MDEV-25594: Improve debug checks

trx_t::will_lock: Changed the type to bool.

trx_t::is_autocommit_non_locking(): Replaces
trx_is_autocommit_non_locking().

trx_is_ac_nl_ro(): Remove (replaced with equivalent assertion expressions).

assert_trx_nonlocking_or_in_list(): Remove.
Replaced with at least as strict checks in each place.

check_trx_state(): Moved to a static function; partially replaced with
individual debug assertions implementing equivalent or stricter checks.

This is a backport of commit 7b51d11cca8898f319ddde5d7048cb81b43fef06
from 10.5.

12 files changed, 185 insertions, 238 deletions

diff --git a/storage/innobase/handler/ha_innodb.cc b/storage/innobase/handler/ha_innodb.cc
index 81f1dae85b6..00c9595aa87 100644
--- a/storage/innobase/handler/ha_innodb.cc
+++ b/storage/innobase/handler/ha_innodb.cc
@@ -4503,7 +4503,7 @@ innobase_commit_low(
 	if (trx_is_started(trx)) {
 		trx_commit_for_mysql(trx);
 	} else {
-		trx->will_lock = 0;
+		trx->will_lock = false;
 #ifdef WITH_WSREP
 		trx->wsrep = false;
 #endif /* WITH_WSREP */
@@ -4860,7 +4860,7 @@ innobase_rollback_trx(
 	lock_unlock_table_autoinc(trx);
 
 	if (!trx->has_logged()) {
-		trx->will_lock = 0;
+		trx->will_lock = false;
 #ifdef WITH_WSREP
 		trx->wsrep = false;
 #endif
@@ -8176,20 +8176,12 @@ ha_innobase::write_row(
 	if (high_level_read_only) {
 		ib_senderrf(ha_thd(), IB_LOG_LEVEL_WARN, ER_READ_ONLY_MODE);
 		DBUG_RETURN(HA_ERR_TABLE_READONLY);
-	} else if (UNIV_UNLIKELY(m_prebuilt->trx != trx)) {
-		ib::error() << "The transaction object for the table handle is"
-			" at " << static_cast<const void*>(m_prebuilt->trx)
-			<< ", but for the current thread it is at "
-			<< static_cast<const void*>(trx);
-
-		fputs("InnoDB: Dump of 200 bytes around m_prebuilt: ", stderr);
-		ut_print_buf(stderr, ((const byte*) m_prebuilt) - 100, 200);
-		fputs("\nInnoDB: Dump of 200 bytes around ha_data: ", stderr);
-		ut_print_buf(stderr, ((const byte*) trx) - 100, 200);
-		putc('\n', stderr);
-		ut_error;
-	} else if (!trx_is_started(trx)) {
-		++trx->will_lock;
+	}
+
+	ut_a(m_prebuilt->trx == trx);
+
+	if (!trx_is_started(trx)) {
+		trx->will_lock = true;
 	}
 
 #ifdef WITH_WSREP
@@ -8964,7 +8956,7 @@ ha_innobase::update_row(
 		ib_senderrf(ha_thd(), IB_LOG_LEVEL_WARN, ER_READ_ONLY_MODE);
 		DBUG_RETURN(HA_ERR_TABLE_READONLY);
 	} else if (!trx_is_started(trx)) {
-		++trx->will_lock;
+		trx->will_lock = true;
 	}
 
 	if (m_upd_buf == NULL) {
@@ -9110,7 +9102,7 @@ ha_innobase::delete_row(
 		ib_senderrf(ha_thd(), IB_LOG_LEVEL_WARN, ER_READ_ONLY_MODE);
 		DBUG_RETURN(HA_ERR_TABLE_READONLY);
 	} else if (!trx_is_started(trx)) {
-		++trx->will_lock;
+		trx->will_lock = true;
 	}
 
 	if (!m_prebuilt->upd_node) {
@@ -9990,7 +9982,7 @@ ha_innobase::ft_init()
 	them as regular read only transactions for now. */
 
 	if (!trx_is_started(trx)) {
-		++trx->will_lock;
+		trx->will_lock = true;
 	}
 
 	DBUG_RETURN(rnd_init(false));
@@ -10056,7 +10048,7 @@ ha_innobase::ft_init_ext(
 	them as regular read only transactions for now. */
 
 	if (!trx_is_started(trx)) {
-		++trx->will_lock;
+		trx->will_lock = true;
 	}
 
 	dict_table_t*	ft_table = m_prebuilt->table;
@@ -13081,7 +13073,7 @@ create_table_info_t::allocate_trx()
 {
 	m_trx = innobase_trx_allocate(m_thd);
 
-	m_trx->will_lock++;
+	m_trx->will_lock = true;
 	m_trx->ddl = true;
 }
 
@@ -13372,13 +13364,7 @@ inline int ha_innobase::delete_table(const char* name, enum_sql_command sqlcom)
 
 	ut_a(name_len < 1000);
 
-	/* Either the transaction is already flagged as a locking transaction
-	or it hasn't been started yet. */
-
-	ut_a(!trx_is_started(trx) || trx->will_lock > 0);
-
-	/* We are doing a DDL operation. */
-	++trx->will_lock;
+	trx->will_lock = true;
 
 	/* Drop the table in InnoDB */
 
@@ -13555,14 +13541,7 @@ innobase_drop_database(
 #endif /* _WIN32 */
 
 	trx_t*	trx = innobase_trx_allocate(thd);
-
-	/* Either the transaction is already flagged as a locking transaction
-	or it hasn't been started yet. */
-
-	ut_a(!trx_is_started(trx) || trx->will_lock > 0);
-
-	/* We are doing a DDL operation. */
-	++trx->will_lock;
+	trx->will_lock = true;
 
 	ulint	dummy;
 
