4 * Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
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8 * modification, are permitted provided that the following conditions
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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.
21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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>
103 #include <rte_memzone.h>
105 #define RTE_TAILQ_RING_NAME "RTE_RING"
107 enum rte_ring_queue_behavior {
108 RTE_RING_QUEUE_FIXED = 0, /* Enq/Deq a fixed number of items from a ring */
109 RTE_RING_QUEUE_VARIABLE /* Enq/Deq as many items as possible from ring */
112 #ifdef RTE_LIBRTE_RING_DEBUG
114 * A structure that stores the ring statistics (per-lcore).
116 struct rte_ring_debug_stats {
117 uint64_t enq_success_bulk; /**< Successful enqueues number. */
118 uint64_t enq_success_objs; /**< Objects successfully enqueued. */
119 uint64_t enq_quota_bulk; /**< Successful enqueues above watermark. */
120 uint64_t enq_quota_objs; /**< Objects enqueued above watermark. */
121 uint64_t enq_fail_bulk; /**< Failed enqueues number. */
122 uint64_t enq_fail_objs; /**< Objects that failed to be enqueued. */
123 uint64_t deq_success_bulk; /**< Successful dequeues number. */
124 uint64_t deq_success_objs; /**< Objects successfully dequeued. */
125 uint64_t deq_fail_bulk; /**< Failed dequeues number. */
126 uint64_t deq_fail_objs; /**< Objects that failed to be dequeued. */
127 } __rte_cache_aligned;
130 #define RTE_RING_MZ_PREFIX "RG_"
131 /**< The maximum length of a ring name. */
132 #define RTE_RING_NAMESIZE (RTE_MEMZONE_NAMESIZE - \
133 sizeof(RTE_RING_MZ_PREFIX) + 1)
135 #ifndef RTE_RING_PAUSE_REP_COUNT
136 #define RTE_RING_PAUSE_REP_COUNT 0 /**< Yield after pause num of times, no yield
137 * if RTE_RING_PAUSE_REP not defined. */
140 struct rte_memzone; /* forward declaration, so as not to require memzone.h */
143 * An RTE ring structure.
145 * The producer and the consumer have a head and a tail index. The particularity
146 * of these index is that they are not between 0 and size(ring). These indexes
147 * are between 0 and 2^32, and we mask their value when we access the ring[]
148 * field. Thanks to this assumption, we can do subtractions between 2 index
149 * values in a modulo-32bit base: that's why the overflow of the indexes is not
154 * Note: this field kept the RTE_MEMZONE_NAMESIZE size due to ABI
155 * compatibility requirements, it could be changed to RTE_RING_NAMESIZE
156 * next time the ABI changes
158 char name[RTE_MEMZONE_NAMESIZE]; /**< Name of the ring. */
159 int flags; /**< Flags supplied at creation. */
160 const struct rte_memzone *memzone;
161 /**< Memzone, if any, containing the rte_ring */
163 /** Ring producer status. */
165 uint32_t watermark; /**< Maximum items before EDQUOT. */
166 uint32_t sp_enqueue; /**< True, if single producer. */
167 uint32_t size; /**< Size of ring. */
168 uint32_t mask; /**< Mask (size-1) of ring. */
169 volatile uint32_t head; /**< Producer head. */
170 volatile uint32_t tail; /**< Producer tail. */
171 } prod __rte_cache_aligned;
173 /** Ring consumer status. */
175 uint32_t sc_dequeue; /**< True, if single consumer. */
176 uint32_t size; /**< Size of the ring. */
177 uint32_t mask; /**< Mask (size-1) of ring. */
178 volatile uint32_t head; /**< Consumer head. */
179 volatile uint32_t tail; /**< Consumer tail. */
180 #ifdef RTE_RING_SPLIT_PROD_CONS
181 } cons __rte_cache_aligned;
186 #ifdef RTE_LIBRTE_RING_DEBUG
187 struct rte_ring_debug_stats stats[RTE_MAX_LCORE];
190 void *ring[] __rte_cache_aligned; /**< Memory space of ring starts here.
191 * not volatile so need to be careful
192 * about compiler re-ordering */
195 #define RING_F_SP_ENQ 0x0001 /**< The default enqueue is "single-producer". */
196 #define RING_F_SC_DEQ 0x0002 /**< The default dequeue is "single-consumer". */
197 #define RTE_RING_QUOT_EXCEED (1 << 31) /**< Quota exceed for burst ops */
198 #define RTE_RING_SZ_MASK (unsigned)(0x0fffffff) /**< Ring size mask */
201 * @internal When debug is enabled, store ring statistics.
203 * A pointer to the ring.
