Allocate purge_sys statically

There is only one purge_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.

purge_sys_t::create(): The deferred constructor.

purge_sys_t::close(): The early destructor.

undo::Truncate::create(): The deferred constructor.
Because purge_sys.undo_trunc is constructed before the start-up
parameters are parsed, the normal constructor would copy a
wrong value of srv_purge_rseg_truncate_frequency.

TrxUndoRsegsIterator: Do not forward-declare an inline constructor,
because the static construction of purge_sys.rseg_iter would not have
access to it.

storage/innobase/include/trx0purge.h

@@ -142,7 +142,7 @@ typedef std::priority_queue<
 /** Chooses the rollback segment with the oldest committed transaction */
 struct TrxUndoRsegsIterator {
 	/** Constructor */
-	inline TrxUndoRsegsIterator();
+	TrxUndoRsegsIterator();
 	/** Sets the next rseg to purge in purge_sys.
 	Executed in the purge coordinator thread.
 	@return whether anything is to be purged */
@@ -204,17 +204,12 @@ namespace undo {
 	/** Track UNDO tablespace mark for truncate. */
 	class Truncate {
 	public:
-
-		Truncate()
-			:
-			m_undo_for_trunc(ULINT_UNDEFINED),
-			m_rseg_for_trunc(),
-			m_scan_start(1),
-			m_purge_rseg_truncate_frequency(
-				static_cast<ulint>(
-				srv_purge_rseg_truncate_frequency))
+		void create()
 		{
-			/* Do Nothing. */
+			m_undo_for_trunc = ULINT_UNDEFINED;
+			m_scan_start = 1;
+			m_purge_rseg_truncate_frequency =
+				ulint(srv_purge_rseg_truncate_frequency);
 		}
 
 		/** Clear the cached rollback segment. Normally done
@@ -401,12 +396,9 @@ namespace undo {
 /** The control structure used in the purge operation */
 class purge_sys_t
 {
+  bool m_initialised;
 public:
-	/** Construct the purge system. */
-	purge_sys_t();
-	/** Destruct the purge system. */
-	~purge_sys_t();
-
+	MY_ALIGNED(CACHE_LINE_SIZE)
 	rw_lock_t	latch;		/*!< The latch protecting the purge
 					view. A purge operation must acquire an
 					x-latch here for the instant at which
@@ -414,11 +406,14 @@ class purge_sys_t
 					log operation can prevent this by
 					obtaining an s-latch here. It also
 					protects state and running */
+	MY_ALIGNED(CACHE_LINE_SIZE)
 	os_event_t	event;		/*!< State signal event;
 					os_event_set() and os_event_reset()
 					are protected by purge_sys_t::latch
 					X-lock */
+	MY_ALIGNED(CACHE_LINE_SIZE)
 	ulint		n_stop;		/*!< Counter to track number stops */
+
 	volatile bool	running;	/*!< true, if purge is active,
 					we check this without the latch too */
 	volatile purge_state_t	state;	/*!< Purge coordinator thread states,
@@ -426,6 +421,7 @@ class purge_sys_t
 					without holding the latch. */
 	que_t*		query;		/*!< The query graph which will do the
 					parallelized purge operation */
+	MY_ALIGNED(CACHE_LINE_SIZE)
 	ReadView	view;		/*!< The purge will not remove undo logs
 					which are >= this view (purge view) */
 	ulint	n_submitted;	/*!< Count of total tasks submitted
@@ -486,10 +482,30 @@ class purge_sys_t
 
 	undo::Truncate	undo_trunc;	/*!< Track UNDO tablespace marked
 					for truncate. */
+
+
+  /**
+    Constructor.
+
+    Some members may require late initialisation, thus we just mark object as
+    uninitialised. Real initialisation happens in create().
+  */
+
+  purge_sys_t() : m_initialised(false) {}
+
+
+  bool is_initialised() const { return m_initialised; }
+
+
+  /** Create the instance */
+  void create();
+
+  /** Close the purge system on shutdown */
+  void close();
 };
 
 /** The global data structure coordinating a purge */
-extern purge_sys_t*	purge_sys;
+extern purge_sys_t	purge_sys;
 
 /** Info required to purge a record */
 struct trx_purge_rec_t {

storage/innobase/include/trx0sys.h

@@ -996,10 +996,10 @@ class trx_sys_t
   bool is_initialised() { return m_initialised; }
 
 
-  /** Create the instance */
+  /** Initialise the purge subsystem. */
   void create();
 
-  /** Close the transaction system on shutdown */
+  /** Close the purge subsystem on shutdown. */
   void close();
 
   /** @return total number of active (non-prepared) transactions */

storage/innobase/lock/lock0lock.cc

@@ -5258,14 +5258,14 @@ lock_print_info_summary(
 	fprintf(file,
 		"Purge done for trx's n:o < " TRX_ID_FMT
 		" undo n:o < " TRX_ID_FMT " state: ",
-		purge_sys->tail.trx_no(),
-		purge_sys->tail.undo_no);
+		purge_sys.tail.trx_no(),
+		purge_sys.tail.undo_no);
 
 	/* Note: We are reading the state without the latch. One because it
 	will violate the latching order and two because we are merely querying
 	the state of the variable for display. */
 
-	switch (purge_sys->state){
+	switch (purge_sys.state){
 	case PURGE_STATE_INIT:
 		/* Should never be in this state while the system is running. */
 		ut_error;
@@ -5281,7 +5281,7 @@ lock_print_info_summary(
 	case PURGE_STATE_RUN:
 		fprintf(file, "running");
 		/* Check if it is waiting for more data to arrive. */
-		if (!purge_sys->running) {
+		if (!purge_sys.running) {
 			fprintf(file, " but idle");
 		}
 		break;

storage/innobase/read/read0read.cc

@@ -319,7 +319,7 @@ void ReadView::close()
 */
 void trx_sys_t::clone_oldest_view()
 {
-  purge_sys->view.snapshot(0);
+  purge_sys.view.snapshot(0);
   mutex_enter(&mutex);
   /* Find oldest view. */
   for (const ReadView *v= UT_LIST_GET_FIRST(m_views); v;
@@ -331,7 +331,7 @@ void trx_sys_t::clone_oldest_view()
       ut_delay(1);
 
     if (state == READ_VIEW_STATE_OPEN)
-      purge_sys->view.copy(*v);
+      purge_sys.view.copy(*v);
   }
   mutex_exit(&mutex);
 }

storage/innobase/row/row0vers.cc

@@ -436,11 +436,11 @@ row_vers_must_preserve_del_marked(
 	const table_name_t&	name,
 	mtr_t*			mtr)
 {
-	ut_ad(!rw_lock_own(&(purge_sys->latch), RW_LOCK_S));
+	ut_ad(!rw_lock_own(&(purge_sys.latch), RW_LOCK_S));
 
