Simulated AIO handler for reaping IO requests. More...

Public Member Functions
	SimulatedAIOHandler (AIO *array, ulint segment)
	Constructor. More...

	~SimulatedAIOHandler ()
	Destructor. More...

void	init (ulint n_slots)
	Reset the state of the handler. More...

Slot *	check_completed (ulint *n_reserved)
	Check if there is a slot for which the i/o has already been done. More...

bool	select (std::chrono::steady_clock::time_point current_time)
	If there are at least 2 seconds old requests, then pick the oldest one to prevent starvation. More...

void	merge ()
	Check if there are several consecutive blocks to read or write. More...

ulint	allocate_buffer ()
	We have now collected n_consecutive I/O requests in the array; allocate a single buffer which can hold all data, and perform the I/O. More...

void	copy_to_buffer (ulint len)
	We have to compress the individual pages and punch holes in them on a page by page basis when writing to tables that can be compressed at the IO level. More...

void	io ()
	Do the I/O with ordinary, synchronous i/o functions: More...

void	io_complete ()
	Do the decompression of the pages read in. More...

void	done ()
	Mark the i/os done in slots. More...

Slot *	first_slot ()

ulint	check_pending (ulint global_segment, os_event_t event)
	Wait for I/O requests. More...

Private Types
typedef std::vector< Slot * >	slots_t

Private Member Functions
void	read (Slot *slot)
	Do the file read. More...

void	write (Slot *slot)
	Do the file write. More...

bool	adjacent (const Slot s1, const Slot s2) const

bool	merge_adjacent (Slot *&current)

bool	select_lowest_offset ()
	There were no old requests. More...

bool	select_oldest (std::chrono::steady_clock::time_point current_time)
	Select the oldest slot in the array if there are any older than 2s. More...

Private Attributes
ulint	m_n_elems

AIO *	m_array

ulint	m_n_slots

ulint	m_segment

slots_t	m_slots

byte *	m_buf

Detailed Description

Simulated AIO handler for reaping IO requests.

Member Typedef Documentation

◆ slots_t

typedef std::vector<Slot *> SimulatedAIOHandler::slots_t

private

Constructor & Destructor Documentation

◆ SimulatedAIOHandler()

SimulatedAIOHandler::SimulatedAIOHandler	(	AIO *	array,
		ulint	segment
	)

inline

Constructor.

Parameters

[in,out]	array	The AIO array
[in]	segment	Local segment in the array

◆ ~SimulatedAIOHandler()

SimulatedAIOHandler::~SimulatedAIOHandler ( )

inline

Destructor.

Member Function Documentation

◆ adjacent()

bool SimulatedAIOHandler::adjacent	(	const Slot *	s1,
		const Slot *	s2
	)		const

inlineprivate

Returns: true if the slots are adjacent and can be merged

◆ allocate_buffer()

ulint SimulatedAIOHandler::allocate_buffer ( )

inline

We have now collected n_consecutive I/O requests in the array; allocate a single buffer which can hold all data, and perform the I/O.

Returns: the length of the buffer

◆ check_completed()

Slot * SimulatedAIOHandler::check_completed ( ulint * n_reserved )

inline

Check if there is a slot for which the i/o has already been done.

Parameters

[out] n_reserved Number of reserved slots

Returns: the first completed slot that is found.

◆ check_pending()

ulint SimulatedAIOHandler::check_pending	(	ulint	global_segment,
		os_event_t	event
	)

Wait for I/O requests.

Parameters

[in]	global_segment	The global segment
[in,out]	event	Wait on event if no active requests

Returns: the number of slots; the number of slots

◆ copy_to_buffer()

void SimulatedAIOHandler::copy_to_buffer ( ulint len )

inline

We have to compress the individual pages and punch holes in them on a page by page basis when writing to tables that can be compressed at the IO level.

Parameters

[in] len Value returned by allocate_buffer

◆ done()

void SimulatedAIOHandler::done ( )

inline

Mark the i/os done in slots.

◆ first_slot()

Slot * SimulatedAIOHandler::first_slot ( )

inline

Returns: the first slot in the consecutive array

◆ init()

void SimulatedAIOHandler::init ( ulint n_slots )

inline

Reset the state of the handler.

Parameters

[in] n_slots Number of pending AIO operations supported

◆ io()

void SimulatedAIOHandler::io ( )

inline

Do the I/O with ordinary, synchronous i/o functions:

◆ io_complete()

void SimulatedAIOHandler::io_complete ( )

inline

Do the decompression of the pages read in.

◆ merge()

void SimulatedAIOHandler::merge ( )

inline

Check if there are several consecutive blocks to read or write.

Merge them if found.

◆ merge_adjacent()

bool SimulatedAIOHandler::merge_adjacent ( Slot *& current )

inlineprivate

Returns: true if merge limit reached or no adjacent slots found.

◆ read()

void SimulatedAIOHandler::read ( Slot * slot )

inlineprivate

Do the file read.

Parameters

[in,out] slot Slot that has the IO context

◆ select()

bool SimulatedAIOHandler::select ( std::chrono::steady_clock::time_point current_time )

inline

If there are at least 2 seconds old requests, then pick the oldest one to prevent starvation.

If several requests have the same age, then pick the one at the lowest offset.

Parameters

[in] current_time Time of start of the slot selection.

Returns: true if request was selected

◆ select_lowest_offset()

bool SimulatedAIOHandler::select_lowest_offset ( )

inlineprivate

There were no old requests.

Look for an I/O request at the lowest offset in the array (we ignore the high 32 bits of the offset in these heuristics)

◆ select_oldest()

bool SimulatedAIOHandler::select_oldest ( std::chrono::steady_clock::time_point current_time )

inlineprivate

Select the oldest slot in the array if there are any older than 2s.

Parameters

[in] current_time Time of start of the slot selection.

Returns: true if any slot older than 2s is found

◆ write()

void SimulatedAIOHandler::write ( Slot * slot )

inlineprivate

Do the file write.

Parameters

[in,out] slot Slot that has the IO context

Member Data Documentation

◆ m_array

AIO* SimulatedAIOHandler::m_array

private

◆ m_buf

byte* SimulatedAIOHandler::m_buf

private

◆ m_n_elems

ulint SimulatedAIOHandler::m_n_elems

private

◆ m_n_slots

ulint SimulatedAIOHandler::m_n_slots

private

◆ m_segment

ulint SimulatedAIOHandler::m_segment

private

◆ m_slots

slots_t SimulatedAIOHandler::m_slots

private

The documentation for this class was generated from the following file:

storage/innobase/os/os0file.cc

Public Member Functions

Private Types

Private Member Functions

Private Attributes

Detailed Description

Member Typedef Documentation

◆ slots_t

Constructor & Destructor Documentation

◆ SimulatedAIOHandler()

◆ ~SimulatedAIOHandler()

Member Function Documentation

◆ adjacent()

◆ allocate_buffer()

◆ check_completed()

◆ check_pending()

◆ copy_to_buffer()

◆ done()

◆ first_slot()

◆ init()

◆ io()

◆ io_complete()

◆ merge()

◆ merge_adjacent()

◆ read()

◆ select()

◆ select_lowest_offset()

◆ select_oldest()

◆ write()

Member Data Documentation

◆ m_array

◆ m_buf

◆ m_n_elems

◆ m_n_slots

◆ m_segment

◆ m_slots