New version of the VATS algorithm (Largest Dependency Set First)

mysql-test/suite/perfschema/r/show_sanity.result

@@ -409,6 +409,7 @@ order by show_mode, source, variable_name;
 SHOW_MODE	SOURCE	VARIABLE_NAME
 5.6	I_S.SESSION_VARIABLES	GTID_EXECUTED
 5.6	I_S.SESSION_VARIABLES	INNODB_DEADLOCK_DETECT
+5.6	I_S.SESSION_VARIABLES	INNODB_LOCK_SCHEDULE_ALGORITHM
 5.6	I_S.SESSION_VARIABLES	INNODB_STATS_INCLUDE_DELETE_MARKED
 5.6	I_S.SESSION_VARIABLES	LOG_STATEMENTS_UNSAFE_FOR_BINLOG
 5.6	I_S.SESSION_VARIABLES	TLS_VERSION
@@ -434,6 +435,7 @@ order by show_mode, source, variable_name;
 SHOW_MODE	SOURCE	VARIABLE_NAME
 5.6	I_S.SESSION_VARIABLES	GTID_EXECUTED
 5.6	I_S.SESSION_VARIABLES	INNODB_DEADLOCK_DETECT
+5.6	I_S.SESSION_VARIABLES	INNODB_LOCK_SCHEDULE_ALGORITHM
 5.6	I_S.SESSION_VARIABLES	INNODB_STATS_INCLUDE_DELETE_MARKED
 5.6	I_S.SESSION_VARIABLES	LOG_STATEMENTS_UNSAFE_FOR_BINLOG
 5.6	I_S.SESSION_VARIABLES	TLS_VERSION

mysql-test/suite/sys_vars/r/innodb_lock_schedule_algorithm_basic.result

@@ -0,0 +1,12 @@
+SELECT @@global.innodb_lock_schedule_algorithm;
+@@global.innodb_lock_schedule_algorithm
+fcfs
+SET GLOBAL innodb_lock_schedule_algorithm = 'FCFS';
+SELECT @@global.innodb_lock_schedule_algorithm;
+@@global.innodb_lock_schedule_algorithm
+fcfs
+SET GLOBAL innodb_lock_schedule_algorithm = 'VATS';
+SELECT @@global.innodb_lock_schedule_algorithm;
+@@global.innodb_lock_schedule_algorithm
+vats
+SET GLOBAL innodb_lock_schedule_algorithm = 'FCFS';

mysql-test/suite/sys_vars/t/innodb_lock_schedule_algorithm_basic.test

@@ -0,0 +1,16 @@
+-- source include/have_innodb.inc
+# This is a debug variable for now
+-- source include/have_debug.inc
+
+SELECT @@global.innodb_lock_schedule_algorithm;
+
+SET GLOBAL innodb_lock_schedule_algorithm = 'FCFS';
+
+SELECT @@global.innodb_lock_schedule_algorithm;
+
+SET GLOBAL innodb_lock_schedule_algorithm = 'VATS';
+
+SELECT @@global.innodb_lock_schedule_algorithm;
+
+# Reset state
+SET GLOBAL innodb_lock_schedule_algorithm = 'FCFS';

storage/innobase/handler/ha_innodb.cc

@@ -300,6 +300,22 @@ static TYPELIB innodb_default_row_format_typelib = {
 	NULL
 };
 
+/** Possible values of the parameter innodb_lock_schedule_algorithm */
+static const char* innodb_lock_schedule_algorithm_names[] = {
+	"fcfs",
+	"vats",
+	NullS
+};
+
+/** Used to define an enumerate type of the system variable
+innodb_lock_schedule_algorithm. */
+static TYPELIB innodb_lock_schedule_algorithm_typelib = {
+	array_elements(innodb_lock_schedule_algorithm_names) - 1,
+	"innodb_lock_schedule_algorithm_typelib",
+	innodb_lock_schedule_algorithm_names,
+	NULL
+};
+
 /* The following counter is used to convey information to InnoDB
 about server activity: in case of normal DML ops it is not
 sensible to call srv_active_wake_master_thread after each
@@ -1364,7 +1380,7 @@ thd_is_replication_slave_thread(
 /*============================*/
 	THD*	thd)	/*!< in: thread handle */
 {
-	return((ibool) thd_slave_thread(thd));
+	return(thd && (ibool) thd_slave_thread(thd));
 }
 
 /******************************************************************//**
@@ -19528,6 +19544,18 @@ static MYSQL_SYSVAR_ULONG(doublewrite_batch_size, srv_doublewrite_batch_size,
   NULL, NULL, 120, 1, 127, 0);
 #endif /* defined UNIV_DEBUG || defined UNIV_PERF_DEBUG */
 
+static MYSQL_SYSVAR_ENUM(lock_schedule_algorithm, innodb_lock_schedule_algorithm,
+  PLUGIN_VAR_RQCMDARG,
+  "The algorithm Innodb uses for deciding which locks to grant next when"
+  " a lock is released. Possible values are"
+  " FCFS"
+  " grant the locks in First-Come-First-Served order;"
+  " VATS"
+  " use the Variance-Aware-Transaction-Scheduling algorithm, which"
+  " uses an Eldest-Transaction-First heuristic.",
+  NULL, NULL, INNODB_LOCK_SCHEDULE_ALGORITHM_FCFS,
+  &innodb_lock_schedule_algorithm_typelib);
+
 static MYSQL_SYSVAR_ULONG(buffer_pool_instances, srv_buf_pool_instances,
   PLUGIN_VAR_RQCMDARG | PLUGIN_VAR_READONLY,
   "Number of buffer pool instances, set to higher value on high-end machines to increase scalability",
@@ -20131,7 +20159,8 @@ static struct st_mysql_sys_var* innobase_system_variables[]= {
   MYSQL_SYSVAR(ft_num_word_optimize),
   MYSQL_SYSVAR(ft_sort_pll_degree),
   MYSQL_SYSVAR(large_prefix),
-  MYSQL_SYSVAR(force_load_corrupted),
+	MYSQL_SYSVAR(force_load_corrupted),
+	MYSQL_SYSVAR(lock_schedule_algorithm),
   MYSQL_SYSVAR(locks_unsafe_for_binlog),
   MYSQL_SYSVAR(lock_wait_timeout),
   MYSQL_SYSVAR(deadlock_detect),

storage/innobase/include/lock0lock.h

@@ -45,6 +45,17 @@ class ReadView;
 
 extern my_bool	innobase_deadlock_detect;
 
+/** Alternatives for innodb_lock_schedule_algorithm, which can be changed by
+ setting innodb_lock_schedule_algorithm. */
+enum innodb_lock_schedule_algorithm_t {
+	/*!< First Come First Served */
+	INNODB_LOCK_SCHEDULE_ALGORITHM_FCFS,
+	/*!< Variance-Aware-Transaction-Scheduling */
+	INNODB_LOCK_SCHEDULE_ALGORITHM_VATS
+};
+
+extern ulong innodb_lock_schedule_algorithm;
+
 /*********************************************************************//**
 Gets the size of a lock struct.
 @return size in bytes */

storage/innobase/include/trx0trx.h

@@ -1089,6 +1089,9 @@ struct trx_t {
 
 	time_t		start_time;	/*!< time the state last time became
 					TRX_STATE_ACTIVE */
+	long			dep_size;
+	bool			size_updated;
+	long			seq;
 	lsn_t		commit_lsn;	/*!< lsn at the time of the commit */
 	table_id_t	table_id;	/*!< Table to drop iff dict_operation
 					== TRX_DICT_OP_TABLE, or 0. */