mysql-test/t/ndb_dd_basic.test

    fixed the test
sql/ha_ndbcluster.cc
    LOCK_plugin is used in ha_ndbcluster.cc
sql/sql_plugin.cc
    LOCK_plugin is used in ha_ndbcluster.cc

mysql-test/t/ndb_dd_basic.test

@@ -25,7 +25,6 @@ INITIAL_SIZE 16M
 UNDO_BUFFER_SIZE = 1M
 ENGINE=MYISAM;
 
---error ER_UNKNOWN_STORAGE_ENGINE
 ALTER LOGFILE GROUP lg1
 ADD UNDOFILE 'undofile02.dat'
 INITIAL_SIZE = 4M 

sql/ha_ndbcluster.cc

@@ -6851,6 +6851,7 @@ static int connect_callback()
 }
 
 extern int ndb_dictionary_is_mysqld;
+extern pthread_mutex_t LOCK_plugin;
 
 static int ndbcluster_init(void *p)
 {
@@ -6860,6 +6861,13 @@ static int ndbcluster_init(void *p)
   if (ndbcluster_inited)
     DBUG_RETURN(FALSE);
 
+  /*
+    Below we create new THD's. They'll need LOCK_plugin, but it's taken now by
+    plugin initialization code. Release it to avoid deadlocks.  It's safe, as
+    there're no threads that may concurrently access plugin control structures.
+  */
+  pthread_mutex_unlock(&LOCK_plugin);
+
   pthread_mutex_init(&ndbcluster_mutex,MY_MUTEX_INIT_FAST);
   pthread_mutex_init(&LOCK_ndb_util_thread, MY_MUTEX_INIT_FAST);
   pthread_cond_init(&COND_ndb_util_thread, NULL);
@@ -6998,6 +7006,8 @@ static int ndbcluster_init(void *p)
     goto ndbcluster_init_error;
   }
 
+  pthread_mutex_lock(&LOCK_plugin);
+
   ndbcluster_inited= 1;
   DBUG_RETURN(FALSE);
 
@@ -7010,6 +7020,8 @@ ndbcluster_init_error:
   g_ndb_cluster_connection= NULL;
   ndbcluster_hton->state= SHOW_OPTION_DISABLED;               // If we couldn't use handler
 
+  pthread_mutex_lock(&LOCK_plugin);
+
   DBUG_RETURN(TRUE);
 }
 

sql/sql_plugin.cc

@@ -99,7 +99,7 @@ static bool initialized= 0;
   following variables/structures.
   We are always manipulating ref count, so a rwlock here is unneccessary.
 */
-static pthread_mutex_t LOCK_plugin;
+pthread_mutex_t LOCK_plugin;
 static DYNAMIC_ARRAY plugin_dl_array;
 static DYNAMIC_ARRAY plugin_array;
 static HASH plugin_hash[MYSQL_MAX_PLUGIN_TYPE_NUM];