/*- * BSD LICENSE * * Copyright(c) 2010-2017 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 #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 as possible from ring */ }; #define RTE_RING_MZ_PREFIX "RG_" /**< The maximum length of a ring name. */ #define RTE_RING_NAMESIZE (RTE_MEMZONE_NAMESIZE - \ sizeof(RTE_RING_MZ_PREFIX) + 1) struct rte_memzone; /* forward declaration, so as not to require memzone.h */ #if RTE_CACHE_LINE_SIZE < 128 #define PROD_ALIGN (RTE_CACHE_LINE_SIZE * 2) #define CONS_ALIGN (RTE_CACHE_LINE_SIZE * 2) #else #define PROD_ALIGN RTE_CACHE_LINE_SIZE #define CONS_ALIGN RTE_CACHE_LINE_SIZE #endif /* structure to hold a pair of head/tail values and other metadata */ struct rte_ring_headtail { volatile uint32_t head; /**< Prod/consumer head. */ volatile uint32_t tail; /**< Prod/consumer tail. */ uint32_t single; /**< True if single prod/cons */ }; /** * 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 { /* * Note: this field kept the RTE_MEMZONE_NAMESIZE size due to ABI * compatibility requirements, it could be changed to RTE_RING_NAMESIZE * next time the ABI changes */ char name[RTE_MEMZONE_NAMESIZE] __rte_cache_aligned; /**< Name of the ring. */ int flags; /**< Flags supplied at creation. */ const struct rte_memzone *memzone; /**< Memzone, if any, containing the rte_ring */ uint32_t size; /**< Size of ring. */ uint32_t mask; /**< Mask (size-1) of ring. */ uint32_t capacity; /**< Usable size of ring */ /** Ring producer status. */ struct rte_ring_headtail prod __rte_aligned(PROD_ALIGN); /** Ring consumer status. */ struct rte_ring_headtail cons __rte_aligned(CONS_ALIGN); }; #define RING_F_SP_ENQ 0x0001 /**< The default enqueue is "single-producer". */ #define RING_F_SC_DEQ 0x0002 /**< The default dequeue is "single-consumer". */ /** * Ring is to hold exactly requested number of entries. * Without this flag set, the ring size requested must be a power of 2, and the * usable space will be that size - 1. With the flag, the requested size will * be rounded up to the next power of two, but the usable space will be exactly * that requested. Worst case, if a power-of-2 size is requested, half the * ring space will be wasted. */ #define RING_F_EXACT_SZ 0x0004 #define RTE_RING_SZ_MASK (0x7fffffffU) /**< Ring size mask */ /* @internal defines for passing to the enqueue dequeue worker functions */ #define __IS_SP 1 #define __IS_MP 0 #define __IS_SC 1 #define __IS_MC 0 /** * 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); /** * Dump the status of the ring to a file. * * @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(r, ring_start, prod_head, obj_table, n, obj_type) do { \ unsigned int i; \ const uint32_t size = (r)->size; \ uint32_t idx = prod_head & (r)->mask; \ obj_type *ring = (obj_type *)ring_start; \ if (likely(idx + n < size)) { \ for (i = 0; i < (n & ((~(unsigned)0x3))); i+=4, idx+=4) { \ ring[idx] = obj_table[i]; \ ring[idx+1] = obj_table[i+1]; \ ring[idx+2] = obj_table[i+2]; \ ring[idx+3] = obj_table[i+3]; \ } \ switch (n & 0x3) { \ case 3: \ ring[idx++] = obj_table[i++]; /* fallthrough */ \ case 2: \ ring[idx++] = obj_table[i++]; /* fallthrough */ \ case 1: \ ring[idx++] = obj_table[i++]; \ } \ } else { \ for (i = 0; idx < size; i++, idx++)\ ring[idx] = obj_table[i]; \ for (idx = 0; i < n; i++, idx++) \ 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(r, ring_start, cons_head, obj_table, n, obj_type) do { \ unsigned int i; \ uint32_t idx = cons_head & (r)->mask; \ const uint32_t size = (r)->size; \ obj_type *ring = (obj_type *)ring_start; \ if (likely(idx + n < size)) { \ for (i = 0; i < (n & (~(unsigned)0x3)); i+=4, idx+=4) {\ obj_table[i] = ring[idx]; \ obj_table[i+1] = ring[idx+1]; \ obj_table[i+2] = ring[idx+2]; \ obj_table[i+3] = ring[idx+3]; \ } \ switch (n & 0x3) { \ case 3: \ obj_table[i++] = ring[idx++]; /* fallthrough */ \ case 2: \ obj_table[i++] = ring[idx++]; /* fallthrough */ \ case 1: \ obj_table[i++] = ring[idx++]; \ } \ } else { \ for (i = 0; idx < size; i++, idx++) \ obj_table[i] = ring[idx]; \ for (idx = 0; i < n; i++, idx++) \ obj_table[i] = ring[idx]; \ } \ } while (0) static __rte_always_inline void update_tail(struct rte_ring_headtail *ht, uint32_t old_val, uint32_t new_val, uint32_t single) { /* * If there are other enqueues/dequeues in progress that preceded us, * we need to wait for them to complete */ if (!single) while (unlikely(ht->tail != old_val)) rte_pause(); ht->tail = new_val; } /** * @internal This function updates the producer head for enqueue * * @param r * A pointer to the ring structure * @param is_sp * Indicates whether multi-producer path is needed or not * @param n * The number of elements we will want to enqueue, i.e. how far should the * head be moved * @param behavior * RTE_RING_QUEUE_FIXED: Enqueue a fixed number of items from a ring * RTE_RING_QUEUE_VARIABLE: Enqueue as many items as possible from ring * @param old_head * Returns head value as it was before the move, i.e. where enqueue starts * @param new_head * Returns the current/new head value i.e. where enqueue finishes * @param free_entries * Returns the amount of free space in the ring BEFORE head was moved * @return * Actual number of objects enqueued. * If behavior == RTE_RING_QUEUE_FIXED, this will be 0 or n only. */ static __rte_always_inline unsigned int __rte_ring_move_prod_head(struct rte_ring *r, unsigned int is_sp, unsigned int n, enum rte_ring_queue_behavior behavior, uint32_t *old_head, uint32_t *new_head, uint32_t *free_entries) { const uint32_t capacity = r->capacity; unsigned int max = n; int success; do { /* Reset n to the initial burst count */ n = max; *old_head = r->prod.head; /* add rmb barrier to avoid load/load reorder in weak * memory model. It is noop on x86 */ rte_smp_rmb(); /* * The subtraction is done between two unsigned 32bits value * (the result is always modulo 32 bits even if we have * *old_head > cons_tail). So 'free_entries' is always between 0 * and capacity (which is < size). */ *free_entries = (capacity + r->cons.tail - *old_head); /* check that we have enough room in ring */ if (unlikely(n > *free_entries)) n = (behavior == RTE_RING_QUEUE_FIXED) ? 0 : *free_entries; if (n == 0) return 0; *new_head = *old_head + n; if (is_sp) r->prod.head = *new_head, success = 1; else success = rte_atomic32_cmpset(&r->prod.head, *old_head, *new_head); } while (unlikely(success == 0)); return n; } /** * @internal Enqueue several objects on the ring * * @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 as possible from ring * @param is_sp * Indicates whether to use single producer or multi-producer head update * @param free_space * returns the amount of space after the enqueue operation has finished * @return * Actual number of objects enqueued. * If behavior == RTE_RING_QUEUE_FIXED, this will be 0 or n only. */ static __rte_always_inline unsigned int __rte_ring_do_enqueue(struct rte_ring *r, void * const *obj_table, unsigned int n, enum rte_ring_queue_behavior behavior, unsigned int is_sp, unsigned int *free_space) { uint32_t prod_head, prod_next; uint32_t free_entries; n = __rte_ring_move_prod_head(r, is_sp, n, behavior, &prod_head, &prod_next, &free_entries); if (n == 0) goto end; ENQUEUE_PTRS(r, &r[1], prod_head, obj_table, n, void *); rte_smp_wmb(); update_tail(&r->prod, prod_head, prod_next, is_sp); end: if (free_space != NULL) *free_space = free_entries - n; return n; } /** * @internal This function updates the