Cleanup: Remove trx_get_id_for_print()

Any transaction that has requested a lock must have trx->id!=0.

trx_print_low(): Distinguish non-locking or inactive transaction
objects by displaying the pointer in parentheses.

fill_trx_row(): Do not try to map trx->id to a pointer-based value.

Author: dr-m

storage/innobase/btr/btr0cur.cc

@@ -5377,7 +5377,7 @@ btr_cur_del_mark_set_clust_rec(
 	DBUG_LOG("ib_cur",
 		 "delete-mark clust " << index->table->name
 		 << " (" << index->id << ") by "
-		 << ib::hex(trx_get_id_for_print(trx)) << ": "
+		 << ib::hex(trx->id) << ": "
 		 << rec_printer(rec, offsets).str());
 
 	if (dict_index_is_online_ddl(index)) {

storage/innobase/include/trx0trx.h

@@ -342,19 +342,6 @@ trx_get_que_state_str(
 /*==================*/
 	const trx_t*	trx);	/*!< in: transaction */
 
-/** Retreieves the transaction ID.
-In a given point in time it is guaranteed that IDs of the running
-transactions are unique. The values returned by this function for readonly
-transactions may be reused, so a subsequent RO transaction may get the same ID
-as a RO transaction that existed in the past. The values returned by this
-function should be used for printing purposes only.
-@param[in]	trx	transaction whose id to retrieve
-@return transaction id */
-UNIV_INLINE
-trx_id_t
-trx_get_id_for_print(
-	const trx_t*	trx);
-
 /** Create the trx_t pool */
 void
 trx_pool_init();

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
@@ -106,42 +106,6 @@ trx_get_que_state_str(
 	}
 }
 
-/** Retreieves the transaction ID.
-In a given point in time it is guaranteed that IDs of the running
-transactions are unique. The values returned by this function for readonly
-transactions may be reused, so a subsequent RO transaction may get the same ID
-as a RO transaction that existed in the past. The values returned by this
-function should be used for printing purposes only.
-@param[in]	trx	transaction whose id to retrieve
-@return transaction id */
-UNIV_INLINE
-trx_id_t
-trx_get_id_for_print(
-	const trx_t*	trx)
-{
-	/* Readonly and transactions whose intentions are unknown (whether
-	they will eventually do a WRITE) don't have trx_t::id assigned (it is
-	0 for those transactions). Transaction IDs in
-	innodb_trx.trx_id,
-	innodb_locks.lock_id,
-	innodb_locks.lock_trx_id,
-	innodb_lock_waits.requesting_trx_id,
-	innodb_lock_waits.blocking_trx_id should match because those tables
-	could be used in an SQL JOIN on those columns. Also trx_t::id is
-	printed by SHOW ENGINE INNODB STATUS, and in logs, so we must have the
-	same value printed everywhere consistently. */
-
-	/* DATA_TRX_ID_LEN is the storage size in bytes. */
-	static const trx_id_t	max_trx_id
-		= (1ULL << (DATA_TRX_ID_LEN * CHAR_BIT)) - 1;
-
-	ut_ad(trx->id <= max_trx_id);
-
-	return(trx->id != 0
-	       ? trx->id
-	       : reinterpret_cast<trx_id_t>(trx) | (max_trx_id + 1));
-}
-
 /**********************************************************************//**
 Determine if a transaction is a dictionary operation.
 @return dictionary operation mode */

storage/innobase/lock/lock0lock.cc

@@ -1757,7 +1757,7 @@ static void lock_grant_after_reset(lock_t* lock)
 	}
 
 	DBUG_PRINT("ib_lock", ("wait for trx " TRX_ID_FMT " ends",
-			       trx_get_id_for_print(lock->trx)));
+			       lock->trx->id));
 
 	/* If we are resolving a deadlock by choosing another transaction
 	as a victim, then our original transaction may not be in the
@@ -3928,7 +3928,7 @@ lock_table_print(FILE* file, const lock_t* lock)
 	fputs("TABLE LOCK table ", file);
 	ut_print_name(file, lock->trx,
 		      lock->un_member.tab_lock.table->name.m_name);
-	fprintf(file, " trx id " TRX_ID_FMT, trx_get_id_for_print(lock->trx));
+	fprintf(file, " trx id " TRX_ID_FMT, lock->trx->id);
 
 	if (lock_get_mode(lock) == LOCK_S) {
 		fputs(" lock mode S", file);
@@ -3971,7 +3971,7 @@ static void lock_rec_print(FILE* file, const lock_t* lock, mtr_t& mtr)
 		lock_rec_get_n_bits(lock),
 		lock->index->name());
 	ut_print_name(file, lock->trx, lock->index->table->name.m_name);
-	fprintf(file, " trx id " TRX_ID_FMT, trx_get_id_for_print(lock->trx));
+	fprintf(file, " trx id " TRX_ID_FMT, lock->trx->id);
 
 	if (lock_get_mode(lock) == LOCK_S) {
 		fputs(" lock mode S", file);
@@ -5458,17 +5458,6 @@ lock_get_type(
 	return(lock_get_type_low(lock));
 }
 
-/*******************************************************************//**
-Gets the id of the transaction owning a lock.
-@return transaction id */
-trx_id_t
-lock_get_trx_id(
-/*============*/
-	const lock_t*	lock)	/*!< in: lock */
-{
-	return(trx_get_id_for_print(lock->trx));
-}
-
 /*******************************************************************//**
 Gets the table on which the lock is.
 @return table */

storage/innobase/trx/trx0i_s.cc

@@ -424,7 +424,7 @@ fill_trx_row(
 
 	lock_sys.mutex_assert_locked();
 
-	row->trx_id = trx_get_id_for_print(trx);
+	row->trx_id = trx->id;
 	row->trx_started = trx->start_time;
 	row->trx_state = trx_get_que_state_str(trx);
 	row->requested_lock_row = requested_lock_row;

storage/innobase/trx/trx0trx.cc

@@ -1766,7 +1766,11 @@ trx_print_low(
 	ibool		newline;
 	const char*	op_info;
 
-	fprintf(f, "TRANSACTION " TRX_ID_FMT, trx_get_id_for_print(trx));
+	if (const trx_id_t id = trx->id) {
+		fprintf(f, "TRANSACTION " TRX_ID_FMT, trx->id);
+	} else {
+		fprintf(f, "TRANSACTION (%p)", trx);
+	}
 
 	switch (trx->state) {
 	case TRX_STATE_NOT_STARTED: