Adding in an ha_end() call. This is the first part of the patch I and Monty...

Adding in an ha_end() call. This is the first part of the patch I and Monty have agreed on. In the future engines will have the option of shutting down more quickly via the panic call, or just shutting down during the unloading of a plugin. 

sql/handler.cc

@@ -510,6 +510,23 @@ int ha_init()
   DBUG_RETURN(error);
 }
 
+int ha_end()
+{
+  int error= 0;
+  DBUG_ENTER("ha_end");
+
+
+  /* 
+    This should be eventualy based  on the graceful shutdown flag.
+    So if flag is equal to HA_PANIC_CLOSE, the deallocate
+    the errors.
+  */
+  if (ha_finish_errors())
+    error= 1;
+
+  DBUG_RETURN(error);
+}
+
 static my_bool dropdb_handlerton(THD *unused1, st_plugin_int *plugin,
                                  void *path)
 {

sql/handler.h

@@ -1654,6 +1654,7 @@ static inline bool ha_storage_engine_is_enabled(const handlerton *db_type)
 
 /* basic stuff */
 int ha_init(void);
+int ha_end(void);
 int ha_initialize_handlerton(st_plugin_int *plugin);
 int ha_finalize_handlerton(st_plugin_int *plugin);
 

sql/mysqld.cc

@@ -1193,6 +1193,7 @@ void clean_up(bool print_message)
 #endif
   }
   plugin_shutdown();
+  ha_end();
   if (tc_log)
     tc_log->close();
   xid_cache_free();