consumer head for dequeue * * @param r * A pointer to the ring structure * @param is_sc * Indicates whether multi-consumer path is needed or not * @param n * The number of elements we will want to enqueue, i.e. how far should the * head be moved * @param behavior * RTE_RING_QUEUE_FIXED: Dequeue a fixed number of items from a ring * RTE_RING_QUEUE_VARIABLE: Dequeue as many items as possible from ring * @param old_head * Returns head value as it was before the move, i.e. where dequeue starts * @param new_head * Returns the current/new head value i.e. where dequeue finishes * @param entries * Returns the number of entries in the ring BEFORE head was moved * @return * - Actual number of objects dequeued. * If behavior == RTE_RING_QUEUE_FIXED, this will be 0 or n only. */ static __rte_always_inline unsigned int __rte_ring_move_cons_head(struct rte_ring *r, unsigned int is_sc, unsigned int n, enum rte_ring_queue_behavior behavior, uint32_t *old_head, uint32_t *new_head, uint32_t *entries) { unsigned int max = n; int success; /* move cons.head atomically */ do { /* Restore n as it may change every loop */ n = max; *old_head = r->cons.head; /* add rmb barrier to avoid load/load reorder in weak * memory model. It is noop on x86 */ rte_smp_rmb(); /* 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 = (r->prod.tail - *old_head); /* Set the actual entries for dequeue */ if (n > *entries) n = (behavior == RTE_RING_QUEUE_FIXED) ? 0 : *entries; if (unlikely(n == 0)) return 0; *new_head = *old_head + n; if (is_sc) r->cons.head = *new_head, success = 1; else success = rte_atomic32_cmpset(&r->cons.head, *old_head, *new_head); } while (unlikely(success == 0)); return n; } /** * @internal Dequeue several objects from the ring * * @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 pull from the ring. * @param behavior * RTE_RING_QUEUE_FIXED: Dequeue a fixed number of items from a ring * RTE_RING_QUEUE_VARIABLE: Dequeue as many items as possible from ring * @param is_sc * Indicates whether to use single consumer or multi-consumer head update * @param available * returns the number of remaining ring entries after the dequeue has finished * @return * - Actual number of objects dequeued. * If behavior == RTE_RING_QUEUE_FIXED, this will be 0 or n only. */ static __rte_always_inline unsigned int __rte_ring_do_dequeue(struct rte_ring *r, void **obj_table, unsigned int n, enum rte_ring_queue_behavior behavior, unsigned int is_sc, unsigned int *available) { uint32_t cons_head, cons_next; uint32_t entries; n = __rte_ring_move_cons_head(r, (int)is_sc, n, behavior, &cons_head, &cons_next, &entries); if (n == 0) goto end; DEQUEUE_PTRS(r, &r[1], cons_head, obj_table, n, void *); rte_smp_rmb(); update_tail(&r->cons, cons_head, cons_next, is_sc); end: if (available != NULL) *available = entries - n; return 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. * @param free_space * if non-NULL, returns the amount of space in the ring after the * enqueue operation has finished. * @return * The number of objects enqueued, either 0 or n */ static __rte_always_inline unsigned int rte_ring_mp_enqueue_bulk(struct rte_ring *r, void * const *obj_table, unsigned int n, unsigned int *free_space) { return __rte_ring_do_enqueue(r, obj_table, n, RTE_RING_QUEUE_FIXED, __IS_MP, free_space); } /** * 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 free_space * if non-NULL, returns the amount of space in the ring after the * enqueue operation has finished. * @return * The number of objects enqueued, either 0 or n */ static __rte_always_inline unsigned int rte_ring_sp_enqueue_bulk(struct rte_ring *r, void * const *obj_table, unsigned int n, unsigned int *free_space) { return __rte_ring_do_enqueue(r, obj_table, n, RTE_RING_QUEUE_FIXED, __IS_SP, free_space); } /** * 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. * @param free_space * if non-NULL, returns the amount of space in the ring after the * enqueue operation has finished. * @return * The number of objects enqueued, either 0 or n */ static __rte_always_inline unsigned int rte_ring_enqueue_bulk(struct rte_ring *r, void * const *obj_table, unsigned int n, unsigned int *free_space) { return __rte_ring_do_enqueue(r, obj_table, n, RTE_RING_QUEUE_FIXED, r->prod.single, free_space); } /** * 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. * - -ENOBUFS: Not enough room in the ring to enqueue; no object is enqueued. */ static __rte_always_inline int rte_ring_mp_enqueue(struct rte_ring *r, void *obj) { return rte_ring_mp_enqueue_bulk(r, &obj, 1, NULL) ? 0 : -ENOBUFS; } /** * 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. * - -ENOBUFS: Not enough room in the ring to enqueue; no object is enqueued. */ static __rte_always_inline int rte_ring_sp_enqueue(struct rte_ring *r, void *obj) { return rte_ring_sp_enqueue_bulk(r, &obj, 1, NULL) ? 0 : -ENOBUFS; } /** * 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. * - -ENOBUFS: Not enough room in the ring to enqueue; no object is enqueued. */ static __rte_always_inline int rte_ring_enqueue(struct rte_ring *r, void *obj) { return rte_ring_enqueue_bulk(r, &obj, 1, NULL) ? 0 : -ENOBUFS; } /** * 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. * @param available * If non-NULL, returns the number of remaining ring entries after the * dequeue has finished. * @return * The number of objects dequeued, either 0 or n */ static __rte_always_inline unsigned int rte_ring_mc_dequeue_bulk(struct rte_ring *r, void **obj_table, unsigned int n, unsigned int *available) { return __rte_ring_do_dequeue(r, obj_table, n, RTE_RING_QUEUE_FIXED, __IS_MC, available); } /** * 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. * @param available * If non-NULL, returns the number of remaining ring entries after the * dequeue has finished. * @return * The number of objects dequeued, either 0 or n */ static __rte_always_inline unsigned int rte_ring_sc_dequeue_bulk(struct rte_ring *r, void **obj_table, unsigned int n, unsigned int *available) { return __rte_ring_do_dequeue(r, obj_table, n, RTE_RING_QUEUE_FIXED, __IS_SC, available); } /** * 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. * @param available * If non-NULL, returns the number of remaining ring entries after the * dequeue has finished. * @return * The number of objects dequeued, either 0 or n */ static __rte_always_inline unsigned int rte_ring_dequeue_bulk(struct rte_ring *r, void **obj_table, unsigned int n, unsigned int *available) { return __rte_ring_do_dequeue(r, obj_table, n, RTE_RING_QUEUE_FIXED, r->cons.single, available); } /** * 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 __rte_always_inline int rte_ring_mc_dequeue(struct rte_ring *r, void **obj_p) { return rte_ring_mc_dequeue_bulk(r, obj_p, 1, NULL) ? 0 : -ENOENT; } /** * 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 __rte_always_inline int rte_ring_sc_dequeue(struct rte_ring *r, void **obj_p) { return rte_ring_sc_dequeue_bulk(r, obj_p, 1, NULL) ? 0 : -ENOENT; } /** * 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 __rte_always_inline int rte_ring_dequeue(struct rte_ring *r, void **obj_p) { return rte_ring_dequeue_bulk(r, obj_p, 1, NULL) ? 