/*- * 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 #include #include #include #include #include #include #include #include #define RTE_TAILQ_RING_NAME "RTE_RING" 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_" #ifndef RTE_RING_PAUSE_REP_COUNT #define RTE_RING_PAUSE_REP_COUNT 0 /**< Yield after pause num of times, no yield * if RTE_RING_PAUSE_REP not defined. */ #endif struct rte_memzone; /* forward declaration, so as not to require memzone.h */ /** * 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. */ const struct rte_memzone *memzone; /**< Memzone, if any, containing the rte_ring */ /** 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(); \ if (__lcore_id < RTE_MAX_LCORE) { \ 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 * - 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); /** * De-allocate all memory used by the ring. * * @param r * Ring to free */ void rte_ring_free(struct rte_ring *r); /** * 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, rep = 0; uint32_t mask = r->prod.mask; int ret; /* Avoid the unnecessary cmpset operation below, which is also * potentially harmful when n equals 0. */ if (n == 0) return 0; /* 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_smp_wmb(); /* 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(); /* Set RTE_RING_PAUSE_REP_COUNT to avoid spin too long waiting * for other thread finish. It gives pre-empted thread a chance * to proceed and finish with ring dequeue operation. */ if (RTE_RING_PAUSE_REP_COUNT && ++rep == RTE_RING_PAUSE_REP_COUNT) { rep = 0; sched_yield(); } } 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_smp_wmb(); /* 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, rep = 0; uint32_t mask = r->prod.mask; /* Avoid the unnecessary cmpset operation below, which is also * potentially harmful when n equals 0. */ if (n == 0) return 0; /* 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_smp_rmb(); /* * 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(); /* Set RTE_RING_PAUSE_REP_COUNT to avoid spin too long waiting * for other thread finish. It gives pre-empted thread a chance * to proceed and finish with ring dequeue operation. */ if (RTE_RING_PAUSE_REP_COUNT && ++rep == RTE_RING_PAUSE_REP_COUNT) { rep = 0; sched_yield(); } } __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_smp_rmb(); __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_ */