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Diffstat (limited to 'src/spdk/dpdk/lib/librte_ring/rte_ring.h')
| -rw-r--r-- | src/spdk/dpdk/lib/librte_ring/rte_ring.h | 1037 |
1 files changed, 1037 insertions, 0 deletions
diff --git a/src/spdk/dpdk/lib/librte_ring/rte_ring.h b/src/spdk/dpdk/lib/librte_ring/rte_ring.h new file mode 100644 index 000000000..86faede81 --- /dev/null +++ b/src/spdk/dpdk/lib/librte_ring/rte_ring.h @@ -0,0 +1,1037 @@ +/* SPDX-License-Identifier: BSD-3-Clause + * + * Copyright (c) 2010-2020 Intel Corporation + * Copyright (c) 2007-2009 Kip Macy kmacy@freebsd.org + * All rights reserved. + * Derived from FreeBSD's bufring.h + * Used as BSD-3 Licensed with permission from Kip Macy. + */ + +#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. + * - Ability to select different sync modes for producer/consumer. + * - Dequeue start/finish (depending on consumer sync modes). + * - Enqueue start/finish (depending on producer sync mode). + * + * Note: the ring implementation is not preemptible. Refer to Programmer's + * guide/Environment Abstraction Layer/Multiple pthread/Known Issues/rte_ring + * for more information. + * + */ + +#ifdef __cplusplus +extern "C" { +#endif + +#include <rte_ring_core.h> + +/** + * 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: + * - One of mutually exclusive flags that define producer behavior: + * - 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". + * - RING_F_MP_RTS_ENQ: If this flag is set, the default behavior when + * using ``rte_ring_enqueue()`` or ``rte_ring_enqueue_bulk()`` + * is "multi-producer RTS mode". + * - RING_F_MP_HTS_ENQ: If this flag is set, the default behavior when + * using ``rte_ring_enqueue()`` or ``rte_ring_enqueue_bulk()`` + * is "multi-producer HTS mode". + * If none of these flags is set, then default "multi-producer" + * behavior is selected. + * - One of mutually exclusive flags that define consumer behavior: + * - 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". + * - RING_F_MC_RTS_DEQ: If this flag is set, the default behavior when + * using ``rte_ring_dequeue()`` or ``rte_ring_dequeue_bulk()`` + * is "multi-consumer RTS mode". + * - RING_F_MC_HTS_DEQ: If this flag is set, the default behavior when + * using ``rte_ring_dequeue()`` or ``rte_ring_dequeue_bulk()`` + * is "multi-consumer HTS mode". + * If none of these flags is set, then default "multi-consumer" + * behavior is selected. + * @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: + * - One of mutually exclusive flags that define producer behavior: + * - 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". + * - RING_F_MP_RTS_ENQ: If this flag is set, the default behavior when + * using ``rte_ring_enqueue()`` or ``rte_ring_enqueue_bulk()`` + * is "multi-producer RTS mode". + * - RING_F_MP_HTS_ENQ: If this flag is set, the default behavior when + * using ``rte_ring_enqueue()`` or ``rte_ring_enqueue_bulk()`` + * is "multi-producer HTS mode". + * If none of these flags is set, then default "multi-producer" + * behavior is selected. + * - One of mutually exclusive flags that define consumer behavior: + * - 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". + * - RING_F_MC_RTS_DEQ: If this flag is set, the default behavior when + * using ``rte_ring_dequeue()`` or ``rte_ring_dequeue_bulk()`` + * is "multi-consumer RTS mode". + * - RING_F_MC_HTS_DEQ: If this flag is set, the default behavior when + * using ``rte_ring_dequeue()`` or ``rte_ring_dequeue_bulk()`` + * is "multi-consumer HTS mode". + * If none of these flags is set, then default "multi-consumer" + * behavior is selected. + * @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) + +/* Between load and load. there might be cpu reorder in weak model + * (powerpc/arm). + * There are 2 choices for the users + * 1.use rmb() memory barrier + * 2.use one-direction load_acquire/store_release barrier,defined by + * CONFIG_RTE_USE_C11_MEM_MODEL=y + * It depends on performance test results. + * By default, move common functions to rte_ring_generic.h + */ +#ifdef RTE_USE_C11_MEM_MODEL +#include "rte_ring_c11_mem.h" +#else +#include "rte_ring_generic.h" +#endif + +/** + * @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 *); + + update_tail(&r->prod, prod_head, prod_next, is_sp, 1); +end: + if (free_space != NULL) + *free_space = free_entries - n; + 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 *); + + update_tail(&r->cons, cons_head, cons_next, is_sc, 0); + +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, + RTE_RING_SYNC_MT, 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, + RTE_RING_SYNC_ST, free_space); +} + +#ifdef