4 * Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
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14 * notice, this list of conditions and the following disclaimer in
15 * the documentation and/or other materials provided with the
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18 * contributors may be used to endorse or promote products derived
19 * from this software without specific prior written permission.
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22 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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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_memory.h>
100 #include <rte_lcore.h>
101 #include <rte_atomic.h>
102 #include <rte_branch_prediction.h>
104 #define RTE_TAILQ_RING_NAME "RTE_RING"
106 enum rte_ring_queue_behavior {
107 RTE_RING_QUEUE_FIXED = 0, /* Enq/Deq a fixed number of items from a ring */
108 RTE_RING_QUEUE_VARIABLE /* Enq/Deq as many items a possible from ring */
111 #ifdef RTE_LIBRTE_RING_DEBUG
113 * A structure that stores the ring statistics (per-lcore).
115 struct rte_ring_debug_stats {
116 uint64_t enq_success_bulk; /**< Successful enqueues number. */
117 uint64_t enq_success_objs; /**< Objects successfully enqueued. */
118 uint64_t enq_quota_bulk; /**< Successful enqueues above watermark. */
119 uint64_t enq_quota_objs; /**< Objects enqueued above watermark. */
120 uint64_t enq_fail_bulk; /**< Failed enqueues number. */
121 uint64_t enq_fail_objs; /**< Objects that failed to be enqueued. */
122 uint64_t deq_success_bulk; /**< Successful dequeues number. */
123 uint64_t deq_success_objs; /**< Objects successfully dequeued. */
124 uint64_t deq_fail_bulk; /**< Failed dequeues number. */
125 uint64_t deq_fail_objs; /**< Objects that failed to be dequeued. */
126 } __rte_cache_aligned;
129 #define RTE_RING_NAMESIZE 32 /**< The maximum length of a ring name. */
130 #define RTE_RING_MZ_PREFIX "RG_"
132 #ifndef RTE_RING_PAUSE_REP_COUNT
133 #define RTE_RING_PAUSE_REP_COUNT 0 /**< Yield after pause num of times, no yield
134 * if RTE_RING_PAUSE_REP not defined. */
137 struct rte_memzone; /* forward declaration, so as not to require memzone.h */
140 * An RTE ring structure.
142 * The producer and the consumer have a head and a tail index. The particularity
143 * of these index is that they are not between 0 and size(ring). These indexes
144 * are between 0 and 2^32, and we mask their value when we access the ring[]
145 * field. Thanks to this assumption, we can do subtractions between 2 index
146 * values in a modulo-32bit base: that's why the overflow of the indexes is not
150 char name[RTE_RING_NAMESIZE]; /**< Name of the ring. */
151 int flags; /**< Flags supplied at creation. */
152 const struct rte_memzone *memzone;
153 /**< Memzone, if any, containing the rte_ring */
155 /** Ring producer status. */
157 uint32_t watermark; /**< Maximum items before EDQUOT. */
158 uint32_t sp_enqueue; /**< True, if single producer. */
159 uint32_t size; /**< Size of ring. */
160 uint32_t mask; /**< Mask (size-1) of ring. */
161 volatile uint32_t head; /**< Producer head. */
162 volatile uint32_t tail; /**< Producer tail. */
163 } prod __rte_cache_aligned;
165 /** Ring consumer status. */
167 uint32_t sc_dequeue; /**< True, if single consumer. */
168 uint32_t size; /**< Size of the ring. */
169 uint32_t mask; /**< Mask (size-1) of ring. */
170 volatile uint32_t head; /**< Consumer head. */
171 volatile uint32_t tail; /**< Consumer tail. */
172 #ifdef RTE_RING_SPLIT_PROD_CONS
173 } cons __rte_cache_aligned;
178 #ifdef RTE_LIBRTE_RING_DEBUG
179 struct rte_ring_debug_stats stats[RTE_MAX_LCORE];
182 void * ring[0] __rte_cache_aligned; /**< Memory space of ring starts here.
183 * not volatile so need to be careful
184 * about compiler re-ordering */
187 #define RING_F_SP_ENQ 0x0001 /**< The default enqueue is "single-producer". */
188 #define RING_F_SC_DEQ 0x0002 /**< The default dequeue is "single-consumer". */
189 #define RTE_RING_QUOT_EXCEED (1 << 31) /**< Quota exceed for burst ops */
190 #define RTE_RING_SZ_MASK (unsigned)(0x0fffffff) /**< Ring size mask */
193 * @internal When debug is enabled, store ring statistics.
195 * A pointer to the ring.
197 * The name of the statistics field to increment in the ring.
199 * The number to add to the object-oriented statistics.
