MDEV-12353 preparation: Clean up mtr_t

mtr_t::Impl, mtr_t::Command: Merge to mtr_t.

MTR_MAGIC_N: Remove.

MTR_STATE_COMMITTING: Remove. This state was only being set
internally during mtr_t::commit().

mtr_t::Command::m_locks_released: Remove (set-and-never-read member).

mtr_t::Command::m_start_lsn: Replaced with the return value of
finish_write() and a parameter to release_blocks().

mtr_t::Command::m_end_lsn: Removed as a duplicate of mtr_t::m_commit_lsn.

mtr_t::Command::prepare_write(): Replace a switch () with a
comparison against 0. Only 2 m_log_mode are allowed.

storage/innobase/include/mtr0mtr.h

@@ -2,7 +2,7 @@
 
 Copyright (c) 1995, 2017, Oracle and/or its affiliates. All Rights Reserved.
 Copyright (c) 2012, Facebook Inc.
-Copyright (c) 2013, 2018, MariaDB Corporation.
+Copyright (c) 2013, 2019, 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
@@ -146,68 +146,7 @@ struct mtr_memo_slot_t {
 
 /** Mini-transaction handle and buffer */
 struct mtr_t {
-
-	/** State variables of the mtr */
-	struct Impl {
-
-		/** memo stack for locks etc. */
-		mtr_buf_t	m_memo;
-
-		/** mini-transaction log */
-		mtr_buf_t	m_log;
-
-		/** true if mtr has made at least one buffer pool page dirty */
-		bool		m_made_dirty;
-
-		/** true if inside ibuf changes */
-		bool		m_inside_ibuf;
-
-		/** true if the mini-transaction modified buffer pool pages */
-		bool		m_modifications;
-
-		/** Count of how many page initial log records have been
-		written to the mtr log */
-		ib_uint32_t	m_n_log_recs;
-
-		/** specifies which operations should be logged; default
-		value MTR_LOG_ALL */
-		mtr_log_t	m_log_mode;
-#ifdef UNIV_DEBUG
-		/** Persistent user tablespace associated with the
-		mini-transaction, or 0 (TRX_SYS_SPACE) if none yet */
-		ulint		m_user_space_id;
-#endif /* UNIV_DEBUG */
-		/** User tablespace that is being modified by the
-		mini-transaction */
-		fil_space_t*	m_user_space;
-		/** Undo tablespace that is being modified by the
-		mini-transaction */
-		fil_space_t*	m_undo_space;
-		/** System tablespace if it is being modified by the
-		mini-transaction */
-		fil_space_t*	m_sys_space;
-
-		/** State of the transaction */
-		mtr_state_t	m_state;
-
-		/** Flush Observer */
-		FlushObserver*	m_flush_observer;
-
-#ifdef UNIV_DEBUG
-		/** For checking corruption. */
-		ulint		m_magic_n;
-#endif /* UNIV_DEBUG */
-
-		/** Owning mini-transaction */
-		mtr_t*		m_mtr;
-	};
-
-	mtr_t()
-	{
-		m_impl.m_state = MTR_STATE_INIT;
-	}
-
-	~mtr_t() { }
+	mtr_t() : m_state(MTR_STATE_INIT) {}
 
 	/** Release the free extents that was reserved using
 	fsp_reserve_free_extents().  This is equivalent to calling
@@ -236,14 +175,7 @@ struct mtr_t {
 
 	/** Return current size of the buffer.
 	@return	savepoint */
-	ulint get_savepoint() const
-		MY_ATTRIBUTE((warn_unused_result))
-	{
-		ut_ad(is_active());
-		ut_ad(m_impl.m_magic_n == MTR_MAGIC_N);
-
-		return(m_impl.m_memo.size());
-	}
+	ulint get_savepoint() const {ut_ad(is_active()); return m_memo.size();}
 
 	/** Release the (index tree) s-latch stored in an mtr memo after a
 	savepoint.
@@ -279,10 +211,10 @@ struct mtr_t {
 	@return the system tablespace */
 	fil_space_t* set_sys_modified()
 	{
-		if (!m_impl.m_sys_space) {
+		if (!m_sys_space) {
 			lookup_sys_space();
 		}
-		return(m_impl.m_sys_space);
+		return m_sys_space;
 	}
 
