* Lai Jiangshan ([email protected]) wrote:
> We use hash value to determine the range of the object
> and use cds_lfht_lookup_fct to lookup them.
>
> Signed-off-by: Lai Jiangshan <[email protected]>
> ---
> rculfhash.c | 8 ++++----
> tests/test_urcu_hash.c | 25 ++++++++++++++++++++++---
> urcu/rculfhash.h | 4 +++-
> 3 files changed, 29 insertions(+), 8 deletions(-)
>
> diff --git a/rculfhash.c b/rculfhash.c
> index d1a1766..29054cd 100644
> --- a/rculfhash.c
> +++ b/rculfhash.c
> @@ -1391,14 +1391,14 @@ struct cds_lfht *_cds_lfht_new(cds_lfht_hash_fct
> hash_fct,
> return ht;
> }
>
> -void cds_lfht_lookup(struct cds_lfht *ht, void *key, size_t key_len,
> +void cds_lfht_lookup(struct cds_lfht *ht, unsigned long hash,
> + cds_lfht_lookup_fct match, void *arg,
arg -> key ?
for "match", our approach is to provide this function as parameter to
cds_lfht_new rather than pass it as parameter each time a lookup is
performed. What is the reason why we should pass it here as a parameter?
Thanks,
Mathieu
> struct cds_lfht_iter *iter)
> {
> struct cds_lfht_node *node, *next, *dummy_node;
> struct _cds_lfht_node *lookup;
> - unsigned long hash, reverse_hash, size;
> + unsigned long reverse_hash, size;
>
> - hash = ht->hash_fct(key, key_len, ht->hash_seed);
> reverse_hash = bit_reverse_ulong(hash);
>
> size = rcu_dereference(ht->t.size);
> @@ -1421,7 +1421,7 @@ void cds_lfht_lookup(struct cds_lfht *ht, void *key,
> size_t key_len,
> if (caa_likely(!is_removed(next))
> && !is_dummy(next)
> && node->p.reverse_hash == reverse_hash
> - && caa_likely(!ht->compare_fct(node->key, node->key_len,
> key, key_len))) {
> + && caa_likely(match(node, arg))) {
> break;
> }
> node = clear_flag(next);
> diff --git a/tests/test_urcu_hash.c b/tests/test_urcu_hash.c
> index e28c14a..4c45573 100644
> --- a/tests/test_urcu_hash.c
> +++ b/tests/test_urcu_hash.c
> @@ -41,6 +41,8 @@
> #define DEFAULT_MIN_ALLOC_SIZE 1
> #define DEFAULT_RAND_POOL 1000000
>
> +#define TEST_HASH_SEED 0x42UL
> +
> /* Make this big enough to include the POWER5+ L3 cacheline size of 256B */
> #define CACHE_LINE_SIZE 4096
>
> @@ -419,6 +421,23 @@ unsigned long test_compare(void *key1, size_t key1_len,
> return 1;
> }
>
> +static
> +int test_match(struct cds_lfht_node *node, void *arg)
> +{
> + return !test_compare(node->key, node->key_len,
> + arg, sizeof(unsigned long));
> +}
> +
> +static
> +void cds_lfht_test_lookup(struct cds_lfht *ht, void *key, size_t key_len,
> + struct cds_lfht_iter *iter)
> +{
> + assert(key_len == sizeof(unsigned long));
> +
> + cds_lfht_lookup(ht, test_hash(key, key_len, TEST_HASH_SEED),
> + test_match, key, iter);
> +}
> +
> void *thr_count(void *arg)
> {
> printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
> @@ -479,7 +498,7 @@ void *thr_reader(void *_count)
>
> for (;;) {
> rcu_read_lock();
> - cds_lfht_lookup(test_ht,
> + cds_lfht_test_lookup(test_ht,
> (void *)(((unsigned long) rand_r(&rand_lookup) %
> lookup_pool_size) + lookup_pool_offset),
> sizeof(void *), &iter);
> node = cds_lfht_iter_get_test_node(&iter);
> @@ -574,7 +593,7 @@ void *thr_writer(void *_count)
> } else {
> /* May delete */
> rcu_read_lock();
> - cds_lfht_lookup(test_ht,
> + cds_lfht_test_lookup(test_ht,
> (void *)(((unsigned long) rand_r(&rand_lookup)
> % write_pool_size) + write_pool_offset),
> sizeof(void *), &iter);
> ret = cds_lfht_del(test_ht, &iter);
> @@ -932,7 +951,7 @@ int main(int argc, char **argv)
> * thread from the point of view of resize.
> */
> rcu_register_thread();
> - test_ht = cds_lfht_new(test_hash, test_compare, 0x42UL,
> + test_ht = cds_lfht_new(test_hash, test_compare, TEST_HASH_SEED,
> init_hash_size, min_hash_alloc_size,
> (opt_auto_resize ? CDS_LFHT_AUTO_RESIZE : 0) |
> CDS_LFHT_ACCOUNTING, NULL);
> diff --git a/urcu/rculfhash.h b/urcu/rculfhash.h
> index f4f3373..b56fe56 100644
> --- a/urcu/rculfhash.h
> +++ b/urcu/rculfhash.h
> @@ -86,6 +86,7 @@ typedef unsigned long (*cds_lfht_hash_fct)(void *key,
> size_t length,
> unsigned long seed);
> typedef unsigned long (*cds_lfht_compare_fct)(void *key1, size_t key1_len,
> void *key2, size_t key2_len);
> +typedef int (*cds_lfht_lookup_fct)(struct cds_lfht_node *node, void *arg);
>
> /*
> * cds_lfht_node_init - initialize a hash table node
> @@ -203,7 +204,8 @@ void cds_lfht_count_nodes(struct cds_lfht *ht,
> * Call with rcu_read_lock held.
> * Threads calling this API need to be registered RCU read-side threads.
> */
> -void cds_lfht_lookup(struct cds_lfht *ht, void *key, size_t key_len,
> +void cds_lfht_lookup(struct cds_lfht *ht, unsigned long hash,
> + cds_lfht_lookup_fct match, void *arg,
> struct cds_lfht_iter *iter);
>
> /*
> --
> 1.7.4.4
>
--
Mathieu Desnoyers
Operating System Efficiency R&D Consultant
EfficiOS Inc.
http://www.efficios.com
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