201 #ifdef RTE_LIBRTE_RING_DEBUG
202 #define __RING_STAT_ADD(r, name, n) do { \
203 unsigned __lcore_id = rte_lcore_id(); \
204 if (__lcore_id < RTE_MAX_LCORE) { \
205 r->stats[__lcore_id].name##_objs += n; \
206 r->stats[__lcore_id].name##_bulk += 1; \
210 #define __RING_STAT_ADD(r, name, n) do {} while(0)
214 * Calculate the memory size needed for a ring
216 * This function returns the number of bytes needed for a ring, given
217 * the number of elements in it. This value is the sum of the size of
218 * the structure rte_ring and the size of the memory needed by the
219 * objects pointers. The value is aligned to a cache line size.
222 * The number of elements in the ring (must be a power of 2).
224 * - The memory size needed for the ring on success.
225 * - -EINVAL if count is not a power of 2.
227 ssize_t rte_ring_get_memsize(unsigned count);
230 * Initialize a ring structure.
232 * Initialize a ring structure in memory pointed by "r". The size of the
233 * memory area must be large enough to store the ring structure and the
234 * object table. It is advised to use rte_ring_get_memsize() to get the
237 * The ring size is set to *count*, which must be a power of two. Water
238 * marking is disabled by default. The real usable ring size is
239 * *count-1* instead of *count* to differentiate a free ring from an
242 * The ring is not added in RTE_TAILQ_RING global list. Indeed, the
243 * memory given by the caller may not be shareable among dpdk
247 * The pointer to the ring structure followed by the objects table.
249 * The name of the ring.
251 * The number of elements in the ring (must be a power of 2).
253 * An OR of the following:
254 * - RING_F_SP_ENQ: If this flag is set, the default behavior when
255 * using ``rte_ring_enqueue()`` or ``rte_ring_enqueue_bulk()``
256 * is "single-producer". Otherwise, it is "multi-producers".
257 * - RING_F_SC_DEQ: If this flag is set, the default behavior when
258 * using ``rte_ring_dequeue()`` or ``rte_ring_dequeue_bulk()``
259 * is "single-consumer". Otherwise, it is "multi-consumers".
261 * 0 on success, or a negative value on error.
263 int rte_ring_init(struct rte_ring *r, const char *name, unsigned count,
267 * Create a new ring named *name* in memory.
269 * This function uses ``memzone_reserve()`` to allocate memory. Then it
270 * calls rte_ring_init() to initialize an empty ring.
272 * The new ring size is set to *count*, which must be a power of
273 * two. Water marking is disabled by default. The real usable ring size
274 * is *count-1* instead of *count* to differentiate a free ring from an
277 * The ring is added in RTE_TAILQ_RING list.
280 * The name of the ring.
282 * The size of the ring (must be a power of 2).
284 * The *socket_id* argument is the socket identifier in case of
285 * NUMA. The value can be *SOCKET_ID_ANY* if there is no NUMA
286 * constraint for the reserved zone.
288 * An OR of the following:
289 * - RING_F_SP_ENQ: If this flag is set, the default behavior when
290 * using ``rte_ring_enqueue()`` or ``rte_ring_enqueue_bulk()``
291 * is "single-producer". Otherwise, it is "multi-producers".
292 * - RING_F_SC_DEQ: If this flag is set, the default behavior when
293 * using ``rte_ring_dequeue()`` or ``rte_ring_dequeue_bulk()``
294 * is "single-consumer". Otherwise, it is "multi-consumers".
296 * On success, the pointer to the new allocated ring. NULL on error with
297 * rte_errno set appropriately. Possible errno values include:
298 * - E_RTE_NO_CONFIG - function could not get pointer to rte_config structure
299 * - E_RTE_SECONDARY - function was called from a secondary process instance
300 * - EINVAL - count provided is not a power of 2
301 * - ENOSPC - the maximum number of memzones has already been allocated
302 * - EEXIST - a memzone with the same name already exists
303 * - ENOMEM - no appropriate memory area found in which to create memzone
305 struct rte_ring *rte_ring_create(const char *name, unsigned count,
306 int socket_id, unsigned flags);
309 * Change the high water mark.
311 * If *count* is 0, water marking is disabled. Otherwise, it is set to the
312 * *count* value. The *count* value must be greater than 0 and less
313 * than the ring size.
315 * This function can be called at any time (not necessarily at
319 * A pointer to the ring structure.
321 * The new water mark value.
323 * - 0: Success; water mark changed.
324 * - -EINVAL: Invalid water mark value.
326 int rte_ring_set_water_mark(struct rte_ring *r, unsigned count);
329 * Dump the status of the ring to the console.
332 * A pointer to a file for output
334 * A pointer to the ring structure.
