Allocate lock_sys statically

There is only one lock_sys. Allocate it statically in order to avoid
dereferencing a pointer whenever accessing it. Also, align some
members to their own cache line in order to avoid false sharing.

lock_sys_t::create(): The deferred constructor.

lock_sys_t::close(): The early destructor.

extra/mariabackup/xtrabackup.cc

@@ -3672,8 +3672,6 @@ xtrabackup_backup_func()
 		"innodb_redo_log", SRV_LOG_SPACE_FIRST_ID, 0,
 		FIL_TYPE_LOG, NULL);
 
-	lock_sys_create(srv_lock_table_size);
-
 	for (i = 0; i < srv_n_log_files; i++) {
 		err = open_or_create_log_file(space, &log_file_created, i);
 		if (err != DB_SUCCESS) {

storage/innobase/btr/btr0btr.cc

@@ -3675,7 +3675,7 @@ btr_lift_page_up(
 		if (dict_index_is_spatial(index)) {
 			lock_mutex_enter();
 			lock_prdt_page_free_from_discard(
-				block, lock_sys->prdt_page_hash);
+				block, lock_sys.prdt_page_hash);
 			lock_mutex_exit();
 		}
 		lock_update_copy_and_discard(father_block, block);
@@ -3968,7 +3968,7 @@ btr_compress(
 			/* No GAP lock needs to be worrying about */
 			lock_mutex_enter();
 			lock_prdt_page_free_from_discard(
-				block, lock_sys->prdt_page_hash);
+				block, lock_sys.prdt_page_hash);
 			lock_rec_free_all_from_discard_page(block);
 			lock_mutex_exit();
 		} else {
@@ -4126,7 +4126,7 @@ btr_compress(
 			}
 			lock_mutex_enter();
 			lock_prdt_page_free_from_discard(
-				block, lock_sys->prdt_page_hash);
+				block, lock_sys.prdt_page_hash);
 			lock_rec_free_all_from_discard_page(block);
 			lock_mutex_exit();
 		} else {

storage/innobase/buf/buf0buf.cc

@@ -3058,7 +3058,7 @@ buf_pool_resize()
 
 		/* normalize lock_sys */
 		srv_lock_table_size = 5 * (srv_buf_pool_size / UNIV_PAGE_SIZE);
-		lock_sys_resize(srv_lock_table_size);
+		lock_sys.resize(srv_lock_table_size);
 
 		/* normalize btr_search_sys */
 		btr_search_sys_resize(

storage/innobase/gis/gis0sea.cc

@@ -1255,8 +1255,8 @@ rtr_check_discard_page(
 	mutex_exit(&index->rtr_track->rtr_active_mutex);
 
 	lock_mutex_enter();
-	lock_prdt_page_free_from_discard(block, lock_sys->prdt_hash);
-	lock_prdt_page_free_from_discard(block, lock_sys->prdt_page_hash);
+	lock_prdt_page_free_from_discard(block, lock_sys.prdt_hash);
+	lock_prdt_page_free_from_discard(block, lock_sys.prdt_page_hash);
 	lock_mutex_exit();
 }
 

storage/innobase/include/dict0mem.h

@@ -1908,7 +1908,7 @@ struct dict_table_t {
 	ulong					n_waiting_or_granted_auto_inc_locks;
 
 	/** The transaction that currently holds the the AUTOINC lock on this
-	table. Protected by lock_sys->mutex. */
+	table. Protected by lock_sys.mutex. */
 	const trx_t*				autoinc_trx;
 
 	/* @} */
@@ -1923,7 +1923,7 @@ struct dict_table_t {
 
 	/** Count of the number of record locks on this table. We use this to
 	determine whether we can evict the table from the dictionary cache.
-	It is protected by lock_sys->mutex. */
+	It is protected by lock_sys.mutex. */
 	ulint					n_rec_locks;
 
 #ifndef DBUG_ASSERT_EXISTS
@@ -1935,7 +1935,7 @@ struct dict_table_t {
 	ulint					n_ref_count;
 
 public:
-	/** List of locks on the table. Protected by lock_sys->mutex. */
+	/** List of locks on the table. Protected by lock_sys.mutex. */
 	table_lock_list_t			locks;
 