205 * The name of the statistics field to increment in the ring.
207 * The number to add to the object-oriented statistics.
209 #ifdef RTE_LIBRTE_RING_DEBUG
210 #define __RING_STAT_ADD(r, name, n) do { \
211 unsigned __lcore_id = rte_lcore_id(); \
212 if (__lcore_id < RTE_MAX_LCORE) { \
213 r->stats[__lcore_id].name##_objs += n; \
214 r->stats[__lcore_id].name##_bulk += 1; \
218 #define __RING_STAT_ADD(r, name, n) do {} while(0)
222 * Calculate the memory size needed for a ring
224 * This function returns the number of bytes needed for a ring, given
225 * the number of elements in it. This value is the sum of the size of
226 * the structure rte_ring and the size of the memory needed by the
227 * objects pointers. The value is aligned to a cache line size.
230 * The number of elements in the ring (must be a power of 2).
232 * - The memory size needed for the ring on success.
233 * - -EINVAL if count is not a power of 2.
235 ssize_t rte_ring_get_memsize(unsigned count);
238 * Initialize a ring structure.
240 * Initialize a ring structure in memory pointed by "r". The size of the
241 * memory area must be large enough to store the ring structure and the
242 * object table. It is advised to use rte_ring_get_memsize() to get the
245 * The ring size is set to *count*, which must be a power of two. Water
246 * marking is disabled by default. The real usable ring size is
247 * *count-1* instead of *count* to differentiate a free ring from an
250 * The ring is not added in RTE_TAILQ_RING global list. Indeed, the
251 * memory given by the caller may not be shareable among dpdk
255 * The pointer to the ring structure followed by the objects table.
257 * The name of the ring.
259 * The number of elements in the ring (must be a power of 2).
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 * 0 on success, or a negative value on error.
271 int rte_ring_init(struct rte_ring *r, const char *name, unsigned count,
275 * Create a new ring named *name* in memory.
277 * This function uses ``memzone_reserve()`` to allocate memory. Then it
278 * calls rte_ring_init() to initialize an empty ring.
280 * The new ring size is set to *count*, which must be a power of
281 * two. Water marking is disabled by default. The real usable ring size
282 * is *count-1* instead of *count* to differentiate a free ring from an
285 * The ring is added in RTE_TAILQ_RING list.
288 * The name of the ring.
290 * The size of the ring (must be a power of 2).
292 * The *socket_id* argument is the socket identifier in case of
293 * NUMA. The value can be *SOCKET_ID_ANY* if there is no NUMA
294 * constraint for the reserved zone.
296 * An OR of the following:
297 * - RING_F_SP_ENQ: If this flag is set, the default behavior when
298 * using ``rte_ring_enqueue()`` or ``rte_ring_enqueue_bulk()``
299 * is "single-producer". Otherwise, it is "multi-producers".
300 * - RING_F_SC_DEQ: If this flag is set, the default behavior when
301 * using ``rte_ring_dequeue()`` or ``rte_ring_dequeue_bulk()``
302 * is "single-consumer". Otherwise, it is "multi-consumers".
304 * On success, the pointer to the new allocated ring. NULL on error with
305 * rte_errno set appropriately. Possible errno values include:
306 * - E_RTE_NO_CONFIG - function could not get pointer to rte_config structure
307 * - E_RTE_SECONDARY - function was called from a secondary process instance
308 * - EINVAL - count provided is not a power of 2
309 * - ENOSPC - the maximum number of memzones has already been allocated
310 * - EEXIST - a memzone with the same name already exists
311 * - ENOMEM - no appropriate memory area found in which to create memzone
313 struct rte_ring *rte_ring_create(const char *name, unsigned count,
314 int socket_id, unsigned flags);
316 * De-allocate all memory used by the ring.
321 void rte_ring_free(struct rte_ring *r);
324 * Change the high water mark.
326 * If *count* is 0, water marking is disabled. Otherwise, it is set to the
327 * *count* value. The *count* value must be greater than 0 and less
328 * than the ring size.
330 * This function can be called at any time (not necessarily at
334 * A pointer to the ring structure.
336 * The new water mark value.
338 * - 0: Success; water mark changed.
339 * - -EINVAL: Invalid water mark value.
341 int rte_ring_set_water_mark(struct rte_ring *r, unsigned count);
344 * Dump the status of the ring to a file.
347 * A pointer to a file for output
349 * A pointer to the ring structure.
351 void rte_ring_dump(FILE *f, const struct rte_ring *r);
353 /* the actual enqueue of pointers on the ring.
