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Diffstat (limited to 'src/dpdk_lib18/librte_ring/rte_ring.h')
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diff --git a/src/dpdk_lib18/librte_ring/rte_ring.h b/src/dpdk_lib18/librte_ring/rte_ring.h new file mode 100755 index 00000000..7cd5f2d4 --- /dev/null +++ b/src/dpdk_lib18/librte_ring/rte_ring.h @@ -0,0 +1,1214 @@ +/*- + * BSD LICENSE + * + * Copyright(c) 2010-2014 Intel Corporation. All rights reserved. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * * Neither the name of Intel Corporation nor the names of its + * contributors may be used to endorse or promote products derived + * from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +/* + * Derived from FreeBSD's bufring.h + * + ************************************************************************** + * + * Copyright (c) 2007-2009 Kip Macy kmacy@freebsd.org + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * + * 2. The name of Kip Macy nor the names of other + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + * + ***************************************************************************/ + +#ifndef _RTE_RING_H_ +#define _RTE_RING_H_ + +/** + * @file + * RTE Ring + * + * The Ring Manager is a fixed-size queue, implemented as a table of + * pointers. Head and tail pointers are modified atomically, allowing + * concurrent access to it. It has the following features: + * + * - FIFO (First In First Out) + * - Maximum size is fixed; the pointers are stored in a table. + * - Lockless implementation. + * - Multi- or single-consumer dequeue. + * - Multi- or single-producer enqueue. + * - Bulk dequeue. + * - Bulk enqueue. + * + * Note: the ring implementation is not preemptable. A lcore must not + * be interrupted by another task that uses the same ring. + * + */ + +#ifdef __cplusplus +extern "C" { +#endif + +#include <stdio.h> +#include <stdint.h> +#include <sys/queue.h> +#include <errno.h> +#include <rte_common.h> +#include <rte_memory.h> +#include <rte_lcore.h> +#include <rte_atomic.h> +#include <rte_branch_prediction.h> + +enum rte_ring_queue_behavior { + RTE_RING_QUEUE_FIXED = 0, /* Enq/Deq a fixed number of items from a ring */ + RTE_RING_QUEUE_VARIABLE /* Enq/Deq as many items a possible from ring */ +}; + +#ifdef RTE_LIBRTE_RING_DEBUG +/** + * A structure that stores the ring statistics (per-lcore). + */ +struct rte_ring_debug_stats { + uint64_t enq_success_bulk; /**< Successful enqueues number. */ + uint64_t enq_success_objs; /**< Objects successfully enqueued. */ + uint64_t enq_quota_bulk; /**< Successful enqueues above watermark. */ + uint64_t enq_quota_objs; /**< Objects enqueued above watermark. */ + uint64_t enq_fail_bulk; /**< Failed enqueues number. */ + uint64_t enq_fail_objs; /**< Objects that failed to be enqueued. */ + uint64_t deq_success_bulk; /**< Successful dequeues number. */ + uint64_t deq_success_objs; /**< Objects successfully dequeued. */ + uint64_t deq_fail_bulk; /**< Failed dequeues number. */ + uint64_t deq_fail_objs; /**< Objects that failed to be dequeued. */ +} __rte_cache_aligned; +#endif + +#define RTE_RING_NAMESIZE 32 /**< The maximum length of a ring name. */ +#define RTE_RING_MZ_PREFIX "RG_" + +/** + * An RTE ring structure. + * + * The producer and the consumer have a head and a tail index. The particularity + * of these index is that they are not between 0 and size(ring). These indexes + * are between 0 and 2^32, and we mask their value when we access the ring[] + * field. Thanks to this assumption, we can do subtractions between 2 index + * values in a modulo-32bit base: that's why the overflow of the indexes is not + * a problem. + */ +struct rte_ring { + char name[RTE_RING_NAMESIZE]; /**< Name of the ring. */ + int flags; /**< Flags supplied at creation. */ + + /** Ring producer status. */ + struct prod { + uint32_t watermark; /**< Maximum items before EDQUOT. */ + uint32_t sp_enqueue; /**< True, if single producer. */ + uint32_t size; /**< Size of ring. */ + uint32_t mask; /**< Mask (size-1) of ring. */ + volatile uint32_t head; /**< Producer head. */ + volatile uint32_t tail; /**< Producer tail. */ + } prod __rte_cache_aligned; + + /** Ring consumer status. */ + struct cons { + uint32_t sc_dequeue; /**< True, if single consumer. */ + uint32_t size; /**< Size of the ring. */ + uint32_t mask; /**< Mask (size-1) of ring. */ + volatile uint32_t head; /**< Consumer head. */ + volatile uint32_t tail; /**< Consumer tail. */ +#ifdef RTE_RING_SPLIT_PROD_CONS + } cons __rte_cache_aligned; +#else + } cons; +#endif + +#ifdef RTE_LIBRTE_RING_DEBUG + struct rte_ring_debug_stats stats[RTE_MAX_LCORE]; +#endif + + void * ring[0] __rte_cache_aligned; /**< Memory space of ring starts here. + * not volatile so need to be careful + * about compiler re-ordering */ +}; + +#define RING_F_SP_ENQ 0x0001 /**< The default enqueue is "single-producer". */ +#define RING_F_SC_DEQ 0x0002 /**< The default dequeue is "single-consumer". */ +#define RTE_RING_QUOT_EXCEED (1 << 31) /**< Quota exceed for burst ops */ +#define RTE_RING_SZ_MASK (unsigned)(0x0fffffff) /**< Ring size mask */ + +/** + * @internal When debug is enabled, store ring statistics. + * @param r + * A pointer to the ring. + * @param name + * The name of the statistics field to increment in the ring. + * @param n + * The number to add to the object-oriented statistics. + */ +#ifdef RTE_LIBRTE_RING_DEBUG +#define __RING_STAT_ADD(r, name, n) do { \ + unsigned __lcore_id = rte_lcore_id(); \ + r->stats[__lcore_id].name##_objs += n; \ + r->stats[__lcore_id].name##_bulk += 1; \ + } while(0) +#else +#define __RING_STAT_ADD(r, name, n) do {} while(0) +#endif + +/** + * Calculate the memory size needed for a ring + * + * This function returns the number of bytes needed for a ring, given + * the number of elements in it. This value is the sum of the size of + * the structure rte_ring and the size of the memory needed by the + * objects pointers. The value is aligned to a cache line size. + * + * @param count + * The number of elements in the ring (must be a power of 2). + * @return + * - The memory size needed for the ring on success. + * - -EINVAL if count is not a power of 2. + */ +ssize_t rte_ring_get_memsize(unsigned count); + +/** + * Initialize a ring structure. + * + * Initialize a ring structure in memory pointed by "r". The size of the + * memory area must be large enough to store the ring structure and the + * object table. It is advised to use rte_ring_get_memsize() to get the + * appropriate size. + * + * The ring size is set to *count*, which must be a power of two. Water + * marking is disabled by default. The real usable ring size is + * *count-1* instead of *count* to differentiate a free ring from an + * empty ring. + * + * The ring is not added in RTE_TAILQ_RING global list. Indeed, the + * memory given by the caller may not be shareable among dpdk + * processes. + * + * @param r + * The pointer to the ring structure followed by the objects table. + * @param name + * The name of the ring. + * @param count + * The number of elements in the ring (must be a power of 2). + * @param flags + * An OR of the following: + * - RING_F_SP_ENQ: If this flag is set, the default behavior when + * using ``rte_ring_enqueue()`` or ``rte_ring_enqueue_bulk()`` + * is "single-producer". Otherwise, it is "multi-producers". + * - RING_F_SC_DEQ: If this flag is set, the default behavior when + * using ``rte_ring_dequeue()`` or ``rte_ring_dequeue_bulk()`` + * is "single-consumer". Otherwise, it is "multi-consumers". + * @return + * 0 on success, or a negative value on error. + */ +int rte_ring_init(struct rte_ring *r, const char *name, unsigned count, + unsigned flags); + +/** + * Create a new ring named *name* in memory. + * + * This function uses ``memzone_reserve()`` to allocate memory. Then it + * calls rte_ring_init() to initialize an empty ring. + * + * The new ring size is set to *count*, which must be a power of + * two. Water marking is disabled by default. The real usable ring size + * is *count-1* instead of *count* to differentiate a free ring from an + * empty ring. + * + * The ring is added in RTE_TAILQ_RING list. + * + * @param name + * The name of the ring. + * @param count + * The size of the ring (must be a power of 2). + * @param socket_id + * The *socket_id* argument is the socket identifier in case of + * NUMA. The value can be *SOCKET_ID_ANY* if there is no NUMA + * constraint for the reserved zone. + * @param flags + * An OR of the following: + * - RING_F_SP_ENQ: If this flag is set, the default behavior when + * using ``rte_ring_enqueue()`` or ``rte_ring_enqueue_bulk()`` + * is "single-producer". Otherwise, it is "multi-producers". + * - RING_F_SC_DEQ: If this flag is set, the default behavior when + * using ``rte_ring_dequeue()`` or ``rte_ring_dequeue_bulk()`` + * is "single-consumer". Otherwise, it is "multi-consumers". + * @return + * On success, the pointer to the new allocated ring. NULL on error with + * rte_errno set appropriately. Possible errno values include: + * - E_RTE_NO_CONFIG - function could not get pointer to rte_config structure + * - E_RTE_SECONDARY - function was called