0 : -ENOENT; } /** * 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; uint32_t count = (prod_tail - cons_tail) & r->mask; return (count > r->capacity) ? r->capacity : count; } /** * 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) { return r->capacity - rte_ring_count(r); } /** * 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) { return rte_ring_free_count(r) == 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) { return rte_ring_count(r) == 0; } /** * Return the size of the ring. * * @param r * A pointer to the ring structure. * @return * The size of the data store used by the ring. * NOTE: this is not the same as the usable space in the ring. To query that * use ``rte_ring_get_capacity()``. */ static inline unsigned int rte_ring_get_size(const struct rte_ring *r) { return r->size; } /** * Return the number of elements which can be stored in the ring. * * @param r * A pointer to the ring structure. * @return * The usable size of the ring. */ static inline unsigned int rte_ring_get_capacity(const struct rte_ring *r) { return r->capacity; } /** * 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. * @param free_space * if non-NULL, returns the amount of space in the ring after the * enqueue operation has finished. * @return * - n: Actual number of objects enqueued. */ static __rte_always_inline unsigned rte_ring_mp_enqueue_burst(struct rte_ring *r, void * const *obj_table, unsigned int n, unsigned int *free_space) { return __rte_ring_do_enqueue(r, obj_table, n, RTE_RING_QUEUE_VARIABLE, __IS_MP, free_space); } /** * 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 free_space * if non-NULL, returns the amount of space in the ring after the * enqueue operation has finished. * @return * - n: Actual number of objects enqueued. */ static __rte_always_inline unsigned rte_ring_sp_enqueue_burst(struct rte_ring *r, void * const *obj_table, unsigned int n, unsigned int *free_space) { return __rte_ring_do_enqueue(r, obj_table, n, RTE_RING_QUEUE_VARIABLE, __IS_SP, free_space); } /** * 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. * @param free_space * if non-NULL, returns the amount of space in the ring after the * enqueue operation has finished. * @return * - n: Actual number of objects enqueued. */ static __rte_always_inline unsigned rte_ring_enqueue_burst(struct rte_ring *r, void * const *obj_table, unsigned int n, unsigned int *free_space) { return __rte_ring_do_enqueue(r, obj_table, n, RTE_RING_QUEUE_VARIABLE, r->prod.single, free_space); } /** * 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 available * If non-NULL, returns the number of remaining ring entries after the * dequeue has finished. * @return * - n: Actual number of objects dequeued, 0 if ring is empty */ static __rte_always_inline unsigned rte_ring_mc_dequeue_burst(struct rte_ring *r, void **obj_table, unsigned int n, unsigned int *available) { return __rte_ring_do_dequeue(r, obj_table, n, RTE_RING_QUEUE_VARIABLE, __IS_MC, available); } /** * 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 available * If non-NULL, returns the number of remaining ring entries after the * dequeue has finished. * @return * - n: Actual number of objects dequeued, 0 if ring is empty */ static __rte_always_inline unsigned rte_ring_sc_dequeue_burst(struct rte_ring *r, void **obj_table, unsigned int n, unsigned int *available) { return __rte_ring_do_dequeue(r, obj_table, n, RTE_RING_QUEUE_VARIABLE, __IS_SC, available); } /** * 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. * @param available * If non-NULL, returns the number of remaining ring entries after the * dequeue has finished. * @return * - Number of objects dequeued */ static __rte_always_inline unsigned rte_ring_dequeue_burst(struct rte_ring *r, void **obj_table, unsigned int n, unsigned int *available) { return __rte_ring_do_dequeue(r, obj_table, n, RTE_RING_QUEUE_VARIABLE, r->cons.single, available); } #ifdef __cplusplus } #endif #endif /* _RTE_RING_H_ */