-	mtr_s_lock(&purge_sys->latch, mtr);
+	mtr_s_lock(&purge_sys.latch, mtr);
 
-	return(!purge_sys->view.changes_visible(trx_id,	name));
+	return(!purge_sys.view.changes_visible(trx_id,	name));
 }
 
 /** build virtual column value from current cluster index record data
@@ -866,7 +866,7 @@ row_vers_old_has_index_entry(
 
 	ut_ad(mtr_memo_contains_page_flagged(mtr, rec, MTR_MEMO_PAGE_X_FIX
 					     | MTR_MEMO_PAGE_S_FIX));
-	ut_ad(!rw_lock_own(&(purge_sys->latch), RW_LOCK_S));
+	ut_ad(!rw_lock_own(&(purge_sys.latch), RW_LOCK_S));
 
 	clust_index = dict_table_get_first_index(index->table);
 
@@ -889,7 +889,7 @@ row_vers_old_has_index_entry(
 		/* The top of the stack of versions is locked by the
 		mtr holding a latch on the page containing the
 		clustered index record. The bottom of the stack is
-		locked by the fact that the purge_sys->view must
+		locked by the fact that the purge_sys.view must
 		'overtake' any read view of an active transaction.
 		Thus, it is safe to fetch the prefixes for
 		externally stored columns. */
@@ -1121,7 +1121,7 @@ row_vers_build_for_consistent_read(
 	ut_ad(dict_index_is_clust(index));
 	ut_ad(mtr_memo_contains_page_flagged(mtr, rec, MTR_MEMO_PAGE_X_FIX
 					     | MTR_MEMO_PAGE_S_FIX));
-	ut_ad(!rw_lock_own(&(purge_sys->latch), RW_LOCK_S));
+	ut_ad(!rw_lock_own(&(purge_sys.latch), RW_LOCK_S));
 
 	ut_ad(rec_offs_validate(rec, index, *offsets));
 
@@ -1234,7 +1234,7 @@ row_vers_build_for_semi_consistent_read(
 	ut_ad(dict_index_is_clust(index));
 	ut_ad(mtr_memo_contains_page_flagged(mtr, rec, MTR_MEMO_PAGE_X_FIX
 					     | MTR_MEMO_PAGE_S_FIX));
-	ut_ad(!rw_lock_own(&(purge_sys->latch), RW_LOCK_S));
+	ut_ad(!rw_lock_own(&(purge_sys.latch), RW_LOCK_S));
 
 	ut_ad(rec_offs_validate(rec, index, *offsets));
 

storage/innobase/srv/srv0srv.cc

@@ -1923,7 +1923,7 @@ srv_get_active_thread_type(void)
 	srv_sys_mutex_exit();
 
 	if (ret == SRV_NONE && srv_shutdown_state != SRV_SHUTDOWN_NONE
-	    && purge_sys != NULL) {
+	    && purge_sys.is_initialised()) {
 		/* Check only on shutdown. */
 		switch (trx_purge_state()) {
 		case PURGE_STATE_RUN:
@@ -1973,7 +1973,7 @@ srv_wake_purge_thread_if_not_active()
 {
 	ut_ad(!srv_sys_mutex_own());
 
-	if (purge_sys->state == PURGE_STATE_RUN
+	if (purge_sys.state == PURGE_STATE_RUN
 	    && !my_atomic_loadlint(&srv_sys.n_threads_active[SRV_PURGE])
 	    && trx_sys.history_size()) {
 
@@ -2506,7 +2506,7 @@ srv_task_execute(void)
 		que_run_threads(thr);
 
 		my_atomic_addlint(
-			&purge_sys->n_completed, 1);
+			&purge_sys.n_completed, 1);
 	}
 
 	return(thr != NULL);
@@ -2559,17 +2559,17 @@ DECLARE_THREAD(srv_worker_thread)(
 		}
 
 		/* Note: we are checking the state without holding the
-		purge_sys->latch here. */
-	} while (purge_sys->state != PURGE_STATE_EXIT);
+		purge_sys.latch here. */
+	} while (purge_sys.state != PURGE_STATE_EXIT);
 
 	srv_free_slot(slot);
 
-	rw_lock_x_lock(&purge_sys->latch);
+	rw_lock_x_lock(&purge_sys.latch);
 
-	ut_a(!purge_sys->running);
-	ut_a(purge_sys->state == PURGE_STATE_EXIT);
+	ut_a(!purge_sys.running);
+	ut_a(purge_sys.state == PURGE_STATE_EXIT);
 
-	rw_lock_x_unlock(&purge_sys->latch);
+	rw_lock_x_unlock(&purge_sys.latch);
 
 #ifdef UNIV_DEBUG_THREAD_CREATION
 	ib::info() << "Purge worker thread exiting, id "
@@ -2648,7 +2648,7 @@ srv_do_purge(ulint* n_total_purged)
 		}
 
 		ulint	undo_trunc_freq =
-			purge_sys->undo_trunc.get_rseg_truncate_frequency();
+			purge_sys.undo_trunc.get_rseg_truncate_frequency();
 
 		ulint	rseg_truncate_frequency = ut_min(
 			static_cast<ulint>(srv_purge_rseg_truncate_frequency),
@@ -2662,7 +2662,7 @@ srv_do_purge(ulint* n_total_purged)
 
 	} while (!srv_purge_should_exit(n_pages_purged)
 		 && n_pages_purged > 0
-		 && purge_sys->state == PURGE_STATE_RUN);
+		 && purge_sys.state == PURGE_STATE_RUN);
 
 	return(rseg_history_len);
 }
@@ -2689,11 +2689,11 @@ srv_purge_coordinator_suspend(
 	int64_t		sig_count = srv_suspend_thread(slot);
 
 	do {
-		rw_lock_x_lock(&purge_sys->latch);
+		rw_lock_x_lock(&purge_sys.latch);
 
-		purge_sys->running = false;
+		purge_sys.running = false;
 
-		rw_lock_x_unlock(&purge_sys->latch);
+		rw_lock_x_unlock(&purge_sys.latch);
 
 		/* We don't wait right away on the the non-timed wait because
 		we want to signal the thread that wants to suspend purge. */
@@ -2705,14 +2705,14 @@ srv_purge_coordinator_suspend(
 
 		sig_count = srv_suspend_thread(slot);
 