from a secondary process instance + * - E_RTE_NO_TAILQ - no tailq list could be got for the ring list + * - EINVAL - count provided is not a power of 2 + * - ENOSPC - the maximum number of memzones has already been allocated + * - EEXIST - a memzone with the same name already exists + * - ENOMEM - no appropriate memory area found in which to create memzone + */ +struct rte_ring *rte_ring_create(const char *name, unsigned count, + int socket_id, unsigned flags); + +/** + * Change the high water mark. + * + * If *count* is 0, water marking is disabled. Otherwise, it is set to the + * *count* value. The *count* value must be greater than 0 and less + * than the ring size. + * + * This function can be called at any time (not necessarily at + * initialization). + * + * @param r + * A pointer to the ring structure. + * @param count + * The new water mark value. + * @return + * - 0: Success; water mark changed. + * - -EINVAL: Invalid water mark value. + */ +int rte_ring_set_water_mark(struct rte_ring *r, unsigned count); + +/** + * Dump the status of the ring to the console. + * + * @param f + * A pointer to a file for output + * @param r + * A pointer to the ring structure. + */ +void rte_ring_dump(FILE *f, const struct rte_ring *r); + +/* the actual enqueue of pointers on the ring. + * Placed here since identical code needed in both + * single and multi producer enqueue functions */ +#define ENQUEUE_PTRS() do { \ + const uint32_t size = r->prod.size; \ + uint32_t idx = prod_head & mask; \ + if (likely(idx + n < size)) { \ + for (i = 0; i < (n & ((~(unsigned)0x3))); i+=4, idx+=4) { \ + r->ring[idx] = obj_table[i]; \ + r->ring[idx+1] = obj_table[i+1]; \ + r->ring[idx+2] = obj_table[i+2]; \ + r->ring[idx+3] = obj_table[i+3]; \ + } \ + switch (n & 0x3) { \ + case 3: r->ring[idx++] = obj_table[i++]; \ + case 2: r->ring[idx++] = obj_table[i++]; \ + case 1: r->ring[idx++] = obj_table[i++]; \ + } \ + } else { \ + for (i = 0; idx < size; i++, idx++)\ + r->ring[idx] = obj_table[i]; \ + for (idx = 0; i < n; i++, idx++) \ + r->ring[idx] = obj_table[i]; \ + } \ +} while(0) + +/* the actual copy of pointers on the ring to obj_table. + * Placed here since identical code needed in both + * single and multi consumer dequeue functions */ +#define DEQUEUE_PTRS() do { \ + uint32_t idx = cons_head & mask; \ + const uint32_t size = r->cons.size; \ + if (likely(idx + n < size)) { \ + for (i = 0; i < (n & (~(unsigned)0x3)); i+=4, idx+=4) {\ + obj_table[i] = r->ring[idx]; \ + obj_table[i+1] = r->ring[idx+1]; \ + obj_table[i+2] = r->ring[idx+2]; \ + obj_table[i+3] = r->ring[idx+3]; \ + } \ + switch (n & 0x3) { \ + case 3: obj_table[i++] = r->ring[idx++]; \ + case 2: obj_table[i++] = r->ring[idx++]; \ + case 1: obj_table[i++] = r->ring[idx++]; \ + } \ + } else { \ + for (i = 0; idx < size; i++, idx++) \ + obj_table[i] = r->ring[idx]; \ + for (idx = 0; i < n; i++, idx++) \ + obj_table[i] = r->ring[idx]; \ + } \ +} while (0) + +/** + * @internal Enqueue several objects on the ring (multi-producers safe). + * + * This function uses a "compare and set" instruction to move the + * producer index atomically. + * + * @param r + * A pointer to the ring structure. + * @param obj_table + * A pointer to a table of void * pointers (objects). + * @param n + * The number of objects to add in the ring from the obj_table. + * @param behavior + * RTE_RING_QUEUE_FIXED: Enqueue a fixed number of items from a ring + * RTE_RING_QUEUE_VARIABLE: Enqueue as many items a possible from ring + * @return + * Depend on the behavior value + * if behavior = RTE_RING_QUEUE_FIXED + * - 0: Success; objects enqueue. + * - -EDQUOT: Quota exceeded. The objects have been enqueued, but the + * high water mark is exceeded. + * - -ENOBUFS: Not enough room in the ring to enqueue, no object is enqueued. + * if behavior = RTE_RING_QUEUE_VARIABLE + * - n: Actual number of objects enqueued. + */ +static inline int __attribute__((always_inline)) +__rte_ring_mp_do_enqueue(struct rte_ring *r, void * const *obj_table, + unsigned n, enum rte_ring_queue_behavior behavior) +{ + uint32_t prod_head, prod_next; + uint32_t cons_tail, free_entries; + const unsigned max = n; + int success; + unsigned i; + uint32_t mask = r->prod.mask; + int ret; + + /* move prod.head atomically */ + do { + /* Reset n to the initial burst count */ + n = max; + + prod_head = r->prod.head; + cons_tail = r->cons.tail; + /* The subtraction is done between two unsigned 32bits value + * (the result is always modulo 32 bits even if we have + * prod_head > cons_tail). So 'free_entries' is always between 0 + * and