RTE_RING_QUEUE_VARIABLE: Dequeue as many items as possible from ring
418 * Indicates whether to use single consumer or multi-consumer head update
420 * returns the number of remaining ring entries after the dequeue has finished
422 * - Actual number of objects dequeued.
423 * If behavior == RTE_RING_QUEUE_FIXED, this will be 0 or n only.
425 static __rte_always_inline unsigned int
426 __rte_ring_do_dequeue(struct rte_ring *r, void **obj_table,
427 unsigned int n, enum rte_ring_queue_behavior behavior,
428 int is_sc, unsigned int *available)
430 uint32_t cons_head, cons_next;
433 n = __rte_ring_move_cons_head(r, is_sc, n, behavior,
434 &cons_head, &cons_next, &entries);
438 DEQUEUE_PTRS(r, &r[1], cons_head, obj_table, n, void *);
440 update_tail(&r->cons, cons_head, cons_next, is_sc, 0);
443 if (available != NULL)
444 *available = entries - n;
449 * Enqueue several objects on the ring (multi-producers safe).
451 * This function uses a "compare and set" instruction to move the
452 * producer index atomically.
455 * A pointer to the ring structure.
457 * A pointer to a table of void * pointers (objects).
459 * The number of objects to add in the ring from the obj_table.
461 * if non-NULL, returns the amount of space in the ring after the
462 * enqueue operation has finished.
464 * The number of objects enqueued, either 0 or n
466 static __rte_always_inline unsigned int
467 rte_ring_mp_enqueue_bulk(struct rte_ring *r, void * const *obj_table,
468 unsigned int n, unsigned int *free_space)
470 return __rte_ring_do_enqueue(r, obj_table, n, RTE_RING_QUEUE_FIXED,
471 __IS_MP, free_space);
475 * Enqueue several objects on a ring (NOT multi-producers safe).
478 * A pointer to the ring structure.
480 * A pointer to a table of void * pointers (objects).
482 * The number of objects to add in the ring from the obj_table.
484 * if non-NULL, returns the amount of space in the ring after the
485 * enqueue operation has finished.
487 * The number of objects enqueued, either 0 or n
489 static __rte_always_inline unsigned int
490 rte_ring_sp_enqueue_bulk(struct rte_ring *r, void * const *obj_table,
491 unsigned int n, unsigned int *free_space)
493 return __rte_ring_do_enqueue(r, obj_table, n, RTE_RING_QUEUE_FIXED,
494 __IS_SP, free_space);
498 * Enqueue several objects on a ring.
500 * This function calls the multi-producer or the single-producer
501 * version depending on the default behavior that was specified at
502 * ring creation time (see flags).
505 * A pointer to the ring structure.
507 * A pointer to a table of void * pointers (objects).
509 * The number of objects to add in the ring from the obj_table.
511 * if non-NULL, returns the amount of space in the ring after the
512 * enqueue operation has finished.
514 * The number of objects enqueued, either 0 or n
516 static __rte_always_inline unsigned int
517 rte_ring_enqueue_bulk(struct rte_ring *r, void * const *obj_table,
518 unsigned int n, unsigned int *free_space)
520 return __rte_ring_do_enqueue(r, obj_table, n, RTE_RING_QUEUE_FIXED,
521 r->prod.single, free_space);
525 * Enqueue one object on a ring (multi-producers safe).
527 * This function uses a "compare and set" instruction to move the
528 * producer index atomically.
531 * A pointer to the ring structure.
533 * A pointer to the object to be added.
535 * - 0: Success; objects enqueued.
536 * - -ENOBUFS: Not enough room in the ring to enqueue; no object is enqueued.
538 static __rte_always_inline int
539 rte_ring_mp_enqueue(struct rte_ring *r, void *obj)
541 return rte_ring_mp_enqueue_bulk(r, &obj, 1, NULL) ? 0 : -ENOBUFS;
545 * Enqueue one object on a ring (NOT multi-producers safe).
548 * A pointer to the ring structure.
550 * A pointer to the object to be added.