-		rw_lock_x_lock(&purge_sys->latch);
+		rw_lock_x_lock(&purge_sys.latch);
 
 		stop = (srv_shutdown_state == SRV_SHUTDOWN_NONE
-			&& purge_sys->state == PURGE_STATE_STOP);
+			&& purge_sys.state == PURGE_STATE_STOP);
 
 		if (!stop) {
-			ut_a(purge_sys->n_stop == 0);
-			purge_sys->running = true;
+			ut_a(purge_sys.n_stop == 0);
+			purge_sys.running = true;
 
 			if (timeout
 			    && rseg_history_len < 5000
@@ -2727,13 +2727,13 @@ srv_purge_coordinator_suspend(
 				stop = true;
 			}
 		} else {
-			ut_a(purge_sys->n_stop > 0);
+			ut_a(purge_sys.n_stop > 0);
 
 			/* Signal that we are suspended. */
-			os_event_set(purge_sys->event);
+			os_event_set(purge_sys.event);
 		}
 
-		rw_lock_x_unlock(&purge_sys->latch);
+		rw_lock_x_unlock(&purge_sys.latch);
 	} while (stop && srv_undo_sources);
 
 	srv_resume_thread(slot, 0, false);
@@ -2759,12 +2759,12 @@ DECLARE_THREAD(srv_purge_coordinator_thread)(
 	ut_a(trx_purge_state() == PURGE_STATE_INIT);
 	ut_a(srv_force_recovery < SRV_FORCE_NO_BACKGROUND);
 
-	rw_lock_x_lock(&purge_sys->latch);
+	rw_lock_x_lock(&purge_sys.latch);
 
-	purge_sys->running = true;
-	purge_sys->state = PURGE_STATE_RUN;
+	purge_sys.running = true;
+	purge_sys.state = PURGE_STATE_RUN;
 
-	rw_lock_x_unlock(&purge_sys->latch);
+	rw_lock_x_unlock(&purge_sys.latch);
 
 #ifdef UNIV_PFS_THREAD
 	pfs_register_thread(srv_purge_thread_key);
@@ -2785,7 +2785,7 @@ DECLARE_THREAD(srv_purge_coordinator_thread)(
 
 		if (srv_shutdown_state == SRV_SHUTDOWN_NONE
 		    && srv_undo_sources
-		    && (purge_sys->state == PURGE_STATE_STOP
+		    && (purge_sys.state == PURGE_STATE_STOP
 			|| n_total_purged == 0)) {
 
 			srv_purge_coordinator_suspend(slot, rseg_history_len);
@@ -2809,20 +2809,20 @@ DECLARE_THREAD(srv_purge_coordinator_thread)(
 	srv_free_slot(slot);
 
 	/* Note that we are shutting down. */
-	rw_lock_x_lock(&purge_sys->latch);
+	rw_lock_x_lock(&purge_sys.latch);
 
-	purge_sys->state = PURGE_STATE_EXIT;
+	purge_sys.state = PURGE_STATE_EXIT;
 
 	/* If there are any pending undo-tablespace truncate then clear
 	it off as we plan to shutdown the purge thread. */
-	purge_sys->undo_trunc.clear();
+	purge_sys.undo_trunc.clear();
 
-	purge_sys->running = false;
+	purge_sys.running = false;
 
 	/* Ensure that the wait in trx_purge_stop() will terminate. */
-	os_event_set(purge_sys->event);
+	os_event_set(purge_sys.event);
 
-	rw_lock_x_unlock(&purge_sys->latch);
+	rw_lock_x_unlock(&purge_sys.latch);
 
 #ifdef UNIV_DEBUG_THREAD_CREATION
 	ib::info() << "Purge coordinator exiting, id "

storage/innobase/srv/srv0start.cc

@@ -2661,7 +2661,7 @@ innobase_start_or_create_for_mysql()
 
 		srv_start_state_set(SRV_START_STATE_PURGE);
 	} else {
-		purge_sys->state = PURGE_STATE_DISABLED;
+		purge_sys.state = PURGE_STATE_DISABLED;
 	}
 
 	srv_is_being_started = false;
@@ -2871,8 +2871,7 @@ innodb_shutdown()
 		log_shutdown();
 	}
 	trx_sys.close();
-	UT_DELETE(purge_sys);
-	purge_sys = NULL;
+	purge_sys.close();
 	if (buf_dblwr) {
 		buf_dblwr_free();
 	}

storage/innobase/trx/trx0purge.cc

@@ -53,7 +53,7 @@ ulong		srv_max_purge_lag = 0;
 ulong		srv_max_purge_lag_delay = 0;
 
 /** The global data structure coordinating a purge */
-purge_sys_t*	purge_sys;
+purge_sys_t	purge_sys;
 
 /** A dummy undo record used as a return value when we have a whole undo log
 which needs no purge */
@@ -67,7 +67,7 @@ my_bool		srv_purge_view_update_only_debug;
 static const TrxUndoRsegs NullElement;
 
 /** Default constructor */
-inline TrxUndoRsegsIterator::TrxUndoRsegsIterator()
+TrxUndoRsegsIterator::TrxUndoRsegsIterator()
 	: m_rsegs(NullElement), m_iter(m_rsegs.begin())
 {
 }
@@ -77,7 +77,7 @@ Executed in the purge coordinator thread.
 @return whether anything is to be purged */
 inline bool TrxUndoRsegsIterator::set_next()
 {
-	mutex_enter(&purge_sys->pq_mutex);
+	mutex_enter(&purge_sys.pq_mutex);
 
 	/* Only purge consumes events from the priority queue, user
 	threads only produce the events. */
@@ -90,41 +90,41 @@ inline bool TrxUndoRsegsIterator::set_next()
 		number shouldn't increase. Undo the increment of
 		expected commit done by caller assuming rollback
 		segments from given transaction are done. */
-		purge_sys->tail.commit = (*m_iter)->last_commit;
-	} else if (!purge_sys->purge_queue.empty()) {
-		m_rsegs = purge_sys->purge_queue.top();
-		purge_sys->purge_queue.pop();
-		ut_ad(purge_sys->purge_queue.empty()
-		      || purge_sys->purge_queue.top() != m_rsegs);
+		purge_sys.tail.commit = (*m_iter)->last_commit;
+	} else if (!purge_sys.purge_queue.empty()) {
+		m_rsegs = purge_sys.purge_queue.top();
+		purge_sys.purge_queue.pop();
+		ut_ad(purge_sys.purge_queue.empty()
+		      || purge_sys.purge_queue.top() != m_rsegs);
 		m_iter = m_rsegs.begin();
 	} else {
 		/* Queue is empty, reset iterator. */
-		purge_sys->rseg = NULL;
-		mutex_exit(&purge_sys->pq_mutex);
+		purge_sys.rseg = NULL;
+		mutex_exit(&purge_sys.pq_mutex);
 		m_rsegs = NullElement;
 		m_iter = m_rsegs.begin();
 		return false;
 	}
 
