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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);
308 * De-allocate all memory used by the ring.
313 void rte_ring_free(struct rte_ring *r);
316 * Change the high water mark.
318 * If *count* is 0, water marking is disabled. Otherwise, it is set to the
319 * *count* value. The *count* value must be greater than 0 and less
320 * than the ring size.
322 * This function can be called at any time (not necessarily at
326 * A pointer to the ring structure.
328 * The new water mark value.
330 * - 0: Success; water mark changed.
331 * - -EINVAL: Invalid water mark value.
333 int rte_ring_set_water_mark(struct rte_ring *r, unsigned count);
336 * Dump the status of the ring to the console.
339 * A pointer to a file for output
341 * A pointer to the ring structure.
343 void rte_ring_dump(FILE *f, const struct rte_ring *r);
345 /* the actual enqueue of pointers on the ring.
346 * Placed here since identical code needed in both
347 * single and multi producer enqueue functions */
348 #define ENQUEUE_PTRS() do { \
349 const uint32_t size = r->prod.size; \
350 uint32_t idx = prod_head & mask; \
351 if (likely(idx + n < size)) { \
352 for (i = 0; i < (n & ((~(unsigned)0x3))); i+=4, idx+=4) { \
353 r->ring[idx] = obj_table[i]; \
354 r->ring[idx+1] = obj_table[i+1]; \
355 r->ring[idx+2] = obj_table[i+2]; \
356 r->ring[idx+3] = obj_table[i+3]; \
359 case 3: r->ring[idx++] = obj_table[i++]; \
360 case 2: r->ring[idx++] = obj_table[i++]; \
361 case 1: r->ring[idx++] = obj_table[i++]; \
364 for (i = 0; idx < size; i++, idx++)\
365 r->ring[idx] = obj_table[i]; \
366 for (idx = 0; i < n; i++, idx++) \
367 r->ring[idx] = obj_table[i]; \
371 /* the actual copy of pointers on the ring to obj_table.
372 * Placed here since identical code needed in both
373 * single and multi consumer dequeue functions */
374 #define DEQUEUE_PTRS() do { \
375 uint32_t idx = cons_head & mask; \
376 const uint32_t size = r->cons.size; \
377 if (likely(idx + n < size)) { \
378 for (i = 0; i < (n & (~(unsigned)0x3)); i+=4, idx+=4) {\
379 obj_table[i] = r->ring[idx]; \
380 obj_table[i+1] = r->ring[idx+1]; \
381 obj_table[i+2] = r->ring[idx+2]; \
382 obj_table[i+3] = r->ring[idx+3]; \
385 case 3: obj_table[i++] = r->ring[idx++]; \
386 case 2: obj_table[i++] = r->ring[idx++]; \
387 case 1: obj_table[i++] = r->ring[idx++]; \
390 for (i = 0; idx < size; i++, idx++) \
391 obj_table[i] = r->ring[idx]; \
392 for (idx = 0; i < n; i++, idx++) \
393 obj_table[i] = r->ring[idx]; \
398 * @internal Enqueue several objects on the ring (multi-producers safe).
400 * This function uses a "compare and set" instruction to move the
401 * producer index atomically.
404 * A pointer to the ring structure.
406 * A pointer to a table of void * pointers (objects).
408 * The number of objects to add in the ring from the obj_table.
410 * RTE_RING_QUEUE_FIXED: Enqueue a fixed number of items from a ring
411 * RTE_RING_QUEUE_VARIABLE: Enqueue as many items a possible from ring
413 * Depend on the behavior value
414 * if behavior = RTE_RING_QUEUE_FIXED
415 * - 0: Success; objects enqueue.
416 * - -EDQUOT: Quota exceeded. The objects have been enqueued, but the
417 * high water mark is exceeded.
418 * - -ENOBUFS: Not enough room in the ring to enqueue, no object is enqueued.
419 * if behavior = RTE_RING_QUEUE_VARIABLE
420 * - n: Actual number of objects enqueued.