size(ring)-1. */ + free_entries = (mask + cons_tail - prod_head); + + /* check that we have enough room in ring */ + if (unlikely(n > free_entries)) { + if (behavior == RTE_RING_QUEUE_FIXED) { + __RING_STAT_ADD(r, enq_fail, n); + return -ENOBUFS; + } + else { + /* No free entry available */ + if (unlikely(free_entries == 0)) { + __RING_STAT_ADD(r, enq_fail, n); + return 0; + } + + n = free_entries; + } + } + + prod_next = prod_head + n; + success = rte_atomic32_cmpset(&r->prod.head, prod_head, + prod_next); + } while (unlikely(success == 0)); + + /* write entries in ring */ + ENQUEUE_PTRS(); + rte_compiler_barrier(); + + /* if we exceed the watermark */ + if (unlikely(((mask + 1) - free_entries + n) > r->prod.watermark)) { + ret = (behavior == RTE_RING_QUEUE_FIXED) ? -EDQUOT : + (int)(n | RTE_RING_QUOT_EXCEED); + __RING_STAT_ADD(r, enq_quota, n); + } + else { + ret = (behavior == RTE_RING_QUEUE_FIXED) ? 0 : n; + __RING_STAT_ADD(r, enq_success, n); + } + + /* + * If there are other enqueues in progress that preceded us, + * we need to wait for them to complete + */ + while (unlikely(r->prod.tail != prod_head)) + rte_pause(); + + r->prod.tail = prod_next; + return ret; +} + +/** + * @internal Enqueue several objects on a ring (NOT multi-producers safe). + * + * @param r + * A pointer to the ring structure. + * @param obj_table + * A pointer to a table of void * pointers (objects). + * @param n + * The number of objects to add in the ring from the obj_table. + * @param behavior + * RTE_RING_QUEUE_FIXED: Enqueue a fixed number of items from a ring + * RTE_RING_QUEUE_VARIABLE: Enqueue as many items a possible from ring + * @return + * Depend on the behavior value + * if behavior = RTE_RING_QUEUE_FIXED + * - 0: Success; objects enqueue. + * - -EDQUOT: Quota exceeded. The objects have been enqueued, but the + * high water mark is exceeded. + * - -ENOBUFS: Not enough room in the ring to enqueue, no object is enqueued. + * if behavior = RTE_RING_QUEUE_VARIABLE + * - n: Actual number of objects enqueued. + */ +static inline int __attribute__((always_inline)) +__rte_ring_sp_do_enqueue(struct rte_ring *r, void * const *obj_table, + unsigned n, enum rte_ring_queue_behavior behavior) +{ + uint32_t prod_head, cons_tail; + uint32_t prod_next, free_entries; + unsigned i; + uint32_t mask = r->prod.mask; + int ret; + + prod_head = r->prod.head; + cons_tail = r->cons.tail; + /* The subtraction is done between two unsigned 32bits value + * (the result is always modulo 32 bits even if we have + * prod_head > cons_tail). So 'free_entries' is always between 0 + * and size(ring)-1. */ + free_entries = mask + cons_tail - prod_head; + + /* check that we have enough room in ring */ + if (unlikely(n > free_entries)) { + if (behavior == RTE_RING_QUEUE_FIXED) { + __RING_STAT_ADD(r, enq_fail, n); + return -ENOBUFS; + } + else { + /* No free entry available */ + if (unlikely(free_entries == 0)) { + __RING_STAT_ADD(r, enq_fail, n); + return 0; + } + + n = free_entries; + } + } + + prod_next = prod_head + n; + r->prod.head = prod_next; + + /* write entries in ring */ + ENQUEUE_PTRS(); + rte_compiler_barrier(); + + /* if we exceed the watermark */ + if (unlikely(((mask + 1) - free_entries + n) > r->prod.watermark)) { + ret = (behavior == RTE_RING_QUEUE_FIXED) ? -EDQUOT : + (int)(n | RTE_RING_QUOT_EXCEED); + __RING_STAT_ADD(r, enq_quota, n); + } + else { + ret = (behavior == RTE_RING_QUEUE_FIXED) ? 0 : n; + __RING_STAT_ADD(r, enq_success, n); + } + + r->prod.tail = prod_next; + return ret; +} + +/** + * @internal Dequeue several objects from a ring (multi-consumers safe). When + * the request objects are more than the available objects, only dequeue the + * actual number of objects + * + * This function uses a "compare and set" instruction to move the + * consumer index atomically. + * + * @param r + * A pointer to the ring structure. + * @param obj_table + * A pointer to a table of void * pointers (objects) that will be filled. + * @param n + * The number of objects to dequeue from the ring to the obj_table. + * @param behavior + * RTE_RING_QUEUE_FIXED: Dequeue a fixed number of items from a ring + * RTE_RING_QUEUE_VARIABLE: Dequeue as many items a possible from ring + * @return + * Depend on the behavior value + * if behavior = RTE_RING_QUEUE_FIXED + * - 0: Success; objects dequeued. + * - -ENOENT: Not enough entries in the ring to dequeue; no object is + * dequeued. + * if behavior = RTE_RING_QUEUE_VARIABLE + * - n: Actual number of objects dequeued. + */ + +static inline int __attribute__((always_inline)) +__rte_ring_mc_do_dequeue(struct