-	purge_sys->rseg = *m_iter++;
-	mutex_exit(&purge_sys->pq_mutex);
-	mutex_enter(&purge_sys->rseg->mutex);
+	purge_sys.rseg = *m_iter++;
+	mutex_exit(&purge_sys.pq_mutex);
+	mutex_enter(&purge_sys.rseg->mutex);
 
-	ut_a(purge_sys->rseg->last_page_no != FIL_NULL);
-	ut_ad(purge_sys->rseg->last_trx_no() == m_rsegs.trx_no());
+	ut_a(purge_sys.rseg->last_page_no != FIL_NULL);
+	ut_ad(purge_sys.rseg->last_trx_no() == m_rsegs.trx_no());
 
 	/* We assume in purge of externally stored fields that space id is
 	in the range of UNDO tablespace space ids */
-	ut_a(purge_sys->rseg->space == TRX_SYS_SPACE
-	     || srv_is_undo_tablespace(purge_sys->rseg->space));
+	ut_a(purge_sys.rseg->space == TRX_SYS_SPACE
+	     || srv_is_undo_tablespace(purge_sys.rseg->space));
 
-	ut_a(purge_sys->tail.commit <= purge_sys->rseg->last_commit);
+	ut_a(purge_sys.tail.commit <= purge_sys.rseg->last_commit);
 
-	purge_sys->tail.commit = purge_sys->rseg->last_commit;
-	purge_sys->hdr_offset = purge_sys->rseg->last_offset;
-	purge_sys->hdr_page_no = purge_sys->rseg->last_page_no;
+	purge_sys.tail.commit = purge_sys.rseg->last_commit;
+	purge_sys.hdr_offset = purge_sys.rseg->last_offset;
+	purge_sys.hdr_page_no = purge_sys.rseg->last_page_no;
 
-	mutex_exit(&purge_sys->rseg->mutex);
+	mutex_exit(&purge_sys.rseg->mutex);
 
 	return(true);
 }
@@ -157,27 +157,37 @@ purge_graph_build()
 	return(fork);
 }
 
-/** Construct the purge system. */
-purge_sys_t::purge_sys_t()
-	: latch(), event(os_event_create(0)),
-	  n_stop(0), running(false), state(PURGE_STATE_INIT),
-	  query(purge_graph_build()),
-	  view(), n_submitted(0), n_completed(0),
-	  tail(), head(),
-	  next_stored(false), rseg(NULL),
-	  page_no(0), offset(0), hdr_page_no(0), hdr_offset(0),
-	  rseg_iter(), purge_queue(), pq_mutex(), undo_trunc()
+/** Initialise the purge system. */
+void purge_sys_t::create()
 {
-	ut_ad(!purge_sys);
-	rw_lock_create(trx_purge_latch_key, &latch, SYNC_PURGE_LATCH);
-	mutex_create(LATCH_ID_PURGE_SYS_PQ, &pq_mutex);
+  ut_ad(this == &purge_sys);
+  ut_ad(!is_initialised());
+  event= os_event_create(0);
+  n_stop= 0;
+  running= false;
+  state= PURGE_STATE_INIT;
+  query= purge_graph_build();
+  n_submitted= 0;
+  n_completed= 0;
+  next_stored= false;
+  rseg= NULL;
+  page_no= 0;
+  offset= 0;
+  hdr_page_no= 0;
+  hdr_offset= 0;
+  rw_lock_create(trx_purge_latch_key, &latch, SYNC_PURGE_LATCH);
+  mutex_create(LATCH_ID_PURGE_SYS_PQ, &pq_mutex);
+  undo_trunc.create();
+  m_initialised = true;
 }
 
-/** Destruct the purge system. */
-purge_sys_t::~purge_sys_t()
+/** Close the purge subsystem on shutdown. */
+void purge_sys_t::close()
 {
-	ut_ad(this == purge_sys);
+	ut_ad(this == &purge_sys);
+	if (!is_initialised()) return;
 
+	m_initialised = false;
 	trx_t* trx = query->trx;
 	que_graph_free(query);
 	ut_ad(!trx->id);
@@ -268,9 +278,9 @@ trx_purge_add_undo_to_history(const trx_t* trx, trx_undo_t*& undo, mtr_t* mtr)
 	ut_ad(srv_undo_sources
 	      || ((srv_startup_is_before_trx_rollback_phase
 		   || trx_rollback_is_active)
-		  && purge_sys->state == PURGE_STATE_INIT)
+		  && purge_sys.state == PURGE_STATE_INIT)
 	      || (srv_force_recovery >= SRV_FORCE_NO_BACKGROUND
-		  && purge_sys->state == PURGE_STATE_DISABLED)
+		  && purge_sys.state == PURGE_STATE_DISABLED)
 	      || ((trx->undo_no == 0 || trx->in_mysql_trx_list
 		   || trx->internal)
 		  && srv_fast_shutdown));
@@ -842,17 +852,17 @@ void
 trx_purge_cleanse_purge_queue(
 	undo::Truncate*	undo_trunc)
 {
-	mutex_enter(&purge_sys->pq_mutex);
+	mutex_enter(&purge_sys.pq_mutex);
 	typedef	std::vector<TrxUndoRsegs>	purge_elem_list_t;
 	purge_elem_list_t			purge_elem_list;
 
 	/* Remove rseg instances that are in the purge queue before we start
 	truncate of corresponding UNDO truncate. */
-	while (!purge_sys->purge_queue.empty()) {
-		purge_elem_list.push_back(purge_sys->purge_queue.top());
-		purge_sys->purge_queue.pop();
+	while (!purge_sys.purge_queue.empty()) {
+		purge_elem_list.push_back(purge_sys.purge_queue.top());
+		purge_sys.purge_queue.pop();
 	}
-	ut_ad(purge_sys->purge_queue.empty());
+	ut_ad(purge_sys.purge_queue.empty());
 
 	for (purge_elem_list_t::iterator it = purge_elem_list.begin();
 	     it != purge_elem_list.end();
@@ -870,10 +880,10 @@ trx_purge_cleanse_purge_queue(
 		}
 
 		if (!it->empty()) {
-			purge_sys->purge_queue.push(*it);
+			purge_sys.purge_queue.push(*it);
 		}
 	}
-	mutex_exit(&purge_sys->pq_mutex);
+	mutex_exit(&purge_sys.pq_mutex);
 }
 
