SET DEBUG_SYNC = 'dispatch_command_before_set_time WAIT_FOR do_set_time';
SELECT 1;
SET DEBUG_SYNC = 'fill_schema_processlist_after_unow SIGNAL do_set_time WAIT_FOR fill_schema_proceed';
SELECT INFO,TIME,TIME_MS FROM INFORMATION_SCHEMA.PROCESSLIST WHERE INFO IS NULL;
1
1
SET DEBUG_SYNC = 'now SIGNAL fill_schema_proceed';
INFO	TIME	TIME_MS
NULL	0	0.000
select sleep(5);
sleep(5)
0
select command, time < 5 from information_schema.processlist where id != connection_id();
command	time < 5
Sleep	1