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.

storage/innobase/handler/ha_innodb.cc

@@ -4123,7 +4123,7 @@ 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 */
@@ -7610,7 +7610,7 @@ ha_innobase::write_row(
 	ut_a(m_prebuilt->trx == trx);
 
 	if (!trx_is_started(trx)) {
-		++trx->will_lock;
+		trx->will_lock = true;
 	}
 
 	ins_mode_t	vers_set_fields;
@@ -8369,7 +8369,7 @@ 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) {
@@ -8540,7 +8540,7 @@ 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) {
@@ -9377,7 +9377,7 @@ 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));
@@ -9443,7 +9443,7 @@ 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;
@@ -12972,7 +12972,7 @@ 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;
 }
 
@@ -13296,13 +13296,7 @@ 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 */
 
@@ -13481,14 +13475,7 @@ 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;
 
@@ -13532,7 +13519,7 @@ 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:
@@ -13642,8 +13629,7 @@ 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);
@@ -13728,9 +13714,7 @@ 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);
@@ -15602,7 +15586,7 @@ 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);
@@ -15828,7 +15812,7 @@ 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);
@@ -15867,7 +15851,7 @@ 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);
@@ -16540,7 +16524,7 @@ 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);

storage/innobase/handler/handler0alter.cc

@@ -2352,7 +2352,7 @@ ha_innobase::check_if_supported_inplace_alter(
 		}
 	}
 
-	m_prebuilt->trx->will_lock++;
+	m_prebuilt->trx->will_lock = true;
 
 	/* When changing a NULL column to NOT NULL and specifying a
 	DEFAULT value, ensure that the DEFAULT expression is a constant.
@@ -11458,7 +11458,6 @@ ha_innobase::commit_inplace_alter_table(
 				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",

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, 2020, 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
@@ -151,7 +151,7 @@ struct i_s_trx_row_t {
 	bool		trx_is_read_only;
 					/*!< trx_t::read_only */
 	bool		trx_is_autocommit_non_locking;
-					/*!< trx_is_autocommit_non_locking(trx)
+					/*!< trx:t::is_autocommit_non_locking()
 					*/
 };
 

storage/innobase/include/trx0sys.h

@@ -513,7 +513,7 @@ class rw_trx_hash_t
   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));
+    ut_ad(!trx->is_autocommit_non_locking());
     /* trx->state can be anything except TRX_STATE_NOT_STARTED */
     mutex_enter(&trx->mutex);
     ut_ad(trx_state_eq(trx, TRX_STATE_ACTIVE) ||

storage/innobase/include/trx0trx.h

@@ -393,64 +393,6 @@ 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)))
-
-/**
-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)
-
-#ifdef UNIV_DEBUG
-/*******************************************************************//**
-Assert that an autocommit non-locking select cannot be in the
-rw_trx_hash and that it is a read-only transaction.
-The transaction must have mysql_thd assigned. */
-# 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)->mysql_thd);				\
-			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_hash and that it is a read-only transaction.
-The transaction must have mysql_thd assigned. */
-# 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;
 
 /*******************************************************************//**
@@ -947,16 +889,15 @@ struct trx_t : ilist_node<> {
 	/*------------------------------*/
 	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
@@ -1103,11 +1044,13 @@ struct trx_t : ilist_node<> {
     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();
 };
 
 /**

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
@@ -49,11 +49,15 @@ trx_state_eq(
 	case TRX_STATE_PREPARED:
 	case TRX_STATE_PREPARED_RECOVERED:
 	case TRX_STATE_COMMITTED_IN_MEMORY:
-		ut_ad(!trx_is_autocommit_non_locking(trx));
+		ut_ad(!trx->is_autocommit_non_locking());
 		return(trx->state == state);
 
 	case TRX_STATE_ACTIVE:
-		assert_trx_nonlocking_or_in_list(trx);
+		if (trx->is_autocommit_non_locking()) {
+			ut_ad(!trx->is_recovered);
+			ut_ad(trx->read_only);
+			ut_ad(trx->mysql_thd);
+		}
 		return(state == trx->state);
 
 	case TRX_STATE_NOT_STARTED: