WL#6599 - New Data Dictionary and I_S integration.

This is a post-push patch to fix memory leak identified by the
ASAN in the unit test.

Issue here is, memory allocated for Dictionary_impl class's
instance is not deallocated in the unit test.
Modified code to deallocate memory now to fix this issue.
Even modified code to create instance of Dictionary_impl class
only once at the test start and deallocate at the end.

Author: phulakun

sql/dd/impl/dictionary_impl.h

@@ -30,7 +30,7 @@ namespace dd_schema_unittest {
 }
 
 namespace my_testing {
-  class Server_initializer;
+  class DD_initializer;
 }
 
 namespace dd {
@@ -46,7 +46,7 @@ namespace cache {
 class Dictionary_impl : public Dictionary
 {
   friend class dd_schema_unittest::SchemaTest;
-  friend class my_testing::Server_initializer;
+  friend class my_testing::DD_initializer;
 
   /////////////////////////////////////////////////////////////////////////
   // Implementation details.

unittest/gunit/test_utils.cc

@@ -21,6 +21,7 @@
 #include "rpl_handler.h"                        // delegates_init()
 #include "mysqld_thd_manager.h"                 // Global_THD_manager
 #include "opt_costconstantcache.h"              // optimizer cost constant cache
+#include "my_dbug.h"                            // DBUG_ASSERT
 #include "mysqld.h"                             // set_remaining_args
 #include "log.h"                                // query_logger
 
@@ -67,6 +68,7 @@ void setup_server_for_unit_tests()
   // Initialize Query_logger last, to avoid spurious warnings to stderr.
   query_logger.init();
   init_optimizer_cost_module(false);
+  DD_initializer::SetUp();
 }
 
 void teardown_server_for_unit_tests()
@@ -77,6 +79,7 @@ void teardown_server_for_unit_tests()
   gtid_server_cleanup();
   query_logger.cleanup();
   delete_optimizer_cost_module();
+  DD_initializer::TearDown();
 }
 
 void Server_initializer::set_expected_error(uint val)
@@ -96,15 +99,6 @@ void Server_initializer::SetUp()
   m_thd->store_globals();
   lex_start(m_thd);
 
-  /*
-    With WL#6599, SELECT_LEX::add_table_to_list() will invoke
-    dd::Dictionary::is_system_view_name() method. E.g., the unit
-    test InsertDelayed would invoke above API. This requires us
-    to have a instance of dictionary_impl. We do not really need
-    to initialize dd::System_views for this test. Also, there can
-    be future test cases that need the same.
-  */
-  dd::Dictionary_impl::s_instance= new dd::Dictionary_impl();
 }
 
 void Server_initializer::TearDown()
@@ -149,5 +143,24 @@ bool Mock_error_handler::handle_condition(THD *thd,
   return true;
 }
 
+void DD_initializer::SetUp()
+{
+  /*
+    With WL#6599, SELECT_LEX::add_table_to_list() will invoke
+    dd::Dictionary::is_system_view_name() method. E.g., the unit
+    test InsertDelayed would invoke above API. This requires us
+    to have a instance of dictionary_impl. We do not really need
+    to initialize dd::System_views for this test. Also, there can
+    be future test cases that need the same.
+  */
+  dd::Dictionary_impl::s_instance= new (std::nothrow)dd::Dictionary_impl();
+  DBUG_ASSERT(dd::Dictionary_impl::s_instance != nullptr);
+}
+
+void DD_initializer::TearDown()
+{
+  DBUG_ASSERT(dd::Dictionary_impl::s_instance != nullptr);
+  delete dd::Dictionary_impl::s_instance;
+}
 
 }  // namespace my_testing

unittest/gunit/test_utils.h

@@ -111,6 +111,16 @@ void expect_null(T *t)
   EXPECT_EQ(t_null, t);
 }
 
+/*
+  A class which wraps the necessary setup/teardown logic for
+  Data Dictionary.
+*/
+class DD_initializer
+{
+public:
+  static void SetUp();
+  static void TearDown();
+};
 
 }  // namespace my_testing