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/*
Copyright (c) 2014 Cisco and/or its affiliates.
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/** @cond DOCUMENTATION_IS_IN_BIHASH_DOC_H */
/*
* Note: to instantiate the template multiple times in a single file,
* #undef __included_bihash_template_h__...
*/
#ifndef __included_bihash_template_h__
#define __included_bihash_template_h__
#include <vppinfra/heap.h>
#include <vppinfra/format.h>
#include <vppinfra/pool.h>
#include <vppinfra/cache.h>
#include <vppinfra/lock.h>
#ifndef BIHASH_TYPE
#error BIHASH_TYPE not defined
#endif
#define _bv(a,b) a##b
#define __bv(a,b) _bv(a,b)
#define BV(a) __bv(a,BIHASH_TYPE)
#define _bvt(a,b) a##b##_t
#define __bvt(a,b) _bvt(a,b)
#define BVT(a) __bvt(a,BIHASH_TYPE)
typedef struct BV (clib_bihash_value)
{
union
{
BVT (clib_bihash_kv) kvp[BIHASH_KVP_PER_PAGE];
struct BV (clib_bihash_value) * next_free;
};
} BVT (clib_bihash_value);
#define BIHASH_BUCKET_OFFSET_BITS 36
typedef struct
{
union
{
struct
{
u64 offset:BIHASH_BUCKET_OFFSET_BITS;
u64 lock:1;
u64 linear_search:1;
u64 log2_pages:8;
i64 refcnt:16;
};
u64 as_u64;
};
} BVT (clib_bihash_bucket);
STATIC_ASSERT_SIZEOF (BVT (clib_bihash_bucket), sizeof (u64));
typedef struct
{
BVT (clib_bihash_value) * values;
BVT (clib_bihash_bucket) * buckets;
volatile u32 *alloc_lock;
BVT (clib_bihash_value) ** working_copies;
int *working_copy_lengths;
BVT (clib_bihash_bucket) saved_bucket;
u32 nbuckets;
u32 log2_nbuckets;
u8 *name;
u64 cache_hits;
u64 cache_misses;
BVT (clib_bihash_value) ** freelists;
/*
* Backing store allocation. Since bihash manages its own
* freelists, we simple dole out memory at alloc_arena_next.
*/
uword alloc_arena;
uword alloc_arena_next;
uword alloc_arena_size;
/**
* A custom format function to print the Key and Value of bihash_key instead of default hexdump
*/
format_function_t *fmt_fn;
} BVT (clib_bihash);
static inline void BV (clib_bihash_alloc_lock) (BVT (clib_bihash) * h)
{
while (__atomic_test_and_set (h->alloc_lock, __ATOMIC_ACQUIRE))
CLIB_PAUSE ();
}
static inline void BV (clib_bihash_alloc_unlock) (BVT (clib_bihash) * h)
{
__atomic_clear (h->alloc_lock, __ATOMIC_RELEASE);
}
static inline void BV (clib_bihash_lock_bucket) (BVT (clib_bihash_bucket) * b)
{
BVT (clib_bihash_bucket) unlocked_bucket, locked_bucket;
do
{
locked_bucket.as_u64 = unlocked_bucket.as_u64 = b->as_u64;
unlocked_bucket.lock = 0;
locked_bucket.lock = 1;
CLIB_PAUSE ();
}
while (__atomic_compare_exchange_n (&b->as_u64, &unlocked_bucket.as_u64,
locked_bucket.as_u64, 1 /* weak */ ,
__ATOMIC_ACQUIRE,
__ATOMIC_ACQUIRE) == 0);
}
static inline void BV (clib_bihash_unlock_bucket)
(BVT (clib_bihash_bucket) * b)
{
CLIB_MEMORY_BARRIER ();
b->lock = 0;
}
static inline void *BV (clib_bihash_get_value) (BVT (clib_bihash) * h,
uword offset)
{
u8 *hp = (u8 *) h->alloc_arena;
u8 *vp = hp + offset;
return (void *) vp;
}
static inline int BV (clib_bihash_bucket_is_empty)
(BVT (clib_bihash_bucket) * b)
{
/* Note: applied to locked buckets, test offset */
return b->offset == 0;
}
static inline uword BV (clib_bihash_get_offset) (BVT (clib_bihash) * h,
void *v)
{
u8 *hp, *vp;
hp = (u8 *) h->alloc_arena;
vp = (u8 *) v;
return vp - hp;
}
void BV (clib_bihash_init)
(BVT (clib_bihash) * h, char *name, u32 nbuckets, uword memory_size);
void BV (clib_bihash_set_kvp_format_fn) (BVT (clib_bihash) * h,
format_function_t * fmt_fn);
void BV (clib_bihash_free) (BVT (clib_bihash) * h);
int BV (clib_bihash_add_del) (BVT (clib_bihash) * h,
BVT (clib_bihash_kv) * add_v, int is_add);
int BV (clib_bihash_search) (BVT (clib_bihash) * h,