422 static inline int __attribute__((always_inline))
423 __rte_ring_mp_do_enqueue(struct rte_ring *r, void * const *obj_table,
424 unsigned n, enum rte_ring_queue_behavior behavior)
426 uint32_t prod_head, prod_next;
427 uint32_t cons_tail, free_entries;
428 const unsigned max = n;
431 uint32_t mask = r->prod.mask;
434 /* Avoid the unnecessary cmpset operation below, which is also
435 * potentially harmful when n equals 0. */
439 /* move prod.head atomically */
441 /* Reset n to the initial burst count */
444 prod_head = r->prod.head;
445 cons_tail = r->cons.tail;
446 /* The subtraction is done between two unsigned 32bits value
447 * (the result is always modulo 32 bits even if we have
448 * prod_head > cons_tail). So 'free_entries' is always between 0
449 * and size(ring)-1. */
450 free_entries = (mask + cons_tail - prod_head);
452 /* check that we have enough room in ring */
453 if (unlikely(n > free_entries)) {
454 if (behavior == RTE_RING_QUEUE_FIXED) {
455 __RING_STAT_ADD(r, enq_fail, n);
459 /* No free entry available */
460 if (unlikely(free_entries == 0)) {
461 __RING_STAT_ADD(r, enq_fail, n);
469 prod_next = prod_head + n;
470 success = rte_atomic32_cmpset(&r->prod.head, prod_head,
472 } while (unlikely(success == 0));
474 /* write entries in ring */
478 /* if we exceed the watermark */
479 if (unlikely(((mask + 1) - free_entries + n) > r->prod.watermark)) {
480 ret = (behavior == RTE_RING_QUEUE_FIXED) ? -EDQUOT :
481 (int)(n | RTE_RING_QUOT_EXCEED);
482 __RING_STAT_ADD(r, enq_quota, n);
485 ret = (behavior == RTE_RING_QUEUE_FIXED) ? 0 : n;
486 __RING_STAT_ADD(r, enq_success, n);
490 * If there are other enqueues in progress that preceded us,
491 * we need to wait for them to complete
493 while (unlikely(r->prod.tail != prod_head)) {
496 /* Set RTE_RING_PAUSE_REP_COUNT to avoid spin too long waiting
497 * for other thread finish. It gives pre-empted thread a chance
498 * to proceed and finish with ring dequeue operation. */
499 if (RTE_RING_PAUSE_REP_COUNT &&
500 ++rep == RTE_RING_PAUSE_REP_COUNT) {
505 r->prod.tail = prod_next;
510 * @internal Enqueue several objects on a ring (NOT multi-producers safe).
513 * A pointer to the ring structure.
515 * A pointer to a table of void * pointers (objects).
517 * The number of objects to add in the ring from the obj_table.
519 * RTE_RING_QUEUE_FIXED: Enqueue a fixed number of items from a ring
520 * RTE_RING_QUEUE_VARIABLE: Enqueue as many items a possible from ring
522 * Depend on the behavior value
523 * if behavior = RTE_RING_QUEUE_FIXED
524 * - 0: Success; objects enqueue.
525 * - -EDQUOT: Quota exceeded. The objects have been enqueued, but the
526 * high water mark is exceeded.
527 * - -ENOBUFS: Not enough room in the ring to enqueue, no object is enqueued.
528 * if behavior = RTE_RING_QUEUE_VARIABLE
529 * - n: Actual number of objects enqueued.