@@ -13606,7 +13585,7 @@ inline dberr_t innobase_rename_table(trx_t *trx, const char *from,
 	DEBUG_SYNC_C("innodb_rename_table_ready");
 
 	trx_start_if_not_started(trx, true);
-	ut_ad(trx->will_lock > 0);
+	ut_ad(trx->will_lock);
 
 	if (commit) {
 		/* Serialize data dictionary operations with dictionary mutex:
@@ -13651,7 +13630,7 @@ inline dberr_t innobase_rename_table(trx_t *trx, const char *from,
 	/* Transaction must be flagged as a locking transaction or it hasn't
 	been started yet. */
 
-	ut_a(trx->will_lock > 0);
+	ut_a(trx->will_lock);
 
 	error = row_rename_table_for_mysql(norm_from, norm_to, trx, commit,
 					   commit);
@@ -13737,7 +13716,7 @@ int ha_innobase::truncate()
 
 	if (!srv_safe_truncate) {
 		if (!trx_is_started(m_prebuilt->trx)) {
-			++m_prebuilt->trx->will_lock;
+			m_prebuilt->trx->will_lock = true;
 		}
 
 		dberr_t	err = row_truncate_table_for_mysql(
@@ -13791,8 +13770,7 @@ int ha_innobase::truncate()
 		heap, ib_table->name.m_name, ib_table->id);
 	const char* name = mem_heap_strdup(heap, ib_table->name.m_name);
 	trx_t*	trx = innobase_trx_allocate(m_user_thd);
-
-	++trx->will_lock;
+	trx->will_lock = true;
 	trx_set_dict_operation(trx, TRX_DICT_OP_TABLE);
 	row_mysql_lock_data_dictionary(trx);
 	dict_stats_wait_bg_to_stop_using_table(ib_table, trx);
@@ -13877,9 +13855,7 @@ ha_innobase::rename_table(
 	}
 
 	trx_t*	trx = innobase_trx_allocate(thd);
-
-	/* We are doing a DDL operation. */
-	++trx->will_lock;
+	trx->will_lock = true;
 	trx_set_dict_operation(trx, TRX_DICT_OP_INDEX);
 
 	dberr_t	error = innobase_rename_table(trx, from, to, true);
@@ -15880,7 +15856,7 @@ ha_innobase::start_stmt(
 	innobase_register_trx(ht, thd, trx);
 
 	if (!trx_is_started(trx)) {
-		++trx->will_lock;
+		trx->will_lock = true;
 	}
 
 	DBUG_RETURN(0);
@@ -16103,7 +16079,7 @@ ha_innobase::external_lock(
 		    && (m_prebuilt->select_lock_type != LOCK_NONE
 			|| m_prebuilt->stored_select_lock_type != LOCK_NONE)) {
 
-			++trx->will_lock;
+			trx->will_lock = true;
 		}
 
 		DBUG_RETURN(0);
@@ -16150,7 +16126,7 @@ ha_innobase::external_lock(
 	    && (m_prebuilt->select_lock_type != LOCK_NONE
 		|| m_prebuilt->stored_select_lock_type != LOCK_NONE)) {
 
-		++trx->will_lock;
+		trx->will_lock = true;
 	}
 
 	DBUG_RETURN(0);
@@ -16829,7 +16805,7 @@ ha_innobase::store_lock(
 	    && (m_prebuilt->select_lock_type != LOCK_NONE
 	        || m_prebuilt->stored_select_lock_type != LOCK_NONE)) {
 
-		++trx->will_lock;
+		trx->will_lock = true;
 	}
 
 	return(to);
diff --git a/storage/innobase/handler/handler0alter.cc b/storage/innobase/handler/handler0alter.cc
index 24a7c4a74ad..88e02ee4e32 100644
--- a/storage/innobase/handler/handler0alter.cc
+++ b/storage/innobase/handler/handler0alter.cc
@@ -967,7 +967,7 @@ ha_innobase::check_if_supported_inplace_alter(
 		}
 	}
 
-	m_prebuilt->trx->will_lock++;
+	m_prebuilt->trx->will_lock = true;
 
 	if (!online) {
 		/* We already determined that only a non-locking
@@ -8954,7 +8954,6 @@ foreign_fail:
 				m_prebuilt = ctx->prebuilt;
 			}
 			trx_start_if_not_started(user_trx, true);
-			user_trx->will_lock++;
 			m_prebuilt->trx = user_trx;
 		}
 		DBUG_INJECT_CRASH("ib_commit_inplace_crash",
diff --git a/storage/innobase/include/trx0i_s.h b/storage/innobase/include/trx0i_s.h
index 7e766072272..ca65e053502 100644
--- a/storage/innobase/include/trx0i_s.h
+++ b/storage/innobase/include/trx0i_s.h
@@ -1,7 +1,7 @@
 /*****************************************************************************
 
 Copyright (c) 2007, 2015, Oracle and/or its affiliates. All Rights Reserved.
-Copyright (c) 2017, 2019, MariaDB Corporation.
+Copyright (c) 2017, 2021, MariaDB Corporation.
 
