diff options
Diffstat (limited to 'assoc.c')
| -rw-r--r-- | assoc.c | 30 |
1 files changed, 25 insertions, 5 deletions
@@ -32,7 +32,7 @@ typedef unsigned long int ub4; /* unsigned 4-byte quantities */ typedef unsigned char ub1; /* unsigned 1-byte quantities */ /* how many powers of 2's worth of buckets we use */ -static unsigned int hashpower = HASHPOWER_DEFAULT; +unsigned int hashpower = HASHPOWER_DEFAULT; #define hashsize(n) ((ub4)1<<(n)) #define hashmask(n) (hashsize(n)-1) @@ -51,6 +51,7 @@ static unsigned int hash_items = 0; /* Flag: Are we in the middle of expanding now? */ static bool expanding = false; +static bool started_expanding = false; /* * During expansion we migrate values with bucket granularity; this is how @@ -136,13 +137,19 @@ static void assoc_expand(void) { stats.hash_bytes += hashsize(hashpower) * sizeof(void *); stats.hash_is_expanding = 1; STATS_UNLOCK(); - pthread_cond_signal(&maintenance_cond); } else { primary_hashtable = old_hashtable; /* Bad news, but we can keep running. */ } } +static void assoc_start_expand(void) { + if (started_expanding) + return; + started_expanding = true; + pthread_cond_signal(&maintenance_cond); +} + /* Note: this isn't an assoc_update. The key must not already exist to call this */ int assoc_insert(item *it, const uint32_t hv) { unsigned int oldbucket; @@ -161,7 +168,7 @@ int assoc_insert(item *it, const uint32_t hv) { hash_items++; if (! expanding && hash_items > (hashsize(hashpower) * 3) / 2) { - assoc_expand(); + assoc_start_expand(); } MEMCACHED_ASSOC_INSERT(ITEM_key(it), it->nkey, hash_items); @@ -201,6 +208,7 @@ static void *assoc_maintenance_thread(void *arg) { /* Lock the cache, and bulk move multiple buckets to the new * hash table. */ + item_lock_global(); mutex_lock(&cache_lock); for (ii = 0; ii < hash_bulk_move && expanding; ++ii) { @@ -230,12 +238,24 @@ static void *assoc_maintenance_thread(void *arg) { } } + mutex_unlock(&cache_lock); + item_unlock_global(); + if (!expanding) { + /* finished expanding. tell all threads to use fine-grained locks */ + switch_item_lock_type(ITEM_LOCK_GRANULAR); + started_expanding = false; + slabs_rebalancer_resume(); /* We are done expanding.. just wait for next invocation */ pthread_cond_wait(&maintenance_cond, &cache_lock); + /* Before doing anything, tell threads to use a global lock */ + mutex_unlock(&cache_lock); + slabs_rebalancer_pause(); + switch_item_lock_type(ITEM_LOCK_GLOBAL); + mutex_lock(&cache_lock); + assoc_expand(); + mutex_unlock(&cache_lock); } - - mutex_unlock(&cache_lock); } return NULL; } |