1berry/MariaDB-server
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Fix possible race condition in Query cache.

Browse Source
This commit is contained in:
unknown 2013-08-05 17:34:38 +03:00
parent 96340a405a
commit 220623572d
1 changed files with 6 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
sql/sql_cache.cc
View File

@ -1312,17 +1312,17 @@ ulong Query_cache::resize(ulong query_cache_size_arg)
{ {
BLOCK_LOCK_WR(block); BLOCK_LOCK_WR(block);
Query_cache_query *query= block->query(); Query_cache_query *query= block->query();
if (query && query->writer()) if (query->writer())
{ {
/* /*
Drop the writer; this will cancel any attempts to store Drop the writer; this will cancel any attempts to store
the processed statement associated with this writer. the processed statement associated with this writer.
*/ */
query->writer()->first_query_block= NULL; query->writer()->first_query_block= NULL;
query->writer(0); query->writer(0);
refused++; refused++;
} }
BLOCK_UNLOCK_WR(block); query->unlock_n_destroy();
block= block->next; block= block->next;
} while (block != queries_blocks); } while (block != queries_blocks);
} }
@ -4247,11 +4247,11 @@ my_bool Query_cache::move_by_type(uchar **border,
size_t key_length; size_t key_length;
key=query_cache_query_get_key((uchar*) block, &key_length, 0); key=query_cache_query_get_key((uchar*) block, &key_length, 0);
my_hash_first(&queries, (uchar*) key, key_length, &record_idx); my_hash_first(&queries, (uchar*) key, key_length, &record_idx);
// Move table of used tables
memmove((char*) new_block->table(0), (char*) block->table(0),
ALIGN_SIZE(n_tables*sizeof(Query_cache_block_table)));
block->query()->unlock_n_destroy(); block->query()->unlock_n_destroy();
block->destroy(); block->destroy();
// Move table of used tables
memmove((char*) new_block->table(0), (char*) block->table(0),
ALIGN_SIZE(n_tables*sizeof(Query_cache_block_table)));
new_block->init(len); new_block->init(len);
new_block->type=Query_cache_block::QUERY; new_block->type=Query_cache_block::QUERY;
new_block->used=used; new_block->used=used;