 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free Software
@@ -164,8 +164,8 @@ struct i_s_trx_row_t {
 					/*!< detailed_error in trx_t */
 	ulint		trx_is_read_only;
 					/*!< trx_t::read_only */
-	ulint		trx_is_autocommit_non_locking;
-					/*!< trx_is_autocommit_non_locking(trx)
+	bool		trx_is_autocommit_non_locking;
+					/*!< trx:t::is_autocommit_non_locking()
 					*/
 };
 
diff --git a/storage/innobase/include/trx0sys.ic b/storage/innobase/include/trx0sys.ic
index c85695630f0..8518934e94f 100644
--- a/storage/innobase/include/trx0sys.ic
+++ b/storage/innobase/include/trx0sys.ic
@@ -1,7 +1,7 @@
 /*****************************************************************************
 
 Copyright (c) 1996, 2015, Oracle and/or its affiliates. All Rights Reserved.
-Copyright (c) 2018, 2019, MariaDB Corporation.
+Copyright (c) 2018, 2021, MariaDB Corporation.
 
 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free Software
@@ -251,7 +251,9 @@ trx_rw_min_trx_id_low(void)
 	if (trx == NULL) {
 		id = trx_sys->max_trx_id;
 	} else {
-		assert_trx_in_rw_list(trx);
+		ut_ad(!trx->read_only);
+		ut_ad(trx->in_rw_trx_list);
+		ut_ad(!trx->is_autocommit_non_locking());
 		id = trx->id;
 	}
 
diff --git a/storage/innobase/include/trx0trx.h b/storage/innobase/include/trx0trx.h
index a7591fa1b19..90365400d72 100644
--- a/storage/innobase/include/trx0trx.h
+++ b/storage/innobase/include/trx0trx.h
@@ -502,99 +502,6 @@ from innodb_lock_wait_timeout via trx_t::mysql_thd.
 	 ? thd_lock_wait_timeout((t)->mysql_thd)			\
 	 : 0)
 
-/**
-Determine if the transaction is a non-locking autocommit select
-(implied read-only).
-@param t transaction
-@return true if non-locking autocommit select transaction. */
-#define trx_is_autocommit_non_locking(t)				\
-((t)->auto_commit && (t)->will_lock == 0)
-
-/**
-Determine if the transaction is a non-locking autocommit select
-with an explicit check for the read-only status.
-@param t transaction
-@return true if non-locking autocommit read-only transaction. */
-#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 {						\
-	ut_ad(!trx_is_autocommit_non_locking((t)));			\
-	switch ((t)->state) {						\
-	case TRX_STATE_PREPARED:					\
-	case TRX_STATE_PREPARED_RECOVERED:				\
-	case TRX_STATE_ACTIVE:						\
-	case TRX_STATE_COMMITTED_IN_MEMORY:				\
-		continue;						\
-	case TRX_STATE_NOT_STARTED:					\
-		break;							\
-	}								\
-	ut_error;							\
-} while (0)
-
-/** Check if transaction is free so that it can be re-initialized.
-@param t transaction handle */
-#define	assert_trx_is_free(t)	do {					\
-	ut_ad(trx_state_eq((t), TRX_STATE_NOT_STARTED));		\
-	ut_ad(!(t)->id);						\
-	ut_ad(!(t)->has_logged());					\
-	ut_ad(!(t)->is_referenced());					\
-	ut_ad(!(t)->is_wsrep());					\
-	ut_ad(!MVCC::is_view_active((t)->read_view));			\
-	ut_ad((t)->lock.wait_thr == NULL);				\
-	ut_ad(UT_LIST_GET_LEN((t)->lock.trx_locks) == 0);		\
-	ut_ad((t)->lock.table_locks.empty());				\
-	ut_ad(!(t)->autoinc_locks					\
-	      || ib_vector_is_empty((t)->autoinc_locks));		\
-	ut_ad((t)->dict_operation == TRX_DICT_OP_NONE);			\
-} while(0)
-
-/** Check if transaction is in-active so that it can be freed and put back to
-transaction pool.
-@param t transaction handle */
-#define assert_trx_is_inactive(t) do {					\
-	assert_trx_is_free((t));					\
-	ut_ad((t)->dict_operation_lock_mode == 0);			\
-} while(0)
-
-#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.
-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_ACTIVE);		\
-		} else {						\
-			check_trx_state(t);				\
-		}							\
-	} while (0)
-#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.
-The tranasction must be in the mysql_trx_list. */
-# define assert_trx_nonlocking_or_in_list(trx) ((void)0)
-#endif /* UNIV_DEBUG */
-
 typedef std::vector<ib_lock_t*, ut_allocator<ib_lock_t*> >	lock_list;
 
 /*******************************************************************//**
@@ -1070,16 +977,15 @@ public:
 	/*------------------------------*/
 	bool		read_only;	/*!< true if transaction is flagged
 					as a READ-ONLY transaction.
-					if auto_commit && will_lock == 0
+					if auto_commit && !will_lock
 					then it will be handled as a
 					AC-NL-RO-SELECT (Auto Commit Non-Locking
 					Read Only Select). A read only
 					transaction will not be assigned an
 					UNDO log. */
 	bool		auto_commit;	/*!< true if it is an autocommit */
-	ib_uint32_t	will_lock;	/*!< Will acquire some locks. Increment
-					each time we determine that a lock will
-					be acquired by the MySQL layer. */
+	bool		will_lock;	/*!< set to inform trx_start_low() that
+					the transaction may acquire locks */
 	/*------------------------------*/
 	fts_trx_t*	fts_trx;	/*!< FTS information, or NULL if
 					transaction hasn't modified tables
@@ -1199,10 +1105,28 @@ public:
   inline void free();
 
