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Diffstat (limited to 'lib/librte_eal/common/include/rte_fbarray.h')
-rw-r--r-- | lib/librte_eal/common/include/rte_fbarray.h | 470 |
1 files changed, 470 insertions, 0 deletions
diff --git a/lib/librte_eal/common/include/rte_fbarray.h b/lib/librte_eal/common/include/rte_fbarray.h new file mode 100644 index 00000000..5d880551 --- /dev/null +++ b/lib/librte_eal/common/include/rte_fbarray.h @@ -0,0 +1,470 @@ +/* SPDX-License-Identifier: BSD-3-Clause + * Copyright(c) 2017-2018 Intel Corporation + */ + +#ifndef RTE_FBARRAY_H +#define RTE_FBARRAY_H + +/** + * @file + * + * File-backed shared indexed array for DPDK. + * + * Basic workflow is expected to be the following: + * 1) Allocate array either using ``rte_fbarray_init()`` or + * ``rte_fbarray_attach()`` (depending on whether it's shared between + * multiple DPDK processes) + * 2) find free spots using ``rte_fbarray_find_next_free()`` + * 3) get pointer to data in the free spot using ``rte_fbarray_get()``, and + * copy data into the pointer (element size is fixed) + * 4) mark entry as used using ``rte_fbarray_set_used()`` + * + * Calls to ``rte_fbarray_init()`` and ``rte_fbarray_destroy()`` will have + * consequences for all processes, while calls to ``rte_fbarray_attach()`` and + * ``rte_fbarray_detach()`` will only have consequences within a single process. + * Therefore, it is safe to call ``rte_fbarray_attach()`` or + * ``rte_fbarray_detach()`` while another process is using ``rte_fbarray``, + * provided no other thread within the same process will try to use + * ``rte_fbarray`` before attaching or after detaching. It is not safe to call + * ``rte_fbarray_init()`` or ``rte_fbarray_destroy()`` while another thread or + * another process is using ``rte_fbarray``. + */ + +#ifdef __cplusplus +extern "C" { +#endif + +#include <stdbool.h> +#include <stdio.h> + +#include <rte_compat.h> +#include <rte_rwlock.h> + +#define RTE_FBARRAY_NAME_LEN 64 + +struct rte_fbarray { + char name[RTE_FBARRAY_NAME_LEN]; /**< name associated with an array */ + unsigned int count; /**< number of entries stored */ + unsigned int len; /**< current length of the array */ + unsigned int elt_sz; /**< size of each element */ + void *data; /**< data pointer */ + rte_rwlock_t rwlock; /**< multiprocess lock */ +}; + +/** + * Set up ``rte_fbarray`` structure and allocate underlying resources. + * + * Call this function to correctly set up ``rte_fbarray`` and allocate + * underlying files that will be backing the data in the current process. Note + * that in order to use and share ``rte_fbarray`` between multiple processes, + * data pointed to by ``arr`` pointer must itself be allocated in shared memory. + * + * @param arr + * Valid pointer to allocated ``rte_fbarray`` structure. + * + * @param name + * Unique name to be assigned to this array. + * + * @param len + * Number of elements initially available in the array. + * + * @param elt_sz + * Size of each element. + * + * @return + * - 0 on success. + * - -1 on failure, with ``rte_errno`` indicating reason for failure. + */ +int __rte_experimental +rte_fbarray_init(struct rte_fbarray *arr, const char *name, unsigned int len, + unsigned int elt_sz); + + +/** + * Attach to a file backing an already allocated and correctly set up + * ``rte_fbarray`` structure. + * + * Call this function to attach to file that will be backing the data in the + * current process. The structure must have been previously correctly set up + * with a call to ``rte_fbarray_init()``. Calls to ``rte_fbarray_attach()`` are + * usually meant to be performed in a multiprocessing scenario, with data + * pointed to by ``arr`` pointer allocated in shared memory. + * + * @param arr + * Valid pointer to allocated and correctly set up rte_fbarray structure. + * + * @return + * - 0 on success. + * - -1 on failure, with ``rte_errno`` indicating reason for failure. + */ +int __rte_experimental +rte_fbarray_attach(struct rte_fbarray *arr); + + +/** + * Deallocate resources for an already allocated and correctly set up + * ``rte_fbarray`` structure, and remove the underlying file. + * + * Call this function to deallocate all resources associated with an + * ``rte_fbarray`` structure within the current process. This will also + * zero-fill data pointed to by ``arr`` pointer and remove the underlying file + * backing the data, so it is expected that by the time this function is called, + * all other processes have detached from this ``rte_fbarray``. + * + * @param arr + * Valid pointer to allocated and correctly set up ``rte_fbarray`` structure. + * + * @return + * - 0 on success. + * - -1 on