354 * Placed here since identical code needed in both
355 * single and multi producer enqueue functions */
356 #define ENQUEUE_PTRS() do { \
357 const uint32_t size = r->prod.size; \
358 uint32_t idx = prod_head & mask; \
359 if (likely(idx + n < size)) { \
360 for (i = 0; i < (n & ((~(unsigned)0x3))); i+=4, idx+=4) { \
361 r->ring[idx] = obj_table[i]; \
362 r->ring[idx+1] = obj_table[i+1]; \
363 r->ring[idx+2] = obj_table[i+2]; \
364 r->ring[idx+3] = obj_table[i+3]; \
367 case 3: r->ring[idx++] = obj_table[i++]; \
368 case 2: r->ring[idx++] = obj_table[i++]; \
369 case 1: r->ring[idx++] = obj_table[i++]; \
372 for (i = 0; idx < size; i++, idx++)\
373 r->ring[idx] = obj_table[i]; \
374 for (idx = 0; i < n; i++, idx++) \
375 r->ring[idx] = obj_table[i]; \
379 /* the actual copy of pointers on the ring to obj_table.
380 * Placed here since identical code needed in both
381 * single and multi consumer dequeue functions */
382 #define DEQUEUE_PTRS() do { \
383 uint32_t idx = cons_head & mask; \
384 const uint32_t size = r->cons.size; \
385 if (likely(idx + n < size)) { \
386 for (i = 0; i < (n & (~(unsigned)0x3)); i+=4, idx+=4) {\
387 obj_table[i] = r->ring[idx]; \
388 obj_table[i+1] = r->ring[idx+1]; \
389 obj_table[i+2] = r->ring[idx+2]; \
390 obj_table[i+3] = r->ring[idx+3]; \
393 case 3: obj_table[i++] = r->ring[idx++]; \
394 case 2: obj_table[i++] = r->ring[idx++]; \
395 case 1: obj_table[i++] = r->ring[idx++]; \
398 for (i = 0; idx < size; i++, idx++) \
399 obj_table[i] = r->ring[idx]; \
400 for (idx = 0; i < n; i++, idx++) \
401 obj_table[i] = r->ring[idx]; \
406 * @internal Enqueue several objects on the ring (multi-producers safe).
408 * This function uses a "compare and set" instruction to move the
409 * producer index atomically.
412 * A pointer to the ring structure.
414 * A pointer to a table of void * pointers (objects).
416 * The number of objects to add in the ring from the obj_table.
418 * RTE_RING_QUEUE_FIXED: Enqueue a fixed number of items from a ring
419 * RTE_RING_QUEUE_VARIABLE: Enqueue as many items a possible from ring
421 * Depend on the behavior value
422 * if behavior = RTE_RING_QUEUE_FIXED
423 * - 0: Success; objects enqueue.
424 * - -EDQUOT: Quota exceeded. The objects have been enqueued, but the
425 * high water mark is exceeded.
426 * - -ENOBUFS: Not enough room in the ring to enqueue, no object is enqueued.
427 * if behavior = RTE_RING_QUEUE_VARIABLE
428 * - n: Actual number of objects enqueued.
430 static inline int __attribute__((always_inline))
431 __rte_ring_mp_do_enqueue(struct rte_ring *r, void * const *obj_table,
432 unsigned n, enum rte_ring_queue_behavior behavior)
434 uint32_t prod_head, prod_next;
435 uint32_t cons_tail, free_entries;
436 const unsigned max = n;
439 uint32_t mask = r->prod.mask;
442 /* Avoid the unnecessary cmpset operation below, which is also
443 * potentially harmful when n equals 0. */
447 /* move prod.head atomically */
449 /* Reset n to the initial burst count */
452 prod_head = r->prod.head;
453 cons_tail = r->cons.tail;
454 /* The subtraction is done between two unsigned 32bits value
455 * (the result is always modulo 32 bits even if we have
456 * prod_head > cons_tail). So 'free_entries' is always between 0
457 * and size(ring)-1. */
458 free_entries = (mask + cons_tail - prod_head);
460 /* check that we have enough room in ring */
461 if (unlikely(n > free_entries)) {
462 if (behavior == RTE_RING_QUEUE_FIXED) {
463 __RING_STAT_ADD(r, enq_fail, n);
467 /* No free entry available */
468 if (unlikely(free_entries == 0)) {
469 __RING_STAT_ADD(r, enq_fail, n);
477 prod_next = prod_head + n;
478 success = rte_atomic32_cmpset(&r->prod.head, prod_head,
480 } while (unlikely(success == 0));
482 /* write entries in ring */
486 /* if we exceed the watermark */
487 if (unlikely(((mask + 1) - free_entries + n) > r->prod.watermark)) {
488 ret = (behavior == RTE_RING_QUEUE_FIXED) ? -EDQUOT :
489 (int)(n | RTE_RING_QUOT_EXCEED);
490 __RING_STAT_ADD(r, enq_quota, n);
493 ret = (behavior == RTE_RING_QUEUE_FIXED) ? 0 : n;
494 __RING_STAT_ADD(r, enq_success, n);
498 * If there are other enqueues in progress that preceded us,
499 * we need to wait for them to complete
501 while (unlikely(r->prod.tail != prod_head)) {
504 /* Set RTE_RING_PAUSE_REP_COUNT to avoid spin too long waiting
505 * for other thread finish. It gives pre-empted thread a chance
506 * to proceed and finish with ring dequeue operation. */
507 if (RTE_RING_PAUSE_REP_COUNT &&
508 ++rep == RTE_RING_PAUSE_REP_COUNT) {
513 r->prod.tail = prod_next;
518 * @internal Enqueue several objects on a ring (NOT multi-producers safe).
