char val[];
} string_t;
-typedef struct hash_table_i {
+typedef struct hti {
volatile entry_t *table;
- hash_table_t *ht; // parent ht;
- struct hash_table_i *next;
- struct hash_table_i *next_free;
+ hashtable_t *ht; // parent ht;
+ struct hti *next;
+ struct hti *next_free;
unsigned int scale;
int max_probe;
int count; // TODO: make these counters distributed
int num_entries_copied;
int scan;
-} hash_table_i_t;
+} hashtable_i_t;
static const uint64_t COPIED_VALUE = -1;
static const uint64_t TOMBSTONE = STRIP_TAG(-1);
static const unsigned MAX_BUCKETS_TO_PROBE = 250;
static int hti_copy_entry
- (hash_table_i_t *ht1, volatile entry_t *e, uint32_t e_key_hash, hash_table_i_t *ht2);
+ (hashtable_i_t *ht1, volatile entry_t *e, uint32_t e_key_hash, hashtable_i_t *ht2);
// Choose the next bucket to probe using the high-order bits of <key_hash>.
static inline int get_next_ndx(int old_ndx, uint32_t key_hash, int ht_scale) {
//
// Record if the entry being returned is empty. Otherwise the caller will have to waste time with
// ht_key_equals() to confirm that it did not lose a race to fill an empty entry.
-static volatile entry_t *hti_lookup (hash_table_i_t *hti, uint32_t key_hash, const char *key_val, uint32_t key_len, int *is_empty) {
+static volatile entry_t *hti_lookup (hashtable_i_t *hti, uint32_t key_hash, const char *key_val, uint32_t key_len, int *is_empty) {
TRACE("h2", "hti_lookup(key %p in hti %p)", key_val, hti);
*is_empty = 0;
return NULL;
}
-// Allocate and initialize a hash_table_i_t with 2^<scale> entries.
-static hash_table_i_t *hti_alloc (hash_table_t *parent, int scale) {
+// Allocate and initialize a hashtable_i_t with 2^<scale> entries.
+static hashtable_i_t *hti_alloc (hashtable_t *parent, int scale) {
// Include enough slop to align the actual table on a cache line boundry
- size_t n = sizeof(hash_table_i_t)
+ size_t n = sizeof(hashtable_i_t)
+ sizeof(entry_t) * (1 << scale)
+ (CACHE_LINE_SIZE - 1);
- hash_table_i_t *hti = (hash_table_i_t *)calloc(n, 1);
+ hashtable_i_t *hti = (hashtable_i_t *)calloc(n, 1);
// Align the table of hash entries on a cache line boundry.
- hti->table = (entry_t *)(((uint64_t)hti + sizeof(hash_table_i_t) + (CACHE_LINE_SIZE-1))
+ hti->table = (entry_t *)(((uint64_t)hti + sizeof(hashtable_i_t) + (CACHE_LINE_SIZE-1))
& ~(CACHE_LINE_SIZE-1));
hti->scale = scale;
// Called when <hti> runs out of room for new keys.
//
-// Initiates a copy by creating a larger hash_table_i_t and installing it in <hti->next>.
-static void hti_start_copy (hash_table_i_t *hti) {
+// Initiates a copy by creating a larger hashtable_i_t and installing it in <hti->next>.
+static void hti_start_copy (hashtable_i_t *hti) {
TRACE("h0", "hti_start_copy(hti %p scale %llu)", hti, hti->scale);
// heuristics to determine the size of the new table
new_scale += (count > (1 << (new_scale - 2))); // double size again if more than 1/2 full
// Allocate the new table and attempt to install it.
- hash_table_i_t *next = hti_alloc(hti->ht, new_scale);
- hash_table_i_t *old_next = SYNC_CAS(&hti->next, NULL, next);
+ hashtable_i_t *next = hti_alloc(hti->ht, new_scale);
+ hashtable_i_t *old_next = SYNC_CAS(&hti->next, NULL, next);
if (old_next != NULL) {
// Another thread beat us to it.
TRACE("h0", "hti_start_copy: lost race to install new hti; found %p", old_next, 0);
//
// Return 1 unless <ht1_e> is already copied (then return 0), so the caller can account for the total
// number of entries left to copy.