 /** Iterate over selected UNDO tablespace and check if all the rsegs
@@ -994,17 +1004,17 @@ trx_purge_initiate_truncate(
 		return;
 	}
 
-	if (purge_sys->rseg != NULL
-	    && purge_sys->rseg->last_page_no == FIL_NULL) {
-		/* If purge_sys->rseg is pointing to rseg that was recently
+	if (purge_sys.rseg != NULL
+	    && purge_sys.rseg->last_page_no == FIL_NULL) {
+		/* If purge_sys.rseg is pointing to rseg that was recently
 		truncated then move to next rseg element.
-		Note: Ideally purge_sys->rseg should be NULL because purge
+		Note: Ideally purge_sys.rseg should be NULL because purge
 		should complete processing of all the records but there is
 		purge_batch_size that can force the purge loop to exit before
-		all the records are purged and in this case purge_sys->rseg
+		all the records are purged and in this case purge_sys.rseg
 		could point to a valid rseg waiting for next purge cycle. */
-		purge_sys->next_stored = false;
-		purge_sys->rseg = NULL;
+		purge_sys.next_stored = false;
+		purge_sys.rseg = NULL;
 	}
 
 	DBUG_EXECUTE_IF("ib_undo_trunc_before_ddl_log_end",
@@ -1037,13 +1047,13 @@ function is called, the caller must not have any latches on undo log pages!
 */
 static void trx_purge_truncate_history()
 {
-	ut_ad(purge_sys->head <= purge_sys->tail);
-	purge_sys_t::iterator& head = purge_sys->head.commit
-		? purge_sys->head : purge_sys->tail;
+	ut_ad(purge_sys.head <= purge_sys.tail);
+	purge_sys_t::iterator& head = purge_sys.head.commit
+		? purge_sys.head : purge_sys.tail;
 
-	if (head.trx_no() >= purge_sys->view.low_limit_no()) {
+	if (head.trx_no() >= purge_sys.view.low_limit_no()) {
 		/* This is sometimes necessary. TODO: find out why. */
-		head.reset_trx_no(purge_sys->view.low_limit_no());
+		head.reset_trx_no(purge_sys.view.low_limit_no());
 		head.undo_no = 0;
 	}
 
@@ -1058,14 +1068,14 @@ static void trx_purge_truncate_history()
 	can (greedy approach). This will ensure when the server is idle we
 	try and truncate all the UNDO tablespaces. */
 	for (ulint i = srv_undo_tablespaces_active; i--; ) {
-		trx_purge_mark_undo_for_truncate(&purge_sys->undo_trunc);
-		trx_purge_initiate_truncate(head, &purge_sys->undo_trunc);
+		trx_purge_mark_undo_for_truncate(&purge_sys.undo_trunc);
+		trx_purge_initiate_truncate(head, &purge_sys.undo_trunc);
 	}
 }
 
 /***********************************************************************//**
 Updates the last not yet purged history log info in rseg when we have purged
-a whole undo log. Advances also purge_sys->purge_trx_no past the purged log. */
+a whole undo log. Advances also purge_sys.purge_trx_no past the purged log. */
 static
 void
 trx_purge_rseg_get_next_history_log(
@@ -1084,9 +1094,9 @@ trx_purge_rseg_get_next_history_log(
 
 	ut_a(rseg->last_page_no != FIL_NULL);
 
-	purge_sys->tail.commit = rseg->last_commit + 1;
-	purge_sys->tail.undo_no = 0;
-	purge_sys->next_stored = false;
+	purge_sys.tail.commit = rseg->last_commit + 1;
+	purge_sys.tail.undo_no = 0;
+	purge_sys.next_stored = false;
 
 	mtr_start(&mtr);
 
@@ -1142,11 +1152,11 @@ trx_purge_rseg_get_next_history_log(
 	than the events that Purge produces. ie. Purge can never produce
 	events from an empty rollback segment. */
 
-	mutex_enter(&purge_sys->pq_mutex);
+	mutex_enter(&purge_sys.pq_mutex);
 
-	purge_sys->purge_queue.push(*rseg);
+	purge_sys.purge_queue.push(*rseg);
 
-	mutex_exit(&purge_sys->pq_mutex);
+	mutex_exit(&purge_sys.pq_mutex);
 
 	mutex_exit(&rseg->mutex);
 }
@@ -1160,15 +1170,15 @@ trx_purge_read_undo_rec()
 	ulint		page_no;
 	ib_uint64_t	undo_no;
 
-	purge_sys->hdr_offset = purge_sys->rseg->last_offset;
-	page_no = purge_sys->hdr_page_no = purge_sys->rseg->last_page_no;
+	purge_sys.hdr_offset = purge_sys.rseg->last_offset;
+	page_no = purge_sys.hdr_page_no = purge_sys.rseg->last_page_no;
 
-	if (purge_sys->rseg->needs_purge) {
+	if (purge_sys.rseg->needs_purge) {
 		mtr_t		mtr;
 		mtr.start();
 		if (trx_undo_rec_t* undo_rec = trx_undo_get_first_rec(
-			    purge_sys->rseg->space, purge_sys->hdr_page_no,
-			    purge_sys->hdr_offset, RW_S_LATCH, &mtr)) {
+			    purge_sys.rseg->space, purge_sys.hdr_page_no,
+			    purge_sys.hdr_offset, RW_S_LATCH, &mtr)) {
 
 			offset = page_offset(undo_rec);
 			undo_no = trx_undo_rec_get_undo_no(undo_rec);
@@ -1184,11 +1194,11 @@ trx_purge_read_undo_rec()
 		undo_no = 0;
 	}
 
-	purge_sys->offset = offset;
-	purge_sys->page_no = page_no;
-	purge_sys->tail.undo_no = undo_no;
+	purge_sys.offset = offset;
+	purge_sys.page_no = page_no;
+	purge_sys.tail.undo_no = undo_no;
 
-	purge_sys->next_stored = true;
+	purge_sys.next_stored = true;
 }
 
 /***********************************************************************//**
@@ -1201,9 +1211,9 @@ void
 trx_purge_choose_next_log(void)
 /*===========================*/
 {
-	ut_ad(!purge_sys->next_stored);
+	ut_ad(!purge_sys.next_stored);
 
-	if (purge_sys->rseg_iter.set_next()) {
+	if (purge_sys.rseg_iter.set_next()) {
 		trx_purge_read_undo_rec();
 	} else {
 		/* There is nothing to do yet. */
@@ -1232,19 +1242,19 @@ trx_purge_get_next_rec(
 	ulint		space;
 	mtr_t		mtr;
 
