X-Git-Url: http://git.droids-corp.org/?a=blobdiff_plain;f=lib%2Flibrte_hash%2Frte_hash.h;h=4432aef7673f4df725ff13ab79216a98435ea57d;hb=5897ac139355e2d6602c89b0a1d28e609d6f6ebc;hp=ecb49e4ff58a3282fce043ca7e7d829f7f0f3530;hpb=f2e3001b53ec107cf0ff26a89dd1b1bd29d51038;p=dpdk.git diff --git a/lib/librte_hash/rte_hash.h b/lib/librte_hash/rte_hash.h index ecb49e4ff5..4432aef767 100644 --- a/lib/librte_hash/rte_hash.h +++ b/lib/librte_hash/rte_hash.h @@ -14,6 +14,8 @@ #include #include +#include + #ifdef __cplusplus extern "C" { #endif @@ -37,7 +39,27 @@ extern "C" { /** Flag to support reader writer concurrency */ #define RTE_HASH_EXTRA_FLAGS_RW_CONCURRENCY 0x04 -/** Signature of key that is stored internally. */ +/** Flag to indicate the extendable bucket table feature should be used */ +#define RTE_HASH_EXTRA_FLAGS_EXT_TABLE 0x08 + +/** Flag to disable freeing of key index on hash delete. + * Refer to rte_hash_del_xxx APIs for more details. + * This is enabled by default when RTE_HASH_EXTRA_FLAGS_RW_CONCURRENCY_LF + * is enabled. + */ +#define RTE_HASH_EXTRA_FLAGS_NO_FREE_ON_DEL 0x10 + +/** Flag to support lock free reader writer concurrency. Both single writer + * and multi writer use cases are supported. + * Currently, extendable bucket table feature is not supported with + * this feature. + */ +#define RTE_HASH_EXTRA_FLAGS_RW_CONCURRENCY_LF 0x20 + +/** + * The type of hash value of a key. + * It should be a value of at least 32bit with fully random pattern. + */ typedef uint32_t hash_sig_t; /** Type of function that can be used for calculating the hash value. */ @@ -119,17 +141,40 @@ void rte_hash_free(struct rte_hash *h); /** - * Reset all hash structure, by zeroing all entries + * Reset all hash structure, by zeroing all entries. + * When RTE_HASH_EXTRA_FLAGS_RW_CONCURRENCY_LF is enabled, + * it is application's responsibility to make sure that + * none of the readers are referencing the hash table + * while calling this API. + * * @param h * Hash table to reset */ void rte_hash_reset(struct rte_hash *h); +/** + * Return the number of keys in the hash table + * @param h + * Hash table to query from + * @return + * - -EINVAL if parameters are invalid + * - A value indicating how many keys were inserted in the table. + */ +int32_t +rte_hash_count(const struct rte_hash *h); + /** * Add a key-value pair to an existing hash table. * This operation is not multi-thread safe - * and should only be called from one thread. + * and should only be called from one thread by default. + * Thread safety can be enabled by setting flag during + * table creation. + * If the key exists already in the table, this API updates its value + * with 'data' passed in this API. It is the responsibility of + * the application to manage any memory associated with the old value. + * The readers might still be using the old value even after this API + * has returned. * * @param h * Hash table to add the key to. @@ -149,7 +194,14 @@ rte_hash_add_key_data(const struct rte_hash *h, const void *key, void *data); * Add a key-value pair with a pre-computed hash value * to an existing hash table. * This operation is not multi-thread safe - * and should only be called from one thread. + * and should only be called from one thread by default. + * Thread safety can be enabled by setting flag during + * table creation. + * If the key exists already in the table, this API updates its value + * with 'data' passed in this API. It is the responsibility of + * the application to manage any memory associated with the old value. + * The readers might still be using the old value even after this API + * has returned. * * @param h * Hash table to add the key to. @@ -170,7 +222,9 @@ rte_hash_add_key_with_hash_data(const struct rte_hash *h, const void *key, /** * Add a key to an existing hash table. This operation is not multi-thread safe - * and should only be called from one thread. + * and should only be called from one thread by default. + * Thread safety can be enabled by setting flag during + * table creation. * * @param h * Hash table to add the key to. @@ -188,7 +242,9 @@ rte_hash_add_key(const struct rte_hash *h, const void *key); /** * Add a key to an existing hash table. * This operation is not multi-thread safe - * and should only be called from one thread. + * and should only be called from one thread by default. + * Thread safety can be enabled by setting flag during + * table creation. * * @param h * Hash table to add the key to. @@ -208,7 +264,17 @@ rte_hash_add_key_with_hash(const struct rte_hash *h, const void *key, hash_sig_t /** * Remove a key from an existing hash table. * This operation is not multi-thread safe - * and should only be called from one thread. + * and should only be called from one thread by default. + * Thread safety can be enabled by setting flag during + * table creation. + * If RTE_HASH_EXTRA_FLAGS_NO_FREE_ON_DEL or + * RTE_HASH_EXTRA_FLAGS_RW_CONCURRENCY_LF is enabled, + * the key index returned by rte_hash_add_key_xxx APIs will not be + * freed by this API. rte_hash_free_key_with_position API must be called + * additionally to free the index associated with the key. + * rte_hash_free_key_with_position API should be called after all + * the readers have stopped referencing the entry corresponding to + * this key. RCU mechanisms could be used to determine such a state. * * @param h * Hash table to remove the key from. @@ -227,7 +293,17 @@ rte_hash_del_key(const struct rte_hash *h, const void *key); /** * Remove a key from an existing hash table. * This operation is not multi-thread safe - * and should only be called from one thread. + * and should only be called from one thread by default. + * Thread safety can be enabled by setting flag during + * table creation. + * If RTE_HASH_EXTRA_FLAGS_NO_FREE_ON_DEL or + * RTE_HASH_EXTRA_FLAGS_RW_CONCURRENCY_LF is enabled, + * the key index returned by rte_hash_add_key_xxx APIs will not be + * freed by this API. rte_hash_free_key_with_position API must be called + * additionally to free the index associated with the key. + * rte_hash_free_key_with_position API should be called after all + * the readers have stopped referencing the entry corresponding to + * this key. RCU mechanisms could be used to determine such a state. * * @param h * Hash table to remove the key from. @@ -247,7 +323,9 @@ rte_hash_del_key_with_hash(const struct rte_hash *h, const void *key, hash_sig_t /** * Find a key in the hash table given the position. - * This operation is multi-thread safe. + * This operation is multi-thread safe with regarding to other lookup threads. + * Read-write concurrency can be enabled by setting flag during + * table creation. * * @param h * Hash table to get the key from. @@ -257,16 +335,46 @@ rte_hash_del_key_with_hash(const struct rte_hash *h, const void *key, hash_sig_t * Output containing a pointer to the key * @return * - 0 if retrieved successfully - * - EINVAL if the parameters are invalid. - * - ENOENT if no valid key is found in the given position. + * - -EINVAL if the parameters are invalid. + * - -ENOENT if no valid key is found in the given position. */ int rte_hash_get_key_with_position(const struct rte_hash *h, const int32_t position, void **key); +/** + * @warning + * @b EXPERIMENTAL: this API may change without prior notice + * + * Free a hash key in the hash table given the position + * of the key. This operation is not multi-thread safe and should + * only be called from one thread by default. Thread safety + * can be enabled by setting flag during table creation. + * If RTE_HASH_EXTRA_FLAGS_NO_FREE_ON_DEL or + * RTE_HASH_EXTRA_FLAGS_RW_CONCURRENCY_LF is enabled, + * the key index returned by rte_hash_del_key_xxx APIs must be freed + * using this API. This API should be called after all the readers + * have stopped referencing the entry corresponding to this key. + * RCU mechanisms could be used to determine such a state. + * This API does not validate if the key is already freed. + * + * @param h + * Hash table to free the key from. + * @param