 	/** Copy the tablespaces associated with the mini-transaction
@@ -291,15 +223,15 @@ struct mtr_t {
 	the same set of tablespaces as this one */
 	void set_spaces(const mtr_t& mtr)
 	{
-		ut_ad(!m_impl.m_user_space_id);
-		ut_ad(!m_impl.m_user_space);
-		ut_ad(!m_impl.m_undo_space);
-		ut_ad(!m_impl.m_sys_space);
-
-		ut_d(m_impl.m_user_space_id = mtr.m_impl.m_user_space_id);
-		m_impl.m_user_space = mtr.m_impl.m_user_space;
-		m_impl.m_undo_space = mtr.m_impl.m_undo_space;
-		m_impl.m_sys_space = mtr.m_impl.m_sys_space;
+		ut_ad(!m_user_space_id);
+		ut_ad(!m_user_space);
+		ut_ad(!m_undo_space);
+		ut_ad(!m_sys_space);
+
+		ut_d(m_user_space_id = mtr.m_user_space_id);
+		m_user_space = mtr.m_user_space;
+		m_undo_space = mtr.m_undo_space;
+		m_sys_space = mtr.m_sys_space;
 	}
 
 	/** Set the tablespace associated with the mini-transaction
@@ -308,13 +240,13 @@ struct mtr_t {
 	@return	the tablespace */
 	fil_space_t* set_named_space(ulint space_id)
 	{
-		ut_ad(!m_impl.m_user_space_id);
-		ut_d(m_impl.m_user_space_id = space_id);
+		ut_ad(!m_user_space_id);
+		ut_d(m_user_space_id = space_id);
 		if (!space_id) {
 			return(set_sys_modified());
 		} else {
 			lookup_user_space(space_id);
-			return(m_impl.m_user_space);
+			return m_user_space;
 		}
 	}
 
@@ -381,18 +313,12 @@ struct mtr_t {
 	void release_page(const void* ptr, mtr_memo_type_t type);
 
 	/** Note that the mini-transaction has modified data. */
-	void set_modified()
-	{
-		m_impl.m_modifications = true;
-	}
+	void set_modified() { m_modifications = true; }
 
 	/** Set the state to not-modified. This will not log the
 	changes.  This is only used during redo log apply, to avoid
 	logging the changes. */
-	void discard_modifications()
-	{
-		m_impl.m_modifications = false;
-	}
+	void discard_modifications() { m_modifications = false; }
 
 	/** Get the LSN of commit().
 	@return the commit LSN
@@ -404,45 +330,28 @@ struct mtr_t {
 	}
 
 	/** Note that we are inside the change buffer code. */
-	void enter_ibuf()
-	{
-		m_impl.m_inside_ibuf = true;
-	}
+	void enter_ibuf() { m_inside_ibuf = true; }
 
 	/** Note that we have exited from the change buffer code. */
-	void exit_ibuf()
-	{
-		m_impl.m_inside_ibuf = false;
-	}
+	void exit_ibuf() { m_inside_ibuf = false; }
 
 	/** @return true if we are inside the change buffer code */
-	bool is_inside_ibuf() const
-	{
-		return(m_impl.m_inside_ibuf);
-	}
+	bool is_inside_ibuf() const { return m_inside_ibuf; }
 
 	/*
 	@return true if the mini-transaction is active */
-	bool is_active() const
-	{
-		return(m_impl.m_state == MTR_STATE_ACTIVE);
-	}
+	bool is_active() const { return m_state == MTR_STATE_ACTIVE; }
 
 	/** Get flush observer
 	@return flush observer */
-	FlushObserver* get_flush_observer() const
-	{
-		return(m_impl.m_flush_observer);
-	}
+	FlushObserver* get_flush_observer() const { return m_flush_observer; }
 
 	/** Set flush observer
 	@param[in]	observer	flush observer */
 	void set_flush_observer(FlushObserver*	observer)
 	{
-		ut_ad(observer == NULL
-		      || m_impl.m_log_mode == MTR_LOG_NO_REDO);
-
-		m_impl.m_flush_observer = observer;
+		ut_ad(observer == NULL || m_log_mode == MTR_LOG_NO_REDO);
+		m_flush_observer = observer;
 	}
 
 #ifdef UNIV_DEBUG
@@ -482,65 +391,31 @@ struct mtr_t {
 	void print() const;
 
 	/** @return true if the mini-transaction has committed */
-	bool has_committed() const
-	{
-		return(m_impl.m_state == MTR_STATE_COMMITTED);
-	}
-
-	/** @return true if the mini-transaction is committing */
-	bool is_committing() const
-	{
-		return(m_impl.m_state == MTR_STATE_COMMITTING);
-	}
+	bool has_committed() const { return m_state == MTR_STATE_COMMITTED; }
 