-	ut_ad(purge_sys->next_stored);
-	ut_ad(purge_sys->tail.trx_no() < purge_sys->view.low_limit_no());
+	ut_ad(purge_sys.next_stored);
+	ut_ad(purge_sys.tail.trx_no() < purge_sys.view.low_limit_no());
 
-	space = purge_sys->rseg->space;
-	page_no = purge_sys->page_no;
-	offset = purge_sys->offset;
+	space = purge_sys.rseg->space;
+	page_no = purge_sys.page_no;
+	offset = purge_sys.offset;
 
 	if (offset == 0) {
 		/* It is the dummy undo log record, which means that there is
 		no need to purge this undo log */
 
 		trx_purge_rseg_get_next_history_log(
-			purge_sys->rseg, n_pages_handled);
+			purge_sys.rseg, n_pages_handled);
 
 		/* Look for the next undo log and record to purge */
 
@@ -1260,19 +1270,19 @@ trx_purge_get_next_rec(
 
 	rec = undo_page + offset;
 
-	rec2 = trx_undo_page_get_next_rec(rec, purge_sys->hdr_page_no,
-					  purge_sys->hdr_offset);
+	rec2 = trx_undo_page_get_next_rec(rec, purge_sys.hdr_page_no,
+					  purge_sys.hdr_offset);
 
 	if (rec2 == NULL) {
-		rec2 = trx_undo_get_next_rec(rec, purge_sys->hdr_page_no,
-					     purge_sys->hdr_offset, &mtr);
+		rec2 = trx_undo_get_next_rec(rec, purge_sys.hdr_page_no,
+					     purge_sys.hdr_offset, &mtr);
 	}
 
 	if (rec2 == NULL) {
 		mtr_commit(&mtr);
 
 		trx_purge_rseg_get_next_history_log(
-			purge_sys->rseg, n_pages_handled);
+			purge_sys.rseg, n_pages_handled);
 
 		/* Look for the next undo log and record to purge */
 
@@ -1287,9 +1297,9 @@ trx_purge_get_next_rec(
 	} else {
 		page = page_align(rec2);
 
-		purge_sys->offset = rec2 - page;
-		purge_sys->page_no = page_get_page_no(page);
-		purge_sys->tail.undo_no = trx_undo_rec_get_undo_no(rec2);
+		purge_sys.offset = rec2 - page;
+		purge_sys.page_no = page_get_page_no(page);
+		purge_sys.tail.undo_no = trx_undo_rec_get_undo_no(rec2);
 
 		if (undo_page != page) {
 			/* We advance to a new page of the undo log: */
@@ -1318,17 +1328,17 @@ trx_purge_fetch_next_rec(
 					handled */
 	mem_heap_t*	heap)		/*!< in: memory heap where copied */
 {
-	if (!purge_sys->next_stored) {
+	if (!purge_sys.next_stored) {
 		trx_purge_choose_next_log();
 
-		if (!purge_sys->next_stored) {
+		if (!purge_sys.next_stored) {
 			DBUG_PRINT("ib_purge",
 				   ("no logs left in the history list"));
 			return(NULL);
 		}
 	}
 
-	if (purge_sys->tail.trx_no() >= purge_sys->view.low_limit_no()) {
+	if (purge_sys.tail.trx_no() >= purge_sys.view.low_limit_no()) {
 
 		return(NULL);
 	}
@@ -1340,8 +1350,8 @@ trx_purge_fetch_next_rec(
 		/* row_purge_record_func() will later set
 		ROLL_PTR_INSERT_FLAG for TRX_UNDO_INSERT_REC */
 		false,
-		purge_sys->rseg->id,
-		purge_sys->page_no, purge_sys->offset);
+		purge_sys.rseg->id,
+		purge_sys.page_no, purge_sys.offset);
 
 	/* The following call will advance the stored values of the
 	purge iterator. */
@@ -1359,14 +1369,14 @@ trx_purge_attach_undo_recs(ulint n_purge_threads)
 	que_thr_t*	thr;
 	ulint		i = 0;
 	ulint		n_pages_handled = 0;
-	ulint		n_thrs = UT_LIST_GET_LEN(purge_sys->query->thrs);
+	ulint		n_thrs = UT_LIST_GET_LEN(purge_sys.query->thrs);
 
 	ut_a(n_purge_threads > 0);
 
-	purge_sys->head = purge_sys->tail;
+	purge_sys.head = purge_sys.tail;
 
 	/* Debug code to validate some pre-requisites and reset done flag. */
-	for (thr = UT_LIST_GET_FIRST(purge_sys->query->thrs);
+	for (thr = UT_LIST_GET_FIRST(purge_sys.query->thrs);
 	     thr != NULL && i < n_purge_threads;
 	     thr = UT_LIST_GET_NEXT(thrs, thr), ++i) {
 
@@ -1388,10 +1398,10 @@ trx_purge_attach_undo_recs(ulint n_purge_threads)
 
 	/* Fetch and parse the UNDO records. The UNDO records are added
 	to a per purge node vector. */
-	thr = UT_LIST_GET_FIRST(purge_sys->query->thrs);
+	thr = UT_LIST_GET_FIRST(purge_sys.query->thrs);
 	ut_a(n_thrs > 0 && thr != NULL);
 
-	ut_ad(purge_sys->head <= purge_sys->tail);
+	ut_ad(purge_sys.head <= purge_sys.tail);
 
 	i = 0;
 
@@ -1413,11 +1423,11 @@ trx_purge_attach_undo_recs(ulint n_purge_threads)
 		/* Track the max {trx_id, undo_no} for truncating the
 		UNDO logs once we have purged the records. */
 
-		if (purge_sys->head <= purge_sys->tail) {
-			purge_sys->head = purge_sys->tail;
+		if (purge_sys.head <= purge_sys.tail) {
+			purge_sys.head = purge_sys.tail;
 		}
 
-		/* Fetch the next record, and advance the purge_sys->tail. */
+		/* Fetch the next record, and advance the purge_sys.tail. */
 		purge_rec->undo_rec = trx_purge_fetch_next_rec(
 			&purge_rec->roll_ptr, &n_pages_handled, node->heap);
 
@@ -1445,13 +1455,13 @@ trx_purge_attach_undo_recs(ulint n_purge_threads)
 		thr = UT_LIST_GET_NEXT(thrs, thr);
 
 		if (!(++i % n_purge_threads)) {
-			thr = UT_LIST_GET_FIRST(purge_sys->query->thrs);
+			thr = UT_LIST_GET_FIRST(purge_sys.query->thrs);
 		}
 
 		ut_a(thr != NULL);
 	}
 
-	ut_ad(purge_sys->head <= purge_sys->tail);
+	ut_ad(purge_sys.head <= purge_sys.tail);
 
 	return(n_pages_handled);
 }
@@ -1501,10 +1511,10 @@ static
 void
 trx_purge_wait_for_workers_to_complete()
 {
-	ulint		n_submitted = purge_sys->n_submitted;
+	ulint		n_submitted = purge_sys.n_submitted;
 
