# Check if lock_row_lock_current_waits counter in
# information_schema.innodb_metrics does not become negative after disabling,
# resetting and enabling.

--source include/have_innodb.inc
--source include/have_debug.inc
--source include/count_sessions.inc

--connect (prevent_purge,localhost,root,,)
START TRANSACTION WITH CONSISTENT SNAPSHOT;

--connection default
SET GLOBAL innodb_monitor_disable='all';
SET GLOBAL innodb_monitor_enable='lock_row_lock_current_waits';
CREATE TABLE `t` (a INT PRIMARY KEY) engine=InnoDB STATS_PERSISTENT=0;
INSERT INTO t VALUES (5);
SELECT name, count FROM information_schema.innodb_metrics
  WHERE name ='lock_row_lock_current_waits';

--connect (con1,localhost,root,,)
BEGIN;
SELECT * FROM t FOR UPDATE;

--connect (con2,localhost,root,,)
SET DEBUG_SYNC="lock_wait_before_suspend SIGNAL blocked WAIT_FOR cont";
BEGIN;
--send SELECT * FROM t FOR UPDATE

--connection default
SET DEBUG_SYNC="now WAIT_FOR blocked";
SELECT name, count FROM information_schema.innodb_metrics
  WHERE name ='lock_row_lock_current_waits';
SET GLOBAL innodb_monitor_disable='lock_row_lock_current_waits';
SET GLOBAL innodb_monitor_reset_all='lock_row_lock_current_waits';
SET GLOBAL innodb_monitor_enable='lock_row_lock_current_waits';
######################################
# Equals to zero if the bug is not fixed, as MONITOR_DISPLAY_CURRENT is not
# set for this counter and its value is reset during previous
# "SET GLOBAL innodb_monitor_reset_all='lock_row_lock_current_waits'" execution.
#####
SELECT name, count FROM information_schema.innodb_metrics
  WHERE name ='lock_row_lock_current_waits';
SET DEBUG_SYNC="now SIGNAL cont";

--disconnect con1

--connection con2
--reap
COMMIT;
--disconnect con2

--connection default
SET DEBUG_SYNC="reset";
######################################
# Equals to -1 if the bug is not fixed. I.e.
# innodb_counter_value[MONITOR_OVLD_ROW_LOCK_CURRENT_WAIT].mon_start_value is
# set to 1 during
# "set global innodb_monitor_disable='lock_row_lock_current_waits'" execution,
# and the value is counted as
# (value = 0) - (mon_value_reset = 0) - (mon_start_value = 1) +
# (mon_last_value = 0) = -1. See MONITOR_SET_DIFF() macro in
# srv_mon_process_existing_counter() for details.
#####
SELECT name, count FROM information_schema.innodb_metrics
  WHERE name ='lock_row_lock_current_waits';
DROP TABLE `t`;
SET GLOBAL innodb_monitor_disable='lock_row_lock_current_waits';
SET GLOBAL innodb_monitor_reset_all='lock_row_lock_current_waits';
SET GLOBAL innodb_monitor_enable='lock_row_lock_current_waits';
--disable_warnings
SET GLOBAL innodb_monitor_disable=default;
SET GLOBAL innodb_monitor_reset_all=default;
SET GLOBAL innodb_monitor_enable=default;
--enable_warnings
--disconnect prevent_purge
--source include/wait_until_count_sessions.inc