Bug#1421360: Add 'FLUSH TABLES' to Total Order Isolation execution.

Before this, FLUSH TABLES and FLUSH TABLES t1 (REFRESH_TABLES hereafter) were executed locally,
which also had implications for GTID. MySQL async replication does
replicate FLUSH TABLES.

Hence, this commit

a)  Adds REFRESH_TABLES to TOI.

b) Skips LOCK-based REFRESH_TABLES from TOI, ie. FLUSH TABLES WITH READ
LOCK and FLUSH TABLES FOR EXPORT.

c) Executes them after reload_acl_and_cache. This is done since
reload_acl_and_cache checks for thd->locked_tables_mode and does upgrade
of MDL locks accordingly. A failure here means REFRESH_TABLES cannot
run.

    i) This is also important since LOCK TABLES is not replicated in
    galera.

d) Test galera_flush has been modified for

    i) wsrep_replicate_myisam SESSION variable.

    ii) Testing REFRESH_TABLES.

    iii) Testing REFRESH_TABLES + LOCK TABLES.

e) Use different WSREP_TO_ISOLATION_BEGIN for global FLUSH TABLES and FLUSH TABLES <table,>.

1 files changed, 19 insertions, 0 deletions

diff --git a/sql/sql_parse.cc b/sql/sql_parse.cc
index f1a3e7cb58e..af35a2a3b55 100644
--- a/sql/sql_parse.cc
+++ b/sql/sql_parse.cc
@@ -4695,6 +4695,25 @@ end_with_restore_list:
     */
     if (!reload_acl_and_cache(thd, lex->type, first_table, &write_to_binlog))
     {
+#ifdef WITH_WSREP
+      if ((lex->type & REFRESH_TABLES) && !(lex->type & (REFRESH_FOR_EXPORT|REFRESH_READ_LOCK)))
+      {
+        /*
+          This is done after reload_acl_and_cache is because
+          LOCK TABLES is not replicated in galera, the upgrade of which
+          is checked in reload_acl_and_cache.
+          Hence, done after/if we are able to upgrade locks.
+        */
+        if (first_table)
+        {
+            WSREP_TO_ISOLATION_BEGIN(NULL, NULL, first_table);
+        }
+        else
+        {
+            WSREP_TO_ISOLATION_BEGIN(WSREP_MYSQL_DB, NULL, NULL);
+        }
+      }
+#endif /* WITH_WSREP */
       /*
         We WANT to write and we CAN write.
         ! we write after unlocking the table.