 	/** @return true if mini-transaction contains modifications. */
-	bool has_modifications() const
-	{
-		return(m_impl.m_modifications);
-	}
+	bool has_modifications() const { return m_modifications; }
 
 	/** @return the memo stack */
-	const mtr_buf_t* get_memo() const
-	{
-		return(&m_impl.m_memo);
-	}
+	const mtr_buf_t* get_memo() const { return &m_memo; }
 
 	/** @return the memo stack */
-	mtr_buf_t* get_memo()
-	{
-		return(&m_impl.m_memo);
-	}
+	mtr_buf_t* get_memo() { return &m_memo; }
 #endif /* UNIV_DEBUG */
 
 	/** @return true if a record was added to the mini-transaction */
-	bool is_dirty() const
-	{
-		return(m_impl.m_made_dirty);
-	}
+	bool is_dirty() const { return m_made_dirty; }
 
 	/** Note that a record has been added to the log */
-	void added_rec()
-	{
-		++m_impl.m_n_log_recs;
-	}
+	void added_rec() { ++m_n_log_recs; }
 
 	/** Get the buffered redo log of this mini-transaction.
 	@return	redo log */
-	const mtr_buf_t* get_log() const
-	{
-		ut_ad(m_impl.m_magic_n == MTR_MAGIC_N);
-
-		return(&m_impl.m_log);
-	}
+	const mtr_buf_t* get_log() const { return &m_log; }
 
 	/** Get the buffered redo log of this mini-transaction.
 	@return	redo log */
-	mtr_buf_t* get_log()
-	{
-		ut_ad(m_impl.m_magic_n == MTR_MAGIC_N);
-
-		return(&m_impl.m_log);
-	}
+	mtr_buf_t* get_log() { return &m_log; }
 
 	/** Push an object to an mtr memo stack.
 	@param object	object
@@ -560,15 +435,60 @@ struct mtr_t {
 	@param[in]	space_id	tablespace ID  */
 	void lookup_user_space(ulint space_id);
 
-	class Command;
+	/** Prepare to write the mini-transaction log to the redo log buffer.
+	@return number of bytes to write in finish_write() */
+	inline ulint prepare_write();
 
-	friend class Command;
+	/** Append the redo log records to the redo log buffer.
+	@param[in]	len	number of bytes to write
+	@return start_lsn */
+	inline lsn_t finish_write(ulint len);
 
-private:
-	Impl			m_impl;
+	/** Release the resources */
+	inline void release_resources();
+
+	/** memo stack for locks etc. */
+	mtr_buf_t	m_memo;
+
+	/** mini-transaction log */
+	mtr_buf_t	m_log;
+
+	/** true if mtr has made at least one buffer pool page dirty */
+	bool		m_made_dirty;
+
+	/** true if inside ibuf changes */
+	bool		m_inside_ibuf;
+
+	/** true if the mini-transaction modified buffer pool pages */
+	bool		m_modifications;
+
+	/** Count of how many page initial log records have been
+	written to the mtr log */
+	ib_uint32_t	m_n_log_recs;
+
+	/** specifies which operations should be logged; default
+	value MTR_LOG_ALL */
+	mtr_log_t	m_log_mode;
+#ifdef UNIV_DEBUG
+	/** Persistent user tablespace associated with the
+	mini-transaction, or 0 (TRX_SYS_SPACE) if none yet */
+	ulint		m_user_space_id;
+#endif /* UNIV_DEBUG */
+	/** User tablespace that is being modified by the mini-transaction */
+	fil_space_t*	m_user_space;
+	/** Undo tablespace that is being modified by the mini-transaction */
+	fil_space_t*	m_undo_space;
+	/** System tablespace if being modified by the mini-transaction */
+	fil_space_t*	m_sys_space;
+
+	/** State of the transaction */
+	mtr_state_t	m_state;
+
+	/** Flush Observer */
+	FlushObserver*	m_flush_observer;
 
 	/** LSN at commit time */
-	volatile lsn_t		m_commit_lsn;
+	lsn_t		m_commit_lsn;
 };
 