failure, with ``rte_errno`` indicating reason for failure. + */ +int __rte_experimental +rte_fbarray_destroy(struct rte_fbarray *arr); + + +/** + * Deallocate resources for an already allocated and correctly set up + * ``rte_fbarray`` structure. + * + * Call this function to deallocate all resources associated with an + * ``rte_fbarray`` structure within current process. + * + * @param arr + * Valid pointer to allocated and correctly set up ``rte_fbarray`` structure. + * + * @return + * - 0 on success. + * - -1 on failure, with ``rte_errno`` indicating reason for failure. + */ +int __rte_experimental +rte_fbarray_detach(struct rte_fbarray *arr); + + +/** + * Get pointer to element residing at specified index. + * + * @param arr + * Valid pointer to allocated and correctly set up ``rte_fbarray`` structure. + * + * @param idx + * Index of an element to get a pointer to. + * + * @return + * - non-NULL pointer on success. + * - NULL on failure, with ``rte_errno`` indicating reason for failure. + */ +void * __rte_experimental +rte_fbarray_get(const struct rte_fbarray *arr, unsigned int idx); + + +/** + * Find index of a specified element within the array. + * + * @param arr + * Valid pointer to allocated and correctly set up ``rte_fbarray`` structure. + * + * @param elt + * Pointer to element to find index to. + * + * @return + * - non-negative integer on success. + * - -1 on failure, with ``rte_errno`` indicating reason for failure. + */ +int __rte_experimental +rte_fbarray_find_idx(const struct rte_fbarray *arr, const void *elt); + + +/** + * Mark specified element as used. + * + * @param arr + * Valid pointer to allocated and correctly set up ``rte_fbarray`` structure. + * + * @param idx + * Element index to mark as used. + * + * @return + * - 0 on success. + * - -1 on failure, with ``rte_errno`` indicating reason for failure. + */ +int __rte_experimental +rte_fbarray_set_used(struct rte_fbarray *arr, unsigned int idx); + + +/** + * Mark specified element as free. + * + * @param arr + * Valid pointer to allocated and correctly set up ``rte_fbarray`` structure. + * + * @param idx + * Element index to mark as free. + * + * @return + * - 0 on success. + * - -1 on failure, with ``rte_errno`` indicating reason for failure. + */ +int __rte_experimental +rte_fbarray_set_free(struct rte_fbarray *arr, unsigned int idx); + + +/** + * Check whether element at specified index is marked as used. + * + * @param arr + * Valid pointer to allocated and correctly set up ``rte_fbarray`` structure. + * + * @param idx + * Element index to check as used. + * + * @return + * - 1 if element is used. + * - 0 if element is unused. + * - -1 on failure, with ``rte_errno`` indicating reason for failure. + */ +int __rte_experimental +rte_fbarray_is_used(struct rte_fbarray *arr, unsigned int idx); + + +/** + * Find index of next free element, starting at specified index. + * + * @param arr + * Valid pointer to allocated and correctly set up ``rte_fbarray`` structure. + * + * @param start + * Element index to start search from. + * + * @return + * - non-negative integer on success. + * - -1 on failure, with ``rte_errno`` indicating reason for failure. + */ +int __rte_experimental +rte_fbarray_find_next_free(struct rte_fbarray *arr, unsigned int start); + + +/** + * Find index of next used element, starting at specified index. + * + * @param arr + * Valid pointer to allocated and correctly set up ``rte_fbarray`` structure. + * + * @param start + * Element index to start search from. + * + * @return + * - non-negative integer on success. + * - -1 on failure, with ``rte_errno`` indicating reason for failure. + */ +int __rte_experimental +rte_fbarray_find_next_used(struct rte_fbarray *arr, unsigned int start); + + +/** + * Find index of next chunk of ``n`` free elements, starting at specified index. + * + * @param arr + * Valid pointer to allocated and correctly set up ``rte_fbarray`` structure. + * + * @param start + * Element index to start search from. + * + * @param n + * Number of free elements to look for. + * + * @return + * - non-negative integer on success. + * - -1 on failure, with ``rte_errno`` indicating reason for failure. + */ +int __rte_experimental +rte_fbarray_find_next_n_free(struct rte_fbarray *arr, unsigned int start, + unsigned int n); + + +/** + * Find index of next chunk of ``n`` used elements, starting at specified index. + * + * @param arr + * Valid pointer to allocated and correctly set up ``rte_fbarray`` structure. + * + * @param start + * Element index to start search from. + * + * @param n + * Number of used elements to look for. + * + * @return + * - non-negative integer on