521 * A pointer to the ring structure.
523 * A pointer to a table of void * pointers (objects).
525 * The number of objects to add in the ring from the obj_table.
527 * RTE_RING_QUEUE_FIXED: Enqueue a fixed number of items from a ring
528 * RTE_RING_QUEUE_VARIABLE: Enqueue as many items a possible from ring
530 * Depend on the behavior value
531 * if behavior = RTE_RING_QUEUE_FIXED
532 * - 0: Success; objects enqueue.
533 * - -EDQUOT: Quota exceeded. The objects have been enqueued, but the
534 * high water mark is exceeded.
535 * - -ENOBUFS: Not enough room in the ring to enqueue, no object is enqueued.
536 * if behavior = RTE_RING_QUEUE_VARIABLE
537 * - n: Actual number of objects enqueued.
539 static inline int __attribute__((always_inline))
540 __rte_ring_sp_do_enqueue(struct rte_ring *r, void * const *obj_table,
541 unsigned n, enum rte_ring_queue_behavior behavior)
543 uint32_t prod_head, cons_tail;
544 uint32_t prod_next, free_entries;
546 uint32_t mask = r->prod.mask;
549 prod_head = r->prod.head;
550 cons_tail = r->cons.tail;
551 /* The subtraction is done between two unsigned 32bits value
552 * (the result is always modulo 32 bits even if we have
553 * prod_head > cons_tail). So 'free_entries' is always between 0
554 * and size(ring)-1. */
555 free_entries = mask + cons_tail - prod_head;
557 /* check that we have enough room in ring */
558 if (unlikely(n > free_entries)) {
559 if (behavior == RTE_RING_QUEUE_FIXED) {
560 __RING_STAT_ADD(r, enq_fail, n);
564 /* No free entry available */
565 if (unlikely(free_entries == 0)) {
566 __RING_STAT_ADD(r, enq_fail, n);
574 prod_next = prod_head + n;
575 r->prod.head = prod_next;
577 /* write entries in ring */
581 /* if we exceed the watermark */
582 if (unlikely(((mask + 1) - free_entries + n) > r->prod.watermark)) {
583 ret = (behavior == RTE_RING_QUEUE_FIXED) ? -EDQUOT :
584 (int)(n | RTE_RING_QUOT_EXCEED);
585 __RING_STAT_ADD(r, enq_quota, n);
588 ret = (behavior == RTE_RING_QUEUE_FIXED) ? 0 : n;
589 __RING_STAT_ADD(r, enq_success, n);
592 r->prod.tail = prod_next;
597 * @internal Dequeue several objects from a ring (multi-consumers safe). When
598 * the request objects are more than the available objects, only dequeue the
599 * actual number of objects
601 * This function uses a "compare and set" instruction to move the
602 * consumer index atomically.
605 * A pointer to the ring structure.
607 * A pointer to a table of void * pointers (objects) that will be filled.
609 * The number of objects to dequeue from the ring to the obj_table.
611 * RTE_RING_QUEUE_FIXED: Dequeue a fixed number of items from a ring
612 * RTE_RING_QUEUE_VARIABLE: Dequeue as many items a possible from ring
614 * Depend on the behavior value
615 * if behavior = RTE_RING_QUEUE_FIXED
616 * - 0: Success; objects dequeued.
617 * - -ENOENT: Not enough entries in the ring to dequeue; no object is
619 * if behavior = RTE_RING_QUEUE_VARIABLE
620 * - n: Actual number of objects dequeued.