 #include "mtr0mtr.ic"

storage/innobase/include/mtr0mtr.ic

@@ -49,7 +49,6 @@ mtr_t::memo_push(void* object, mtr_memo_type_t type)
 	ut_ad(object != NULL);
 	ut_ad(type >= MTR_MEMO_PAGE_S_FIX);
 	ut_ad(type <= MTR_MEMO_SX_LOCK);
-	ut_ad(m_impl.m_magic_n == MTR_MAGIC_N);
 	ut_ad(ut_is_2pow(type));
 
 	/* If this mtr has x-fixed a clean page then we set
@@ -58,15 +57,13 @@ mtr_t::memo_push(void* object, mtr_memo_type_t type)
 	can insert the dirtied page to the flush list. */
 
 	if ((type == MTR_MEMO_PAGE_X_FIX || type == MTR_MEMO_PAGE_SX_FIX)
-	    && !m_impl.m_made_dirty) {
+	    && !m_made_dirty) {
 
-		m_impl.m_made_dirty = is_block_dirtied(
+		m_made_dirty = is_block_dirtied(
 			reinterpret_cast<const buf_block_t*>(object));
 	}
 
-	mtr_memo_slot_t*	slot;
-
-	slot = m_impl.m_memo.push<mtr_memo_slot_t*>(sizeof(*slot));
+	mtr_memo_slot_t* slot = m_memo.push<mtr_memo_slot_t*>(sizeof(*slot));
 
 	slot->type = type;
 	slot->object = object;
@@ -81,11 +78,9 @@ mtr_t::release_s_latch_at_savepoint(
 	rw_lock_t*	lock)
 {
 	ut_ad(is_active());
-	ut_ad(m_impl.m_magic_n == MTR_MAGIC_N);
-
-	ut_ad(m_impl.m_memo.size() > savepoint);
+	ut_ad(m_memo.size() > savepoint);
 
-	mtr_memo_slot_t* slot = m_impl.m_memo.at<mtr_memo_slot_t*>(savepoint);
+	mtr_memo_slot_t* slot = m_memo.at<mtr_memo_slot_t*>(savepoint);
 
 	ut_ad(slot->object == lock);
 	ut_ad(slot->type == MTR_MEMO_S_LOCK);
@@ -104,8 +99,7 @@ mtr_t::sx_latch_at_savepoint(
 	buf_block_t*	block)
 {
 	ut_ad(is_active());
-	ut_ad(m_impl.m_magic_n == MTR_MAGIC_N);
-	ut_ad(m_impl.m_memo.size() > savepoint);
+	ut_ad(m_memo.size() > savepoint);
 
 	ut_ad(!memo_contains_flagged(
 			block,
@@ -113,9 +107,7 @@ mtr_t::sx_latch_at_savepoint(
 			| MTR_MEMO_PAGE_X_FIX
 			| MTR_MEMO_PAGE_SX_FIX));
 
-	mtr_memo_slot_t*	slot;
-
-	slot = m_impl.m_memo.at<mtr_memo_slot_t*>(savepoint);
+	mtr_memo_slot_t* slot = m_memo.at<mtr_memo_slot_t*>(savepoint);
 
 	ut_ad(slot->object == block);
 
@@ -124,8 +116,8 @@ mtr_t::sx_latch_at_savepoint(
 
 	rw_lock_sx_lock(&block->lock);
 
-	if (!m_impl.m_made_dirty) {
-		m_impl.m_made_dirty = is_block_dirtied(block);
+	if (!m_made_dirty) {
+		m_made_dirty = is_block_dirtied(block);
 	}
 
 	slot->type = MTR_MEMO_PAGE_SX_FIX;
@@ -140,8 +132,7 @@ mtr_t::x_latch_at_savepoint(
 	buf_block_t*	block)
 {
 	ut_ad(is_active());
-	ut_ad(m_impl.m_magic_n == MTR_MAGIC_N);
-	ut_ad(m_impl.m_memo.size() > savepoint);
+	ut_ad(m_memo.size() > savepoint);
 
 	ut_ad(!memo_contains_flagged(
 			block,
@@ -149,9 +140,7 @@ mtr_t::x_latch_at_savepoint(
 			| MTR_MEMO_PAGE_X_FIX
 			| MTR_MEMO_PAGE_SX_FIX));
 
-	mtr_memo_slot_t*	slot;
-
-	slot = m_impl.m_memo.at<mtr_memo_slot_t*>(savepoint);
+	mtr_memo_slot_t* slot = m_memo.at<mtr_memo_slot_t*>(savepoint);
 
 	ut_ad(slot->object == block);
 