BVT (clib_bihash_kv) * search_v,
BVT (clib_bihash_kv) * return_v);
void BV (clib_bihash_foreach_key_value_pair) (BVT (clib_bihash) * h,
void *callback, void *arg);
format_function_t BV (format_bihash);
format_function_t BV (format_bihash_kvp);
format_function_t BV (format_bihash_lru);
static inline int BV (clib_bihash_search_inline_with_hash)
(BVT (clib_bihash) * h, u64 hash, BVT (clib_bihash_kv) * key_result)
{
u32 bucket_index;
BVT (clib_bihash_value) * v;
BVT (clib_bihash_bucket) * b;
int i, limit;
bucket_index = hash & (h->nbuckets - 1);
b = &h->buckets[bucket_index];
if (PREDICT_FALSE (BV (clib_bihash_bucket_is_empty) (b)))
return -1;
if (PREDICT_FALSE (b->lock))
{
volatile BVT (clib_bihash_bucket) * bv = b;
while (bv->lock)
CLIB_PAUSE ();
}
hash >>= h->log2_nbuckets;
v = BV (clib_bihash_get_value) (h, b->offset);
/* If the bucket has unresolvable collisions, use linear search */
limit = BIHASH_KVP_PER_PAGE;
v += (b->linear_search == 0) ? hash & ((1 << b->log2_pages) - 1) : 0;
if (PREDICT_FALSE (b->linear_search))
limit <<= b->log2_pages;
for (i = 0; i < limit; i++)
{
if (BV (clib_bihash_key_compare) (v->kvp[i].key, key_result->key))
{
*key_result = v->kvp[i];
return 0;
}
}
return -1;
}
static inline int BV (clib_bihash_search_inline)
(BVT (clib_bihash) * h, BVT (clib_bihash_kv) * key_result)
{
u64 hash;
hash = BV (clib_bihash_hash) (key_result);
return BV (clib_bihash_search_inline_with_hash) (h, hash, key_result);
}
static inline void BV (clib_bihash_prefetch_bucket)
(BVT (clib_bihash) * h, u64 hash)
{
u32 bucket_index;
BVT (clib_bihash_bucket) * b;
bucket_index = hash & (h->nbuckets - 1);
b = &h->buckets[bucket_index];
CLIB_PREFETCH (b, CLIB_CACHE_LINE_BYTES, READ);
}
static inline void BV (clib_bihash_prefetch_data)
(BVT (clib_bihash) * h, u64 hash)
{
u32 bucket_index;
BVT (clib_bihash_value) * v;
BVT (clib_bihash_bucket) * b;
bucket_index = hash & (h->nbuckets - 1);
b = &h->buckets[bucket_index];
if (PREDICT_FALSE (BV (clib_bihash_bucket_is_empty) (b)))
return;
hash >>= h->log2_nbuckets;
v = BV (clib_bihash_get_value) (h, b->offset);
v += (b->linear_search == 0) ? hash & ((1 << b->log2_pages) - 1) : 0;
CLIB_PREFETCH (v, CLIB_CACHE_LINE_BYTES, READ);
}
static inline int BV (clib_bihash_search_inline_2_with_hash)
(BVT (clib_bihash) * h,
u64 hash, BVT (clib_bihash_kv) * search_key, BVT (clib_bihash_kv) * valuep)
{
u32 bucket_index;
BVT (clib_bihash_value) * v;
BVT (clib_bihash_bucket) * b;
int i, limit;
ASSERT (valuep);
bucket_index = hash & (h->nbuckets - 1);
b = &h->buckets[bucket_index];
if (PREDICT_FALSE (BV (clib_bihash_bucket_is_empty) (b)))
return -1;
if (PREDICT_FALSE (b->lock))
{
volatile BVT (clib_bihash_bucket) * bv = b;
while (bv->lock)
CLIB_PAUSE ();
}
hash >>= h->log2_nbuckets;
v = BV (clib_bihash_get_value) (h, b->offset);
/* If the bucket has unresolvable collisions, use linear search */
limit = BIHASH_KVP_PER_PAGE;
v += (b->linear_search == 0) ? hash & ((1 << b->log2_pages) - 1) : 0;
if (PREDICT_FALSE (b->linear_search))
limit <<= b->log2_pages;
for (i = 0; i < limit; i++)
{
if (BV (clib_bihash_key_compare) (v->kvp[i].key, search_key->key))
{
*valuep = v->kvp[i];
return 0;
}
}
return -1;
}
static inline int BV (clib_bihash_search_inline_2)
(BVT (clib_bihash) * h,
BVT (clib_bihash_kv) * search_key, BVT (clib_bihash_kv) * valuep)
{
u64 hash;
hash = BV (clib_bihash_hash) (search_key);
return BV (clib_bihash_search_inline_2_with_hash) (h, hash, search_key,
valuep);
}
#endif /* __included_bihash_template_h__ */
/** @endcond */
/*
* fd.io coding-style-patch-verification: ON
*
* Local Variables:
* eval: (c-set-style "gnu")
* End:
*/