 	/* Ensure that the work queue empties out. */
-	while ((ulint) my_atomic_loadlint(&purge_sys->n_completed) != n_submitted) {
+	while ((ulint) my_atomic_loadlint(&purge_sys.n_completed) != n_submitted) {
 
 		if (srv_get_task_queue_length() > 0) {
 			srv_release_threads(SRV_WORKER, 1);
@@ -1514,7 +1524,7 @@ trx_purge_wait_for_workers_to_complete()
 	}
 
 	/* None of the worker threads should be doing any work. */
-	ut_a(purge_sys->n_submitted == purge_sys->n_completed);
+	ut_a(purge_sys.n_submitted == purge_sys.n_completed);
 
 	/* There should be no outstanding tasks as long
 	as the worker threads are active. */
@@ -1539,11 +1549,11 @@ trx_purge(
 	srv_dml_needed_delay = trx_purge_dml_delay();
 
 	/* The number of tasks submitted should be completed. */
-	ut_a(purge_sys->n_submitted == purge_sys->n_completed);
+	ut_a(purge_sys.n_submitted == purge_sys.n_completed);
 
-	rw_lock_x_lock(&purge_sys->latch);
+	rw_lock_x_lock(&purge_sys.latch);
 	trx_sys.clone_oldest_view();
-	rw_lock_x_unlock(&purge_sys->latch);
+	rw_lock_x_unlock(&purge_sys.latch);
 
 #ifdef UNIV_DEBUG
 	if (srv_purge_view_update_only_debug) {
@@ -1561,39 +1571,38 @@ trx_purge(
 		/* Submit the tasks to the work queue. */
 		for (i = 0; i < n_purge_threads - 1; ++i) {
 			thr = que_fork_scheduler_round_robin(
-				purge_sys->query, thr);
+				purge_sys.query, thr);
 
 			ut_a(thr != NULL);
 
 			srv_que_task_enqueue_low(thr);
 		}
 
-		thr = que_fork_scheduler_round_robin(purge_sys->query, thr);
+		thr = que_fork_scheduler_round_robin(purge_sys.query, thr);
 		ut_a(thr != NULL);
 
-		purge_sys->n_submitted += n_purge_threads - 1;
+		purge_sys.n_submitted += n_purge_threads - 1;
 
 		goto run_synchronously;
 
 	/* Do it synchronously. */
 	} else {
-		thr = que_fork_scheduler_round_robin(purge_sys->query, NULL);
+		thr = que_fork_scheduler_round_robin(purge_sys.query, NULL);
 		ut_ad(thr);
 
 run_synchronously:
-		++purge_sys->n_submitted;
+		++purge_sys.n_submitted;
 
 		que_run_threads(thr);
 
-		my_atomic_addlint(
-			&purge_sys->n_completed, 1);
+		my_atomic_addlint(&purge_sys.n_completed, 1);
 
 		if (n_purge_threads > 1) {
 			trx_purge_wait_for_workers_to_complete();
 		}
 	}
 
-	ut_a(purge_sys->n_submitted == purge_sys->n_completed);
+	ut_a(purge_sys.n_submitted == purge_sys.n_completed);
 
 	if (truncate) {
 		trx_purge_truncate_history();
@@ -1614,11 +1623,11 @@ trx_purge_state(void)
 {
 	purge_state_t	state;
 
-	rw_lock_x_lock(&purge_sys->latch);
+	rw_lock_x_lock(&purge_sys.latch);
 
-	state = purge_sys->state;
+	state = purge_sys.state;
 
-	rw_lock_x_unlock(&purge_sys->latch);
+	rw_lock_x_unlock(&purge_sys.latch);
 
 	return(state);
 }
@@ -1629,9 +1638,9 @@ void
 trx_purge_stop(void)
 /*================*/
 {
-	rw_lock_x_lock(&purge_sys->latch);
+	rw_lock_x_lock(&purge_sys.latch);
 
-	switch (purge_sys->state) {
+	switch (purge_sys.state) {
 	case PURGE_STATE_INIT:
 	case PURGE_STATE_DISABLED:
 		ut_error;
@@ -1640,37 +1649,37 @@ trx_purge_stop(void)
 		FLUSH TABLES FOR EXPORT. */
 		ut_ad(!srv_undo_sources);
 unlock:
-		rw_lock_x_unlock(&purge_sys->latch);
+		rw_lock_x_unlock(&purge_sys.latch);
 		break;
 	case PURGE_STATE_STOP:
 		ut_ad(srv_n_purge_threads > 0);
-		++purge_sys->n_stop;
-		purge_sys->state = PURGE_STATE_STOP;
-		if (!purge_sys->running) {
+		++purge_sys.n_stop;
+		purge_sys.state = PURGE_STATE_STOP;
+		if (!purge_sys.running) {
 			goto unlock;
 		}
 		ib::info() << "Waiting for purge to stop";
 		do {
-			rw_lock_x_unlock(&purge_sys->latch);
+			rw_lock_x_unlock(&purge_sys.latch);
 			os_thread_sleep(10000);
-			rw_lock_x_lock(&purge_sys->latch);
-		} while (purge_sys->running);
+			rw_lock_x_lock(&purge_sys.latch);
+		} while (purge_sys.running);
 		goto unlock;
 	case PURGE_STATE_RUN:
 		ut_ad(srv_n_purge_threads > 0);
-		++purge_sys->n_stop;
+		++purge_sys.n_stop;
 		ib::info() << "Stopping purge";
 
 		/* We need to wakeup the purge thread in case it is suspended,
 		so that it can acknowledge the state change. */
 
-		const int64_t sig_count = os_event_reset(purge_sys->event);
-		purge_sys->state = PURGE_STATE_STOP;
+		const int64_t sig_count = os_event_reset(purge_sys.event);
+		purge_sys.state = PURGE_STATE_STOP;
 		srv_purge_wakeup();
-		rw_lock_x_unlock(&purge_sys->latch);
+		rw_lock_x_unlock(&purge_sys.latch);
 		/* Wait for purge coordinator to signal that it
 		is suspended. */
-		os_event_wait_low(purge_sys->event, sig_count);
+		os_event_wait_low(purge_sys.event, sig_count);
 	}
 
