MDEV-14756 - Remove trx_sys_t::rw_trx_list

Remove rw_trx_list.

storage/innobase/include/trx0sys.h

@@ -575,6 +575,37 @@ class rw_trx_hash_t
   }
 
 
+#ifdef UNIV_DEBUG
+  static void validate_element(trx_t *trx)
+  {
+    ut_ad(!trx->read_only || !trx->rsegs.m_redo.rseg);
+    ut_ad(!trx_is_autocommit_non_locking(trx));
+    mutex_enter(&trx->mutex);
+    ut_ad(trx_state_eq(trx, TRX_STATE_ACTIVE) ||
+          trx_state_eq(trx, TRX_STATE_PREPARED));
+    mutex_exit(&trx->mutex);
+  }
+
+
+  struct debug_iterator_arg
+  {
+    my_hash_walk_action action;
+    void *argument;
+  };
+
+
+  static my_bool debug_iterator(rw_trx_hash_element_t *element,
+                                debug_iterator_arg *arg)
+  {
+    mutex_enter(&element->mutex);
+    if (element->trx)
+      validate_element(element->trx);
+    mutex_exit(&element->mutex);
+    return arg->action(element, arg->argument);
+  }
+#endif
+
+
 public:
   void init()
   {
@@ -675,12 +706,7 @@ class rw_trx_hash_t
       {
         if (do_ref_count)
           trx->reference();
-#ifdef UNIV_DEBUG
-        mutex_enter(&trx->mutex);
-        ut_ad(trx_state_eq(trx, TRX_STATE_ACTIVE) ||
-              trx_state_eq(trx, TRX_STATE_PREPARED));
-        mutex_exit(&trx->mutex);
-#endif
+        ut_d(validate_element(trx));
       }
       mutex_exit(&element->mutex);
     }
@@ -704,8 +730,7 @@ class rw_trx_hash_t
 
   void insert(trx_t *trx)
   {
-    ut_ad(trx_state_eq(trx, TRX_STATE_ACTIVE) ||
-          trx_state_eq(trx, TRX_STATE_PREPARED));
+    ut_d(validate_element(trx));
     int res= lf_hash_insert(&hash, get_pins(trx),
                             reinterpret_cast<void*>(trx));
     ut_a(res == 0);
@@ -722,8 +747,7 @@ class rw_trx_hash_t
 
   void erase(trx_t *trx)
   {
-    ut_ad(trx_state_eq(trx, TRX_STATE_ACTIVE) ||
-          trx_state_eq(trx, TRX_STATE_PREPARED));
+    ut_d(validate_element(trx));
     mutex_enter(&trx->rw_trx_hash_element->mutex);
     trx->rw_trx_hash_element->trx= 0;
     mutex_exit(&trx->rw_trx_hash_element->mutex);
@@ -781,6 +805,11 @@ class rw_trx_hash_t
   {
     LF_PINS *pins= caller_trx ? get_pins(caller_trx) : lf_hash_get_pins(&hash);
     ut_a(pins);
+#ifdef UNIV_DEBUG
+    debug_iterator_arg debug_arg= { action, argument };
+    action= reinterpret_cast<my_hash_walk_action>(debug_iterator);
+    argument= &debug_arg;
+#endif
     int res= lf_hash_iterate(&hash, pins, action, argument);
     if (!caller_trx)
       lf_hash_put_pins(pins);
@@ -840,18 +869,11 @@ struct trx_sys_t {
 					transactions which exist or existed */
 #endif /* UNIV_DEBUG */
 
-	/** Avoid false sharing */
-	const char	pad1[CACHE_LINE_SIZE];
-	trx_ut_list_t	rw_trx_list;	/*!< List of active and committed in
-					memory read-write transactions, sorted
-					on trx id, biggest first. Recovered
-					transactions are always on this list. */
-
 	/** Avoid false sharing */
 	const char	pad2[CACHE_LINE_SIZE];
 	trx_ut_list_t	mysql_trx_list;	/*!< List of transactions created
 					for MySQL. All user transactions are
-					on mysql_trx_list. The rw_trx_list
+					on mysql_trx_list. The rw_trx_hash
 					can contain system transactions and
 					recovered transactions that will not
 					be in the mysql_trx_list.