531 static inline int __attribute__((always_inline))
532 __rte_ring_sp_do_enqueue(struct rte_ring *r, void * const *obj_table,
533 unsigned n, enum rte_ring_queue_behavior behavior)
535 uint32_t prod_head, cons_tail;
536 uint32_t prod_next, free_entries;
538 uint32_t mask = r->prod.mask;
541 prod_head = r->prod.head;
542 cons_tail = r->cons.tail;
543 /* The subtraction is done between two unsigned 32bits value
544 * (the result is always modulo 32 bits even if we have
545 * prod_head > cons_tail). So 'free_entries' is always between 0
546 * and size(ring)-1. */
547 free_entries = mask + cons_tail - prod_head;
549 /* check that we have enough room in ring */
550 if (unlikely(n > free_entries)) {
551 if (behavior == RTE_RING_QUEUE_FIXED) {
552 __RING_STAT_ADD(r, enq_fail, n);
556 /* No free entry available */
557 if (unlikely(free_entries == 0)) {
558 __RING_STAT_ADD(r, enq_fail, n);
566 prod_next = prod_head + n;
567 r->prod.head = prod_next;
569 /* write entries in ring */
573 /* if we exceed the watermark */
574 if (unlikely(((mask + 1) - free_entries + n) > r->prod.watermark)) {
575 ret = (behavior == RTE_RING_QUEUE_FIXED) ? -EDQUOT :
576 (int)(n | RTE_RING_QUOT_EXCEED);
577 __RING_STAT_ADD(r, enq_quota, n);
580 ret = (behavior == RTE_RING_QUEUE_FIXED) ? 0 : n;
581 __RING_STAT_ADD(r, enq_success, n);
584 r->prod.tail = prod_next;
589 * @internal Dequeue several objects from a ring (multi-consumers safe). When
590 * the request objects are more than the available objects, only dequeue the
591 * actual number of objects
593 * This function uses a "compare and set" instruction to move the
594 * consumer index atomically.
597 * A pointer to the ring structure.
599 * A pointer to a table of void * pointers (objects) that will be filled.
601 * The number of objects to dequeue from the ring to the obj_table.
603 * RTE_RING_QUEUE_FIXED: Dequeue a fixed number of items from a ring
604 * RTE_RING_QUEUE_VARIABLE: Dequeue as many items a possible from ring
606 * Depend on the behavior value
607 * if behavior = RTE_RING_QUEUE_FIXED
608 * - 0: Success; objects dequeued.
609 * - -ENOENT: Not enough entries in the ring to dequeue; no object is
611 * if behavior = RTE_RING_QUEUE_VARIABLE
612 * - n: Actual number of objects dequeued.
615 static inline int __attribute__((always_inline))
616 __rte_ring_mc_do_dequeue(struct rte_ring *r, void **obj_table,
617 unsigned n, enum rte_ring_queue_behavior behavior)
619 uint32_t cons_head, prod_tail;
620 uint32_t cons_next, entries;
621 const unsigned max = n;
624 uint32_t mask = r->prod.mask;
626 /* Avoid the unnecessary cmpset operation below, which is also
627 * potentially harmful when n equals 0. */
631 /* move cons.head atomically */
633 /* Restore n as it may change every loop */
636 cons_head = r->cons.head;
637 prod_tail = r->prod.tail;
638 /* The subtraction is done between two unsigned 32bits value
639 * (the result is always modulo 32 bits even if we have
640 * cons_head > prod_tail). So 'entries' is always between 0
641 * and size(ring)-1. */
642 entries = (prod_tail - cons_head);
644 /* Set the actual entries for dequeue */
646 if (behavior == RTE_RING_QUEUE_FIXED) {
647 __RING_STAT_ADD(r, deq_fail, n);
651 if (unlikely(entries == 0)){
652 __RING_STAT_ADD(r, deq_fail, n);
660 cons_next = cons_head + n;
661 success = rte_atomic32_cmpset(&r->cons.head, cons_head,
663 } while (unlikely(success == 0));
670 * If there are other dequeues in progress that preceded us,
671 * we need to wait for them to complete
673 while (unlikely(r->cons.tail != cons_head)) {
676 /* Set RTE_RING_PAUSE_REP_COUNT to avoid spin too long waiting
677 * for other thread finish. It gives pre-empted thread a chance
678 * to proceed and finish with ring dequeue operation. */
679 if (RTE_RING_PAUSE_REP_COUNT &&
680 ++rep == RTE_RING_PAUSE_REP_COUNT) {
685 __RING_STAT_ADD(r, deq_success, n);
686 r->cons.tail = cons_next;
688 return behavior == RTE_RING_QUEUE_FIXED ? 0 : n;
692 * @internal Dequeue several objects from a ring (NOT multi-consumers safe).
693 * When the request objects are more than the available objects, only dequeue
694 * the actual number of objects
697 * A pointer to the ring structure.
699 * A pointer to a table of void * pointers (objects) that will be filled.