 
+  void assert_freed() const
+  {
+    ut_ad(state == TRX_STATE_NOT_STARTED);
+    ut_ad(!id);
+    ut_ad(!has_logged());
+    ut_ad(!const_cast<trx_t*>(this)->is_referenced());
+    ut_ad(!is_wsrep());
+    ut_ad(!trx_get_read_view(this));
+    ut_ad(!lock.wait_thr);
+    ut_ad(UT_LIST_GET_LEN(lock.trx_locks) == 0);
+    ut_ad(lock.table_locks.empty());
+    ut_ad(!autoinc_locks || ib_vector_is_empty(autoinc_locks));
+    ut_ad(dict_operation == TRX_DICT_OP_NONE);
+  }
+
+  /** @return whether this is a non-locking autocommit transaction */
+  bool is_autocommit_non_locking() const { return auto_commit && !will_lock; }
+
 private:
-	/** Assign a rollback segment for modifying temporary tables.
-	@return the assigned rollback segment */
-	trx_rseg_t* assign_temp_rseg();
+  /** Assign a rollback segment for modifying temporary tables.
+  @return the assigned rollback segment */
+  trx_rseg_t *assign_temp_rseg();
 };
 
 /**
diff --git a/storage/innobase/include/trx0trx.ic b/storage/innobase/include/trx0trx.ic
index 4a5b1ba717f..2a53509b206 100644
--- a/storage/innobase/include/trx0trx.ic
+++ b/storage/innobase/include/trx0trx.ic
@@ -1,7 +1,7 @@
 /*****************************************************************************
 
 Copyright (c) 1996, 2015, Oracle and/or its affiliates. All Rights Reserved.
-Copyright (c) 2016, 2019, MariaDB Corporation.
+Copyright (c) 2016, 2021, MariaDB Corporation.
 
 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free Software
@@ -50,17 +50,18 @@ trx_state_eq(
 	switch (trx->state) {
 	case TRX_STATE_PREPARED:
 	case TRX_STATE_PREPARED_RECOVERED:
-		ut_ad(!trx_is_autocommit_non_locking(trx));
+	case TRX_STATE_COMMITTED_IN_MEMORY:
+		ut_ad(!trx->is_autocommit_non_locking());
 		return(trx->state == state);
 
 	case TRX_STATE_ACTIVE:
-
-		assert_trx_nonlocking_or_in_list(trx);
-		return(state == trx->state);
-
-	case TRX_STATE_COMMITTED_IN_MEMORY:
-
-		check_trx_state(trx);
+		if (trx->is_autocommit_non_locking()) {
+			ut_ad(!trx->is_recovered);
+			ut_ad(trx->read_only);
+			ut_ad(trx->mysql_thd);
+			ut_ad(!trx->in_rw_trx_list);
+			ut_ad(trx->in_mysql_trx_list);
+		}
 		return(state == trx->state);
 
 	case TRX_STATE_NOT_STARTED:
diff --git a/storage/innobase/lock/lock0lock.cc b/storage/innobase/lock/lock0lock.cc
index 506106a2269..4daf4fb07b8 100644
--- a/storage/innobase/lock/lock0lock.cc
+++ b/storage/innobase/lock/lock0lock.cc
@@ -1376,6 +1376,19 @@ wsrep_print_wait_locks(
 }
 #endif /* WITH_WSREP */
 
+#ifdef UNIV_DEBUG
+/** Check transaction state */
+static void check_trx_state(const trx_t *trx)
+{
+  ut_ad(!trx->auto_commit || trx->will_lock);
+  const trx_state_t state= trx->state;
+  ut_ad(state == TRX_STATE_ACTIVE ||
+        state == TRX_STATE_PREPARED_RECOVERED ||
+        state == TRX_STATE_PREPARED ||
+        state == TRX_STATE_COMMITTED_IN_MEMORY);
+}
+#endif
+
 /** Create a new record lock and inserts it to the lock queue,
 without checking for deadlocks or conflicts.
 @param[in]	type_mode	lock mode and wait flag; type will be replaced
@@ -3589,8 +3602,8 @@ lock_table_create(
 	ut_ad(table && trx);
 	ut_ad(lock_mutex_own());
 	ut_ad(trx_mutex_own(trx));
-
-	check_trx_state(trx);
+	ut_ad(trx->is_recovered || trx->state == TRX_STATE_ACTIVE);
+	ut_ad(!trx->auto_commit || trx->will_lock);
 
 	if ((type_mode & LOCK_MODE_MASK) == LOCK_AUTO_INC) {
 		++table->n_waiting_or_granted_auto_inc_locks;
@@ -4545,7 +4558,10 @@ lock_remove_recovered_trx_record_locks(
 	     trx != NULL;
 	     trx = UT_LIST_GET_NEXT(trx_list, trx)) {
 
-		assert_trx_in_rw_list(trx);
+		ut_ad(!trx->read_only);
+		ut_ad(trx->in_rw_trx_list);
+		ut_ad(!trx->is_autocommit_non_locking());
+		ut_ad(trx->state != TRX_STATE_NOT_STARTED);
 
 		if (!trx->is_recovered) {
 			continue;
@@ -5181,7 +5197,8 @@ lock_rec_queue_validate(
 			ut_ad(!index || lock->index == index);
 
 			trx_mutex_enter(lock->trx);
-			ut_ad(!trx_is_ac_nl_ro(lock->trx));
+			ut_ad(!lock->trx->read_only
+			      || !lock->trx->is_autocommit_non_locking());
 			ut_ad(trx_state_eq(lock->trx,
 					   TRX_STATE_COMMITTED_IN_MEMORY)
 			      || !lock_get_wait(lock)
@@ -5260,8 +5277,7 @@ lock_rec_queue_validate(
 	for (lock = lock_rec_get_first(lock_sys->rec_hash, block, heap_no);
 	     lock != NULL;
 	     lock = lock_rec_get_next_const(heap_no, lock)) {
-
-		ut_ad(!trx_is_ac_nl_ro(lock->trx));
+		ut_ad(!lock->trx->is_autocommit_non_locking());
 
 		if (index) {
 			ut_a(lock->index == index);
@@ -5357,7 +5373,8 @@ loop:
 		}
 	}
 
