Schedules swapping of blocks and provides blocks for temporary storage. More...

#include <block_scheduler.h>

Inheritance diagram for stxxl::block_scheduler< SwappableBlockType >:

Collaboration diagram for stxxl::block_scheduler< SwappableBlockType >:

Classes
struct	prediction_sequence_element
Public Types
enum	block_scheduler_operation { op_acquire, op_acquire_uninitialized, op_release, op_release_dirty, op_deinitialize, op_initialize, op_extract_external_block }
typedef SwappableBlockType::internal_block_type	internal_block_type
typedef SwappableBlockType::external_block_type	external_block_type
typedef std::vector < SwappableBlockType > ::size_type	swappable_block_identifier_type
typedef std::deque < prediction_sequence_element >	prediction_sequence_type
Public Member Functions
	block_scheduler (const int_type max_internal_memory)
	create a block_scheduler with empty prediction sequence in simple mode.
	~block_scheduler ()
internal_block_type &	acquire (const swappable_block_identifier_type sbid, const bool uninitialized=false)
	Acquire the given block. Has to be in pairs with release. Pairs may be nested and interleaved.
void	release (const swappable_block_identifier_type sbid, const bool dirty)
	Release the given block. Has to be in pairs with acquire. Pairs may be nested and interleaved.
void	deinitialize (const swappable_block_identifier_type sbid)
	Drop all data in the given block, freeing in- and external memory.
void	initialize (const swappable_block_identifier_type sbid, external_block_type eblock)
	Initialize the swappable_block with the given external_block.
external_block_type	extract_external_block (const swappable_block_identifier_type sbid)
	deinitialize the swappable_block and return it's contents in an external_block.
bool	is_initialized (const swappable_block_identifier_type sbid) const
	check if the swappable_block is initialized
void	explicit_timestep ()
	Record a timestep in the prediction sequence to seperate consecutive acquire rsp. release-operations. Has an effect only in simulation mode.
internal_block_type &	get_internal_block (const swappable_block_identifier_type sbid) const
	Get a const reference to given block's data. Block has to be already acquired.
swappable_block_identifier_type	allocate_swappable_block ()
	Allocate an uninitialized swappable_block.
void	free_swappable_block (const swappable_block_identifier_type sbid)
	Free given no longer used temporary swappable_block.
bool	is_simulating () const
	Returns if simulation mode is on, i.e. if a prediction sequence is being recorded.
block_scheduler_algorithm < SwappableBlockType > *	switch_algorithm_to (block_scheduler_algorithm< SwappableBlockType > *new_algo)
	Switch the used algorithm, e.g. to simulation etc..
const prediction_sequence_type &	get_prediction_sequence () const
	get the prediction_sequence
void	flush ()
Protected Types
typedef int_type	time_type
Protected Member Functions
internal_block_type *	get_free_internal_block ()
	Get an internal_block from the freelist or a newly allocated one if available.
void	return_free_internal_block (internal_block_type *iblock)
	Return an internal_block to the freelist.
Protected Attributes
const int_type	max_internal_blocks
int_type	remaining_internal_blocks
std::stack< internal_block_type * >	internal_blocks_blocks
	Stores pointers to arrays of internal_blocks. Used to deallocate them only.
std::stack< internal_block_type * >	free_internal_blocks
	holds free internal_blocks with attributes reset
std::vector< SwappableBlockType >	swappable_blocks
	temporary blocks that will not be needed after algorithm termination
std::priority_queue < swappable_block_identifier_type, std::vector < swappable_block_identifier_type > , std::greater < swappable_block_identifier_type > >	free_swappable_blocks
	holds indices of free swappable_blocks with attributes reset
block_manager *	bm
block_scheduler_algorithm < SwappableBlockType > *	algo
Static Protected Attributes
static const int_type	max_internal_blocks_alloc_at_once = 128

Detailed Description

template<class SwappableBlockType>
class stxxl::block_scheduler< SwappableBlockType >

Schedules swapping of blocks and provides blocks for temporary storage.

In simple mode, it tries to save I/Os through caching only. In simulation mode, it records access patterns into a prediction sequence. The prediction sequence can then be used for prefetching in the (offline) execute mode. This will only work for algorithms with deterministic, data oblivious access patterns. In simulation mode, no I/O is performed; the data provided is accessible but undefined. In execute mode, it does caching, prefetching, and possibly other optimizations.