ALLOW_EXPERIMENTAL_API +#include <rte_ring_elem.h> +#endif + +/** + * 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) +{ + switch (r->prod.sync_type) { + case RTE_RING_SYNC_MT: + return rte_ring_mp_enqueue_bulk(r, obj_table, n, free_space); + case RTE_RING_SYNC_ST: + return rte_ring_sp_enqueue_bulk(r, obj_table, n, free_space); +#ifdef ALLOW_EXPERIMENTAL_API + case RTE_RING_SYNC_MT_RTS: + return rte_ring_mp_rts_enqueue_bulk(r, obj_table, n, + free_space); + case RTE_RING_SYNC_MT_HTS: + return rte_ring_mp_hts_enqueue_bulk(r, obj_table, n, + free_space); +#endif + } + + /* valid ring should never reach this point */ + RTE_ASSERT(0); + return 0; +} + +/** + * 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, + RTE_RING_SYNC_MT, 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, + RTE_RING_SYNC_ST, 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) +{ + switch (r->cons.sync_type) { + case RTE_RING_SYNC_MT: + return rte_ring_mc_dequeue_bulk(r, obj_table, n, available); + case RTE_RING_SYNC_ST: + return rte_ring_sc_dequeue_bulk(r, obj_table, n, available); +#ifdef ALLOW_EXPERIMENTAL_API + case RTE_RING_SYNC_MT_RTS: + return rte_ring_mc_rts_dequeue_bulk(r, obj_table, n, available); + case RTE_RING_SYNC_MT_HTS: + return rte_ring_mc_hts_dequeue_bulk(r, obj_table, n, available); +#endif + } + + /* valid ring should never reach this point */ + RTE_ASSERT(0); + return 0; +} + +/** + * 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; +} + +/** + * Flush a ring. + * + * This function flush all the elements in a ring + * + * @b EXPERIMENTAL: this API may change without prior notice + * + * @warning + * Make sure the ring is not in use while calling this function. + * + * @param r + * A pointer to the ring structure. + */ +__rte_experimental +void +rte_ring_reset(struct rte_ring *r); + +/** + * 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; +} + +/** + * Return sync type used by producer in the ring. + * + * @param r + * A pointer to the ring structure. + * @return + * Producer sync type value. + */ +static inline enum rte_ring_sync_type +rte_ring_get_prod_sync_type(const struct rte_ring *r) +{ + return r->prod.sync_type; +} + +/** + * Check is the ring for single producer. + * + * @param r + * A pointer to the ring structure. + * @return + * true if ring is SP, zero otherwise. + */ +static inline int +rte_ring_is_prod_single(const struct rte_ring *r) +{ + return (rte_ring_get_prod_sync_type(r) == RTE_RING_SYNC_ST); +} + +/** + * Return sync type used by consumer in the ring. + * + * @param r + * A pointer to the ring structure. + * @return + * Consumer sync type value. + */ +static inline enum rte_ring_sync_type +rte_ring_get_cons_sync_type(const struct rte_ring *r) +{ + return r->cons.sync_type; +} + +/** + * Check is the ring for single consumer. + * + * @param r + * A pointer to the ring structure. + * @return + * true if ring is SC, zero otherwise. + */ +static inline int +rte_ring_is_cons_single(const struct rte_ring *r) +{ + return (rte_ring_get_cons_sync_type(r) == RTE_RING_SYNC_ST); +} + +/** + * 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, RTE_RING_SYNC_MT, 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, RTE_RING_SYNC_ST, 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) +{ + switch (r->prod.sync_type) { + case RTE_RING_SYNC_MT: + return rte_ring_mp_enqueue_burst(r, obj_table, n, free_space); + case RTE_RING_SYNC_ST: + return rte_ring_sp_enqueue_burst(r, obj_table, n, free_space); +#ifdef ALLOW_EXPERIMENTAL_API + case RTE_RING_SYNC_MT_RTS: + return rte_ring_mp_rts_enqueue_burst(r, obj_table, n, + free_space); + case RTE_RING_SYNC_MT_HTS: + return rte_ring_mp_hts_enqueue_burst(r, obj_table, n, + free_space); +#endif + } + + /* valid ring should never reach this point */ + RTE_ASSERT(0); + return 0; +} + +/** + * 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, RTE_RING_SYNC_MT, 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, RTE_RING_SYNC_ST, 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) +{ + switch (r->cons.sync_type) { + case RTE_RING_SYNC_MT: + return rte_ring_mc_dequeue_burst(r, obj_table, n, available); + case RTE_RING_SYNC_ST: + return rte_ring_sc_dequeue_burst(r, obj_table, n, available); +#ifdef ALLOW_EXPERIMENTAL_API + case RTE_RING_SYNC_MT_RTS: + return rte_ring_mc_rts_dequeue_burst(r, obj_table, n, + available); + case RTE_RING_SYNC_MT_HTS: + return rte_ring_mc_hts_dequeue_burst(r, obj_table, n, + available); +#endif + } + + /* valid ring should never reach this point */ + RTE_ASSERT(0); + return 0; +} + +#ifdef __cplusplus +} +#endif + +#endif /* _RTE_RING_H_ */ |