 	MONITOR_INC_VALUE(MONITOR_PURGE_STOP_COUNT, 1);
@@ -1682,9 +1691,9 @@ void
 trx_purge_run(void)
 /*===============*/
 {
-	rw_lock_x_lock(&purge_sys->latch);
+	rw_lock_x_lock(&purge_sys.latch);
 
-	switch (purge_sys->state) {
+	switch (purge_sys.state) {
 	case PURGE_STATE_EXIT:
 		/* Shutdown must have been initiated during
 		FLUSH TABLES FOR EXPORT. */
@@ -1695,21 +1704,21 @@ trx_purge_run(void)
 		ut_error;
 
 	case PURGE_STATE_RUN:
-		ut_a(!purge_sys->n_stop);
+		ut_a(!purge_sys.n_stop);
 		break;
 	case PURGE_STATE_STOP:
-		ut_a(purge_sys->n_stop);
-		if (--purge_sys->n_stop == 0) {
+		ut_a(purge_sys.n_stop);
+		if (--purge_sys.n_stop == 0) {
 
 			ib::info() << "Resuming purge";
 
-			purge_sys->state = PURGE_STATE_RUN;
+			purge_sys.state = PURGE_STATE_RUN;
 		}
 
 		MONITOR_INC_VALUE(MONITOR_PURGE_RESUME_COUNT, 1);
 	}
 
-	rw_lock_x_unlock(&purge_sys->latch);
+	rw_lock_x_unlock(&purge_sys.latch);
 
 	srv_purge_wakeup();
 }

storage/innobase/trx/trx0rec.cc

@@ -2204,14 +2204,14 @@ trx_undo_get_undo_rec(
 {
 	bool		missing_history;
 
-	rw_lock_s_lock(&purge_sys->latch);
+	rw_lock_s_lock(&purge_sys.latch);
 
-	missing_history = purge_sys->view.changes_visible(trx_id, name);
+	missing_history = purge_sys.view.changes_visible(trx_id, name);
 	if (!missing_history) {
 		*undo_rec = trx_undo_get_undo_rec_low(roll_ptr, is_temp, heap);
 	}
 
-	rw_lock_s_unlock(&purge_sys->latch);
+	rw_lock_s_unlock(&purge_sys.latch);
 
 	return(missing_history);
 }
@@ -2273,7 +2273,7 @@ trx_undo_prev_version_build(
 	bool		dummy_extern;
 	byte*		buf;
 
-	ut_ad(!rw_lock_own(&purge_sys->latch, RW_LOCK_S));
+	ut_ad(!rw_lock_own(&purge_sys.latch, RW_LOCK_S));
 	ut_ad(mtr_memo_contains_page_flagged(index_mtr, index_rec,
 					     MTR_MEMO_PAGE_S_FIX
 					     | MTR_MEMO_PAGE_X_FIX));
@@ -2323,12 +2323,12 @@ trx_undo_prev_version_build(
 					       &info_bits);
 
 	/* (a) If a clustered index record version is such that the
-	trx id stamp in it is bigger than purge_sys->view, then the
+	trx id stamp in it is bigger than purge_sys.view, then the
 	BLOBs in that version are known to exist (the purge has not
 	progressed that far);
 
 	(b) if the version is the first version such that trx id in it
-	is less than purge_sys->view, and it is not delete-marked,
+	is less than purge_sys.view, and it is not delete-marked,
 	then the BLOBs in that version are known to exist (the purge
 	cannot have purged the BLOBs referenced by that version
 	yet).
@@ -2367,19 +2367,19 @@ trx_undo_prev_version_build(
 		the BLOB. */
 
 		/* the row_upd_changes_disowned_external(update) call could be
-		omitted, but the synchronization on purge_sys->latch is likely
+		omitted, but the synchronization on purge_sys.latch is likely
 		more expensive. */
 
 		if ((update->info_bits & REC_INFO_DELETED_FLAG)
 		    && row_upd_changes_disowned_external(update)) {
 			bool	missing_extern;
 
-			rw_lock_s_lock(&purge_sys->latch);
+			rw_lock_s_lock(&purge_sys.latch);
 
-			missing_extern = purge_sys->view.changes_visible(
+			missing_extern = purge_sys.view.changes_visible(
 				trx_id,	index->table->name);
 
-			rw_lock_s_unlock(&purge_sys->latch);
+			rw_lock_s_unlock(&purge_sys.latch);
 
 			if (missing_extern) {
 				/* treat as a fresh insert, not to

storage/innobase/trx/trx0rseg.cc

@@ -483,7 +483,7 @@ trx_rseg_mem_restore(
 
 			/* There is no need to cover this operation by the purge
 			mutex because we are still bootstrapping. */
-			purge_sys->purge_queue.push(*rseg);
+			purge_sys.purge_queue.push(*rseg);
 		}
 	}
 }

storage/innobase/trx/trx0trx.cc

@@ -883,7 +883,7 @@ trx_lists_init_at_db_start()
 {
 	ut_a(srv_is_being_started);
 	ut_ad(!srv_was_started);
-	ut_ad(!purge_sys);
+	ut_ad(!purge_sys.is_initialised());
 
 	if (srv_operation == SRV_OPERATION_RESTORE) {
 		/* mariabackup --prepare only deals with
@@ -893,12 +893,11 @@ trx_lists_init_at_db_start()
 		return;
 	}
 
-	purge_sys = UT_NEW_NOKEY(purge_sys_t());
-
 	if (srv_force_recovery >= SRV_FORCE_NO_UNDO_LOG_SCAN) {
 		return;
 	}
 
+	purge_sys.create();
 	trx_rseg_array_init();
 
 	/* Look from the rollback segments if there exist undo logs for
@@ -1219,7 +1218,7 @@ trx_serialise(trx_t* trx)
 	ut_ad(mutex_own(&rseg->mutex));
 
 	if (rseg->last_page_no == FIL_NULL) {
-		mutex_enter(&purge_sys->pq_mutex);
+		mutex_enter(&purge_sys.pq_mutex);
 	}
 
 	trx_sys.assign_new_trx_no(trx);
@@ -1229,8 +1228,8 @@ trx_serialise(trx_t* trx)
 	already in the rollback segment. User threads only
 	produce events when a rollback segment is empty. */
 	if (rseg->last_page_no == FIL_NULL) {
-		purge_sys->purge_queue.push(TrxUndoRsegs(trx->no, *rseg));
-		mutex_exit(&purge_sys->pq_mutex);
+		purge_sys.purge_queue.push(TrxUndoRsegs(trx->no, *rseg));
+		mutex_exit(&purge_sys.pq_mutex);
 	}
 }