Template Parameters:

SwappableBlockType Type of swappable_blocks to manage. Can be some specialized subclass.

Examples:: containers/test_matrix.cpp.

Definition at line 246 of file block_scheduler.h.

Member Typedef Documentation

template<class SwappableBlockType >

typedef SwappableBlockType::external_block_type stxxl::block_scheduler< SwappableBlockType >::external_block_type

Definition at line 257 of file block_scheduler.h.

template<class SwappableBlockType >

typedef SwappableBlockType::internal_block_type stxxl::block_scheduler< SwappableBlockType >::internal_block_type

Definition at line 256 of file block_scheduler.h.

template<class SwappableBlockType >

typedef std::deque<prediction_sequence_element> stxxl::block_scheduler< SwappableBlockType >::prediction_sequence_type

Definition at line 294 of file block_scheduler.h.

template<class SwappableBlockType >

typedef std::vector<SwappableBlockType>::size_type stxxl::block_scheduler< SwappableBlockType >::swappable_block_identifier_type

Definition at line 258 of file block_scheduler.h.

template<class SwappableBlockType >

typedef int_type stxxl::block_scheduler< SwappableBlockType >::time_type [protected]

Definition at line 253 of file block_scheduler.h.

Member Enumeration Documentation

template<class SwappableBlockType >

enum stxxl::block_scheduler::block_scheduler_operation

Enumerator:

op_acquire
op_acquire_uninitialized
op_release
op_release_dirty
op_deinitialize
op_initialize
op_extract_external_block

Definition at line 271 of file block_scheduler.h.

Constructor & Destructor Documentation

template<class SwappableBlockType >

stxxl::block_scheduler< SwappableBlockType >::block_scheduler ( const int_type max_internal_memory ) [inline, explicit]

create a block_scheduler with empty prediction sequence in simple mode.

Parameters:

max_internal_memory Amount of internal memory (in bytes) the scheduler is allowed to use for acquiring, prefetching and caching.

Definition at line 350 of file block_scheduler.h.

template<class SwappableBlockType >

stxxl::block_scheduler< SwappableBlockType >::~block_scheduler ( ) [inline]

Definition at line 357 of file block_scheduler.h.

Member Function Documentation

template<class SwappableBlockType >

internal_block_type& stxxl::block_scheduler< SwappableBlockType >::acquire	(	const swappable_block_identifier_type	sbid,
		const bool	uninitialized = `false`
	)		`[inline]`

Acquire the given block. Has to be in pairs with release. Pairs may be nested and interleaved.

Returns:: Reference to the block's data.

Parameters:

sblock Swappable block to acquire.

Definition at line 384 of file block_scheduler.h.

Referenced by stxxl::matrix_operations< ValueType, BlockSideLength >::element_op_swappable_block(), stxxl::matrix_operations< ValueType, BlockSideLength >::matrix_col_vector_multiply_and_add_swappable_block(), stxxl::matrix_operations< ValueType, BlockSideLength >::matrix_from_vectors_swappable_block(), stxxl::matrix_operations< ValueType, BlockSideLength >::matrix_row_vector_multiply_and_add_swappable_block(), and stxxl::matrix_operations< ValueType, BlockSideLength >::multiply_and_add_swappable_block().

template<class SwappableBlockType >

swappable_block_identifier_type stxxl::block_scheduler< SwappableBlockType >::allocate_swappable_block ( ) [inline]

Allocate an uninitialized swappable_block.

Returns:: An identifier of the block.

Definition at line 431 of file block_scheduler.h.

Referenced by stxxl::swappable_block_matrix< ValueType, BlockSideLength >::swappable_block_matrix().

template<class SwappableBlockType >

void stxxl::block_scheduler< SwappableBlockType >::deinitialize ( const swappable_block_identifier_type sbid ) [inline]

Drop all data in the given block, freeing in- and external memory.

Definition at line 395 of file block_scheduler.h.

Referenced by stxxl::matrix_operations< ValueType, BlockSideLength >::element_op_swappable_block().

template<class SwappableBlockType >

void stxxl::block_scheduler< SwappableBlockType >::explicit_timestep ( ) [inline]

Record a timestep in the prediction sequence to seperate consecutive acquire rsp. release-operations. Has an effect only in simulation mode.