-	ut_ad(!trx_is_ac_nl_ro(lock->trx));
+	ut_ad(!lock->trx->read_only
+	      || !lock->trx->is_autocommit_non_locking());
 
 	/* Only validate the record queues when this thread is not
 	holding a space->latch. */
@@ -5465,7 +5482,7 @@ lock_rec_validate(
 
 		ib_uint64_t	current;
 
-		ut_ad(!trx_is_ac_nl_ro(lock->trx));
+		ut_ad(!lock->trx->is_autocommit_non_locking());
 		ut_ad(lock_get_type(lock) == LOCK_REC);
 
 		current = ut_ull_create(
@@ -7075,7 +7092,8 @@ DeadlockChecker::search()
 
 	ut_ad(m_start != NULL);
 	ut_ad(m_wait_lock != NULL);
-	check_trx_state(m_wait_lock->trx);
+	ut_ad(!m_wait_lock->trx->auto_commit || m_wait_lock->trx->will_lock);
+	ut_d(check_trx_state(m_wait_lock->trx));
 	ut_ad(m_mark_start <= s_lock_mark_counter);
 
 	/* Look at the locks ahead of wait_lock in the lock queue. */
@@ -7235,7 +7253,8 @@ DeadlockChecker::check_and_resolve(const lock_t* lock, trx_t* trx)
 {
 	ut_ad(lock_mutex_own());
 	ut_ad(trx_mutex_own(trx));
-	check_trx_state(trx);
+	ut_ad(trx->state == TRX_STATE_ACTIVE);
+	ut_ad(!trx->auto_commit || trx->will_lock);
 	ut_ad(!srv_read_only_mode);
 
 	if (!innobase_deadlock_detect) {
diff --git a/storage/innobase/read/read0read.cc b/storage/innobase/read/read0read.cc
index 3fd52d5d6dd..a115672a8a6 100644
--- a/storage/innobase/read/read0read.cc
+++ b/storage/innobase/read/read0read.cc
@@ -1,7 +1,7 @@
 /*****************************************************************************
 
 Copyright (c) 1996, 2015, Oracle and/or its affiliates. All Rights Reserved.
-Copyright (c) 2019, MariaDB Corporation.
+Copyright (c) 2019, 2021, MariaDB Corporation.
 
 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free Software
@@ -574,7 +574,7 @@ MVCC::view_open(ReadView*& view, trx_t* trx)
 		Therefore we must set the low limit id after we reset the
 		closed status after the check. */
 
-		if (trx_is_autocommit_non_locking(trx) && view->empty()) {
+		if (trx->is_autocommit_non_locking() && view->empty()) {
 
 			view->m_closed = false;
 
diff --git a/storage/innobase/trx/trx0i_s.cc b/storage/innobase/trx/trx0i_s.cc
index 2b9d6c96acd..05579aeb223 100644
--- a/storage/innobase/trx/trx0i_s.cc
+++ b/storage/innobase/trx/trx0i_s.cc
@@ -1,7 +1,7 @@
 /*****************************************************************************
 
 Copyright (c) 2007, 2015, Oracle and/or its affiliates. All Rights Reserved.
-Copyright (c) 2017, 2019, MariaDB Corporation.
+Copyright (c) 2017, 2021, MariaDB Corporation.
 
 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free Software
@@ -577,7 +577,7 @@ thd_done:
 
 	row->trx_is_read_only = trx->read_only;
 
-	row->trx_is_autocommit_non_locking = trx_is_autocommit_non_locking(trx);
+	row->trx_is_autocommit_non_locking = trx->is_autocommit_non_locking();
 
 	return(TRUE);
 }
@@ -1259,7 +1259,21 @@ fetch_data_into_cache_low(
 			continue;
 		}
 
-		assert_trx_nonlocking_or_in_list(trx);
+
+#ifdef UNIV_DEBUG
+		if (trx->is_autocommit_non_locking()) {
+			ut_ad(trx->read_only);
+			ut_ad(!trx->is_recovered);
+			ut_ad(trx->mysql_thd);
+			ut_ad(trx->in_mysql_trx_list);
+			const trx_state_t state = trx->state;
+			ut_ad(state == TRX_STATE_NOT_STARTED
+			      || state == TRX_STATE_ACTIVE);
+		}
+		else {
+			ut_ad(trx->state != TRX_STATE_NOT_STARTED);
+		}
+#endif /* UNIV_DEBUG */
 
 		ut_ad(trx->in_rw_trx_list == rw_trx_list);
 
diff --git a/storage/innobase/trx/trx0roll.cc b/storage/innobase/trx/trx0roll.cc
index c986a866fe2..ec2d3c1d03f 100644
--- a/storage/innobase/trx/trx0roll.cc
+++ b/storage/innobase/trx/trx0roll.cc
@@ -1,7 +1,7 @@
 /*****************************************************************************
 
 Copyright (c) 1996, 2017, Oracle and/or its affiliates. All Rights Reserved.
-Copyright (c) 2016, 2020, MariaDB Corporation.
+Copyright (c) 2016, 2021, MariaDB Corporation.
 
