struct file_buffer *cache_lookup(struct cache *cache, long long index)
{
/* Lookup block in the cache, if found return with usage count
* incremented, if not found return NULL */
int hash = CALCULATE_CACHE_HASH(index);
struct file_buffer *entry;
pthread_cleanup_push((void *) pthread_mutex_unlock, &cache->mutex);
pthread_mutex_lock(&cache->mutex);
for(entry = cache->hash_table[hash]; entry; entry = entry->hash_next)
if(entry->index == index)
break;
if(entry) {
/* found the block in the cache, increment used count and
* if necessary remove from free list so it won't disappear
*/
if(entry->used == 0) {
remove_free_list(&cache->free_list, entry);
cache->used ++;
}
entry->used ++;
}
pthread_cleanup_pop(1);
return entry;
}
Ndb*
NdbPool::get_hint_ndb(Uint32 hint_id, Uint32 hash_entry)
{
Ndb* ret_ndb = NULL;
do {
if ((hint_id != 0) &&
(hint_id <= m_max_ndb_objects) &&
(m_pool_reference[hint_id].in_use) &&
(m_pool_reference[hint_id].free_entry)) {
ret_ndb = m_pool_reference[hint_id].ndb_reference;
if (ret_ndb != NULL) {
break;
} else {
assert(false);
}
}
return NULL;
} while (1);
/*
This is where we remove the entry from the free list and from the db hash
table.
*/
remove_free_list(hint_id);
remove_db_hash(hint_id, hash_entry);
return ret_ndb;
}
static struct file_buffer *cache_freelist(struct cache *cache)
{
struct file_buffer *entry = cache->free_list;
remove_free_list(&cache->free_list, entry);
/* a block on the free_list is hashed */
remove_cache_hash_table(cache, entry);
cache->used ++;
return entry;
}