rte_ring *r, void **obj_table, + unsigned n, enum rte_ring_queue_behavior behavior) +{ + uint32_t cons_head, prod_tail; + uint32_t cons_next, entries; + const unsigned max = n; + int success; + unsigned i; + uint32_t mask = r->prod.mask; + + /* move cons.head atomically */ + do { + /* Restore n as it may change every loop */ + n = max; + + cons_head = r->cons.head; + prod_tail = r->prod.tail; + /* The subtraction is done between two unsigned 32bits value + * (the result is always modulo 32 bits even if we have + * cons_head > prod_tail). So 'entries' is always between 0 + * and size(ring)-1. */ + entries = (prod_tail - cons_head); + + /* Set the actual entries for dequeue */ + if (n > entries) { + if (behavior == RTE_RING_QUEUE_FIXED) { + __RING_STAT_ADD(r, deq_fail, n); + return -ENOENT; + } + else { + if (unlikely(entries == 0)){ + __RING_STAT_ADD(r, deq_fail, n); + return 0; + } + + n = entries; + } + } + + cons_next = cons_head + n; + success = rte_atomic32_cmpset(&r->cons.head, cons_head, + cons_next); + } while (unlikely(success == 0)); + + /* copy in table */ + DEQUEUE_PTRS(); + rte_compiler_barrier(); + + /* + * If there are other dequeues in progress that preceded us, + * we need to wait for them to complete + */ + while (unlikely(r->cons.tail != cons_head)) + rte_pause(); + + __RING_STAT_ADD(r, deq_success, n); + r->cons.tail = cons_next; + + return behavior == RTE_RING_QUEUE_FIXED ? 0 : n; +} + +/** + * @internal Dequeue several objects from a ring (NOT multi-consumers safe). + * When the request objects are more than the available objects, only dequeue + * the actual number of objects + * + * @param r + * A pointer to the ring structure. + * @param obj_table + * A pointer to a table of void * pointers (objects) that will be filled. + * @param n + * The number of objects to dequeue from the ring to the obj_table. + * @param behavior + * RTE_RING_QUEUE_FIXED: Dequeue a fixed number of items from a ring + * RTE_RING_QUEUE_VARIABLE: Dequeue as many items a possible from ring + * @return + * Depend on the behavior value + * if behavior = RTE_RING_QUEUE_FIXED + * - 0: Success; objects dequeued. + * - -ENOENT: Not enough entries in the ring to dequeue; no object is + * dequeued. + * if behavior = RTE_RING_QUEUE_VARIABLE + * - n: Actual number of objects dequeued. + */ +static inline int __attribute__((always_inline)) +__rte_ring_sc_do_dequeue(struct rte_ring *r, void **obj_table, + unsigned n, enum rte_ring_queue_behavior behavior) +{ + uint32_t cons_head, prod_tail; + uint32_t cons_next, entries; + unsigned i; + uint32_t mask = r->prod.mask; + + cons_head = r->cons.head; + prod_tail = r->prod.tail; + /* The subtraction is done between two unsigned 32bits value + * (the result is always modulo 32 bits even if we have + * cons_head > prod_tail). So 'entries' is always between 0 + * and size(ring)-1. */ + entries = prod_tail - cons_head; + + if (n > entries) { + if (behavior == RTE_RING_QUEUE_FIXED) { + __RING_STAT_ADD(r, deq_fail, n); + return -ENOENT; + } + else { + if (unlikely(entries == 0)){ + __RING_STAT_ADD(r, deq_fail, n); + return 0; + } + + n = entries; + } + } + + cons_next = cons_head + n; + r->cons.head = cons_next; + + /* copy in table */ + DEQUEUE_PTRS(); + rte_compiler_barrier(); + + __RING_STAT_ADD(r, deq_success, n); + r->cons.tail = cons_next; + return behavior == RTE_RING_QUEUE_FIXED ? 0 : n; +} + +/** + * Enqueue several objects on the ring (multi-producers safe). + * + * This function uses a "compare and set" instruction to move the + * producer index atomically. + * + * @param r + * A pointer to the ring structure. + * @param obj_table + * A pointer to a table of void * pointers (objects). + * @param n + * The number of objects to add in the ring from the obj_table. + * @return + * - 0: Success; objects enqueue. + * - -EDQUOT: Quota exceeded. The objects have been enqueued, but the + * high water mark is exceeded. + * - -ENOBUFS: Not enough room in the ring to enqueue, no object is enqueued. + */ +static inline int __attribute__((always_inline)) +rte_ring_mp_enqueue_bulk(struct rte_ring *r, void * const *obj_table, + unsigned n) +{ + return __rte_ring_mp_do_enqueue(r, obj_table, n, RTE_RING_QUEUE_FIXED); +} + +/** + * Enqueue several objects on a ring (NOT multi-producers safe). + * + * @param r + * A pointer to the ring structure. + * @param obj_table + * A pointer to a table of void * pointers (objects). + * @param n + * The number of objects to add in the ring from the obj_table. + * @return + * - 0: Success; objects enqueued. + * - -EDQUOT: Quota exceeded. The objects