701 * The number of objects to dequeue from the ring to the obj_table.
703 * RTE_RING_QUEUE_FIXED: Dequeue a fixed number of items from a ring
704 * RTE_RING_QUEUE_VARIABLE: Dequeue as many items a possible from ring
706 * Depend on the behavior value
707 * if behavior = RTE_RING_QUEUE_FIXED
708 * - 0: Success; objects dequeued.
709 * - -ENOENT: Not enough entries in the ring to dequeue; no object is
711 * if behavior = RTE_RING_QUEUE_VARIABLE
712 * - n: Actual number of objects dequeued.
714 static inline int __attribute__((always_inline))
715 __rte_ring_sc_do_dequeue(struct rte_ring *r, void **obj_table,
716 unsigned n, enum rte_ring_queue_behavior behavior)
718 uint32_t cons_head, prod_tail;
719 uint32_t cons_next, entries;
721 uint32_t mask = r->prod.mask;
723 cons_head = r->cons.head;
724 prod_tail = r->prod.tail;
725 /* The subtraction is done between two unsigned 32bits value
726 * (the result is always modulo 32 bits even if we have
727 * cons_head > prod_tail). So 'entries' is always between 0
728 * and size(ring)-1. */
729 entries = prod_tail - cons_head;
732 if (behavior == RTE_RING_QUEUE_FIXED) {
733 __RING_STAT_ADD(r, deq_fail, n);
737 if (unlikely(entries == 0)){
738 __RING_STAT_ADD(r, deq_fail, n);
746 cons_next = cons_head + n;
747 r->cons.head = cons_next;
753 __RING_STAT_ADD(r, deq_success, n);
754 r->cons.tail = cons_next;
755 return behavior == RTE_RING_QUEUE_FIXED ? 0 : n;
759 * Enqueue several objects on the ring (multi-producers safe).
761 * This function uses a "compare and set" instruction to move the
762 * producer index atomically.
765 * A pointer to the ring structure.
767 * A pointer to a table of void * pointers (objects).
769 * The number of objects to add in the ring from the obj_table.
771 * - 0: Success; objects enqueue.
772 * - -EDQUOT: Quota exceeded. The objects have been enqueued, but the
773 * high water mark is exceeded.
774 * - -ENOBUFS: Not enough room in the ring to enqueue, no object is enqueued.
776 static inline int __attribute__((always_inline))
777 rte_ring_mp_enqueue_bulk(struct rte_ring *r, void * const *obj_table,
780 return __rte_ring_mp_do_enqueue(r, obj_table, n, RTE_RING_QUEUE_FIXED);
784 * Enqueue several objects on a ring (NOT multi-producers safe).
787 * A pointer to the ring structure.
789 * A pointer to a table of void * pointers (objects).
791 * The number of objects to add in the ring from the obj_table.
793 * - 0: Success; objects enqueued.
794 * - -EDQUOT: Quota exceeded. The objects have been enqueued, but the
795 * high water mark is exceeded.
796 * - -ENOBUFS: Not enough room in the ring to enqueue; no object is enqueued.
798 static inline int __attribute__((always_inline))
799 rte_ring_sp_enqueue_bulk(struct rte_ring *r, void * const *obj_table,
802 return __rte_ring_sp_do_enqueue(r, obj_table, n, RTE_RING_QUEUE_FIXED);
806 * Enqueue several objects on a ring.
808 * This function calls the multi-producer or the single-producer
809 * version depending on the default behavior that was specified at
810 * ring creation time (see flags).
813 * A pointer to the ring structure.
815 * A pointer to a table of void * pointers (objects).
817 * The number of objects to add in the ring from the obj_table.
819 * - 0: Success; objects enqueued.
820 * - -EDQUOT: Quota exceeded. The objects have been enqueued, but the
821 * high water mark is exceeded.
822 * - -ENOBUFS: Not enough room in the ring to enqueue; no object is enqueued.
824 static inline int __attribute__((always_inline))
825 rte_ring_enqueue_bulk(struct rte_ring *r, void * const *obj_table,
828 if (r->prod.sp_enqueue)
829 return rte_ring_sp_enqueue_bulk(r, obj_table, n);
831 return rte_ring_mp_enqueue_bulk(r, obj_table, n);
835 * Enqueue one object on a ring (multi-producers safe).