552 * - 0: Success; objects enqueued.
553 * - -ENOBUFS: Not enough room in the ring to enqueue; no object is enqueued.
555 static __rte_always_inline int
556 rte_ring_sp_enqueue(struct rte_ring *r, void *obj)
558 return rte_ring_sp_enqueue_bulk(r, &obj, 1, NULL) ? 0 : -ENOBUFS;
562 * Enqueue one object on a ring.
564 * This function calls the multi-producer or the single-producer
565 * version, depending on the default behaviour that was specified at
566 * ring creation time (see flags).
569 * A pointer to the ring structure.
571 * A pointer to the object to be added.
573 * - 0: Success; objects enqueued.
574 * - -ENOBUFS: Not enough room in the ring to enqueue; no object is enqueued.
576 static __rte_always_inline int
577 rte_ring_enqueue(struct rte_ring *r, void *obj)
579 return rte_ring_enqueue_bulk(r, &obj, 1, NULL) ? 0 : -ENOBUFS;
583 * Dequeue several objects from a ring (multi-consumers safe).
585 * This function uses a "compare and set" instruction to move the
586 * consumer index atomically.
589 * A pointer to the ring structure.
591 * A pointer to a table of void * pointers (objects) that will be filled.
593 * The number of objects to dequeue from the ring to the obj_table.
595 * If non-NULL, returns the number of remaining ring entries after the
596 * dequeue has finished.
598 * The number of objects dequeued, either 0 or n
600 static __rte_always_inline unsigned int
601 rte_ring_mc_dequeue_bulk(struct rte_ring *r, void **obj_table,
602 unsigned int n, unsigned int *available)
604 return __rte_ring_do_dequeue(r, obj_table, n, RTE_RING_QUEUE_FIXED,
609 * Dequeue several objects from a ring (NOT multi-consumers safe).
612 * A pointer to the ring structure.
614 * A pointer to a table of void * pointers (objects) that will be filled.
616 * The number of objects to dequeue from the ring to the obj_table,
617 * must be strictly positive.
619 * If non-NULL, returns the number of remaining ring entries after the
620 * dequeue has finished.
622 * The number of objects dequeued, either 0 or n
624 static __rte_always_inline unsigned int
625 rte_ring_sc_dequeue_bulk(struct rte_ring *r, void **obj_table,
626 unsigned int n, unsigned int *available)
628 return __rte_ring_do_dequeue(r, obj_table, n, RTE_RING_QUEUE_FIXED,
633 * Dequeue several objects from a ring.
635 * This function calls the multi-consumers or the single-consumer
636 * version, depending on the default behaviour that was specified at
637 * ring creation time (see flags).
640 * A pointer to the ring structure.
642 * A pointer to a table of void * pointers (objects) that will be filled.
644 * The number of objects to dequeue from the ring to the obj_table.
646 * If non-NULL, returns the number of remaining ring entries after the
647 * dequeue has finished.
649 * The number of objects dequeued, either 0 or n
651 static __rte_always_inline unsigned int
652 rte_ring_dequeue_bulk(struct rte_ring *r, void **obj_table, unsigned int n,
653 unsigned int *available)
655 return __rte_ring_do_dequeue(r, obj_table, n, RTE_RING_QUEUE_FIXED,
656 r->cons.single, available);
660 * Dequeue one object from a ring (multi-consumers safe).
662 * This function uses a "compare and set" instruction to move the
663 * consumer index atomically.
666 * A pointer to the ring structure.
668 * A pointer to a void * pointer (object) that will be filled.
670 * - 0: Success; objects dequeued.
671 * - -ENOENT: Not enough entries in the ring to dequeue; no object is
674 static __rte_always_inline int
675 rte_ring_mc_dequeue(struct rte_ring *r, void **obj_p)
677 return rte_ring_mc_dequeue_bulk(r, obj_p, 1, NULL) ? 0 : -ENOENT;
681 * Dequeue one object from a ring (NOT multi-consumers safe).
684 * A pointer to the ring structure.