@@ -160,8 +149,8 @@ mtr_t::x_latch_at_savepoint(
 
 	rw_lock_x_lock(&block->lock);
 
-	if (!m_impl.m_made_dirty) {
-		m_impl.m_made_dirty = is_block_dirtied(block);
+	if (!m_made_dirty) {
+		m_made_dirty = is_block_dirtied(block);
 	}
 
 	slot->type = MTR_MEMO_PAGE_X_FIX;
@@ -176,11 +165,8 @@ mtr_t::release_block_at_savepoint(
 	buf_block_t*	block)
 {
 	ut_ad(is_active());
-	ut_ad(m_impl.m_magic_n == MTR_MAGIC_N);
-
-	mtr_memo_slot_t*	slot;
 
-	slot = m_impl.m_memo.at<mtr_memo_slot_t*>(savepoint);
+	mtr_memo_slot_t* slot = m_memo.at<mtr_memo_slot_t*>(savepoint);
 
 	ut_a(slot->object == block);
 
@@ -198,10 +184,10 @@ Gets the logging mode of a mini-transaction.
 mtr_log_t
 mtr_t::get_log_mode() const
 {
-	ut_ad(m_impl.m_log_mode >= MTR_LOG_ALL);
-	ut_ad(m_impl.m_log_mode <= MTR_LOG_SHORT_INSERTS);
+	ut_ad(m_log_mode >= MTR_LOG_ALL);
+	ut_ad(m_log_mode <= MTR_LOG_SHORT_INSERTS);
 
-	return(m_impl.m_log_mode);
+	return m_log_mode;
 }
 
 /**
@@ -214,7 +200,7 @@ mtr_t::set_log_mode(mtr_log_t mode)
 	ut_ad(mode >= MTR_LOG_ALL);
 	ut_ad(mode <= MTR_LOG_SHORT_INSERTS);
 
-	const mtr_log_t	old_mode = m_impl.m_log_mode;
+	const mtr_log_t	old_mode = m_log_mode;
 
 	switch (old_mode) {
 	case MTR_LOG_NO_REDO:
@@ -233,9 +219,8 @@ mtr_t::set_log_mode(mtr_log_t mode)
 	case MTR_LOG_ALL:
 		/* MTR_LOG_NO_REDO can only be set before generating
 		any redo log records. */
-		ut_ad(mode != MTR_LOG_NO_REDO
-		      || m_impl.m_n_log_recs == 0);
-		m_impl.m_log_mode = mode;
+		ut_ad(mode != MTR_LOG_NO_REDO || m_n_log_recs == 0);
+		m_log_mode = mode;
 		return(old_mode);
 	}
 

storage/innobase/include/mtr0types.h

 /*****************************************************************************
 
 Copyright (c) 1995, 2015, Oracle and/or its affiliates. All Rights Reserved.
-Copyright (c) 2017, MariaDB Corporation.
+Copyright (c) 2017, 2019, 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
@@ -36,18 +36,18 @@ struct mtr_t;
 /** Logging modes for a mini-transaction */
 enum mtr_log_t {
 	/** Default mode: log all operations modifying disk-based data */
-	MTR_LOG_ALL = 21,
+	MTR_LOG_ALL = 0,
 
 	/** Log no operations and dirty pages are not added to the flush list.
 	Set when applying log in crash recovery or when a modification of a
 	ROW_FORMAT=COMPRESSED page is attempted. */
-	MTR_LOG_NONE = 22,
+	MTR_LOG_NONE,
 
 	/** Don't generate REDO log but add dirty pages to flush list */
-	MTR_LOG_NO_REDO = 23,
+	MTR_LOG_NO_REDO,
 
 	/** Inserts are logged in a shorter form */
-	MTR_LOG_SHORT_INSERTS = 24
+	MTR_LOG_SHORT_INSERTS
 };
 
 /** @name Log item types
@@ -267,15 +267,10 @@ enum mtr_memo_type_t {
 };
 #endif /* !UNIV_CHECKSUM */
 
-#ifdef UNIV_DEBUG
-# define MTR_MAGIC_N		54551
-#endif /* UNIV_DEBUG */
-
 enum mtr_state_t {
 	MTR_STATE_INIT = 0,
-	MTR_STATE_ACTIVE = 12231,
-	MTR_STATE_COMMITTING = 56456,
-	MTR_STATE_COMMITTED = 34676
+	MTR_STATE_ACTIVE,
+	MTR_STATE_COMMITTED
 };
 
 #endif /* mtr0types_h */