-static int hti_copy_entry (hash_table_i_t *ht1, volatile entry_t *ht1_e, uint32_t key_hash,
- hash_table_i_t *ht2) {
+static int hti_copy_entry (hashtable_i_t *ht1, volatile entry_t *ht1_e, uint32_t key_hash,
+ hashtable_i_t *ht2) {
TRACE("h2", "hti_copy_entry: entry %p to table %p", ht1_e, ht2);
assert(ht1);
assert(ht1->next);
//
// NOTE: the returned value matches <expected> iff the set succeeds
//
-// Certain values of <expected> have special meaning. If <expected> is HT_EXPECT_EXISTS then any
+// Certain values of <expected> have special meaning. If <expected> is EXPECT_EXISTS then any
// real value matches (i.e. not a TOMBSTONE or DOES_NOT_EXIST) as long as <key> is in the table. If
-// <expected> is HT_EXPECT_WHATEVER then skip the test entirely.
+// <expected> is EXPECT_WHATEVER then skip the test entirely.
//
-static uint64_t hti_compare_and_set (hash_table_i_t *hti, uint32_t key_hash, const char *key_val,
+static uint64_t hti_compare_and_set (hashtable_i_t *hti, uint32_t key_hash, const char *key_val,
uint32_t key_len, uint64_t expected, uint64_t new) {
TRACE("h1", "hti_compare_and_set: hti %p key %p", hti, key_val);
TRACE("h1", "hti_compare_and_set: value %p expect %p", new, expected);
// Install <key> in the table if it doesn't exist.
if (is_empty) {
TRACE("h0", "hti_compare_and_set: entry %p is empty", e, 0);
- if (expected != HT_EXPECT_WHATEVER && expected != HT_EXPECT_NOT_EXISTS)
+ if (expected != EXPECT_WHATEVER && expected != EXPECT_DOES_NOT_EXIST)
return DOES_NOT_EXIST;
// No need to do anything, <key> is already deleted.
uint64_t e_value = e->value;
if (EXPECT_FALSE(IS_TAGGED(e_value))) {
if (e_value != COPIED_VALUE) {
- int did_copy = hti_copy_entry(hti, e, key_hash, ((volatile hash_table_i_t *)hti)->next);
+ int did_copy = hti_copy_entry(hti, e, key_hash, ((volatile hashtable_i_t *)hti)->next);
if (did_copy) {
SYNC_ADD(&hti->num_entries_copied, 1);
}
// Fail if the old value is not consistent with the caller's expectation.
int old_existed = (e_value != TOMBSTONE && e_value != DOES_NOT_EXIST);
- if (EXPECT_FALSE(expected != HT_EXPECT_WHATEVER && expected != e_value)) {
- if (EXPECT_FALSE(expected != (old_existed ? HT_EXPECT_EXISTS : HT_EXPECT_NOT_EXISTS))) {
+ if (EXPECT_FALSE(expected != EXPECT_WHATEVER && expected != e_value)) {
+ if (EXPECT_FALSE(expected != (old_existed ? EXPECT_EXISTS : EXPECT_DOES_NOT_EXIST))) {
TRACE("h1", "hti_compare_and_set: value %p expected by caller not found; found value %p",
expected, e_value);
return e_value;
}
//
-static uint64_t hti_get (hash_table_i_t *hti, uint32_t key_hash, const char *key_val, uint32_t key_len) {
+static uint64_t hti_get (hashtable_i_t *hti, uint32_t key_hash, const char *key_val, uint32_t key_len) {
assert(key_val);
int is_empty;
// searching the table. In that case, if a copy is in progress the key
// might exist in the copy.