336 void rte_ring_dump(FILE *f, const struct rte_ring *r);
338 /* the actual enqueue of pointers on the ring.
339 * Placed here since identical code needed in both
340 * single and multi producer enqueue functions */
341 #define ENQUEUE_PTRS() do { \
342 const uint32_t size = r->prod.size; \
343 uint32_t idx = prod_head & mask; \
344 if (likely(idx + n < size)) { \
345 for (i = 0; i < (n & ((~(unsigned)0x3))); i+=4, idx+=4) { \
346 r->ring[idx] = obj_table[i]; \
347 r->ring[idx+1] = obj_table[i+1]; \
348 r->ring[idx+2] = obj_table[i+2]; \
349 r->ring[idx+3] = obj_table[i+3]; \
352 case 3: r->ring[idx++] = obj_table[i++]; \
353 case 2: r->ring[idx++] = obj_table[i++]; \
354 case 1: r->ring[idx++] = obj_table[i++]; \
357 for (i = 0; idx < size; i++, idx++)\
358 r->ring[idx] = obj_table[i]; \
359 for (idx = 0; i < n; i++, idx++) \
360 r->ring[idx] = obj_table[i]; \
364 /* the actual copy of pointers on the ring to obj_table.
365 * Placed here since identical code needed in both
366 * single and multi consumer dequeue functions */
367 #define DEQUEUE_PTRS() do { \
368 uint32_t idx = cons_head & mask; \
369 const uint32_t size = r->cons.size; \
370 if (likely(idx + n < size)) { \
371 for (i = 0; i < (n & (~(unsigned)0x3)); i+=4, idx+=4) {\
372 obj_table[i] = r->ring[idx]; \
373 obj_table[i+1] = r->ring[idx+1]; \
374 obj_table[i+2] = r->ring[idx+2]; \
375 obj_table[i+3] = r->ring[idx+3]; \
378 case 3: obj_table[i++] = r->ring[idx++]; \
379 case 2: obj_table[i++] = r->ring[idx++]; \
380 case 1: obj_table[i++] = r->ring[idx++]; \
383 for (i = 0; idx < size; i++, idx++) \
384 obj_table[i] = r->ring[idx]; \
385 for (idx = 0; i < n; i++, idx++) \
386 obj_table[i] = r->ring[idx]; \
391 * @internal Enqueue several objects on the ring (multi-producers safe).
393 * This function uses a "compare and set" instruction to move the
394 * producer index atomically.
397 * A pointer to the ring structure.
399 * A pointer to a table of void * pointers (objects).
401 * The number of objects to add in the ring from the obj_table.
403 * RTE_RING_QUEUE_FIXED: Enqueue a fixed number of items from a ring
404 * RTE_RING_QUEUE_VARIABLE: Enqueue as many items a possible from ring
406 * Depend on the behavior value
407 * if behavior = RTE_RING_QUEUE_FIXED
408 * - 0: Success; objects enqueue.
409 * - -EDQUOT: Quota exceeded. The objects have been enqueued, but the
410 * high water mark is exceeded.
411 * - -ENOBUFS: Not enough room in the ring to enqueue, no object is enqueued.
412 * if behavior = RTE_RING_QUEUE_VARIABLE
413 * - n: Actual number of objects enqueued.
415 static inline int __attribute__((always_inline))
416 __rte_ring_mp_do_enqueue(struct rte_ring *r, void * const *obj_table,
417 unsigned n, enum rte_ring_queue_behavior behavior)
419 uint32_t prod_head, prod_next;
420 uint32_t cons_tail, free_entries;
421 const unsigned max = n;
424 uint32_t mask = r->prod.mask;
427 /* move prod.head atomically */
429 /* Reset n to the initial burst count */
432 prod_head = r->prod.head;
433 cons_tail = r->cons.tail;
434 /* The subtraction is done between two unsigned 32bits value
435 * (the result is always modulo 32 bits even if we have
436 * prod_head > cons_tail). So 'free_entries' is always between 0
437 * and size(ring)-1. */
438 free_entries = (mask + cons_tail - prod_head);
440 /* check that we have enough room in ring */
441 if (unlikely(n > free_entries)) {
442 if (behavior == RTE_RING_QUEUE_FIXED) {
443 __RING_STAT_ADD(r, enq_fail, n);
447 /* No free entry available */
448 if (unlikely(free_entries == 0)) {
449 __RING_STAT_ADD(r, enq_fail, n);
457 prod_next = prod_head + n;
458 success = rte_atomic32_cmpset(&r->prod.head, prod_head,
460 } while (unlikely(success == 0));
462 /* write entries in ring */
464 rte_compiler_barrier();
466 /* if we exceed the watermark */
467 if (unlikely(((mask + 1) - free_entries + n) > r->prod.watermark)) {
468 ret = (behavior == RTE_RING_QUEUE_FIXED) ? -EDQUOT :
469 (int)(n | RTE_RING_QUOT_EXCEED);
470 __RING_STAT_ADD(r, enq_quota, n);
473 ret = (behavior == RTE_RING_QUEUE_FIXED) ? 0 : n;
474 __RING_STAT_ADD(r, enq_success, n);
478 * If there are other enqueues in progress that preceded us,
479 * we need to wait for them to complete
481 while (unlikely(r->prod.tail != prod_head)) {
484 /* Set RTE_RING_PAUSE_REP_COUNT to avoid spin too long waiting
485 * for other thread finish. It gives pre-empted thread a chance
486 * to proceed and finish with ring dequeue operation. */
487 if (RTE_RING_PAUSE_REP_COUNT &&
488 ++rep == RTE_RING_PAUSE_REP_COUNT) {
493 r->prod.tail = prod_next;
498 * @internal Enqueue several objects on a ring (NOT multi-producers safe).
