#define dbg_printf(args...)
#endif
-#define BUCKET_SIZE_RESIZE_THRESHOLD 8
+#define BUCKET_SIZE_RESIZE_THRESHOLD 4
#ifndef max
#define max(a, b) ((a) > (b) ? (a) : (b))
struct rcu_ht {
struct rcu_table *t; /* shared */
ht_hash_fct hash_fct;
- void *hashseed;
+ ht_compare_fct compare_fct;
+ unsigned long hash_seed;
pthread_mutex_t resize_mutex; /* resize mutex: add/del mutex */
void (*ht_call_rcu)(struct rcu_head *head,
void (*func)(struct rcu_head *head));
}
struct rcu_ht *ht_new(ht_hash_fct hash_fct,
- void *hashseed,
+ ht_compare_fct compare_fct,
+ unsigned long hash_seed,
unsigned long init_size,
void (*ht_call_rcu)(struct rcu_head *head,
void (*func)(struct rcu_head *head)))
ht = calloc(1, sizeof(struct rcu_ht));
ht->hash_fct = hash_fct;
- ht->hashseed = hashseed;
+ ht->compare_fct = compare_fct;
+ ht->hash_seed = hash_seed;
ht->ht_call_rcu = ht_call_rcu;
/* this mutex should not nest in read-side C.S. */
pthread_mutex_init(&ht->resize_mutex, NULL);
return ht;
}
-struct rcu_ht_node *ht_lookup(struct rcu_ht *ht, void *key)
+struct rcu_ht_node *ht_lookup(struct rcu_ht *ht, void *key, size_t key_len)
{
struct rcu_table *t;
struct rcu_ht_node *node;
unsigned long hash, reverse_hash;
- hash = ht->hash_fct(ht->hashseed, key);
+ hash = ht->hash_fct(key, key_len, ht->hash_seed);
reverse_hash = bit_reverse_ulong(hash);
t = rcu_dereference(ht->t);
node = NULL;
break;
}
- if (node->key == key) {
+ if (!ht->compare_fct(node->key, node->key_len, key, key_len)) {
if (is_removed(rcu_dereference(node->next)))
node = NULL;
break;
{
struct rcu_table *t;
- node->hash = ht->hash_fct(ht->hashseed, node->key);
+ node->hash = ht->hash_fct(node->key, node->key_len, ht->hash_seed);
node->reverse_hash = bit_reverse_ulong((unsigned long) node->hash);
t = rcu_dereference(ht->t);
memcpy(&new_t->tbl, &old_t->tbl,
old_size * sizeof(struct rcu_ht_node *));
init_table(ht, new_t, old_size, new_size - old_size);
- new_t->size = new_size;
/* Changing table and size atomically wrt lookups */
rcu_assign_pointer(ht->t, new_t);
ht->ht_call_rcu(&old_t->head, ht_free_table_cb);
}
}
+/*
+ * Hash function
+ * Source: http://burtleburtle.net/bob/c/lookup3.c
+ * Originally Public Domain
+ */
+
+#define rot(x, k) (((x) << (k)) | ((x) >> (32 - (k))))
+
+#define mix(a, b, c) \
+do { \
+ a -= c; a ^= rot(c, 4); c += b; \
+ b -= a; b ^= rot(a, 6); a += c; \
+ c -= b; c ^= rot(b, 8); b += a; \
+ a -= c; a ^= rot(c, 16); c += b; \
+ b -= a; b ^= rot(a, 19); a += c; \
+ c -= b; c ^= rot(b, 4); b += a; \
+} while (0)
+
+#define final(a, b, c) \
+{ \
+ c ^= b; c -= rot(b, 14); \
+ a ^= c; a -= rot(c, 11); \
+ b ^= a; b -= rot(a, 25); \
+ c ^= b; c -= rot(b, 16); \
+ a ^= c; a -= rot(c, 4);\
+ b ^= a; b -= rot(a, 14); \
+ c ^= b; c -= rot(b, 24); \
+}
+
+static __attribute__((unused))
+uint32_t hash_u32(
+ const uint32_t *k, /* the key, an array of uint32_t values */
+ size_t length, /* the length of the key, in uint32_ts */
+ uint32_t initval) /* the previous hash, or an arbitrary value */
+{
+ uint32_t a, b, c;
+
+ /* Set up the internal state */
+ a = b = c = 0xdeadbeef + (((uint32_t) length) << 2) + initval;
+
+ /*----------------------------------------- handle most of the key */
+ while (length > 3) {
+ a += k[0];
+ b += k[1];
+ c += k[2];
+ mix(a, b, c);
+ length -= 3;
+ k += 3;
+ }
+
+ /*----------------------------------- handle the last 3 uint32_t's */
+ switch (length) { /* all the case statements fall through */
+ case 3: c += k[2];
+ case 2: b += k[1];
+ case 1: a += k[0];
+ final(a, b, c);
+ case 0: /* case 0: nothing left to add */
+ break;
+ }
+ /*---------------------------------------------- report the result */
+ return c;
+}
+
+static
+void hashword2(
+ const uint32_t *k, /* the key, an array of uint32_t values */
+ size_t length, /* the length of the key, in uint32_ts */
+ uint32_t *pc, /* IN: seed OUT: primary hash value */
+ uint32_t *pb) /* IN: more seed OUT: secondary hash value */
+{
+ uint32_t a, b, c;
+
+ /* Set up the internal state */
+ a = b = c = 0xdeadbeef + ((uint32_t) (length << 2)) + *pc;
