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, 9 insertions, 9 deletions

diff --git a/sql/sql_delete.cc b/sql/sql_delete.cc
index fb48f32660b..f5c6dfd8986 100644
--- a/sql/sql_delete.cc
+++ b/sql/sql_delete.cc
@@ -1089,7 +1089,7 @@ bool mysql_truncate(THD *thd, TABLE_LIST *table_list, bool dont_send_ok)
   TABLE *table;
   bool error;
   uint path_length;
-  MDL_LOCK *mdl_lock= 0;
+  MDL_LOCK_DATA *mdl_lock_data= 0;
   DBUG_ENTER("mysql_truncate");
 
   bzero((char*) &create_info,sizeof(create_info));
@@ -1164,10 +1164,10 @@ bool mysql_truncate(THD *thd, TABLE_LIST *table_list, bool dont_send_ok)
              tries to get table enging and therefore accesses table in some way
              without holding any kind of meta-data lock.
     */
-    mdl_lock= mdl_alloc_lock(0, table_list->db, table_list->table_name,
-                             thd->mem_root);
-    mdl_set_lock_type(mdl_lock, MDL_EXCLUSIVE);
-    mdl_add_lock(&thd->mdl_context, mdl_lock);
+    mdl_lock_data= mdl_alloc_lock(0, table_list->db, table_list->table_name,
+                                  thd->mem_root);
+    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))
       DBUG_RETURN(TRUE);
     pthread_mutex_lock(&LOCK_open);
@@ -1197,13 +1197,13 @@ end:
       write_bin_log(thd, TRUE, thd->query(), thd->query_length());
       my_ok(thd);		// This should return record count
     }
-    if (mdl_lock)
-      mdl_release_lock(&thd->mdl_context, mdl_lock);
+    if (mdl_lock_data)
+      mdl_release_lock(&thd->mdl_context, mdl_lock_data);
   }
   else if (error)
   {
-    if (mdl_lock)
-      mdl_release_lock(&thd->mdl_context, mdl_lock);
+    if (mdl_lock_data)
+      mdl_release_lock(&thd->mdl_context, mdl_lock_data);
   }
   DBUG_RETURN(error);