 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free Software
@@ -81,12 +81,19 @@ trx_rollback_to_savepoint_low(
 	heap = mem_heap_create(512);
 
 	roll_node = roll_node_create(heap);
+	ut_ad(!trx->in_rollback);
 
 	if (savept != NULL) {
 		roll_node->savept = savept;
-		check_trx_state(trx);
+		ut_ad(trx->mysql_thd);
+		ut_ad(trx->in_mysql_trx_list);
+		ut_ad(!trx->is_recovered);
+		ut_ad(trx->state == TRX_STATE_ACTIVE);
 	} else {
-		assert_trx_nonlocking_or_in_list(trx);
+		ut_d(trx_state_t state = trx->state);
+		ut_ad(state == TRX_STATE_ACTIVE
+		      || state == TRX_STATE_PREPARED
+		      || state == TRX_STATE_PREPARED_RECOVERED);
 	}
 
 	trx->error_state = DB_SUCCESS;
@@ -187,7 +194,8 @@ dberr_t trx_rollback_for_mysql(trx_t* trx)
 
 	switch (trx->state) {
 	case TRX_STATE_NOT_STARTED:
-		trx->will_lock = 0;
+		trx->will_lock = false;
+		ut_ad(trx->mysql_thd);
 		ut_ad(trx->in_mysql_trx_list);
 #ifdef WITH_WSREP
 		trx->wsrep = false;
@@ -196,12 +204,14 @@ dberr_t trx_rollback_for_mysql(trx_t* trx)
 
 	case TRX_STATE_ACTIVE:
 		ut_ad(trx->in_mysql_trx_list);
-		assert_trx_nonlocking_or_in_list(trx);
+		ut_ad(trx->mysql_thd);
+		ut_ad(!trx->is_recovered);
+		ut_ad(!trx->is_autocommit_non_locking() || trx->read_only);
 		return(trx_rollback_for_mysql_low(trx));
 
 	case TRX_STATE_PREPARED:
 	case TRX_STATE_PREPARED_RECOVERED:
-		ut_ad(!trx_is_autocommit_non_locking(trx));
+		ut_ad(!trx->is_autocommit_non_locking());
 		if (trx->has_logged_persistent()) {
 			/* The XA ROLLBACK of a XA PREPARE transaction
 			will consist of multiple mini-transactions.
@@ -245,7 +255,7 @@ dberr_t trx_rollback_for_mysql(trx_t* trx)
 		return(trx_rollback_for_mysql_low(trx));
 
 	case TRX_STATE_COMMITTED_IN_MEMORY:
-		check_trx_state(trx);
+		ut_ad(!trx->is_autocommit_non_locking());
 		break;
 	}
 
@@ -274,7 +284,9 @@ trx_rollback_last_sql_stat_for_mysql(
 		return(DB_SUCCESS);
 
 	case TRX_STATE_ACTIVE:
-		assert_trx_nonlocking_or_in_list(trx);
+		ut_ad(trx->mysql_thd);
+		ut_ad(!trx->is_recovered);
+		ut_ad(!trx->is_autocommit_non_locking() || trx->read_only);
 
 		trx->op_info = "rollback of SQL statement";
 
@@ -768,7 +780,11 @@ trx_roll_must_shutdown()
 		     t != NULL;
 		     t = UT_LIST_GET_NEXT(trx_list, t)) {
 
-			assert_trx_in_rw_list(t);
+			ut_ad(!t->read_only);
+			ut_ad(t->in_rw_trx_list);
+			ut_ad(!t->is_autocommit_non_locking());
+			ut_ad(t->state != TRX_STATE_NOT_STARTED);
+
 			if (t->is_recovered
 			    && trx_state_eq(t, TRX_STATE_ACTIVE)) {
 				n_trx++;
@@ -831,7 +847,10 @@ trx_rollback_or_clean_recovered(
 		     trx != NULL;
 		     trx = UT_LIST_GET_NEXT(trx_list, trx)) {
 
-			assert_trx_in_rw_list(trx);
+			ut_ad(!trx->read_only);
+			ut_ad(trx->in_rw_trx_list);
+			ut_ad(!trx->is_autocommit_non_locking());
+			ut_ad(trx->state != TRX_STATE_NOT_STARTED);
 
 			/* If this function does a cleanup or rollback
 			then it will release the trx_sys->mutex, therefore
diff --git a/storage/innobase/trx/trx0sys.cc b/storage/innobase/trx/trx0sys.cc
index 9138e9475bf..c8c68c37333 100644
--- a/storage/innobase/trx/trx0sys.cc
+++ b/storage/innobase/trx/trx0sys.cc
@@ -513,7 +513,9 @@ trx_sys_init_at_db_start()
 		     trx = UT_LIST_GET_NEXT(trx_list, trx)) {
 
 			ut_ad(trx->is_recovered);
-			assert_trx_in_rw_list(trx);
+			ut_ad(!trx->read_only);
+			ut_ad(trx->in_rw_trx_list);
+			ut_ad(!trx->is_autocommit_non_locking());
 
 			if (trx_state_eq(trx, TRX_STATE_ACTIVE)) {
 				rows_to_undo += trx->undo_no;
@@ -1026,7 +1028,8 @@ trx_sys_validate_trx_list_low(
 	     trx != NULL;
 	     prev_trx = trx, trx = UT_LIST_GET_NEXT(trx_list, prev_trx)) {
 