623 static inline int __attribute__((always_inline))
624 __rte_ring_mc_do_dequeue(struct rte_ring *r, void **obj_table,
625 unsigned n, enum rte_ring_queue_behavior behavior)
627 uint32_t cons_head, prod_tail;
628 uint32_t cons_next, entries;
629 const unsigned max = n;
632 uint32_t mask = r->prod.mask;
634 /* Avoid the unnecessary cmpset operation below, which is also
635 * potentially harmful when n equals 0. */
639 /* move cons.head atomically */
641 /* Restore n as it may change every loop */
644 cons_head = r->cons.head;
645 prod_tail = r->prod.tail;
646 /* The subtraction is done between two unsigned 32bits value
647 * (the result is always modulo 32 bits even if we have
648 * cons_head > prod_tail). So 'entries' is always between 0
649 * and size(ring)-1. */
650 entries = (prod_tail - cons_head);
652 /* Set the actual entries for dequeue */
654 if (behavior == RTE_RING_QUEUE_FIXED) {
655 __RING_STAT_ADD(r, deq_fail, n);
659 if (unlikely(entries == 0)){
660 __RING_STAT_ADD(r, deq_fail, n);
668 cons_next = cons_head + n;
669 success = rte_atomic32_cmpset(&r->cons.head, cons_head,
671 } while (unlikely(success == 0));
678 * If there are other dequeues in progress that preceded us,
679 * we need to wait for them to complete
681 while (unlikely(r->cons.tail != cons_head)) {
684 /* Set RTE_RING_PAUSE_REP_COUNT to avoid spin too long waiting
685 * for other thread finish. It gives pre-empted thread a chance
686 * to proceed and finish with ring dequeue operation. */
687 if (RTE_RING_PAUSE_REP_COUNT &&
688 ++rep == RTE_RING_PAUSE_REP_COUNT) {
693 __RING_STAT_ADD(r, deq_success, n);
694 r->cons.tail = cons_next;
696 return behavior == RTE_RING_QUEUE_FIXED ? 0 : n;
700 * @internal Dequeue several objects from a ring (NOT multi-consumers safe).
701 * When the request objects are more than the available objects, only dequeue
702 * the actual number of objects
705 * A pointer to the ring structure.
707 * A pointer to a table of void * pointers (objects) that will be filled.
709 * The number of objects to dequeue from the ring to the obj_table.
711 * RTE_RING_QUEUE_FIXED: Dequeue a fixed number of items from a ring
712 * RTE_RING_QUEUE_VARIABLE: Dequeue as many items a possible from ring
714 * Depend on the behavior value
715 * if behavior = RTE_RING_QUEUE_FIXED
716 * - 0: Success; objects dequeued.
717 * - -ENOENT: Not enough entries in the ring to dequeue; no object is
719 * if behavior = RTE_RING_QUEUE_VARIABLE
720 * - n: Actual number of objects dequeued.
722 static inline int __attribute__((always_inline))
723 __rte_ring_sc_do_dequeue(struct rte_ring *r, void **obj_table,
724 unsigned n, enum rte_ring_queue_behavior behavior)
726 uint32_t cons_head, prod_tail;
727 uint32_t cons_next, entries;
729 uint32_t mask = r->prod.mask;
731 cons_head = r->cons.head;
732 prod_tail = r->prod.tail;
733 /* The subtraction is done between two unsigned 32bits value
734 * (the result is always modulo 32 bits even if we have
735 * cons_head > prod_tail). So 'entries' is always between 0
736 * and size(ring)-1. */
737 entries = prod_tail - cons_head;
740 if (behavior == RTE_RING_QUEUE_FIXED) {
741 __RING_STAT_ADD(r, deq_fail, n);
745 if (unlikely(entries == 0)){
746 __RING_STAT_ADD(r, deq_fail, n);
754 cons_next = cons_head + n;
755 r->cons.head = cons_next;
761 __RING_STAT_ADD(r, deq_success, n);
762 r->cons.tail = cons_next;
763 return behavior == RTE_RING_QUEUE_FIXED ? 0 : n;
767 * Enqueue several objects on the ring (multi-producers safe).
769 * This function uses a "compare and set" instruction to move the
770 * producer index atomically.
773 * A pointer to the ring structure.
775 * A pointer to a table of void * pointers (objects).
777 * The number of objects to add in the ring from the obj_table.
779 * - 0: Success; objects enqueue.
780 * - -EDQUOT: Quota exceeded. The objects have been enqueued, but the
781 * high water mark is exceeded.
782 * - -ENOBUFS: Not enough room in the ring to enqueue, no object is enqueued.