501 * A pointer to the ring structure.
503 * A pointer to a table of void * pointers (objects).
505 * The number of objects to add in the ring from the obj_table.
507 * RTE_RING_QUEUE_FIXED: Enqueue a fixed number of items from a ring
508 * RTE_RING_QUEUE_VARIABLE: Enqueue as many items a possible from ring
510 * Depend on the behavior value
511 * if behavior = RTE_RING_QUEUE_FIXED
512 * - 0: Success; objects enqueue.
513 * - -EDQUOT: Quota exceeded. The objects have been enqueued, but the
514 * high water mark is exceeded.
515 * - -ENOBUFS: Not enough room in the ring to enqueue, no object is enqueued.
516 * if behavior = RTE_RING_QUEUE_VARIABLE
517 * - n: Actual number of objects enqueued.
519 static inline int __attribute__((always_inline))
520 __rte_ring_sp_do_enqueue(struct rte_ring *r, void * const *obj_table,
521 unsigned n, enum rte_ring_queue_behavior behavior)
523 uint32_t prod_head, cons_tail;
524 uint32_t prod_next, free_entries;
526 uint32_t mask = r->prod.mask;
529 prod_head = r->prod.head;
530 cons_tail = r->cons.tail;
531 /* The subtraction is done between two unsigned 32bits value
532 * (the result is always modulo 32 bits even if we have
533 * prod_head > cons_tail). So 'free_entries' is always between 0
534 * and size(ring)-1. */
535 free_entries = mask + cons_tail - prod_head;
537 /* check that we have enough room in ring */
538 if (unlikely(n > free_entries)) {
539 if (behavior == RTE_RING_QUEUE_FIXED) {
540 __RING_STAT_ADD(r, enq_fail, n);
544 /* No free entry available */
545 if (unlikely(free_entries == 0)) {
546 __RING_STAT_ADD(r, enq_fail, n);
554 prod_next = prod_head + n;
555 r->prod.head = prod_next;
557 /* write entries in ring */
559 rte_compiler_barrier();
561 /* if we exceed the watermark */
562 if (unlikely(((mask + 1) - free_entries + n) > r->prod.watermark)) {
563 ret = (behavior == RTE_RING_QUEUE_FIXED) ? -EDQUOT :
564 (int)(n | RTE_RING_QUOT_EXCEED);
565 __RING_STAT_ADD(r, enq_quota, n);
568 ret = (behavior == RTE_RING_QUEUE_FIXED) ? 0 : n;
569 __RING_STAT_ADD(r, enq_success, n);
572 r->prod.tail = prod_next;
577 * @internal Dequeue several objects from a ring (multi-consumers safe). When
578 * the request objects are more than the available objects, only dequeue the
579 * actual number of objects
581 * This function uses a "compare and set" instruction to move the
582 * consumer index atomically.
585 * A pointer to the ring structure.
587 * A pointer to a table of void * pointers (objects) that will be filled.
589 * The number of objects to dequeue from the ring to the obj_table.
591 * RTE_RING_QUEUE_FIXED: Dequeue a fixed number of items from a ring
592 * RTE_RING_QUEUE_VARIABLE: Dequeue as many items a possible from ring
594 * Depend on the behavior value
595 * if behavior = RTE_RING_QUEUE_FIXED
596 * - 0: Success; objects dequeued.
597 * - -ENOENT: Not enough entries in the ring to dequeue; no object is
599 * if behavior = RTE_RING_QUEUE_VARIABLE
600 * - n: Actual number of objects dequeued.