storage/innobase/include/trx0trx.h

@@ -402,7 +402,7 @@ trx_set_dict_operation(
 Determines if a transaction is in the given state.
 The caller must hold trx_sys->mutex, or it must be the thread
 that is serving a running transaction.
-A running RW transaction must be in trx_sys->rw_trx_list.
+A running RW transaction must be in trx_sys->rw_trx_hash.
 @return TRUE if trx->state == state */
 UNIV_INLINE
 bool
@@ -556,15 +556,6 @@ with an explicit check for the read-only status.
 #define trx_is_ac_nl_ro(t)						\
 ((t)->read_only && trx_is_autocommit_non_locking((t)))
 
-/**
-Assert that the transaction is in the trx_sys_t::rw_trx_list */
-#define assert_trx_in_rw_list(t) do {					\
-	ut_ad(!(t)->read_only);						\
-	ut_ad((t)->in_rw_trx_list					\
-	      == !((t)->read_only || !(t)->rsegs.m_redo.rseg));		\
-	check_trx_state(t);						\
-} while (0)
-
 /**
 Check transaction state */
 #define check_trx_state(t) do {						\
@@ -605,15 +596,14 @@ transaction pool.
 #ifdef UNIV_DEBUG
 /*******************************************************************//**
 Assert that an autocommit non-locking select cannot be in the
-rw_trx_list and that it is a read-only transaction.
+rw_trx_hash and that it is a read-only transaction.
 The tranasction must be in the mysql_trx_list. */
 # define assert_trx_nonlocking_or_in_list(t)				\
 	do {								\
 		if (trx_is_autocommit_non_locking(t)) {			\
 			trx_state_t	t_state = (t)->state;		\
 			ut_ad((t)->read_only);				\
 			ut_ad(!(t)->is_recovered);			\
-			ut_ad(!(t)->in_rw_trx_list);			\
 			ut_ad((t)->in_mysql_trx_list);			\
 			ut_ad(t_state == TRX_STATE_NOT_STARTED		\
 			      || t_state == TRX_STATE_FORCED_ROLLBACK	\
@@ -625,7 +615,7 @@ The tranasction must be in the mysql_trx_list. */
 #else /* UNIV_DEBUG */
 /*******************************************************************//**
 Assert that an autocommit non-locking slect cannot be in the
-rw_trx_list and that it is a read-only transaction.
+rw_trx_hash and that it is a read-only transaction.
 The tranasction must be in the mysql_trx_list. */
 # define assert_trx_nonlocking_or_in_list(trx) ((void)0)
 #endif /* UNIV_DEBUG */
@@ -946,7 +936,7 @@ struct trx_t {
 					transaction is moved to
 					COMMITTED_IN_MEMORY state.
 					Protected by trx_sys_t::mutex
-					when trx->in_rw_trx_list. Initially
+					when trx is in rw_trx_hash. Initially
 					set to TRX_ID_MAX. */
 
 	/** State of the trx from the point of view of concurrency control
@@ -987,11 +977,11 @@ struct trx_t {
 
 	XA (2PC) transactions are always treated as non-autocommit.
 
-	Transitions to ACTIVE or NOT_STARTED occur when
-	!in_rw_trx_list (no trx_sys->mutex needed).
+	Transitions to ACTIVE or NOT_STARTED occur when transaction
+	is not in rw_trx_hash (no trx_sys->mutex needed).
 
 	Autocommit non-locking read-only transactions move between states
-	without holding any mutex. They are !in_rw_trx_list.
+	without holding any mutex. They are not in rw_trx_hash.
 
 	All transactions, unless they are determined to be ac-nl-ro,
 	explicitly tagged as read-only or read-write, will first be put
@@ -1001,13 +991,13 @@ struct trx_t {
 	list. During this switch we assign it a rollback segment.
 
 	When a transaction is NOT_STARTED, it can be in_mysql_trx_list if
-	it is a user transaction. It cannot be in rw_trx_list.
+	it is a user transaction. It cannot be in rw_trx_hash.
 
-	ACTIVE->PREPARED->COMMITTED is only possible when trx->in_rw_trx_list.
+	ACTIVE->PREPARED->COMMITTED is only possible when trx is in rw_trx_hash.
 	The transition ACTIVE->PREPARED is protected by trx_sys->mutex.
 
 	ACTIVE->COMMITTED is possible when the transaction is in
-	rw_trx_list.
+	rw_trx_hash.
 
