Merge Bug#43230 into mysql-5.1-bugteam

1 files changed, 30 insertions, 3 deletions

diff --git a/sql/sql_parse.cc b/sql/sql_parse.cc
index 2974dff9ea9..6dbe4a4fd8d 100644
--- a/sql/sql_parse.cc
+++ b/sql/sql_parse.cc
@@ -2200,8 +2200,15 @@ mysql_execute_command(THD *thd)
       res= check_access(thd,
                         lex->exchange ? SELECT_ACL | FILE_ACL : SELECT_ACL,
                         any_db, 0, 0, 0, 0);
-    if (!res)
-      res= execute_sqlcom_select(thd, all_tables);
+
+    if (res)
+      break;
+
+    if (!thd->locked_tables && lex->protect_against_global_read_lock &&
+        !(need_start_waiting= !wait_if_global_read_lock(thd, 0, 1)))
+      break;
+
+    res= execute_sqlcom_select(thd, all_tables);
     break;
   case SQLCOM_PREPARE:
   {
@@ -3006,6 +3013,9 @@ end_with_restore_list:
     DBUG_ASSERT(first_table == all_tables && first_table != 0);
     if (update_precheck(thd, all_tables))
       break;
+    if (!thd->locked_tables &&
+        !(need_start_waiting= !wait_if_global_read_lock(thd, 0, 1)))
+      goto error;
     DBUG_ASSERT(select_lex->offset_limit == 0);
     unit->set_limit(select_lex);
     res= (up_result= mysql_update(thd, all_tables,
@@ -3032,6 +3042,15 @@ end_with_restore_list:
     else
       res= 0;
 
+    /*
+      Protection might have already been risen if its a fall through
+      from the SQLCOM_UPDATE case above.
+    */
+    if (!thd->locked_tables &&
+        lex->sql_command == SQLCOM_UPDATE_MULTI &&
+        !(need_start_waiting= !wait_if_global_read_lock(thd, 0, 1)))
+      goto error;
+
     res= mysql_multi_update_prepare(thd);
 
 #ifdef HAVE_REPLICATION
@@ -3229,7 +3248,8 @@ end_with_restore_list:
                  ER(ER_LOCK_OR_ACTIVE_TRANSACTION), MYF(0));
       goto error;
     }
-
+    if (!(need_start_waiting= !wait_if_global_read_lock(thd, 0, 1)))
+      goto error;
     res= mysql_truncate(thd, first_table, 0);
     break;
   case SQLCOM_DELETE:
@@ -3402,6 +3422,10 @@ end_with_restore_list:
     if (check_one_table_access(thd, privilege, all_tables))
       goto error;
 
+    if (!thd->locked_tables &&
+        !(need_start_waiting= !wait_if_global_read_lock(thd, 0, 1)))
+      goto error;
+
     res= mysql_load(thd, lex->exchange, first_table, lex->field_list,
                     lex->update_list, lex->value_list, lex->duplicates,
                     lex->ignore, (bool) lex->local_file);
@@ -3472,6 +3496,9 @@ end_with_restore_list:
     if (check_table_access(thd, LOCK_TABLES_ACL | SELECT_ACL, all_tables,
                            UINT_MAX, FALSE))
       goto error;
+    if (lex->protect_against_global_read_lock &&
+        !(need_start_waiting= !wait_if_global_read_lock(thd, 0, 1)))
+      goto error;
     thd->in_lock_tables=1;
     thd->options|= OPTION_TABLE_LOCK;