Definition at line 421 of file block_scheduler.h.

template<class SwappableBlockType >

external_block_type stxxl::block_scheduler< SwappableBlockType >::extract_external_block ( const swappable_block_identifier_type sbid ) [inline]

deinitialize the swappable_block and return it's contents in an external_block.

Parameters:

sbid	identifier to the swappable_block

Returns:: external_block a.k.a. bid

Definition at line 410 of file block_scheduler.h.

template<class SwappableBlockType >

void stxxl::block_scheduler< SwappableBlockType >::flush ( ) [inline]

Definition at line 479 of file block_scheduler.h.

References stxxl::request_ptr::valid().

template<class SwappableBlockType >

void stxxl::block_scheduler< SwappableBlockType >::free_swappable_block ( const swappable_block_identifier_type sbid ) [inline]

Free given no longer used temporary swappable_block.

Parameters:

sblock Temporary swappable_block to free.

Definition at line 452 of file block_scheduler.h.

template<class SwappableBlockType >

internal_block_type* stxxl::block_scheduler< SwappableBlockType >::get_free_internal_block ( ) [inline, protected]

Get an internal_block from the freelist or a newly allocated one if available.

Returns:: Pointer to the internal_block. NULL if none available.

Definition at line 316 of file block_scheduler.h.

template<class SwappableBlockType >

internal_block_type& stxxl::block_scheduler< SwappableBlockType >::get_internal_block ( const swappable_block_identifier_type sbid ) const [inline]

Get a const reference to given block's data. Block has to be already acquired.

Parameters:

sblock Swappable block to access.

Definition at line 426 of file block_scheduler.h.

template<class SwappableBlockType >

const prediction_sequence_type& stxxl::block_scheduler< SwappableBlockType >::get_prediction_sequence ( ) const [inline]

get the prediction_sequence

Returns:: reference to the prediction_sequence

Definition at line 476 of file block_scheduler.h.

References stxxl::block_scheduler_algorithm< SwappableBlockType >::get_prediction_sequence().

template<class SwappableBlockType >

void stxxl::block_scheduler< SwappableBlockType >::initialize	(	const swappable_block_identifier_type	sbid,
		external_block_type	eblock
	)		`[inline]`

Initialize the swappable_block with the given external_block.

It will use the the external_block for swapping and take care about it's deallocation. Has to be uninitialized.

Parameters:

sbid	identifier to the swappable_block
eblock	external_block a.k.a. bid

Definition at line 403 of file block_scheduler.h.

template<class SwappableBlockType >

bool stxxl::block_scheduler< SwappableBlockType >::is_initialized ( const swappable_block_identifier_type sbid ) const [inline]

check if the swappable_block is initialized

Parameters:

sbid	identifier to the swappable_block

Returns:: if the swappable_block is initialized

Definition at line 416 of file block_scheduler.h.

Referenced by stxxl::matrix_operations< ValueType, BlockSideLength >::element_op_swappable_block(), stxxl::matrix_operations< ValueType, BlockSideLength >::matrix_col_vector_multiply_and_add_swappable_block(), stxxl::matrix_operations< ValueType, BlockSideLength >::matrix_row_vector_multiply_and_add_swappable_block(), and stxxl::matrix_operations< ValueType, BlockSideLength >::multiply_and_add_swappable_block().

template<class SwappableBlockType >

bool stxxl::block_scheduler< SwappableBlockType >::is_simulating ( ) const [inline]

Returns if simulation mode is on, i.e. if a prediction sequence is being recorded.

Returns:: If simulation mode is on.

Definition at line 460 of file block_scheduler.h.

Referenced by stxxl::matrix_operations< ValueType, BlockSideLength >::element_op_swappable_block(), stxxl::matrix_operations< ValueType, BlockSideLength >::matrix_col_vector_multiply_and_add_swappable_block(), stxxl::matrix_operations< ValueType, BlockSideLength >::matrix_from_vectors_swappable_block(), stxxl::matrix_operations< ValueType, BlockSideLength >::matrix_row_vector_multiply_and_add_swappable_block(), stxxl::matrix_operations< ValueType, BlockSideLength >::multiply_and_add_swappable_block(), and stxxl::matrix< ValueType, BlockSideLength >::multiply_internal().

template<class SwappableBlockType >

void stxxl::block_scheduler< SwappableBlockType >::release	(	const swappable_block_identifier_type	sbid,
		const bool	dirty
	)		`[inline]`

Release the given block. Has to be in pairs with acquire. Pairs may be nested and interleaved.