-		check_trx_state(trx);
+		ut_ad(!trx->is_autocommit_non_locking());
+		ut_ad(trx->state != TRX_STATE_NOT_STARTED);
 		ut_a(prev_trx == NULL || prev_trx->id > trx->id);
 	}
 
diff --git a/storage/innobase/trx/trx0trx.cc b/storage/innobase/trx/trx0trx.cc
index d1b35bd84a3..3e558a7181d 100644
--- a/storage/innobase/trx/trx0trx.cc
+++ b/storage/innobase/trx/trx0trx.cc
@@ -133,7 +133,7 @@ trx_init(
 
 	trx->auto_commit = false;
 
-	trx->will_lock = 0;
+	trx->will_lock = false;
 
 	trx->ddl = false;
 
@@ -336,13 +336,13 @@ trx_t *trx_allocate_for_background()
 	MEM_MAKE_DEFINED(trx, sizeof *trx);
 #endif
 
-	assert_trx_is_free(trx);
+	trx->assert_freed();
 
 	mem_heap_t*	heap;
 	ib_alloc_t*	alloc;
 
 	/* We just got trx from pool, it should be non locking */
-	ut_ad(trx->will_lock == 0);
+	ut_ad(!trx->will_lock);
 	ut_ad(trx->state == TRX_STATE_NOT_STARTED);
 
 	DBUG_LOG("trx", "Create: " << trx);
@@ -369,7 +369,8 @@ trx_t *trx_allocate_for_background()
 /** Free the memory to trx_pools */
 inline void trx_t::free()
 {
-  assert_trx_is_inactive(this);
+  assert_freed();
+  ut_ad(!dict_operation_lock_mode);
 
   MEM_CHECK_DEFINED(this, sizeof *this);
 
@@ -539,7 +540,8 @@ trx_validate_state_before_free(trx_t* trx)
 	}
 
 	trx->dict_operation = TRX_DICT_OP_NONE;
-	assert_trx_is_inactive(trx);
+	trx->assert_freed();
+	ut_ad(!trx->dict_operation_lock_mode);
 }
 
 /** Free and initialize a transaction object instantinated during recovery.
@@ -636,7 +638,9 @@ trx_free_prepared(
 	trx->release_locks();
 	trx_undo_free_prepared(trx);
 
-	assert_trx_in_rw_list(trx);
+	ut_ad(!trx->read_only);
+	ut_ad(trx->in_rw_trx_list);
+	ut_ad(!trx->is_autocommit_non_locking());
 
 	ut_a(!trx->read_only);
 
@@ -685,7 +689,7 @@ trx_disconnect_from_mysql(
 		trx->is_recovered = true;
 	        trx->mysql_thd = NULL;
 		/* todo/fixme: suggest to do it at innodb prepare */
-		trx->will_lock = 0;
+		trx->will_lock = false;
 	}
 
 	trx_sys_mutex_exit();
@@ -1177,11 +1181,10 @@ void trx_t::remove_flush_observer()
 
 /** Assign a rollback segment for modifying temporary tables.
 @return the assigned rollback segment */
-trx_rseg_t*
-trx_t::assign_temp_rseg()
+trx_rseg_t *trx_t::assign_temp_rseg()
 {
 	ut_ad(!rsegs.m_noredo.rseg);
-	ut_ad(!trx_is_autocommit_non_locking(this));
+	ut_ad(!is_autocommit_non_locking());
 	compile_time_assert(ut_is_2pow(TRX_SYS_N_RSEGS));
 
 	/* Choose a temporary rollback segment between 0 and 127
@@ -1235,8 +1238,8 @@ trx_start_low(
 		    && thd_trx_is_read_only(trx->mysql_thd));
 
 	if (!trx->auto_commit) {
-		++trx->will_lock;
-	} else if (trx->will_lock == 0) {
+		trx->will_lock = true;
+	} else if (!trx->will_lock) {
 		trx->read_only = true;
 	}
 
@@ -1305,7 +1308,7 @@ trx_start_low(
 
 		trx_sys_mutex_exit();
 	} else {
-		if (!trx_is_autocommit_non_locking(trx)) {
+		if (!trx->is_autocommit_non_locking()) {
 
 			/* If this is a read-only transaction that is writing
 			to a temporary table then it needs a transaction id
@@ -1691,12 +1694,16 @@ trx_commit_in_memory(
 {
 	trx->must_flush_log_later = false;
 
-	if (trx_is_autocommit_non_locking(trx)) {
+	if (trx->is_autocommit_non_locking()) {
 		ut_ad(trx->id == 0);
 		ut_ad(trx->read_only);
+		ut_ad(!trx->will_lock);
 		ut_a(!trx->is_recovered);
 		ut_ad(trx->rsegs.m_redo.rseg == NULL);
 		ut_ad(!trx->in_rw_trx_list);
+		ut_ad(trx->in_mysql_trx_list);
+		ut_ad(trx->mysql_thd);
+		ut_ad(trx->state == TRX_STATE_ACTIVE);
 
 		/* Note: We are asserting without holding the lock mutex. But
 		that is OK because this transaction is not waiting and cannot
@@ -1712,8 +1719,6 @@ trx_commit_in_memory(
 		and it cannot be removed from the mysql_trx_list and freed
 		without first acquiring the trx_sys_t::mutex. */
 
-		ut_ad(trx_state_eq(trx, TRX_STATE_ACTIVE));
-
 		if (trx->read_view != NULL) {
 			trx_sys->mvcc->view_close(trx->read_view, false);
 		}
@@ -1866,7 +1871,7 @@ trx_commit_in_memory(
 	/* trx->in_mysql_trx_list would hold between
 	trx_allocate_for_mysql() and trx_free_for_mysql(). It does not
 	hold for recovered transactions or system transactions. */
-	assert_trx_is_free(trx);
+	trx->assert_freed();
 
 	trx_init(trx);
 