784 static inline int __attribute__((always_inline))
785 rte_ring_mp_enqueue_bulk(struct rte_ring *r, void * const *obj_table,
788 return __rte_ring_mp_do_enqueue(r, obj_table, n, RTE_RING_QUEUE_FIXED);
792 * Enqueue several objects on a ring (NOT multi-producers safe).
795 * A pointer to the ring structure.
797 * A pointer to a table of void * pointers (objects).
799 * The number of objects to add in the ring from the obj_table.
801 * - 0: Success; objects enqueued.
802 * - -EDQUOT: Quota exceeded. The objects have been enqueued, but the
803 * high water mark is exceeded.
804 * - -ENOBUFS: Not enough room in the ring to enqueue; no object is enqueued.
806 static inline int __attribute__((always_inline))
807 rte_ring_sp_enqueue_bulk(struct rte_ring *r, void * const *obj_table,
810 return __rte_ring_sp_do_enqueue(r, obj_table, n, RTE_RING_QUEUE_FIXED);
814 * Enqueue several objects on a ring.
816 * This function calls the multi-producer or the single-producer
817 * version depending on the default behavior that was specified at
818 * ring creation time (see flags).
821 * A pointer to the ring structure.
823 * A pointer to a table of void * pointers (objects).
825 * The number of objects to add in the ring from the obj_table.
827 * - 0: Success; objects enqueued.
828 * - -EDQUOT: Quota exceeded. The objects have been enqueued, but the
829 * high water mark is exceeded.
830 * - -ENOBUFS: Not enough room in the ring to enqueue; no object is enqueued.
832 static inline int __attribute__((always_inline))
833 rte_ring_enqueue_bulk(struct rte_ring *r, void * const *obj_table,
836 if (r->prod.sp_enqueue)
837 return rte_ring_sp_enqueue_bulk(r, obj_table, n);
839 return rte_ring_mp_enqueue_bulk(r, obj_table, n);
843 * Enqueue one object on a ring (multi-producers safe).
845 * This function uses a "compare and set" instruction to move the
846 * producer index atomically.
849 * A pointer to the ring structure.
851 * A pointer to the object to be added.
853 * - 0: Success; objects enqueued.
854 * - -EDQUOT: Quota exceeded. The objects have been enqueued, but the
855 * high water mark is exceeded.
856 * - -ENOBUFS: Not enough room in the ring to enqueue; no object is enqueued.
858 static inline int __attribute__((always_inline))
859 rte_ring_mp_enqueue(struct rte_ring *r, void *obj)
861 return rte_ring_mp_enqueue_bulk(r, &obj, 1);
865 * Enqueue one object on a ring (NOT multi-producers safe).
868 * A pointer to the ring structure.
870 * A pointer to the object to be added.
872 * - 0: Success; objects enqueued.
873 * - -EDQUOT: Quota exceeded. The objects have been enqueued, but the
874 * high water mark is exceeded.
875 * - -ENOBUFS: Not enough room in the ring to enqueue; no object is enqueued.
877 static inline int __attribute__((always_inline))
878 rte_ring_sp_enqueue(struct rte_ring *r, void *obj)
880 return rte_ring_sp_enqueue_bulk(r, &obj, 1);
884 * Enqueue one object on a ring.
886 * This function calls the multi-producer or the single-producer
887 * version, depending on the default behaviour that was specified at
888 * ring creation time (see flags).
891 * A pointer to the ring structure.
893 * A pointer to the object to be added.
895 * - 0: Success; objects enqueued.
896 * - -EDQUOT: Quota exceeded. The objects have been enqueued, but the
897 * high water mark is exceeded.
898 * - -ENOBUFS: Not enough room in the ring to enqueue; no object is enqueued.
900 static inline int __attribute__((always_inline))
901 rte_ring_enqueue(struct rte_ring *r, void *obj)
903 if (r->prod.sp_enqueue)
904 return rte_ring_sp_enqueue(r, obj);
906 return rte_ring_mp_enqueue(r, obj);
910 * Dequeue several objects from a ring (multi-consumers safe).
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 * - 0: Success; objects dequeued.
923 * - -ENOENT: Not enough entries in the ring to dequeue; no object is
926 static inline int __attribute__((always_inline))
927 rte_ring_mc_dequeue_bulk(struct rte_ring *r, void **obj_table, unsigned n)
929 return __rte_ring_mc_do_dequeue(r, obj_table, n, RTE_RING_QUEUE_FIXED);
933 * Dequeue several objects from a ring (NOT multi-consumers safe).
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,
941 * must be strictly positive.
943 * - 0: Success; objects dequeued.