837 * This function uses a "compare and set" instruction to move the
838 * producer index atomically.
841 * A pointer to the ring structure.
843 * A pointer to the object to be added.
845 * - 0: Success; objects enqueued.
846 * - -EDQUOT: Quota exceeded. The objects have been enqueued, but the
847 * high water mark is exceeded.
848 * - -ENOBUFS: Not enough room in the ring to enqueue; no object is enqueued.
850 static inline int __attribute__((always_inline))
851 rte_ring_mp_enqueue(struct rte_ring *r, void *obj)
853 return rte_ring_mp_enqueue_bulk(r, &obj, 1);
857 * Enqueue one object on a ring (NOT multi-producers safe).
860 * A pointer to the ring structure.
862 * A pointer to the object to be added.
864 * - 0: Success; objects enqueued.
865 * - -EDQUOT: Quota exceeded. The objects have been enqueued, but the
866 * high water mark is exceeded.
867 * - -ENOBUFS: Not enough room in the ring to enqueue; no object is enqueued.
869 static inline int __attribute__((always_inline))
870 rte_ring_sp_enqueue(struct rte_ring *r, void *obj)
872 return rte_ring_sp_enqueue_bulk(r, &obj, 1);
876 * Enqueue one object on a ring.
878 * This function calls the multi-producer or the single-producer
879 * version, depending on the default behaviour that was specified at
880 * ring creation time (see flags).
883 * A pointer to the ring structure.
885 * A pointer to the object to be added.
887 * - 0: Success; objects enqueued.
888 * - -EDQUOT: Quota exceeded. The objects have been enqueued, but the
889 * high water mark is exceeded.
890 * - -ENOBUFS: Not enough room in the ring to enqueue; no object is enqueued.
892 static inline int __attribute__((always_inline))
893 rte_ring_enqueue(struct rte_ring *r, void *obj)
895 if (r->prod.sp_enqueue)
896 return rte_ring_sp_enqueue(r, obj);
898 return rte_ring_mp_enqueue(r, obj);
902 * Dequeue several objects from a ring (multi-consumers safe).
904 * This function uses a "compare and set" instruction to move the
905 * consumer index atomically.
908 * A pointer to the ring structure.
910 * A pointer to a table of void * pointers (objects) that will be filled.
912 * The number of objects to dequeue from the ring to the obj_table.
914 * - 0: Success; objects dequeued.
915 * - -ENOENT: Not enough entries in the ring to dequeue; no object is
918 static inline int __attribute__((always_inline))
919 rte_ring_mc_dequeue_bulk(struct rte_ring *r, void **obj_table, unsigned n)
921 return __rte_ring_mc_do_dequeue(r, obj_table, n, RTE_RING_QUEUE_FIXED);
925 * Dequeue several objects from a ring (NOT multi-consumers safe).
928 * A pointer to the ring structure.
930 * A pointer to a table of void * pointers (objects) that will be filled.
932 * The number of objects to dequeue from the ring to the obj_table,
933 * must be strictly positive.
935 * - 0: Success; objects dequeued.
936 * - -ENOENT: Not enough entries in the ring to dequeue; no object is
939 static inline int __attribute__((always_inline))
940 rte_ring_sc_dequeue_bulk(struct rte_ring *r, void **obj_table, unsigned n)
942 return __rte_ring_sc_do_dequeue(r, obj_table, n, RTE_RING_QUEUE_FIXED);
946 * Dequeue several objects from a ring.
948 * This function calls the multi-consumers or the single-consumer
949 * version, depending on the default behaviour that was specified at
950 * ring creation time (see flags).
953 * A pointer to the ring structure.
955 * A pointer to a table of void * pointers (objects) that will be filled.
957 * The number of objects to dequeue from the ring to the obj_table.
959 * - 0: Success; objects dequeued.