+ c += *pb;
+
+ /*----------------------------------------- handle most of the key */
+ while (length > 3) {
+ a += k[0];
+ b += k[1];
+ c += k[2];
+ mix(a, b, c);
+ length -= 3;
+ k += 3;
+ }
+
+ /*----------------------------------- handle the last 3 uint32_t's */
+ switch (length) { /* all the case statements fall through */
+ case 3: c += k[2];
+ case 2: b += k[1];
+ case 1: a += k[0];
+ final(a, b, c);
+ case 0: /* case 0: nothing left to add */
+ break;
+ }
+ /*---------------------------------------------- report the result */
+ *pc = c;
+ *pb = b;
+}
+
+#if (CAA_BITS_PER_LONG == 32)
static
-unsigned long test_hash(void *_hashseed, void *_key)
+unsigned long test_hash(void *_key, size_t length, unsigned long seed)
{
- unsigned long seed = (unsigned long) _hashseed;
unsigned long key = (unsigned long) _key;
unsigned long v;
- v = key ^ seed;
- v ^= v << 8;
- v ^= v << 16;
- v ^= v << 27;
- v ^= v >> 8;
- v ^= v >> 16;
- v ^= v >> 27;
+ assert(length == sizeof(unsigned long));
+ return hash_u32(&v, 1, seed);
+}
+#else
+static
+unsigned long test_hash(void *_key, size_t length, unsigned long seed)
+{
+ union {
+ uint64_t v64;
+ uint32_t v32[2];
+ } v;
+ union {
+ uint64_t v64;
+ uint32_t v32[2];
+ } key;
+
+ assert(length == sizeof(unsigned long));
+ v.v64 = (uint64_t) seed;
+ key.v64 = (uint64_t) _key;
+ hashword2(key.v32, 2, &v.v32[0], &v.v32[1]);
+ return v.v64;
+}
+#endif
- return v;
+static
+unsigned long test_compare(void *key1, size_t key1_len,
+ void *key2, size_t key2_len)
+{
+ if (unlikely(key1_len != key2_len))
+ return -1;
+ assert(key1_len == sizeof(unsigned long));
+ if (key1 == key2)
+ return 0;
+ else
+ return 1;
}
void *thr_reader(void *_count)
for (;;) {
rcu_read_lock();
node = ht_lookup(test_ht,
- (void *)(unsigned long)(rand_r(&rand_lookup) % RAND_POOL));
+ (void *)(unsigned long)(rand_r(&rand_lookup) % RAND_POOL),
+ sizeof(void *));
if (node == NULL)
lookup_fail++;
else
rcu_read_lock();
ht_node_init(node,
(void *)(unsigned long)(rand_r(&rand_lookup) % RAND_POOL),
+ sizeof(void *),
(void *) 0x42);
ht_add(test_ht, node);
rcu_read_unlock();
/* May delete */
rcu_read_lock();
node = ht_lookup(test_ht,
- (void *)(unsigned long)(rand_r(&rand_lookup) % RAND_POOL));
+ (void *)(unsigned long)(rand_r(&rand_lookup) % RAND_POOL),
+ sizeof(void *));
if (node)
ret = ht_remove(test_ht, node);
else
tid_writer = malloc(sizeof(*tid_writer) * nr_writers);
count_reader = malloc(sizeof(*count_reader) * nr_readers);
count_writer = malloc(sizeof(*count_writer) * nr_writers);
- test_ht = ht_new(test_hash, (void *) 0x42,
+ test_ht = ht_new(test_hash, test_compare, 0x42UL,
HASH_SIZE, call_rcu);
next_aff = 0;
struct rcu_ht_node {
struct rcu_ht_node *next;
void *key;
+ size_t key_len;
unsigned long hash;
unsigned long reverse_hash;
unsigned int dummy;
* Ensure reader and writer threads are registered as urcu readers.
*/
-typedef unsigned long (*ht_hash_fct)(void *hashseed, void *key);
+typedef unsigned long (*ht_hash_fct)(void *key, size_t length,
+ unsigned long seed);
+typedef unsigned long (*ht_compare_fct)(void *key1, size_t key1_len,
+ void *key2, size_t key2_len);
static inline
-void ht_node_init(struct rcu_ht_node *node, void *key, void *value)
+void ht_node_init(struct rcu_ht_node *node, void *key,
+ size_t key_len, void *value)
{
node->key = key;
+ node->key_len = key_len;
node->value = value;
node->dummy = 0;
}
* init_size must be power of two.
*/
struct rcu_ht *ht_new(ht_hash_fct hash_fct,
- void *hashseed,
+ ht_compare_fct compare_fct,
+ unsigned long hash_seed,
unsigned long init_size,
void (*ht_call_rcu)(struct rcu_head *head,
void (*func)(struct rcu_head *head)));
int ht_destroy(struct rcu_ht *ht);
/* Call with rcu_read_lock held. */
-struct rcu_ht_node *ht_lookup(struct rcu_ht *ht, void *key);
+struct rcu_ht_node *ht_lookup(struct rcu_ht *ht, void *key, size_t key_len);
/* Call with rcu_read_lock held. */
void ht_add(struct rcu_ht *ht, struct rcu_ht_node *node);
projects / userspace-rcu.git / commitdiff