success. + * - -1 on failure, with ``rte_errno`` indicating reason for failure. + */ +int __rte_experimental +rte_fbarray_find_next_n_used(struct rte_fbarray *arr, unsigned int start, + unsigned int n); + + +/** + * Find how many more free entries there are, starting at specified index. + * + * @param arr + * Valid pointer to allocated and correctly set up ``rte_fbarray`` structure. + * + * @param start + * Element index to start search from. + * + * @return + * - non-negative integer on success. + * - -1 on failure, with ``rte_errno`` indicating reason for failure. + */ +int __rte_experimental +rte_fbarray_find_contig_free(struct rte_fbarray *arr, + unsigned int start); + + +/** + * Find how many more used entries there are, starting at specified index. + * + * @param arr + * Valid pointer to allocated and correctly set up ``rte_fbarray`` structure. + * + * @param start + * Element index to start search from. + * + * @return + * - non-negative integer on success. + * - -1 on failure, with ``rte_errno`` indicating reason for failure. + */ +int __rte_experimental +rte_fbarray_find_contig_used(struct rte_fbarray *arr, unsigned int start); + +/** + * Find index of previous free element, starting at specified index. + * + * @param arr + * Valid pointer to allocated and correctly set up ``rte_fbarray`` structure. + * + * @param start + * Element index to start search from. + * + * @return + * - non-negative integer on success. + * - -1 on failure, with ``rte_errno`` indicating reason for failure. + */ +int __rte_experimental +rte_fbarray_find_prev_free(struct rte_fbarray *arr, unsigned int start); + + +/** + * Find index of previous used element, starting at specified index. + * + * @param arr + * Valid pointer to allocated and correctly set up ``rte_fbarray`` structure. + * + * @param start + * Element index to start search from. + * + * @return + * - non-negative integer on success. + * - -1 on failure, with ``rte_errno`` indicating reason for failure. + */ +int __rte_experimental +rte_fbarray_find_prev_used(struct rte_fbarray *arr, unsigned int start); + + +/** + * Find lowest start index of chunk of ``n`` free elements, down from specified + * index. + * + * @param arr + * Valid pointer to allocated and correctly set up ``rte_fbarray`` structure. + * + * @param start + * Element index to start search from. + * + * @param n + * Number of free elements to look for. + * + * @return + * - non-negative integer on success. + * - -1 on failure, with ``rte_errno`` indicating reason for failure. + */ +int __rte_experimental +rte_fbarray_find_prev_n_free(struct rte_fbarray *arr, unsigned int start, + unsigned int n); + + +/** + * Find lowest start index of chunk of ``n`` used elements, down from specified + * index. + * + * @param arr + * Valid pointer to allocated and correctly set up ``rte_fbarray`` structure. + * + * @param start + * Element index to start search from. + * + * @param n + * Number of used elements to look for. + * + * @return + * - non-negative integer on success. + * - -1 on failure, with ``rte_errno`` indicating reason for failure. + */ +int __rte_experimental +rte_fbarray_find_prev_n_used(struct rte_fbarray *arr, unsigned int start, + unsigned int n); + + +/** + * Find how many more free entries there are before specified index (like + * ``rte_fbarray_find_contig_free`` but going in reverse). + * + * @param arr + * Valid pointer to allocated and correctly set up ``rte_fbarray`` structure. + * + * @param start + * Element index to start search from. + * + * @return + * - non-negative integer on success. + * - -1 on failure, with ``rte_errno`` indicating reason for failure. + */ +int __rte_experimental +rte_fbarray_find_rev_contig_free(struct rte_fbarray *arr, + unsigned int start); + + +/** + * Find how many more used entries there are before specified index (like + * ``rte_fbarray_find_contig_used`` but going in reverse). + * + * @param arr + * Valid pointer to allocated and correctly set up ``rte_fbarray`` structure. + * + * @param start + * Element index to start search from. + * + * @return + * - non-negative integer on success. + * - -1 on failure, with ``rte_errno`` indicating reason for failure. + */ +int __rte_experimental +rte_fbarray_find_rev_contig_used(struct rte_fbarray *arr, unsigned int start); + + +/** + * Dump ``rte_fbarray`` metadata. + * + * @param arr + * Valid pointer to allocated and correctly set up ``rte_fbarray`` structure. + * + * @param f + * File object to dump information into. + */ +void __rte_experimental +rte_fbarray_dump_metadata(struct rte_fbarray *arr, FILE *f); + +#ifdef __cplusplus +} +#endif + +#endif /* RTE_FBARRAY_H */ |