603 static inline int __attribute__((always_inline))
604 __rte_ring_mc_do_dequeue(struct rte_ring *r, void **obj_table,
605 unsigned n, enum rte_ring_queue_behavior behavior)
607 uint32_t cons_head, prod_tail;
608 uint32_t cons_next, entries;
609 const unsigned max = n;
612 uint32_t mask = r->prod.mask;
614 /* move cons.head atomically */
616 /* Restore n as it may change every loop */
619 cons_head = r->cons.head;
620 prod_tail = r->prod.tail;
621 /* The subtraction is done between two unsigned 32bits value
622 * (the result is always modulo 32 bits even if we have
623 * cons_head > prod_tail). So 'entries' is always between 0
624 * and size(ring)-1. */
625 entries = (prod_tail - cons_head);
627 /* Set the actual entries for dequeue */
629 if (behavior == RTE_RING_QUEUE_FIXED) {
630 __RING_STAT_ADD(r, deq_fail, n);
634 if (unlikely(entries == 0)){
635 __RING_STAT_ADD(r, deq_fail, n);
643 cons_next = cons_head + n;
644 success = rte_atomic32_cmpset(&r->cons.head, cons_head,
646 } while (unlikely(success == 0));
650 rte_compiler_barrier();
653 * If there are other dequeues in progress that preceded us,
654 * we need to wait for them to complete
656 while (unlikely(r->cons.tail != cons_head)) {
659 /* Set RTE_RING_PAUSE_REP_COUNT to avoid spin too long waiting
660 * for other thread finish. It gives pre-empted thread a chance
661 * to proceed and finish with ring dequeue operation. */
662 if (RTE_RING_PAUSE_REP_COUNT &&
663 ++rep == RTE_RING_PAUSE_REP_COUNT) {
668 __RING_STAT_ADD(r, deq_success, n);
669 r->cons.tail = cons_next;
671 return behavior == RTE_RING_QUEUE_FIXED ? 0 : n;
675 * @internal Dequeue several objects from a ring (NOT multi-consumers safe).
676 * When the request objects are more than the available objects, only dequeue
677 * the actual number of objects
680 * A pointer to the ring structure.
682 * A pointer to a table of void * pointers (objects) that will be filled.
684 * The number of objects to dequeue from the ring to the obj_table.
686 * RTE_RING_QUEUE_FIXED: Dequeue a fixed number of items from a ring
687 * RTE_RING_QUEUE_VARIABLE: Dequeue as many items a possible from ring
689 * Depend on the behavior value
690 * if behavior = RTE_RING_QUEUE_FIXED
691 * - 0: Success; objects dequeued.
692 * - -ENOENT: Not enough entries in the ring to dequeue; no object is
694 * if behavior = RTE_RING_QUEUE_VARIABLE
695 * - n: Actual number of objects dequeued.
697 static inline int __attribute__((always_inline))
698 __rte_ring_sc_do_dequeue(struct rte_ring *r, void **obj_table,
699 unsigned n, enum rte_ring_queue_behavior behavior)
701 uint32_t cons_head, prod_tail;
702 uint32_t cons_next, entries;
704 uint32_t mask = r->prod.mask;
706 cons_head = r->cons.head;
707 prod_tail = r->prod.tail;
708 /* The subtraction is done between two unsigned 32bits value
709 * (the result is always modulo 32 bits even if we have
710 * cons_head > prod_tail). So 'entries' is always between 0
711 * and size(ring)-1. */
712 entries = prod_tail - cons_head;
715 if (behavior == RTE_RING_QUEUE_FIXED) {
716 __RING_STAT_ADD(r, deq_fail, n);
720 if (unlikely(entries == 0)){
721 __RING_STAT_ADD(r, deq_fail, n);
729 cons_next = cons_head + n;
730 r->cons.head = cons_next;
734 rte_compiler_barrier();
736 __RING_STAT_ADD(r, deq_success, n);
737 r->cons.tail = cons_next;
738 return behavior == RTE_RING_QUEUE_FIXED ? 0 : n;
742 * Enqueue several objects on the ring (multi-producers safe).
744 * This function uses a "compare and set" instruction to move the
745 * producer index atomically.
748 * A pointer to the ring structure.
750 * A pointer to a table of void * pointers (objects).
752 * The number of objects to add in the ring from the obj_table.
754 * - 0: Success; objects enqueue.
755 * - -EDQUOT: Quota exceeded. The objects have been enqueued, but the
756 * high water mark is exceeded.
757 * - -ENOBUFS: Not enough room in the ring to enqueue, no object is enqueued.
759 static inline int __attribute__((always_inline))
760 rte_ring_mp_enqueue_bulk(struct rte_ring *r, void * const *obj_table,
763 return __rte_ring_mp_do_enqueue(r, obj_table, n, RTE_RING_QUEUE_FIXED);
767 * Enqueue several objects on a ring (NOT multi-producers safe).