944 * - -ENOENT: Not enough entries in the ring to dequeue; no object is
947 static inline int __attribute__((always_inline))
948 rte_ring_sc_dequeue_bulk(struct rte_ring *r, void **obj_table, unsigned n)
950 return __rte_ring_sc_do_dequeue(r, obj_table, n, RTE_RING_QUEUE_FIXED);
954 * Dequeue several objects from a ring.
956 * This function calls the multi-consumers or the single-consumer
957 * version, depending on the default behaviour that was specified at
958 * ring creation time (see flags).
961 * A pointer to the ring structure.
963 * A pointer to a table of void * pointers (objects) that will be filled.
965 * The number of objects to dequeue from the ring to the obj_table.
967 * - 0: Success; objects dequeued.
968 * - -ENOENT: Not enough entries in the ring to dequeue, no object is
971 static inline int __attribute__((always_inline))
972 rte_ring_dequeue_bulk(struct rte_ring *r, void **obj_table, unsigned n)
974 if (r->cons.sc_dequeue)
975 return rte_ring_sc_dequeue_bulk(r, obj_table, n);
977 return rte_ring_mc_dequeue_bulk(r, obj_table, n);
981 * Dequeue one object from a ring (multi-consumers safe).
983 * This function uses a "compare and set" instruction to move the
984 * consumer index atomically.
987 * A pointer to the ring structure.
989 * A pointer to a void * pointer (object) that will be filled.
991 * - 0: Success; objects dequeued.
992 * - -ENOENT: Not enough entries in the ring to dequeue; no object is
995 static inline int __attribute__((always_inline))
996 rte_ring_mc_dequeue(struct rte_ring *r, void **obj_p)
998 return rte_ring_mc_dequeue_bulk(r, obj_p, 1);
1002 * Dequeue one object from a ring (NOT multi-consumers safe).
1005 * A pointer to the ring structure.
1007 * A pointer to a void * pointer (object) that will be filled.
1009 * - 0: Success; objects dequeued.
1010 * - -ENOENT: Not enough entries in the ring to dequeue, no object is
1013 static inline int __attribute__((always_inline))
1014 rte_ring_sc_dequeue(struct rte_ring *r, void **obj_p)
1016 return rte_ring_sc_dequeue_bulk(r, obj_p, 1);
1020 * Dequeue one object from a ring.
1022 * This function calls the multi-consumers or the single-consumer
1023 * version depending on the default behaviour that was specified at
1024 * ring creation time (see flags).
1027 * A pointer to the ring structure.
1029 * A pointer to a void * pointer (object) that will be filled.
1031 * - 0: Success, objects dequeued.
1032 * - -ENOENT: Not enough entries in the ring to dequeue, no object is
1035 static inline int __attribute__((always_inline))
1036 rte_ring_dequeue(struct rte_ring *r, void **obj_p)
1038 if (r->cons.sc_dequeue)
1039 return rte_ring_sc_dequeue(r, obj_p);
1041 return rte_ring_mc_dequeue(r, obj_p);
1045 * Test if a ring is full.
1048 * A pointer to the ring structure.
1050 * - 1: The ring is full.
1051 * - 0: The ring is not full.
1054 rte_ring_full(const struct rte_ring *r)
1056 uint32_t prod_tail = r->prod.tail;
1057 uint32_t cons_tail = r->cons.tail;
1058 return ((cons_tail - prod_tail - 1) & r->prod.mask) == 0;
1062 * Test if a ring is empty.
1065 * A pointer to the ring structure.
1067 * - 1: The ring is empty.
1068 * - 0: The ring is not empty.
1071 rte_ring_empty(const struct rte_ring *r)
1073 uint32_t prod_tail = r->prod.tail;
1074 uint32_t cons_tail = r->cons.tail;
1075 return !!(cons_tail == prod_tail);
1079 * Return the number of entries in a ring.
1082 * A pointer to the ring structure.
1084 * The number of entries in the ring.
1086 static inline unsigned
1087 rte_ring_count(const struct rte_ring *r)
1089 uint32_t prod_tail = r->prod.tail;
1090 uint32_t cons_tail = r->cons.tail;
1091 return (prod_tail - cons_tail) & r->prod.mask;
1095 * Return the number of free entries in a ring.
1098 * A pointer to the ring structure.
1100 * The number of free entries in the ring.
1102 static inline unsigned
1103 rte_ring_free_count(const struct rte_ring *r)
1105 uint32_t prod_tail = r->prod.tail;
1106 uint32_t cons_tail = r->cons.tail;
1107 return (cons_tail - prod_tail - 1) & r->prod.mask;
1111 * Dump the status of all rings on the console
1114 * A pointer to a file for output
1116 void rte_ring_list_dump(FILE *f);
1119 * Search a ring from its name
1122 * The name of the ring.