 	/** Timestamp of the last modification of this table. */

storage/innobase/include/lock0lock.h

@@ -65,23 +65,6 @@ ulint
 lock_get_size(void);
 /*===============*/
 /*********************************************************************//**
-Creates the lock system at database start. */
-void
-lock_sys_create(
-/*============*/
-	ulint	n_cells);	/*!< in: number of slots in lock hash table */
-/** Resize the lock hash table.
-@param[in]	n_cells	number of slots in lock hash table */
-void
-lock_sys_resize(
-	ulint	n_cells);
-
-/*********************************************************************//**
-Closes the lock system at database shutdown. */
-void
-lock_sys_close(void);
-/*================*/
-/*********************************************************************//**
 Gets the heap_no of the smallest user record on a page.
 @return heap_no of smallest user record, or PAGE_HEAP_NO_SUPREMUM */
 UNIV_INLINE
@@ -605,7 +588,7 @@ lock_print_info_all_transactions(
 Return approximate number or record locks (bits set in the bitmap) for
 this transaction. Since delete-marked records may be removed, the
 record count will not be precise.
-The caller must be holding lock_sys->mutex. */
+The caller must be holding lock_sys.mutex. */
 ulint
 lock_number_of_rows_locked(
 /*=======================*/
@@ -614,7 +597,7 @@ lock_number_of_rows_locked(
 
 /*********************************************************************//**
 Return the number of table locks for a transaction.
-The caller must be holding lock_sys->mutex. */
+The caller must be holding lock_sys.mutex. */
 ulint
 lock_number_of_tables_locked(
 /*=========================*/
@@ -897,11 +880,12 @@ struct lock_op_t{
 typedef ib_mutex_t LockMutex;
 
 /** The lock system struct */
-struct lock_sys_t{
-	char		pad1[CACHE_LINE_SIZE];	/*!< padding to prevent other
-						memory update hotspots from
-						residing on the same memory
-						cache line */
+class lock_sys_t
+{
+  bool m_initialised;
+
+public:
+	MY_ALIGNED(CACHE_LINE_SIZE)
 	LockMutex	mutex;			/*!< Mutex protecting the
 						locks */
 	hash_table_t*	rec_hash;		/*!< hash table of the record
@@ -911,13 +895,13 @@ struct lock_sys_t{
 	hash_table_t*	prdt_page_hash;		/*!< hash table of the page
 						lock */
 
-	char		pad2[CACHE_LINE_SIZE];	/*!< Padding */
+	MY_ALIGNED(CACHE_LINE_SIZE)
 	LockMutex	wait_mutex;		/*!< Mutex protecting the
 						next two fields */
 	srv_slot_t*	waiting_threads;	/*!< Array  of user threads
 						suspended while waiting for
 						locks within InnoDB, protected
-						by the lock_sys->wait_mutex;
+						by the lock_sys.wait_mutex;
 						os_event_set() and
 						os_event_reset() on
 						waiting_threads[]->event
@@ -926,7 +910,7 @@ struct lock_sys_t{
 	srv_slot_t*	last_slot;		/*!< highest slot ever used
 						in the waiting_threads array,
 						protected by
-						lock_sys->wait_mutex */
+						lock_sys.wait_mutex */
 
 	ulint		n_lock_max_wait_time;	/*!< Max wait time */
 
@@ -938,6 +922,38 @@ struct lock_sys_t{
 
 	bool		timeout_thread_active;	/*!< True if the timeout thread
 						is running */
+
+
+  /**
+    Constructor.
+
+    Some members may require late initialisation, thus we just mark object as
+    uninitialised. Real initialisation happens in create().
+  */
+  lock_sys_t(): m_initialised(false) {}
+
+
+  bool is_initialised() { return m_initialised; }
+
+
+  /**
+    Creates the lock system at database start.
+
+    @param[in] n_cells number of slots in lock hash table
+  */
+  void create(ulint n_cells);
+
+
+  /**
+    Resize the lock hash table.
+
+    @param[in] n_cells number of slots in lock hash table
+  */
+  void resize(ulint n_cells);
+
+
+  /** Closes the lock system at database shutdown. */
+  void close();
 };
 
 /*************************************************************//**
@@ -982,36 +998,36 @@ lock_rec_trx_wait(
 	ulint		type);
 
 /** The lock system */
-extern lock_sys_t*	lock_sys;
+extern lock_sys_t lock_sys;
 