770 * A pointer to the ring structure.
772 * A pointer to a table of void * pointers (objects).
774 * The number of objects to add in the ring from the obj_table.
776 * - 0: Success; objects enqueued.
777 * - -EDQUOT: Quota exceeded. The objects have been enqueued, but the
778 * high water mark is exceeded.
779 * - -ENOBUFS: Not enough room in the ring to enqueue; no object is enqueued.
781 static inline int __attribute__((always_inline))
782 rte_ring_sp_enqueue_bulk(struct rte_ring *r, void * const *obj_table,
785 return __rte_ring_sp_do_enqueue(r, obj_table, n, RTE_RING_QUEUE_FIXED);
789 * Enqueue several objects on a ring.
791 * This function calls the multi-producer or the single-producer
792 * version depending on the default behavior that was specified at
793 * ring creation time (see flags).
796 * A pointer to the ring structure.
798 * A pointer to a table of void * pointers (objects).
800 * The number of objects to add in the ring from the obj_table.
802 * - 0: Success; objects enqueued.
803 * - -EDQUOT: Quota exceeded. The objects have been enqueued, but the
804 * high water mark is exceeded.
805 * - -ENOBUFS: Not enough room in the ring to enqueue; no object is enqueued.
807 static inline int __attribute__((always_inline))
808 rte_ring_enqueue_bulk(struct rte_ring *r, void * const *obj_table,
811 if (r->prod.sp_enqueue)
812 return rte_ring_sp_enqueue_bulk(r, obj_table, n);
814 return rte_ring_mp_enqueue_bulk(r, obj_table, n);
818 * Enqueue one object on a ring (multi-producers safe).
820 * This function uses a "compare and set" instruction to move the
821 * producer index atomically.
824 * A pointer to the ring structure.
826 * A pointer to the object to be added.
828 * - 0: Success; objects enqueued.
829 * - -EDQUOT: Quota exceeded. The objects have been enqueued, but the
830 * high water mark is exceeded.
831 * - -ENOBUFS: Not enough room in the ring to enqueue; no object is enqueued.
833 static inline int __attribute__((always_inline))
834 rte_ring_mp_enqueue(struct rte_ring *r, void *obj)
836 return rte_ring_mp_enqueue_bulk(r, &obj, 1);
840 * Enqueue one object on a ring (NOT multi-producers safe).
843 * A pointer to the ring structure.
845 * A pointer to the object to be added.
847 * - 0: Success; objects enqueued.
848 * - -EDQUOT: Quota exceeded. The objects have been enqueued, but the
849 * high water mark is exceeded.
850 * - -ENOBUFS: Not enough room in the ring to enqueue; no object is enqueued.
852 static inline int __attribute__((always_inline))
853 rte_ring_sp_enqueue(struct rte_ring *r, void *obj)
855 return rte_ring_sp_enqueue_bulk(r, &obj, 1);
859 * Enqueue one object on a ring.
861 * This function calls the multi-producer or the single-producer
862 * version, depending on the default behaviour that was specified at
863 * ring creation time (see flags).
866 * A pointer to the ring structure.
868 * A pointer to the object to be added.
870 * - 0: Success; objects enqueued.
871 * - -EDQUOT: Quota exceeded. The objects have been enqueued, but the
872 * high water mark is exceeded.
873 * - -ENOBUFS: Not enough room in the ring to enqueue; no object is enqueued.
875 static inline int __attribute__((always_inline))
876 rte_ring_enqueue(struct rte_ring *r, void *obj)
878 if (r->prod.sp_enqueue)
879 return rte_ring_sp_enqueue(r, obj);
881 return rte_ring_mp_enqueue(r, obj);
885 * Dequeue several objects from a ring (multi-consumers safe).
887 * This function uses a "compare and set" instruction to move the
888 * consumer index atomically.
891 * A pointer to the ring structure.
893 * A pointer to a table of void * pointers (objects) that will be filled.
895 * The number of objects to dequeue from the ring to the obj_table.
897 * - 0: Success; objects dequeued.
898 * - -ENOENT: Not enough entries in the ring to dequeue; no object is
901 static inline int __attribute__((always_inline))
902 rte_ring_mc_dequeue_bulk(struct rte_ring *r, void **obj_table, unsigned n)
904 return __rte_ring_mc_do_dequeue(r, obj_table, n, RTE_RING_QUEUE_FIXED);
908 * Dequeue several objects from a ring (NOT multi-consumers safe).
911 * A pointer to the ring structure.
913 * A pointer to a table of void * pointers (objects) that will be filled.