have been enqueued, but the + * high water mark is exceeded. + * - -ENOBUFS: Not enough room in the ring to enqueue; no object is enqueued. + */ +static inline int __attribute__((always_inline)) +rte_ring_sp_enqueue_bulk(struct rte_ring *r, void * const *obj_table, + unsigned n) +{ + return __rte_ring_sp_do_enqueue(r, obj_table, n, RTE_RING_QUEUE_FIXED); +} + +/** + * Enqueue several objects on a ring. + * + * This function calls the multi-producer or the single-producer + * version depending on the default behavior that was specified at + * ring creation time (see flags). + * + * @param r + * A pointer to the ring structure. + * @param obj_table + * A pointer to a table of void * pointers (objects). + * @param n + * The number of objects to add in the ring from the obj_table. + * @return + * - 0: Success; objects enqueued. + * - -EDQUOT: Quota exceeded. The objects have been enqueued, but the + * high water mark is exceeded. + * - -ENOBUFS: Not enough room in the ring to enqueue; no object is enqueued. + */ +static inline int __attribute__((always_inline)) +rte_ring_enqueue_bulk(struct rte_ring *r, void * const *obj_table, + unsigned n) +{ + if (r->prod.sp_enqueue) + return rte_ring_sp_enqueue_bulk(r, obj_table, n); + else + return rte_ring_mp_enqueue_bulk(r, obj_table, n); +} + +/** + * Enqueue one object on a ring (multi-producers safe). + * + * This function uses a "compare and set" instruction to move the + * producer index atomically. + * + * @param r + * A pointer to the ring structure. + * @param obj + * A pointer to the object to be added. + * @return + * - 0: Success; objects enqueued. + * - -EDQUOT: Quota exceeded. The objects have been enqueued, but the + * high water mark is exceeded. + * - -ENOBUFS: Not enough room in the ring to enqueue; no object is enqueued. + */ +static inline int __attribute__((always_inline)) +rte_ring_mp_enqueue(struct rte_ring *r, void *obj) +{ + return rte_ring_mp_enqueue_bulk(r, &obj, 1); +} + +/** + * Enqueue one object on a ring (NOT multi-producers safe). + * + * @param r + * A pointer to the ring structure. + * @param obj + * A pointer to the object to be added. + * @return + * - 0: Success; objects enqueued. + * - -EDQUOT: Quota exceeded. The objects have been enqueued, but the + * high water mark is exceeded. + * - -ENOBUFS: Not enough room in the ring to enqueue; no object is enqueued. + */ +static inline int __attribute__((always_inline)) +rte_ring_sp_enqueue(struct rte_ring *r, void *obj) +{ + return rte_ring_sp_enqueue_bulk(r, &obj, 1); +} + +/** + * Enqueue one object on a ring. + * + * This function calls the multi-producer or the single-producer + * version, depending on the default behaviour that was specified at + * ring creation time (see flags). + * + * @param r + * A pointer to the ring structure. + * @param obj + * A pointer to the object to be added. + * @return + * - 0: Success; objects enqueued. + * - -EDQUOT: Quota exceeded. The objects have been enqueued, but the + * high water mark is exceeded. + * - -ENOBUFS: Not enough room in the ring to enqueue; no object is enqueued. + */ +static inline int __attribute__((always_inline)) +rte_ring_enqueue(struct rte_ring *r, void *obj) +{ + if (r->prod.sp_enqueue) + return rte_ring_sp_enqueue(r, obj); + else + return rte_ring_mp_enqueue(r, obj); +} + +/** + * Dequeue several objects from a ring (multi-consumers safe). + * + * This function uses a "compare and set" instruction to move the + * consumer index atomically. + * + * @param r + * A pointer to the ring structure. + * @param obj_table + * A pointer to a table of void * pointers (objects) that will be filled. + * @param n + * The number of objects to dequeue from the ring to the obj_table. + * @return + * - 0: Success; objects dequeued. + * - -ENOENT: Not enough entries in the ring to dequeue; no object is + * dequeued. + */ +static inline int __attribute__((always_inline)) +rte_ring_mc_dequeue_bulk(struct rte_ring *r, void **obj_table, unsigned n) +{ + return __rte_ring_mc_do_dequeue(r, obj_table, n, RTE_RING_QUEUE_FIXED); +} + +/** + * Dequeue several objects from a ring (NOT multi-consumers safe). + * + * @param r + * A pointer to the ring structure. + * @param obj_table + * A pointer to a table of void * pointers (objects) that will be filled. + * @param n + * The number of objects to dequeue from the ring to the obj_table, + * must be strictly positive. + * @return + * - 0: Success; objects dequeued. + * - -ENOENT: Not enough entries in the ring to dequeue; no object is + * dequeued. + */ +static inline int __attribute__((always_inline)) +rte_ring_sc_dequeue_bulk(struct rte_ring *r, void **obj_table, unsigned n) +{ + return __rte_ring_sc_do_dequeue(r, obj_table, n, RTE_RING_QUEUE_FIXED); +} + +/** + * Dequeue several objects from a ring. + * + * This function calls the multi-consumers or the single-consumer + * version, depending on the default behaviour that was specified at + * ring creation time (see flags). + * + * @param r + * A pointer to the ring structure. + * @param obj_table + * A pointer to a table of void * pointers (objects) that will be filled. + * @param n + * The number of objects to dequeue from the ring to the obj_table. + * @return + * - 0: Success; objects dequeued. + * - -ENOENT: Not enough entries in the ring to dequeue, no object is + * dequeued. + */ +static inline int __attribute__((always_inline)) +rte_ring_dequeue_bulk(struct rte_ring *r, void **obj_table, unsigned n) +{ + if (r->cons.sc_dequeue) + return rte_ring_sc_dequeue_bulk(r, obj_table, n); + else + return rte_ring_mc_dequeue_bulk(r, obj_table, n); +} + +/** + * Dequeue one object from a ring (multi-consumers safe). + * + * This function uses a "compare and set" instruction to move the + * consumer index atomically. + * + * @param r + * A pointer to the ring structure. + * @param obj_p + * A pointer to a void * pointer (object) that will be filled. + * @return + * - 0: Success; objects dequeued. + * - -ENOENT: Not enough entries in the ring to dequeue; no object is + * dequeued. + */ +static inline int __attribute__((always_inline)) +rte_ring_mc_dequeue(struct rte_ring *r, void **obj_p) +{ + return rte_ring_mc_dequeue_bulk(r, obj_p, 1); +} + +/** + * Dequeue one object from a ring (NOT multi-consumers safe). + * + * @param r + * A pointer to the ring structure. + * @param obj_p + * A pointer to a void * pointer (object) that will be filled. + * @return + * - 0: Success; objects dequeued. + * - -ENOENT: Not enough entries in the ring to dequeue, no object is + * dequeued. + */ +static inline int __attribute__((always_inline)) +rte_ring_sc_dequeue(struct rte_ring *r, void **obj_p) +{ + return rte_ring_sc_dequeue_bulk(r, obj_p, 1); +} + +/** + * Dequeue one object from a ring. + * + * This function calls the multi-consumers or the single-consumer + * version depending on the default behaviour that was specified at + * ring creation time (see flags). + * + * @param r + * A pointer to the ring structure. + * @param obj_p + * A pointer to a void * pointer (object) that will be filled. + * @return + * - 0: Success, objects dequeued. + * - -ENOENT: Not enough entries in the ring to dequeue, no object is + * dequeued. + */ +static inline int __attribute__((always_inline)) +rte_ring_dequeue(struct rte_ring *r, void **obj_p) +{ + if (r->cons.sc_dequeue) + return rte_ring_sc_dequeue(r, obj_p); + else + return rte_ring_mc_dequeue(r, obj_p); +} + +/** + * Test if a ring is full. + * + * @param r + * A pointer to the ring structure. + * @return + * - 1: The ring is full. + * - 0: The ring is not full. + */ +static inline int +rte_ring_full(const struct rte_ring *r) +{ + uint32_t prod_tail = r->prod.tail; + uint32_t cons_tail = r->cons.tail; + return (((cons_tail - prod_tail - 1) & r->prod.mask) == 0); +} + +/** + * Test if a ring is empty. + * + * @param r + * A pointer to the ring structure. + * @return + * - 1: The ring is empty. + * - 0: The ring is not empty. + */ +static inline int +rte_ring_empty(const struct rte_ring *r) +{ + uint32_t prod_tail = r->prod.tail; + uint32_t cons_tail = r->cons.tail; + return !!(cons_tail == prod_tail); +} + +/** + * Return the number of entries in a ring. + * + * @param r + * A pointer to the ring structure. + * @return + * The number of entries in the ring. + */ +static inline unsigned +rte_ring_count(const struct rte_ring *r) +{ + uint32_t prod_tail = r->prod.tail; + uint32_t cons_tail = r->cons.tail; + return ((prod_tail - cons_tail) & r->prod.mask); +} + +/** + * Return the number of free entries in a ring. + * + * @param r + * A pointer to the ring structure. + * @return + * The number of free entries in the ring. + */ +static inline unsigned +rte_ring_free_count(const struct rte_ring *r) +{ + uint32_t prod_tail = r->prod.tail; + uint32_t cons_tail = r->cons.tail; + return ((cons_tail - prod_tail - 1) & r->prod.mask); +} + +/** + * Dump the status of all rings on the console + * + * @param f + * A pointer to a file for output + */ +void rte_ring_list_dump(FILE *f); + +/** + * Search a ring from its name + * + * @param name + * The name of the ring. + * @return + * The pointer to the ring matching the name, or NULL if not