Backport of:

------------------------------------------------------------
revno: 2630.4.17
committer: Dmitry Lenev <dlenev@mysql.com>
branch nick: mysql-6.0-3726-w2
timestamp: Thu 2008-05-29 16:52:56 +0400
message:
  WL#3726 "DDL locking for all metadata objects".

  After review fixes in progress.

  "The great correction of names".

  Renamed MDL_LOCK and MDL_LOCK_DATA classes to make usage of
  these names in metadata locking subsystem consistent with
  other parts of server (i.e. thr_lock.cc). Now we MDL_LOCK_DATA
  corresponds to request for a lock and MDL_LOCK to the lock
  itself. Adjusted code in MDL subsystem and other places
  using these classes accordingly.
  Did similar thing for GLOBAL_MDL_LOCK_DATA class and also
  changed name of its members to correspond to names of
  MDL_LOCK_DATA members.
  Finally got rid of usage of one letter variables in MDL
  code since it makes code harder to search in (according
  to reviewer).

1 files changed, 6 insertions, 5 deletions

diff --git a/sql/lock.cc b/sql/lock.cc
index 38b2d22f91f..b5eaaa05fff 100644
--- a/sql/lock.cc
+++ b/sql/lock.cc
@@ -966,15 +966,16 @@ static MYSQL_LOCK *get_lock_data(THD *thd, TABLE **table_ptr, uint count,
 bool lock_table_names(THD *thd, TABLE_LIST *table_list)
 {
   TABLE_LIST *lock_table;
-  MDL_LOCK *mdl_lock;
+  MDL_LOCK_DATA *mdl_lock_data;
 
   for (lock_table= table_list; lock_table; lock_table= lock_table->next_local)
   {
-    if (!(mdl_lock= mdl_alloc_lock(0, lock_table->db, lock_table->table_name,
-                                   thd->mem_root)))
+    if (!(mdl_lock_data= mdl_alloc_lock(0, lock_table->db,
+                                        lock_table->table_name,
+                                        thd->mem_root)))
       goto end;
-    mdl_set_lock_type(mdl_lock, MDL_EXCLUSIVE);
-    mdl_add_lock(&thd->mdl_context, mdl_lock);
+    mdl_set_lock_type(mdl_lock_data, MDL_EXCLUSIVE);
+    mdl_add_lock(&thd->mdl_context, mdl_lock_data);
   }
   if (mdl_acquire_exclusive_locks(&thd->mdl_context))
     return 1;