speed up main.alter_table_online_debugbb-10.10-MDEV-28771

3 files changed, 14 insertions, 5 deletions

diff --git a/mysql-test/main/alter_table_online_debug.result b/mysql-test/main/alter_table_online_debug.result
index 08c473906f3..244a926fea9 100644
--- a/mysql-test/main/alter_table_online_debug.result
+++ b/mysql-test/main/alter_table_online_debug.result
@@ -58,8 +58,9 @@ insert t1 values (5);
 connection con2;
 set debug_sync= 'now WAIT_FOR ended';
 connection default;
+set @old_dbug= @@debug_dbug;
+set debug_dbug= "+d,alter_table_online_timeout_fast";
 set debug_sync= 'alter_table_copy_end SIGNAL ended WAIT_FOR end';
-set session lock_wait_timeout=1;
 alter table t1 add b int NULL, algorithm= copy, lock= none;
 connection con2;
 start transaction;
@@ -70,6 +71,7 @@ ERROR HY000: Lock wait timeout exceeded; try restarting transaction
 select * from t1;
 a
 5
+set debug_dbug= @old_dbug;
 set session lock_wait_timeout=default;
 connection con2;
 rollback;
diff --git a/mysql-test/main/alter_table_online_debug.test b/mysql-test/main/alter_table_online_debug.test
index cacd8cd1e12..9f586825b61 100644
--- a/mysql-test/main/alter_table_online_debug.test
+++ b/mysql-test/main/alter_table_online_debug.test
@@ -75,8 +75,9 @@ insert t1 values (5);
 set debug_sync= 'now WAIT_FOR ended';
 
 --connection default
+set @old_dbug= @@debug_dbug;
+set debug_dbug= "+d,alter_table_online_timeout_fast";
 set debug_sync= 'alter_table_copy_end SIGNAL ended WAIT_FOR end';
-set session lock_wait_timeout=1;
 --send
 alter table t1 add b int NULL, algorithm= copy, lock= none;
 
@@ -90,6 +91,7 @@ set debug_sync= 'now SIGNAL end';
 --error ER_LOCK_WAIT_TIMEOUT
 --reap
 select * from t1;
+set debug_dbug= @old_dbug;
 set session lock_wait_timeout=default;
 --connection con2
 rollback;
diff --git a/sql/sql_table.cc b/sql/sql_table.cc
index 8e26593fcb2..9f41faa1cf9 100644
--- a/sql/sql_table.cc
+++ b/sql/sql_table.cc
@@ -11866,9 +11866,14 @@ copy_data_between_tables(THD *thd, TABLE *from, TABLE *to,
 
     DEBUG_SYNC(thd, "alter_table_online_before_lock");
 
-    int lock_error=
-        thd->mdl_context.upgrade_shared_lock(from->mdl_ticket, MDL_EXCLUSIVE,
-                                     (double)thd->variables.lock_wait_timeout);
+    double lock_wait_timeout= (double)thd->variables.lock_wait_timeout;
+    DBUG_EXECUTE_IF("alter_table_online_timeout_fast",
+                    lock_wait_timeout= 0.001;);
+
+
+    int lock_error= thd->mdl_context.upgrade_shared_lock(from->mdl_ticket,
+                                                         MDL_EXCLUSIVE,
+                                                         lock_wait_timeout);
     if (!error)
       error= lock_error;