if (EXPECT_FALSE(e == NULL)) {
- if (((volatile hash_table_i_t *)hti)->next != NULL)
+ if (((volatile hashtable_i_t *)hti)->next != NULL)
return hti_get(hti->next, key_hash, key_val, key_len); // recursive tail-call
return DOES_NOT_EXIST;
}
uint64_t e_value = e->value;
if (EXPECT_FALSE(IS_TAGGED(e_value))) {
if (EXPECT_FALSE(e_value != COPIED_VALUE)) {
- int did_copy = hti_copy_entry(hti, e, key_hash, ((volatile hash_table_i_t *)hti)->next);
+ int did_copy = hti_copy_entry(hti, e, key_hash, ((volatile hashtable_i_t *)hti)->next);
if (did_copy) {
SYNC_ADD(&hti->num_entries_copied, 1);
}
}
- return hti_get(((volatile hash_table_i_t *)hti)->next, key_hash, key_val, key_len); // tail-call
+ return hti_get(((volatile hashtable_i_t *)hti)->next, key_hash, key_val, key_len); // tail-call
}
return (e_value == TOMBSTONE) ? DOES_NOT_EXIST : e_value;
}
//
-uint64_t ht_get (hash_table_t *ht, const char *key_val, uint32_t key_len) {
+uint64_t ht_get (hashtable_t *ht, const char *key_val, uint32_t key_len) {
return hti_get(*ht, murmur32(key_val, key_len), key_val, key_len);
}
//
-uint64_t ht_compare_and_set (hash_table_t *ht, const char *key_val, uint32_t key_len,
+uint64_t ht_compare_and_set (hashtable_t *ht, const char *key_val, uint32_t key_len,
uint64_t expected_val, uint64_t new_val) {
TRACE("h2", "ht_compare_and_set: key %p len %u", key_val, key_len);
assert(key_val);
assert(!IS_TAGGED(new_val) && new_val != DOES_NOT_EXIST);
- hash_table_i_t *hti = *ht;
+ hashtable_i_t *hti = *ht;
// Help with an ongoing copy.
if (EXPECT_FALSE(hti->next != NULL)) {
// Remove the value in <ht> associated with <key_val>. Returns the value removed, or
// DOES_NOT_EXIST if there was no value for that key.
-uint64_t ht_remove (hash_table_t *ht, const char *key_val, uint32_t key_len) {
- hash_table_i_t *hti = *ht;
+uint64_t ht_remove (hashtable_t *ht, const char *key_val, uint32_t key_len) {
+ hashtable_i_t *hti = *ht;
uint64_t val;
uint32_t key_hash = murmur32(key_val, key_len);
do {
- val = hti_compare_and_set(hti, key_hash, key_val, key_len, HT_EXPECT_WHATEVER, TOMBSTONE);
+ val = hti_compare_and_set(hti, key_hash, key_val, key_len, EXPECT_WHATEVER, TOMBSTONE);
if (val != COPIED_VALUE)
return val == TOMBSTONE ? DOES_NOT_EXIST : val;
assert(hti->next);
}
// Returns the number of key-values pairs in <ht>
-uint64_t ht_count (hash_table_t *ht) {
- hash_table_i_t *hti = *ht;
+uint64_t ht_count (hashtable_t *ht) {
+ hashtable_i_t *hti = *ht;
uint64_t count = 0;
while (hti) {
count += hti->count;
}
// Allocate and initialize a new hash table.
-hash_table_t *ht_alloc (void) {
- hash_table_t *ht = nbd_malloc(sizeof(hash_table_t));
- *ht = (hash_table_i_t *)hti_alloc(ht, MIN_SCALE);
+hashtable_t *ht_alloc (void) {
+ hashtable_t *ht = nbd_malloc(sizeof(hashtable_t));
+ *ht = (hashtable_i_t *)hti_alloc(ht, MIN_SCALE);
return ht;
}
// Free <ht> and its internal structures.
-void ht_free (hash_table_t *ht) {
- hash_table_i_t *hti = *ht;
+void ht_free (hashtable_t *ht) {
+ hashtable_i_t *hti = *ht;
do {
for (uint32_t i = 0; i < (1 << hti->scale); ++i) {
assert(hti->table[i].value == COPIED_VALUE || !IS_TAGGED(hti->table[i].value));
nbd_free(GET_PTR(hti->table[i].key));
}
}
- hash_table_i_t *next = hti->next;
+ hashtable_i_t *next = hti->next;
nbd_free(hti);
hti = next;
} while (hti);