-/** Test if lock_sys->mutex can be acquired without waiting. */
+/** Test if lock_sys.mutex can be acquired without waiting. */
 #define lock_mutex_enter_nowait() 		\
-	(lock_sys->mutex.trylock(__FILE__, __LINE__))
+	(lock_sys.mutex.trylock(__FILE__, __LINE__))
 
-/** Test if lock_sys->mutex is owned. */
-#define lock_mutex_own() (lock_sys->mutex.is_owned())
+/** Test if lock_sys.mutex is owned. */
+#define lock_mutex_own() (lock_sys.mutex.is_owned())
 
-/** Acquire the lock_sys->mutex. */
+/** Acquire the lock_sys.mutex. */
 #define lock_mutex_enter() do {			\
-	mutex_enter(&lock_sys->mutex);		\
+	mutex_enter(&lock_sys.mutex);		\
 } while (0)
 
-/** Release the lock_sys->mutex. */
+/** Release the lock_sys.mutex. */
 #define lock_mutex_exit() do {			\
-	lock_sys->mutex.exit();			\
+	lock_sys.mutex.exit();			\
 } while (0)
 
-/** Test if lock_sys->wait_mutex is owned. */
-#define lock_wait_mutex_own() (lock_sys->wait_mutex.is_owned())
+/** Test if lock_sys.wait_mutex is owned. */
+#define lock_wait_mutex_own() (lock_sys.wait_mutex.is_owned())
 
-/** Acquire the lock_sys->wait_mutex. */
+/** Acquire the lock_sys.wait_mutex. */
 #define lock_wait_mutex_enter() do {		\
-	mutex_enter(&lock_sys->wait_mutex);	\
+	mutex_enter(&lock_sys.wait_mutex);	\
 } while (0)
 
-/** Release the lock_sys->wait_mutex. */
+/** Release the lock_sys.wait_mutex. */
 #define lock_wait_mutex_exit() do {		\
-	lock_sys->wait_mutex.exit();		\
+	lock_sys.wait_mutex.exit();		\
 } while (0)
 
 #ifdef WITH_WSREP

storage/innobase/include/lock0lock.ic

@@ -63,7 +63,7 @@ lock_rec_hash(
 	ulint	page_no)/*!< in: page number */
 {
 	return(unsigned(hash_calc_hash(lock_rec_fold(space, page_no),
-				       lock_sys->rec_hash)));
+				       lock_sys.rec_hash)));
 }
 
 /*********************************************************************//**
@@ -99,11 +99,11 @@ lock_hash_get(
 	ulint	mode)	/*!< in: lock mode */
 {
 	if (mode & LOCK_PREDICATE) {
-		return(lock_sys->prdt_hash);
+		return(lock_sys.prdt_hash);
 	} else if (mode & LOCK_PRDT_PAGE) {
-		return(lock_sys->prdt_page_hash);
+		return(lock_sys.prdt_page_hash);
 	} else {
-		return(lock_sys->rec_hash);
+		return(lock_sys.rec_hash);
 	}
 }
 

storage/innobase/include/lock0priv.h

@@ -111,7 +111,7 @@ operator<<(std::ostream& out, const lock_rec_t& lock)
 	return(lock.print(out));
 }
 
-/** Lock struct; protected by lock_sys->mutex */
+/** Lock struct; protected by lock_sys.mutex */
 struct lock_t {
 	trx_t*		trx;		/*!< transaction owning the
 					lock */

storage/innobase/include/lock0types.h

@@ -31,7 +31,6 @@ Created 5/7/1996 Heikki Tuuri
 #define lock_t ib_lock_t
 
 struct lock_t;
-struct lock_sys_t;
 struct lock_table_t;
 
 /* Basic lock modes */

storage/innobase/include/trx0sys.h

@@ -590,10 +590,10 @@ class rw_trx_hash_t
     the transaction may get committed before this method returns.
 
     With do_ref_count == false the caller may dereference returned trx pointer
-    only if lock_sys->mutex was acquired before calling find().
+    only if lock_sys.mutex was acquired before calling find().
 
     With do_ref_count == true caller may dereference trx even if it is not
-    holding lock_sys->mutex. Caller is responsible for calling
+    holding lock_sys.mutex. Caller is responsible for calling
     trx->release_reference() when it is done playing with trx.
 
     Ideally this method should get caller rw_trx_hash_pins along with trx