Parameters:

sblock	Swappable block to release.
dirty	If the data has been changed, invalidating possible data in external storage.

Definition at line 391 of file block_scheduler.h.

Referenced by stxxl::matrix_operations< ValueType, BlockSideLength >::element_op_swappable_block(), stxxl::matrix_operations< ValueType, BlockSideLength >::matrix_col_vector_multiply_and_add_swappable_block(), stxxl::matrix_operations< ValueType, BlockSideLength >::matrix_from_vectors_swappable_block(), stxxl::matrix_operations< ValueType, BlockSideLength >::matrix_row_vector_multiply_and_add_swappable_block(), and stxxl::matrix_operations< ValueType, BlockSideLength >::multiply_and_add_swappable_block().

template<class SwappableBlockType >

void stxxl::block_scheduler< SwappableBlockType >::return_free_internal_block ( internal_block_type * iblock ) [inline, protected]

Return an internal_block to the freelist.

Definition at line 344 of file block_scheduler.h.

template<class SwappableBlockType >

block_scheduler_algorithm<SwappableBlockType>* stxxl::block_scheduler< SwappableBlockType >::switch_algorithm_to ( block_scheduler_algorithm< SwappableBlockType > * new_algo ) [inline]

Switch the used algorithm, e.g. to simulation etc..

Parameters:

new_algo Pointer to the new algorithm object. Has to be instantiated to the block scheduler (or the old algorithm object).

Returns:: Pointer to the old algorithm object.

Definition at line 466 of file block_scheduler.h.

References stxxl::block_scheduler_algorithm< SwappableBlockType >::bs.

Member Data Documentation

template<class SwappableBlockType >

block_scheduler_algorithm<SwappableBlockType>* stxxl::block_scheduler< SwappableBlockType >::algo [protected]

Definition at line 312 of file block_scheduler.h.

template<class SwappableBlockType >

block_manager* stxxl::block_scheduler< SwappableBlockType >::bm [protected]

Definition at line 311 of file block_scheduler.h.

template<class SwappableBlockType >

std::stack<internal_block_type * > stxxl::block_scheduler< SwappableBlockType >::free_internal_blocks [protected]

holds free internal_blocks with attributes reset

Definition at line 305 of file block_scheduler.h.

template<class SwappableBlockType >

std::priority_queue<swappable_block_identifier_type, std::vector<swappable_block_identifier_type>, std::greater<swappable_block_identifier_type> > stxxl::block_scheduler< SwappableBlockType >::free_swappable_blocks [protected]

holds indices of free swappable_blocks with attributes reset

Definition at line 310 of file block_scheduler.h.

template<class SwappableBlockType >

std::stack<internal_block_type *> stxxl::block_scheduler< SwappableBlockType >::internal_blocks_blocks [protected]

Stores pointers to arrays of internal_blocks. Used to deallocate them only.

Definition at line 303 of file block_scheduler.h.

template<class SwappableBlockType >

const int_type stxxl::block_scheduler< SwappableBlockType >::max_internal_blocks [protected]

Definition at line 300 of file block_scheduler.h.

template<class SwappableBlockType >

const int_type stxxl::block_scheduler< SwappableBlockType >::max_internal_blocks_alloc_at_once = 128 [static, protected]

Definition at line 251 of file block_scheduler.h.

template<class SwappableBlockType >

int_type stxxl::block_scheduler< SwappableBlockType >::remaining_internal_blocks [protected]

Definition at line 301 of file block_scheduler.h.

template<class SwappableBlockType >

std::vector<SwappableBlockType> stxxl::block_scheduler< SwappableBlockType >::swappable_blocks [mutable, protected]

temporary blocks that will not be needed after algorithm termination

Definition at line 307 of file block_scheduler.h.

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

include/stxxl/bits/mng/block_scheduler.h

Classes

Public Types

Public Member Functions

Protected Types

Protected Member Functions

Protected Attributes

Static Protected Attributes

Detailed Description

template<class SwappableBlockType> class stxxl::block_scheduler< SwappableBlockType >

Member Typedef Documentation

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation

template<class SwappableBlockType>
class stxxl::block_scheduler< SwappableBlockType >