invalidation of locking for write tables (BUG#2693)

fixed linking query_prealloc_size to query cache presence


mysql-test/r/query_cache.result:
  test of QC invalidation by LOCK command
mysql-test/t/query_cache.test:
  test of QC invalidation by LOCK command
sql/mysqld.cc:
  new variable query_cache_wlock_invalidate
  fixed query_prealloc_size with QC absence
sql/set_var.cc:
  new variable query_cache_wlock_invalidate
sql/sql_cache.cc:
  new method for table invalidation
sql/sql_cache.h:
  new method for table invalidation
sql/sql_class.h:
  new variable query_cache_wlock_invalidate
sql/sql_parse.cc:
  layout fixed

1 files changed, 17 insertions, 0 deletions

diff --git a/mysql-test/r/query_cache.result b/mysql-test/r/query_cache.result
index c7554211a1a..a9e9f167e5f 100644
--- a/mysql-test/r/query_cache.result
+++ b/mysql-test/r/query_cache.result
@@ -687,4 +687,21 @@ select * from t3;
 delete from t4 where a=1;
 flush query cache;
 drop table t1,t2,t3,t4;
+set query_cache_wlock_invalidate=1;
+create table t1 (a int not null);
+create table t2 (a int not null);
+select * from t1;
+a
+select * from t2;
+a
+show status like "Qcache_queries_in_cache";
+Variable_name	Value
+Qcache_queries_in_cache	2
+lock table t1 write, t2 read;
+show status like "Qcache_queries_in_cache";
+Variable_name	Value
+Qcache_queries_in_cache	1
+unlock table;
+drop table t1,t2;
+set query_cache_wlock_invalidate=default;
 set GLOBAL query_cache_size=0;