 	Transitions to COMMITTED are protected by both lock_sys->mutex
 	and trx->mutex.
@@ -1021,9 +1011,6 @@ struct trx_t {
 	ReadView*	read_view;	/*!< consistent read view used in the
 					transaction, or NULL if not yet set */
 
-	UT_LIST_NODE_T(trx_t)
-			trx_list;	/*!< list of transactions;
-					protected by trx_sys->mutex. */
 	UT_LIST_NODE_T(trx_t)
 			no_list;	/*!< Required during view creation
 					to check for the view limit for
@@ -1036,7 +1023,7 @@ struct trx_t {
 	bool		is_recovered;	/*!< 0=normal transaction,
 					1=recovered, must be rolled back,
 					protected by trx_sys->mutex when
-					trx->in_rw_trx_list holds */
+					trx is in rw_trx_hash */
 
 	hit_list_t	hit_list;	/*!< List of transactions to kill,
 					when a high priority transaction
@@ -1145,13 +1132,6 @@ struct trx_t {
 					statement uses, except those
 					in consistent read */
 	/*------------------------------*/
-#ifdef UNIV_DEBUG
-	/** The following two fields are mutually exclusive. */
-	/* @{ */
-
-	bool		in_rw_trx_list;	/*!< true if in trx_sys->rw_trx_list */
-	/* @} */
-#endif /* UNIV_DEBUG */
 	UT_LIST_NODE_T(trx_t)
 			mysql_trx_list;	/*!< list of transactions created for
 					MySQL; protected by trx_sys->mutex */

storage/innobase/include/trx0trx.ic

@@ -30,7 +30,7 @@ Created 3/26/1996 Heikki Tuuri
 Determines if a transaction is in the given state.
 The caller must hold trx_sys->mutex, or it must be the thread
 that is serving a running transaction.
-A running RW transaction must be in trx_sys->rw_trx_list.
+A running RW transaction must be in trx_sys->rw_trx_hash.
 @return TRUE if trx->state == state */
 UNIV_INLINE
 bool
@@ -72,8 +72,6 @@ trx_state_eq(
 		     || (relaxed
 			 && thd_get_error_number(trx->mysql_thd)));
 
-		ut_ad(!trx->in_rw_trx_list);
-
 		return(true);
 	}
 	ut_error;

storage/innobase/trx/trx0i_s.cc

@@ -1280,10 +1280,7 @@ static my_bool fetch_data_into_cache_callback(
 {
   mutex_enter(&element->mutex);
   if (element->trx)
-  {
-    assert_trx_in_rw_list(element->trx);
     fetch_data_into_cache_low(cache, element->trx);
-  }
   mutex_exit(&element->mutex);
   return cache->is_truncated;
 }

storage/innobase/trx/trx0roll.cc

@@ -738,7 +738,6 @@ static my_bool trx_roll_count_callback(rw_trx_hash_element_t *element,
   mutex_enter(&element->mutex);
   if (trx_t *trx= element->trx)
   {
-    assert_trx_in_rw_list(trx);
     if (trx->is_recovered && trx_state_eq(trx, TRX_STATE_ACTIVE))
     {
       arg->n_trx++;
@@ -796,7 +795,6 @@ static my_bool trx_rollback_recovered_callback(rw_trx_hash_element_t *element,
   if (trx_t *trx= element->trx)
   {
     mutex_enter(&trx->mutex);
-    assert_trx_in_rw_list(trx);
     if (trx->is_recovered && trx_state_eq(trx, TRX_STATE_ACTIVE))
       UT_LIST_ADD_FIRST(*trx_list, trx);
     mutex_exit(&trx->mutex);

storage/innobase/trx/trx0sys.cc

@@ -469,7 +469,6 @@ trx_sys_create(void)
 	mutex_create(LATCH_ID_TRX_SYS, &trx_sys->mutex);
 
 	UT_LIST_INIT(trx_sys->serialisation_list, &trx_t::no_list);
-	UT_LIST_INIT(trx_sys->rw_trx_list, &trx_t::trx_list);
 	UT_LIST_INIT(trx_sys->mysql_trx_list, &trx_t::mysql_trx_list);
 
 	trx_sys->mvcc = UT_NEW_NOKEY(MVCC(1024));
@@ -607,7 +606,6 @@ trx_sys_close(void)
 
 	UT_DELETE(trx_sys->mvcc);
 
-	ut_a(UT_LIST_GET_LEN(trx_sys->rw_trx_list) == 0);
 	ut_a(UT_LIST_GET_LEN(trx_sys->mysql_trx_list) == 0);
 	ut_a(UT_LIST_GET_LEN(trx_sys->serialisation_list) == 0);