686 * A pointer to a void * pointer (object) that will be filled.
688 * - 0: Success; objects dequeued.
689 * - -ENOENT: Not enough entries in the ring to dequeue, no object is
692 static __rte_always_inline int
693 rte_ring_sc_dequeue(struct rte_ring *r, void **obj_p)
695 return rte_ring_sc_dequeue_bulk(r, obj_p, 1, NULL) ? 0 : -ENOENT;
699 * Dequeue one object from a ring.
701 * This function calls the multi-consumers or the single-consumer
702 * version depending on the default behaviour that was specified at
703 * ring creation time (see flags).
706 * A pointer to the ring structure.
708 * A pointer to a void * pointer (object) that will be filled.
710 * - 0: Success, objects dequeued.
711 * - -ENOENT: Not enough entries in the ring to dequeue, no object is
714 static __rte_always_inline int
715 rte_ring_dequeue(struct rte_ring *r, void **obj_p)
717 return rte_ring_dequeue_bulk(r, obj_p, 1, NULL) ? 0 : -ENOENT;
721 * Return the number of entries in a ring.
724 * A pointer to the ring structure.
726 * The number of entries in the ring.
728 static inline unsigned
729 rte_ring_count(const struct rte_ring *r)
731 uint32_t prod_tail = r->prod.tail;
732 uint32_t cons_tail = r->cons.tail;
733 uint32_t count = (prod_tail - cons_tail) & r->mask;
734 return (count > r->capacity) ? r->capacity : count;
738 * Return the number of free entries in a ring.
741 * A pointer to the ring structure.
743 * The number of free entries in the ring.
745 static inline unsigned
746 rte_ring_free_count(const struct rte_ring *r)
748 return r->capacity - rte_ring_count(r);
752 * Test if a ring is full.
755 * A pointer to the ring structure.
757 * - 1: The ring is full.
758 * - 0: The ring is not full.
761 rte_ring_full(const struct rte_ring *r)
763 return rte_ring_free_count(r) == 0;
767 * Test if a ring is empty.
770 * A pointer to the ring structure.
772 * - 1: The ring is empty.
773 * - 0: The ring is not empty.
776 rte_ring_empty(const struct rte_ring *r)
778 return rte_ring_count(r) == 0;
782 * Return the size of the ring.
785 * A pointer to the ring structure.
787 * The size of the data store used by the ring.
788 * NOTE: this is not the same as the usable space in the ring. To query that
789 * use ``rte_ring_get_capacity()``.
791 static inline unsigned int
792 rte_ring_get_size(const struct rte_ring *r)
798 * Return the number of elements which can be stored in the ring.
801 * A pointer to the ring structure.
803 * The usable size of the ring.
805 static inline unsigned int
806 rte_ring_get_capacity(const struct rte_ring *r)
812 * Dump the status of all rings on the console
815 * A pointer to a file for output
817 void rte_ring_list_dump(FILE *f);
820 * Search a ring from its name
823 * The name of the ring.
825 * The pointer to the ring matching the name, or NULL if not found,
826 * with rte_errno set appropriately. Possible rte_errno values include:
827 * - ENOENT - required entry not available to return.
829 struct rte_ring *rte_ring_lookup(const char *name);
832 * Enqueue several objects on the ring (multi-producers safe).
834 * This function uses a "compare and set" instruction to move the
835 * producer index atomically.
838 * A pointer to the ring structure.
840 * A pointer to a table of void * pointers (objects).
842 * The number of objects to add in the ring from the obj_table.
844 * if non-NULL, returns the amount of space in the ring after the
845 * enqueue operation has finished.
847 * - n: Actual number of objects enqueued.
849 static __rte_always_inline unsigned
850 rte_ring_mp_enqueue_burst(struct rte_ring *r, void * const *obj_table,
851 unsigned int n, unsigned int *free_space)
853 return __rte_ring_do_enqueue(r, obj_table, n,
854 RTE_RING_QUEUE_VARIABLE, __IS_MP, free_space);
858 * Enqueue several objects on a ring (NOT multi-producers safe).
