/* 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 #include /** * 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 int 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 int count, unsigned int 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 int count, int socket_id, unsigned int 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); /** * 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_mp_enqueue_bulk_elem(r, obj_table, sizeof(void *), n, 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_sp_enqueue_bulk_elem(r, obj_table, sizeof(void *), n, 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_enqueue_bulk_elem(r, obj_table, sizeof(void *), n, 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_elem(r, &obj, sizeof(void *)); } /** * 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_elem(r, &obj, sizeof(void *)); } /** * 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_elem(r, &obj, sizeof(void *)); } /** * 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_mc_dequeue_bulk_elem(r, obj_table, sizeof(void *), n, 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_sc_dequeue_bulk_elem(r, obj_table, sizeof(void *), n, 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_dequeue_bulk_elem(r, obj_table, sizeof(void *), n, 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_elem(r, obj_p, sizeof(void *)); } /** * 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_elem(r, obj_p, sizeof(void *)); } /** * 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_elem(r, obj_p, sizeof(void *)); } /** * Flush a ring. * * This function flush all the elements in a ring * * @warning * Make sure the ring is not in use while calling this function. * * @param r * A pointer to the ring structure. */ 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 int 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 int 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) { uint32_t prod_tail = r->prod.tail; uint32_t cons_tail = r->cons.tail; return cons_tail == prod_tail; } /** * 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 int rte_ring_mp_enqueue_burst(struct rte_ring *r, void * const *obj_table, unsigned int n, unsigned int *free_space) { return rte_ring_mp_enqueue_burst_elem(r, obj_table, sizeof(void *), n, 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 int rte_ring_sp_enqueue_burst(struct rte_ring *r, void * const *obj_table, unsigned int n, unsigned int *free_space) { return rte_ring_sp_enqueue_burst_elem(r, obj_table, sizeof(void *), n, 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 int rte_ring_enqueue_burst(struct rte_ring *r, void * const *obj_table, unsigned int n, unsigned int *free_space) { return rte_ring_enqueue_burst_elem(r, obj_table, sizeof(void *), n, 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 int rte_ring_mc_dequeue_burst(struct rte_ring *r, void **obj_table, unsigned int n, unsigned int *available) { return rte_ring_mc_dequeue_burst_elem(r, obj_table, sizeof(void *), n, 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 int rte_ring_sc_dequeue_burst(struct rte_ring *r, void **obj_table, unsigned int n, unsigned int *available) { return rte_ring_sc_dequeue_burst_elem(r, obj_table, sizeof(void *), n, 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 int rte_ring_dequeue_burst(struct rte_ring *r, void **obj_table, unsigned int n, unsigned int *available) { return rte_ring_dequeue_burst_elem(r, obj_table, sizeof(void *), n, available); } #ifdef __cplusplus } #endif #endif /* _RTE_RING_H_ */