915 * The number of objects to dequeue from the ring to the obj_table,
916 * must be strictly positive.
918 * - 0: Success; objects dequeued.
919 * - -ENOENT: Not enough entries in the ring to dequeue; no object is
922 static inline int __attribute__((always_inline))
923 rte_ring_sc_dequeue_bulk(struct rte_ring *r, void **obj_table, unsigned n)
925 return __rte_ring_sc_do_dequeue(r, obj_table, n, RTE_RING_QUEUE_FIXED);
929 * Dequeue several objects from a ring.
931 * This function calls the multi-consumers or the single-consumer
932 * version, depending on the default behaviour that was specified at
933 * ring creation time (see flags).
936 * A pointer to the ring structure.
938 * A pointer to a table of void * pointers (objects) that will be filled.
940 * The number of objects to dequeue from the ring to the obj_table.
942 * - 0: Success; objects dequeued.
943 * - -ENOENT: Not enough entries in the ring to dequeue, no object is
946 static inline int __attribute__((always_inline))
947 rte_ring_dequeue_bulk(struct rte_ring *r, void **obj_table, unsigned n)
949 if (r->cons.sc_dequeue)
950 return rte_ring_sc_dequeue_bulk(r, obj_table, n);
952 return rte_ring_mc_dequeue_bulk(r, obj_table, n);
956 * Dequeue one object from a ring (multi-consumers safe).
958 * This function uses a "compare and set" instruction to move the
959 * consumer index atomically.
962 * A pointer to the ring structure.
964 * A pointer to a void * pointer (object) that will be filled.
966 * - 0: Success; objects dequeued.
967 * - -ENOENT: Not enough entries in the ring to dequeue; no object is
970 static inline int __attribute__((always_inline))
971 rte_ring_mc_dequeue(struct rte_ring *r, void **obj_p)
973 return rte_ring_mc_dequeue_bulk(r, obj_p, 1);
977 * Dequeue one object from a ring (NOT multi-consumers safe).
980 * A pointer to the ring structure.
982 * A pointer to a void * pointer (object) that will be filled.
984 * - 0: Success; objects dequeued.
985 * - -ENOENT: Not enough entries in the ring to dequeue, no object is
988 static inline int __attribute__((always_inline))
989 rte_ring_sc_dequeue(struct rte_ring *r, void **obj_p)
991 return rte_ring_sc_dequeue_bulk(r, obj_p, 1);
995 * Dequeue one object from a ring.
997 * This function calls the multi-consumers or the single-consumer
998 * version depending on the default behaviour that was specified at
999 * ring creation time (see flags).
1002 * A pointer to the ring structure.
1004 * A pointer to a void * pointer (object) that will be filled.
1006 * - 0: Success, objects dequeued.
1007 * - -ENOENT: Not enough entries in the ring to dequeue, no object is
1010 static inline int __attribute__((always_inline))
1011 rte_ring_dequeue(struct rte_ring *r, void **obj_p)
1013 if (r->cons.sc_dequeue)
1014 return rte_ring_sc_dequeue(r, obj_p);
1016 return rte_ring_mc_dequeue(r, obj_p);
1020 * Test if a ring is full.
1023 * A pointer to the ring structure.
1025 * - 1: The ring is full.
1026 * - 0: The ring is not full.
1029 rte_ring_full(const struct rte_ring *r)
1031 uint32_t prod_tail = r->prod.tail;
1032 uint32_t cons_tail = r->cons.tail;
1033 return (((cons_tail - prod_tail - 1) & r->prod.mask) == 0);
1037 * Test if a ring is empty.
1040 * A pointer to the ring structure.
1042 * - 1: The ring is empty.
1043 * - 0: The ring is not empty.
1046 rte_ring_empty(const struct rte_ring *r)
1048 uint32_t prod_tail = r->prod.tail;
1049 uint32_t cons_tail = r->cons.tail;
1050 return !!(cons_tail == prod_tail);
1054 * Return the number of entries in a ring.
1057 * A pointer to the ring structure.
1059 * The number of entries in the ring.
1061 static inline unsigned
1062 rte_ring_count(const struct rte_ring *r)
1064 uint32_t prod_tail = r->prod.tail;
1065 uint32_t cons_tail = r->cons.tail;
1066 return ((prod_tail - cons_tail) & r->prod.mask);
1070 * Return the number of free entries in a ring.
1073 * A pointer to the ring structure.
1075 * The number of free entries in the ring.
1077 static inline unsigned
1078 rte_ring_free_count(const struct rte_ring *r)
1080 uint32_t prod_tail = r->prod.tail;
1081 uint32_t cons_tail = r->cons.tail;
1082 return ((cons_tail - prod_tail - 1) & r->prod.mask);
1086 * Dump the status of all rings on the console
1089 * A pointer to a file for output
1091 void rte_ring_list_dump(FILE *f);
1094 * Search a ring from its name
1097 * The name of the ring.