861 * A pointer to the ring structure.
863 * A pointer to a table of void * pointers (objects).
865 * The number of objects to add in the ring from the obj_table.
867 * if non-NULL, returns the amount of space in the ring after the
868 * enqueue operation has finished.
870 * - n: Actual number of objects enqueued.
872 static __rte_always_inline unsigned
873 rte_ring_sp_enqueue_burst(struct rte_ring *r, void * const *obj_table,
874 unsigned int n, unsigned int *free_space)
876 return __rte_ring_do_enqueue(r, obj_table, n,
877 RTE_RING_QUEUE_VARIABLE, __IS_SP, free_space);
881 * Enqueue several objects on a ring.
883 * This function calls the multi-producer or the single-producer
884 * version depending on the default behavior that was specified at
885 * ring creation time (see flags).
888 * A pointer to the ring structure.
890 * A pointer to a table of void * pointers (objects).
892 * The number of objects to add in the ring from the obj_table.
894 * if non-NULL, returns the amount of space in the ring after the
895 * enqueue operation has finished.
897 * - n: Actual number of objects enqueued.
899 static __rte_always_inline unsigned
900 rte_ring_enqueue_burst(struct rte_ring *r, void * const *obj_table,
901 unsigned int n, unsigned int *free_space)
903 return __rte_ring_do_enqueue(r, obj_table, n, RTE_RING_QUEUE_VARIABLE,
904 r->prod.single, free_space);
908 * Dequeue several objects from a ring (multi-consumers safe). When the request
909 * objects are more than the available objects, only dequeue the actual number
912 * This function uses a "compare and set" instruction to move the
913 * consumer index atomically.
916 * A pointer to the ring structure.
918 * A pointer to a table of void * pointers (objects) that will be filled.
920 * The number of objects to dequeue from the ring to the obj_table.
922 * If non-NULL, returns the number of remaining ring entries after the
923 * dequeue has finished.
925 * - n: Actual number of objects dequeued, 0 if ring is empty
927 static __rte_always_inline unsigned
928 rte_ring_mc_dequeue_burst(struct rte_ring *r, void **obj_table,
929 unsigned int n, unsigned int *available)
931 return __rte_ring_do_dequeue(r, obj_table, n,
932 RTE_RING_QUEUE_VARIABLE, __IS_MC, available);
936 * Dequeue several objects from a ring (NOT multi-consumers safe).When the
937 * request objects are more than the available objects, only dequeue the
938 * actual number of objects
941 * A pointer to the ring structure.
943 * A pointer to a table of void * pointers (objects) that will be filled.
945 * The number of objects to dequeue from the ring to the obj_table.
947 * If non-NULL, returns the number of remaining ring entries after the
948 * dequeue has finished.
950 * - n: Actual number of objects dequeued, 0 if ring is empty
952 static __rte_always_inline unsigned
953 rte_ring_sc_dequeue_burst(struct rte_ring *r, void **obj_table,
954 unsigned int n, unsigned int *available)
956 return __rte_ring_do_dequeue(r, obj_table, n,
957 RTE_RING_QUEUE_VARIABLE, __IS_SC, available);
961 * Dequeue multiple objects from a ring up to a maximum number.
963 * This function calls the multi-consumers or the single-consumer
964 * version, depending on the default behaviour that was specified at
965 * ring creation time (see flags).
968 * A pointer to the ring structure.
970 * A pointer to a table of void * pointers (objects) that will be filled.
972 * The number of objects to dequeue from the ring to the obj_table.
974 * If non-NULL, returns the number of remaining ring entries after the
975 * dequeue has finished.
977 * - Number of objects dequeued
979 static __rte_always_inline unsigned
980 rte_ring_dequeue_burst(struct rte_ring *r, void **obj_table,
981 unsigned int n, unsigned int *available)
983 return __rte_ring_do_dequeue(r, obj_table, n,
984 RTE_RING_QUEUE_VARIABLE,
985 r->cons.single, available);
992 #endif /* _RTE_RING_H_ */