position + * Position returned when the key was deleted. + * @return + * - 0 if freed successfully + * - -EINVAL if the parameters are invalid. + */ +int __rte_experimental +rte_hash_free_key_with_position(const struct rte_hash *h, + const int32_t position); + /** * Find a key-value pair in the hash table. - * This operation is multi-thread safe. + * This operation is multi-thread safe with regarding to other lookup threads. + * Read-write concurrency can be enabled by setting flag during + * table creation. * * @param h * Hash table to look in. @@ -275,9 +383,11 @@ rte_hash_get_key_with_position(const struct rte_hash *h, const int32_t position, * @param data * Output with pointer to data returned from the hash table. * @return - * 0 if successful lookup - * - EINVAL if the parameters are invalid. - * - ENOENT if the key is not found. + * - A positive value that can be used by the caller as an offset into an + * array of user data. This value is unique for this key, and is the same + * value that was returned when the key was added. + * - -EINVAL if the parameters are invalid. + * - -ENOENT if the key is not found. */ int rte_hash_lookup_data(const struct rte_hash *h, const void *key, void **data); @@ -285,7 +395,9 @@ rte_hash_lookup_data(const struct rte_hash *h, const void *key, void **data); /** * Find a key-value pair with a pre-computed hash value * to an existing hash table. - * This operation is multi-thread safe. + * This operation is multi-thread safe with regarding to other lookup threads. + * Read-write concurrency can be enabled by setting flag during + * table creation. * * @param h * Hash table to look in. @@ -296,9 +408,11 @@ rte_hash_lookup_data(const struct rte_hash *h, const void *key, void **data); * @param data * Output with pointer to data returned from the hash table. * @return - * 0 if successful lookup - * - EINVAL if the parameters are invalid. - * - ENOENT if the key is not found. + * - A positive value that can be used by the caller as an offset into an + * array of user data. This value is unique for this key, and is the same + * value that was returned when the key was added. + * - -EINVAL if the parameters are invalid. + * - -ENOENT if the key is not found. */ int rte_hash_lookup_with_hash_data(const struct rte_hash *h, const void *key, @@ -306,7 +420,9 @@ rte_hash_lookup_with_hash_data(const struct rte_hash *h, const void *key, /** * Find a key in the hash table. - * This operation is multi-thread safe. + * This operation is multi-thread safe with regarding to other lookup threads. + * Read-write concurrency can be enabled by setting flag during + * table creation. * * @param h * Hash table to look in. @@ -324,7 +440,9 @@ rte_hash_lookup(const struct rte_hash *h, const void *key); /** * Find a key in the hash table. - * This operation is multi-thread safe. + * This operation is multi-thread safe with regarding to other lookup threads. + * Read-write concurrency can be enabled by setting flag during + * table creation. * * @param h * Hash table to look in. @@ -345,7 +463,7 @@ rte_hash_lookup_with_hash(const struct rte_hash *h, /** * Calc a hash value by key. - * This operation is not multi-thread safe. + * This operation is not multi-process safe. * * @param h * Hash table to look in. @@ -359,7 +477,9 @@ rte_hash_hash(const struct rte_hash *h, const void *key); /** * Find multiple keys in the hash table. - * This operation is multi-thread safe. + * This operation is multi-thread safe with regarding to other lookup threads. + * Read-write concurrency can be enabled by setting flag during + * table creation. * * @param h * Hash table to look in. @@ -380,7 +500,9 @@ rte_hash_lookup_bulk_data(const struct rte_hash *h, const void **keys, /** * Find multiple keys in the hash table. - * This operation is multi-thread safe. + * This operation is multi-thread safe with regarding to other lookup threads. + * Read-write concurrency can be enabled by setting flag during + * table creation. * * @param h * Hash table to look in.