@@ -1885,30 +1890,20 @@ trx_commit_low(
 	mtr_t*	mtr)	/*!< in/out: mini-transaction (will be committed),
 			or NULL if trx made no modifications */
 {
-	assert_trx_nonlocking_or_in_list(trx);
-	ut_ad(!trx_state_eq(trx, TRX_STATE_COMMITTED_IN_MEMORY));
 	ut_ad(!mtr || mtr->is_active());
 	ut_ad(!mtr == !trx->has_logged());
 
 	/* undo_no is non-zero if we're doing the final commit. */
 	if (trx->fts_trx != NULL && trx->undo_no != 0) {
-		dberr_t	error;
-
-		ut_a(!trx_is_autocommit_non_locking(trx));
-
-		error = fts_commit(trx);
+		ut_a(!trx->is_autocommit_non_locking());
 
 		/* FTS-FIXME: Temporarily tolerate DB_DUPLICATE_KEY
 		instead of dying. This is a possible scenario if there
 		is a crash between insert to DELETED table committing
 		and transaction committing. The fix would be able to
 		return error from this function */
-		if (error != DB_SUCCESS && error != DB_DUPLICATE_KEY) {
-			/* FTS-FIXME: once we can return values from this
-			function, we should do so and signal an error
-			instead of just dying. */
-
-			ut_error;
+		if (dberr_t error = fts_commit(trx)) {
+			ut_a(error == DB_DUPLICATE_KEY);
 		}
 	}
 
@@ -2279,7 +2274,6 @@ trx_print_low(
 			/*!< in: mem_heap_get_size(trx->lock.lock_heap) */
 {
 	ibool		newline;
-	const char*	op_info;
 
 	ut_ad(trx_sys_mutex_own());
 
@@ -2308,9 +2302,7 @@ trx_print_low(
 	fprintf(f, ", state %lu", (ulong) trx->state);
 	ut_ad(0);
 state_ok:
-
-	/* prevent a race condition */
-	op_info = trx->op_info;
+	const char* op_info = trx->op_info;
 
 	if (*op_info) {
 		putc(' ', f);
@@ -2549,7 +2541,7 @@ trx_assert_started(
 
 	/* Non-locking autocommits should not hold any locks and this
 	function is only called from the locking code. */
-	check_trx_state(trx);
+	ut_ad(!trx->is_autocommit_non_locking());
 
 	/* trx->state can change from or to NOT_STARTED while we are holding
 	trx_sys->mutex for non-locking autocommit selects but not for other
@@ -2754,7 +2746,9 @@ trx_recover_for_mysql(
 	     trx != NULL;
 	     trx = UT_LIST_GET_NEXT(trx_list, trx)) {
 
-		assert_trx_in_rw_list(trx);
+		ut_ad(!trx->read_only);
+		ut_ad(trx->in_rw_trx_list);
+		ut_ad(!trx->is_autocommit_non_locking());
 
 		/* The state of a read-write transaction cannot change
 		from or to NOT_STARTED while we are holding the
@@ -2821,7 +2815,9 @@ trx_t* trx_get_trx_by_xid_low(const XID* xid)
 	     trx != NULL;
 	     trx = UT_LIST_GET_NEXT(trx_list, trx)) {
 		trx_mutex_enter(trx);
-		assert_trx_in_rw_list(trx);
+		ut_ad(!trx->read_only);
+		ut_ad(trx->in_rw_trx_list);
+		ut_ad(!trx->is_autocommit_non_locking());
 
 		/* Compare two X/Open XA transaction id's: their
 		length should be the same and binary comparison
@@ -2948,7 +2944,7 @@ trx_start_internal_low(
 	/* Ensure it is not flagged as an auto-commit-non-locking
 	transaction. */
 
-	trx->will_lock = 1;
+	trx->will_lock = true;
 
 	trx->internal = true;
 
@@ -2964,7 +2960,7 @@ trx_start_internal_read_only_low(
 	/* Ensure it is not flagged as an auto-commit-non-locking
 	transaction. */
 
-	trx->will_lock = 1;
+	trx->will_lock = true;
 
 	trx->internal = true;
 
@@ -2985,13 +2981,7 @@ trx_start_for_ddl_low(
 		the data dictionary will be locked in crash recovery. */
 
 		trx_set_dict_operation(trx, op);
-
-		/* Ensure it is not flagged as an auto-commit-non-locking
-		transation. */
-		trx->will_lock = 1;
-
 		trx->ddl= true;
-
 		trx_start_internal_low(trx);
 		return;
 
@@ -3002,7 +2992,7 @@ trx_start_for_ddl_low(
 		trx->ddl = true;
 
 		ut_ad(trx->dict_operation != TRX_DICT_OP_NONE);
-		ut_ad(trx->will_lock > 0);
+		ut_ad(trx->will_lock);
 		return;
 
 	case TRX_STATE_PREPARED:
@@ -3028,7 +3018,7 @@ trx_set_rw_mode(
 {
 	ut_ad(trx->rsegs.m_redo.rseg == 0);
 	ut_ad(!trx->in_rw_trx_list);
-	ut_ad(!trx_is_autocommit_non_locking(trx));
+	ut_ad(!trx->is_autocommit_non_locking());
 	ut_ad(!trx->read_only);
 
 	if (high_level_read_only) {