1099 * The pointer to the ring matching the name, or NULL if not found,
1100 * with rte_errno set appropriately. Possible rte_errno values include:
1101 * - ENOENT - required entry not available to return.
1103 struct rte_ring *rte_ring_lookup(const char *name);
1106 * Enqueue several objects on the ring (multi-producers safe).
1108 * This function uses a "compare and set" instruction to move the
1109 * producer index atomically.
1112 * A pointer to the ring structure.
1114 * A pointer to a table of void * pointers (objects).
1116 * The number of objects to add in the ring from the obj_table.
1118 * - n: Actual number of objects enqueued.
1120 static inline unsigned __attribute__((always_inline))
1121 rte_ring_mp_enqueue_burst(struct rte_ring *r, void * const *obj_table,
1124 return __rte_ring_mp_do_enqueue(r, obj_table, n, RTE_RING_QUEUE_VARIABLE);
1128 * Enqueue several objects on a ring (NOT multi-producers safe).
1131 * A pointer to the ring structure.
1133 * A pointer to a table of void * pointers (objects).
1135 * The number of objects to add in the ring from the obj_table.
1137 * - n: Actual number of objects enqueued.
1139 static inline unsigned __attribute__((always_inline))
1140 rte_ring_sp_enqueue_burst(struct rte_ring *r, void * const *obj_table,
1143 return __rte_ring_sp_do_enqueue(r, obj_table, n, RTE_RING_QUEUE_VARIABLE);
1147 * Enqueue several objects on a ring.
1149 * This function calls the multi-producer or the single-producer
1150 * version depending on the default behavior that was specified at
1151 * ring creation time (see flags).
1154 * A pointer to the ring structure.
1156 * A pointer to a table of void * pointers (objects).
1158 * The number of objects to add in the ring from the obj_table.
1160 * - n: Actual number of objects enqueued.
1162 static inline unsigned __attribute__((always_inline))
1163 rte_ring_enqueue_burst(struct rte_ring *r, void * const *obj_table,
1166 if (r->prod.sp_enqueue)
1167 return rte_ring_sp_enqueue_burst(r, obj_table, n);
1169 return rte_ring_mp_enqueue_burst(r, obj_table, n);
1173 * Dequeue several objects from a ring (multi-consumers safe). When the request
1174 * objects are more than the available objects, only dequeue the actual number
1177 * This function uses a "compare and set" instruction to move the
1178 * consumer index atomically.
1181 * A pointer to the ring structure.
1183 * A pointer to a table of void * pointers (objects) that will be filled.
1185 * The number of objects to dequeue from the ring to the obj_table.
1187 * - n: Actual number of objects dequeued, 0 if ring is empty
1189 static inline unsigned __attribute__((always_inline))
1190 rte_ring_mc_dequeue_burst(struct rte_ring *r, void **obj_table, unsigned n)
1192 return __rte_ring_mc_do_dequeue(r, obj_table, n, RTE_RING_QUEUE_VARIABLE);
1196 * Dequeue several objects from a ring (NOT multi-consumers safe).When the
1197 * request objects are more than the available objects, only dequeue the
1198 * actual number of objects
1201 * A pointer to the ring structure.
1203 * A pointer to a table of void * pointers (objects) that will be filled.
1205 * The number of objects to dequeue from the ring to the obj_table.
1207 * - n: Actual number of objects dequeued, 0 if ring is empty
1209 static inline unsigned __attribute__((always_inline))
1210 rte_ring_sc_dequeue_burst(struct rte_ring *r, void **obj_table, unsigned n)
1212 return __rte_ring_sc_do_dequeue(r, obj_table, n, RTE_RING_QUEUE_VARIABLE);
1216 * Dequeue multiple objects from a ring up to a maximum number.
1218 * This function calls the multi-consumers or the single-consumer
1219 * version, depending on the default behaviour that was specified at
1220 * ring creation time (see flags).
1223 * A pointer to the ring structure.
1225 * A pointer to a table of void * pointers (objects) that will be filled.
1227 * The number of objects to dequeue from the ring to the obj_table.
1229 * - Number of objects dequeued
1231 static inline unsigned __attribute__((always_inline))
1232 rte_ring_dequeue_burst(struct rte_ring *r, void **obj_table, unsigned n)
1234 if (r->cons.sc_dequeue)
1235 return rte_ring_sc_dequeue_burst(r, obj_table, n);
1237 return rte_ring_mc_dequeue_burst(r, obj_table, n);
1244 #endif /* _RTE_RING_H_ */