960 * - -ENOENT: Not enough entries in the ring to dequeue, no object is
963 static inline int __attribute__((always_inline))
964 rte_ring_dequeue_bulk(struct rte_ring *r, void **obj_table, unsigned n)
966 if (r->cons.sc_dequeue)
967 return rte_ring_sc_dequeue_bulk(r, obj_table, n);
969 return rte_ring_mc_dequeue_bulk(r, obj_table, n);
973 * Dequeue one object from a ring (multi-consumers safe).
975 * This function uses a "compare and set" instruction to move the
976 * consumer index atomically.
979 * A pointer to the ring structure.
981 * A pointer to a void * pointer (object) that will be filled.
983 * - 0: Success; objects dequeued.
984 * - -ENOENT: Not enough entries in the ring to dequeue; no object is
987 static inline int __attribute__((always_inline))
988 rte_ring_mc_dequeue(struct rte_ring *r, void **obj_p)
990 return rte_ring_mc_dequeue_bulk(r, obj_p, 1);
994 * Dequeue one object from a ring (NOT multi-consumers safe).
997 * A pointer to the ring structure.
999 * A pointer to a void * pointer (object) that will be filled.
1001 * - 0: Success; objects dequeued.
1002 * - -ENOENT: Not enough entries in the ring to dequeue, no object is
1005 static inline int __attribute__((always_inline))
1006 rte_ring_sc_dequeue(struct rte_ring *r, void **obj_p)
1008 return rte_ring_sc_dequeue_bulk(r, obj_p, 1);
1012 * Dequeue one object from a ring.
1014 * This function calls the multi-consumers or the single-consumer
1015 * version depending on the default behaviour that was specified at
1016 * ring creation time (see flags).
1019 * A pointer to the ring structure.
1021 * A pointer to a void * pointer (object) that will be filled.
1023 * - 0: Success, objects dequeued.
1024 * - -ENOENT: Not enough entries in the ring to dequeue, no object is
1027 static inline int __attribute__((always_inline))
1028 rte_ring_dequeue(struct rte_ring *r, void **obj_p)
1030 if (r->cons.sc_dequeue)
1031 return rte_ring_sc_dequeue(r, obj_p);
1033 return rte_ring_mc_dequeue(r, obj_p);
1037 * Test if a ring is full.
1040 * A pointer to the ring structure.
1042 * - 1: The ring is full.
1043 * - 0: The ring is not full.
1046 rte_ring_full(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 - 1) & r->prod.mask) == 0;
1054 * Test if a ring is empty.
1057 * A pointer to the ring structure.
1059 * - 1: The ring is empty.
1060 * - 0: The ring is not empty.
1063 rte_ring_empty(const struct rte_ring *r)
1065 uint32_t prod_tail = r->prod.tail;
1066 uint32_t cons_tail = r->cons.tail;
1067 return !!(cons_tail == prod_tail);
1071 * Return the number of entries in a ring.
1074 * A pointer to the ring structure.
1076 * The number of entries in the ring.
1078 static inline unsigned
1079 rte_ring_count(const struct rte_ring *r)
1081 uint32_t prod_tail = r->prod.tail;
1082 uint32_t cons_tail = r->cons.tail;
1083 return (prod_tail - cons_tail) & r->prod.mask;
1087 * Return the number of free entries in a ring.
1090 * A pointer to the ring structure.
1092 * The number of free entries in the ring.
1094 static inline unsigned
1095 rte_ring_free_count(const struct rte_ring *r)
1097 uint32_t prod_tail = r->prod.tail;
1098 uint32_t cons_tail = r->cons.tail;
1099 return (cons_tail - prod_tail - 1) & r->prod.mask;
1103 * Dump the status of all rings on the console
1106 * A pointer to a file for output
1108 void rte_ring_list_dump(FILE *f);
1111 * Search a ring from its name
1114 * The name of the ring.
1116 * The pointer to the ring matching the name, or NULL if not found,
1117 * with rte_errno set appropriately. Possible rte_errno values include:
1118 * - ENOENT - required entry not available to return.
1120 struct rte_ring *rte_ring_lookup(const char *name);
1123 * Enqueue several objects on the ring (multi-producers safe).
1125 * This function uses a "compare and set" instruction to move the
1126 * producer index atomically.