1124 * The pointer to the ring matching the name, or NULL if not found,
1125 * with rte_errno set appropriately. Possible rte_errno values include:
1126 * - ENOENT - required entry not available to return.
1128 struct rte_ring *rte_ring_lookup(const char *name);
1131 * Enqueue several objects on the ring (multi-producers safe).
1133 * This function uses a "compare and set" instruction to move the
1134 * producer index atomically.
1137 * A pointer to the ring structure.
1139 * A pointer to a table of void * pointers (objects).
1141 * The number of objects to add in the ring from the obj_table.
1143 * - n: Actual number of objects enqueued.
1145 static inline unsigned __attribute__((always_inline))
1146 rte_ring_mp_enqueue_burst(struct rte_ring *r, void * const *obj_table,
1149 return __rte_ring_mp_do_enqueue(r, obj_table, n, RTE_RING_QUEUE_VARIABLE);
1153 * Enqueue several objects on a ring (NOT multi-producers safe).
1156 * A pointer to the ring structure.
1158 * A pointer to a table of void * pointers (objects).
1160 * The number of objects to add in the ring from the obj_table.
1162 * - n: Actual number of objects enqueued.
1164 static inline unsigned __attribute__((always_inline))
1165 rte_ring_sp_enqueue_burst(struct rte_ring *r, void * const *obj_table,
1168 return __rte_ring_sp_do_enqueue(r, obj_table, n, RTE_RING_QUEUE_VARIABLE);
1172 * Enqueue several objects on a ring.
1174 * This function calls the multi-producer or the single-producer
1175 * version depending on the default behavior that was specified at
1176 * ring creation time (see flags).
1179 * A pointer to the ring structure.
1181 * A pointer to a table of void * pointers (objects).
1183 * The number of objects to add in the ring from the obj_table.
1185 * - n: Actual number of objects enqueued.
1187 static inline unsigned __attribute__((always_inline))
1188 rte_ring_enqueue_burst(struct rte_ring *r, void * const *obj_table,
1191 if (r->prod.sp_enqueue)
1192 return rte_ring_sp_enqueue_burst(r, obj_table, n);
1194 return rte_ring_mp_enqueue_burst(r, obj_table, n);
1198 * Dequeue several objects from a ring (multi-consumers safe). When the request
1199 * objects are more than the available objects, only dequeue the actual number
1202 * This function uses a "compare and set" instruction to move the
1203 * consumer index atomically.
1206 * A pointer to the ring structure.
1208 * A pointer to a table of void * pointers (objects) that will be filled.
1210 * The number of objects to dequeue from the ring to the obj_table.
1212 * - n: Actual number of objects dequeued, 0 if ring is empty
1214 static inline unsigned __attribute__((always_inline))
1215 rte_ring_mc_dequeue_burst(struct rte_ring *r, void **obj_table, unsigned n)
1217 return __rte_ring_mc_do_dequeue(r, obj_table, n, RTE_RING_QUEUE_VARIABLE);
1221 * Dequeue several objects from a ring (NOT multi-consumers safe).When the
1222 * request objects are more than the available objects, only dequeue the
1223 * actual number of objects
1226 * A pointer to the ring structure.
1228 * A pointer to a table of void * pointers (objects) that will be filled.
1230 * The number of objects to dequeue from the ring to the obj_table.
1232 * - n: Actual number of objects dequeued, 0 if ring is empty
1234 static inline unsigned __attribute__((always_inline))
1235 rte_ring_sc_dequeue_burst(struct rte_ring *r, void **obj_table, unsigned n)
1237 return __rte_ring_sc_do_dequeue(r, obj_table, n, RTE_RING_QUEUE_VARIABLE);
1241 * Dequeue multiple objects from a ring up to a maximum number.
1243 * This function calls the multi-consumers or the single-consumer
1244 * version, depending on the default behaviour that was specified at
1245 * ring creation time (see flags).
1248 * A pointer to the ring structure.
1250 * A pointer to a table of void * pointers (objects) that will be filled.
1252 * The number of objects to dequeue from the ring to the obj_table.
1254 * - Number of objects dequeued
1256 static inline unsigned __attribute__((always_inline))
1257 rte_ring_dequeue_burst(struct rte_ring *r, void **obj_table, unsigned n)
1259 if (r->cons.sc_dequeue)
1260 return rte_ring_sc_dequeue_burst(r, obj_table, n);
1262 return rte_ring_mc_dequeue_burst(r, obj_table, n);
1269 #endif /* _RTE_RING_H_ */