found, + * with rte_errno set appropriately. Possible rte_errno values include: + * - ENOENT - required entry not available to return. + */ +struct rte_ring *rte_ring_lookup(const char *name); + +/** + * Enqueue several objects on the ring (multi-producers safe). + * + * This function uses a "compare and set" instruction to move the + * producer index atomically. + * + * @param r + * A pointer to the ring structure. + * @param obj_table + * A pointer to a table of void * pointers (objects). + * @param n + * The number of objects to add in the ring from the obj_table. + * @return + * - n: Actual number of objects enqueued. + */ +static inline unsigned __attribute__((always_inline)) +rte_ring_mp_enqueue_burst(struct rte_ring *r, void * const *obj_table, + unsigned n) +{ + return __rte_ring_mp_do_enqueue(r, obj_table, n, RTE_RING_QUEUE_VARIABLE); +} + +/** + * Enqueue several objects on a ring (NOT multi-producers safe). + * + * @param r + * A pointer to the ring structure. + * @param obj_table + * A pointer to a table of void * pointers (objects). + * @param n + * The number of objects to add in the ring from the obj_table. + * @return + * - n: Actual number of objects enqueued. + */ +static inline unsigned __attribute__((always_inline)) +rte_ring_sp_enqueue_burst(struct rte_ring *r, void * const *obj_table, + unsigned n) +{ + return __rte_ring_sp_do_enqueue(r, obj_table, n, RTE_RING_QUEUE_VARIABLE); +} + +/** + * Enqueue several objects on a ring. + * + * This function calls the multi-producer or the single-producer + * version depending on the default behavior that was specified at + * ring creation time (see flags). + * + * @param r + * A pointer to the ring structure. + * @param obj_table + * A pointer to a table of void * pointers (objects). + * @param n + * The number of objects to add in the ring from the obj_table. + * @return + * - n: Actual number of objects enqueued. + */ +static inline unsigned __attribute__((always_inline)) +rte_ring_enqueue_burst(struct rte_ring *r, void * const *obj_table, + unsigned n) +{ + if (r->prod.sp_enqueue) + return rte_ring_sp_enqueue_burst(r, obj_table, n); + else + return rte_ring_mp_enqueue_burst(r, obj_table, n); +} + +/** + * Dequeue several objects from a ring (multi-consumers safe). When the request + * objects are more than the available objects, only dequeue the actual number + * of objects + * + * This function uses a "compare and set" instruction to move the + * consumer index atomically. + * + * @param r + * A pointer to the ring structure. + * @param obj_table + * A pointer to a table of void * pointers (objects) that will be filled. + * @param n + * The number of objects to dequeue from the ring to the obj_table. + * @return + * - n: Actual number of objects dequeued, 0 if ring is empty + */ +static inline unsigned __attribute__((always_inline)) +rte_ring_mc_dequeue_burst(struct rte_ring *r, void **obj_table, unsigned n) +{ + return __rte_ring_mc_do_dequeue(r, obj_table, n, RTE_RING_QUEUE_VARIABLE); +} + +/** + * Dequeue several objects from a ring (NOT multi-consumers safe).When the + * request objects are more than the available objects, only dequeue the + * actual number of objects + * + * @param r + * A pointer to the ring structure. + * @param obj_table + * A pointer to a table of void * pointers (objects) that will be filled. + * @param n + * The number of objects to dequeue from the ring to the obj_table. + * @return + * - n: Actual number of objects dequeued, 0 if ring is empty + */ +static inline unsigned __attribute__((always_inline)) +rte_ring_sc_dequeue_burst(struct rte_ring *r, void **obj_table, unsigned n) +{ + return __rte_ring_sc_do_dequeue(r, obj_table, n, RTE_RING_QUEUE_VARIABLE); +} + +/** + * Dequeue multiple objects from a ring up to a maximum number. + * + * This function calls the multi-consumers or the single-consumer + * version, depending on the default behaviour that was specified at + * ring creation time (see flags). + * + * @param r + * A pointer to the ring structure. + * @param obj_table + * A pointer to a table of void * pointers (objects) that will be filled. + * @param n + * The number of objects to dequeue from the ring to the obj_table. + * @return + * - Number of objects dequeued + */ +static inline unsigned __attribute__((always_inline)) +rte_ring_dequeue_burst(struct rte_ring *r, void **obj_table, unsigned n) +{ + if (r->cons.sc_dequeue) + return rte_ring_sc_dequeue_burst(r, obj_table, n); + else + return rte_ring_mc_dequeue_burst(r, obj_table, n); +} + +#ifdef __cplusplus +} +#endif + +#endif /* _RTE_RING_H_ */ |