1129 * A pointer to the ring structure.
1131 * A pointer to a table of void * pointers (objects).
1133 * The number of objects to add in the ring from the obj_table.
1135 * - n: Actual number of objects enqueued.
1137 static inline unsigned __attribute__((always_inline))
1138 rte_ring_mp_enqueue_burst(struct rte_ring *r, void * const *obj_table,
1141 return __rte_ring_mp_do_enqueue(r, obj_table, n, RTE_RING_QUEUE_VARIABLE);
1145 * Enqueue several objects on a ring (NOT multi-producers safe).
1148 * A pointer to the ring structure.
1150 * A pointer to a table of void * pointers (objects).
1152 * The number of objects to add in the ring from the obj_table.
1154 * - n: Actual number of objects enqueued.
1156 static inline unsigned __attribute__((always_inline))
1157 rte_ring_sp_enqueue_burst(struct rte_ring *r, void * const *obj_table,
1160 return __rte_ring_sp_do_enqueue(r, obj_table, n, RTE_RING_QUEUE_VARIABLE);
1164 * Enqueue several objects on a ring.
1166 * This function calls the multi-producer or the single-producer
1167 * version depending on the default behavior that was specified at
1168 * ring creation time (see flags).
1171 * A pointer to the ring structure.
1173 * A pointer to a table of void * pointers (objects).
1175 * The number of objects to add in the ring from the obj_table.
1177 * - n: Actual number of objects enqueued.
1179 static inline unsigned __attribute__((always_inline))
1180 rte_ring_enqueue_burst(struct rte_ring *r, void * const *obj_table,
1183 if (r->prod.sp_enqueue)
1184 return rte_ring_sp_enqueue_burst(r, obj_table, n);
1186 return rte_ring_mp_enqueue_burst(r, obj_table, n);
1190 * Dequeue several objects from a ring (multi-consumers safe). When the request
1191 * objects are more than the available objects, only dequeue the actual number
1194 * This function uses a "compare and set" instruction to move the
1195 * consumer index atomically.
1198 * A pointer to the ring structure.
1200 * A pointer to a table of void * pointers (objects) that will be filled.
1202 * The number of objects to dequeue from the ring to the obj_table.
1204 * - n: Actual number of objects dequeued, 0 if ring is empty
1206 static inline unsigned __attribute__((always_inline))
1207 rte_ring_mc_dequeue_burst(struct rte_ring *r, void **obj_table, unsigned n)
1209 return __rte_ring_mc_do_dequeue(r, obj_table, n, RTE_RING_QUEUE_VARIABLE);
1213 * Dequeue several objects from a ring (NOT multi-consumers safe).When the
1214 * request objects are more than the available objects, only dequeue the
1215 * actual number of objects
1218 * A pointer to the ring structure.
1220 * A pointer to a table of void * pointers (objects) that will be filled.
1222 * The number of objects to dequeue from the ring to the obj_table.
1224 * - n: Actual number of objects dequeued, 0 if ring is empty
1226 static inline unsigned __attribute__((always_inline))
1227 rte_ring_sc_dequeue_burst(struct rte_ring *r, void **obj_table, unsigned n)
1229 return __rte_ring_sc_do_dequeue(r, obj_table, n, RTE_RING_QUEUE_VARIABLE);
1233 * Dequeue multiple objects from a ring up to a maximum number.
1235 * This function calls the multi-consumers or the single-consumer
1236 * version, depending on the default behaviour that was specified at
1237 * ring creation time (see flags).
1240 * A pointer to the ring structure.
1242 * A pointer to a table of void * pointers (objects) that will be filled.
1244 * The number of objects to dequeue from the ring to the obj_table.
1246 * - Number of objects dequeued
1248 static inline unsigned __attribute__((always_inline))
1249 rte_ring_dequeue_burst(struct rte_ring *r, void **obj_table, unsigned n)
1251 if (r->cons.sc_dequeue)
1252 return rte_ring_sc_dequeue_burst(r, obj_table, n);
1254 return rte_ring_mc_dequeue_burst(r, obj_table, n);
1261 #endif /* _RTE_RING_H_ */