stxxl::block_prefetcher< block_type, bid_iterator_type > Class Template Reference

Encapsulates asynchronous prefetching engine. More...

#include <block_prefetcher.h>

Collaboration diagram for stxxl::block_prefetcher< block_type, bid_iterator_type >:

List of all members.

Public Member Functions
	block_prefetcher (bid_iterator_type _cons_begin, bid_iterator_type _cons_end, int_type *_pref_seq, int_type _prefetch_buf_size, completion_handler do_after_fetch=default_completion_handler())
	Constructs an object and immediately starts prefetching.
block_type *	pull_block ()
	Pulls next unconsumed block from the consumption sequence.
bool	block_consumed (block_type *&buffer)
	Exchanges buffers between prefetcher and application.
bool	empty () const
unsigned_type	pos () const
	~block_prefetcher ()
	Frees used memory.
Protected Member Functions
block_type *	wait (int_type iblock)
Protected Attributes
bid_iterator_type	consume_seq_begin
bid_iterator_type	consume_seq_end
unsigned_type	seq_length
int_type *	prefetch_seq
unsigned_type	nextread
unsigned_type	nextconsume
const int_type	nreadblocks
block_type *	read_buffers
request_ptr *	read_reqs
bid_type *	read_bids
onoff_switch *	completed
int_type *	pref_buffer
completion_handler	do_after_fetch
Private Types
typedef block_type::bid_type	bid_type
Private Member Functions
	block_prefetcher ()

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Detailed Description

template<typename block_type, typename bid_iterator_type>
class stxxl::block_prefetcher< block_type, bid_iterator_type >

Encapsulates asynchronous prefetching engine.

block_prefetcher overlaps I/Os with consumption of read data. Utilizes optimal asynchronous prefetch scheduling (by Peter Sanders et.al.)

Definition at line 54 of file block_prefetcher.h.

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Member Typedef Documentation

template<typename block_type , typename bid_iterator_type >

typedef block_type::bid_type stxxl::block_prefetcher< block_type, bid_iterator_type >::bid_type [private]

Definition at line 57 of file block_prefetcher.h.

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Constructor & Destructor Documentation

template<typename block_type , typename bid_iterator_type >

stxxl::block_prefetcher< block_type, bid_iterator_type >::block_prefetcher

(

)

[inline, private]

Definition at line 56 of file block_prefetcher.h.

template<typename block_type , typename bid_iterator_type >

stxxl::block_prefetcher< block_type, bid_iterator_type >::block_prefetcher	(	bid_iterator_type	_cons_begin,
		bid_iterator_type	_cons_end,
		int_type *	_pref_seq,
		int_type	_prefetch_buf_size,
		completion_handler	do_after_fetch = default_completion_handler()
	)		[inline]

Constructs an object and immediately starts prefetching.

Parameters:

_cons_begin	bid_iterator pointing to the bid of the first block to be consumed
_cons_end	bid_iterator pointing to the bid of the ( last + 1 ) block of consumption sequence
_pref_seq	gives the prefetch order, is a pointer to the integer array that contains the indices of the blocks in the consumption sequence
_prefetch_buf_size	amount of prefetch buffers to use

Definition at line 102 of file block_prefetcher.h.

template<typename block_type , typename bid_iterator_type >

stxxl::block_prefetcher< block_type, bid_iterator_type >::~block_prefetcher

(

)

[inline]

Frees used memory.

Definition at line 208 of file block_prefetcher.h.

References stxxl::block_prefetcher< block_type, bid_iterator_type >::wait().

---

Member Function Documentation

template<typename block_type , typename bid_iterator_type >

bool stxxl::block_prefetcher< block_type, bid_iterator_type >::block_consumed

(

block_type *&

buffer

)

[inline]

Exchanges buffers between prefetcher and application.

Parameters:

buffer

pointer to the consumed buffer. After call if return value is true buffer contains valid pointer to the next unconsumed prefetched buffer.

Remarks:

parameter buffer must be value returned by pull_block() or block_consumed() methods

Returns:

false if there are no blocks to prefetch left, true if consumption sequence is not emptied

Definition at line 159 of file block_prefetcher.h.

template<typename block_type , typename bid_iterator_type >

bool stxxl::block_prefetcher< block_type, bid_iterator_type >::empty

(

)

const [inline]

Definition at line 196 of file block_prefetcher.h.

template<typename block_type , typename bid_iterator_type >

unsigned_type stxxl::block_prefetcher< block_type, bid_iterator_type >::pos

(

)

const [inline]

Definition at line 202 of file block_prefetcher.h.

template<typename block_type , typename bid_iterator_type >

block_type* stxxl::block_prefetcher< block_type, bid_iterator_type >::pull_block

(

)

[inline]

Pulls next unconsumed block from the consumption sequence.

Returns:

Pointer to the already prefetched block from the internal buffer pool

Definition at line 149 of file block_prefetcher.h.

Referenced by stxxl::stream::basic_runs_merger< sorted_runs_type, CompareType_, AllocStr_ >::initialize().

template<typename block_type , typename bid_iterator_type >

block_type* stxxl::block_prefetcher< block_type, bid_iterator_type >::wait

(

int_type

iblock

)

[inline, protected]

Definition at line 80 of file block_prefetcher.h.

Referenced by stxxl::block_prefetcher< block_type, bid_iterator_type >::~block_prefetcher().

---

Member Data Documentation

template<typename block_type , typename bid_iterator_type >

onoff_switch* stxxl::block_prefetcher< block_type, bid_iterator_type >::completed [protected]

Definition at line 75 of file block_prefetcher.h.

template<typename block_type , typename bid_iterator_type >

bid_iterator_type stxxl::block_prefetcher< block_type, bid_iterator_type >::consume_seq_begin [protected]

Definition at line 60 of file block_prefetcher.h.

template<typename block_type , typename bid_iterator_type >

bid_iterator_type stxxl::block_prefetcher< block_type, bid_iterator_type >::consume_seq_end [protected]

Definition at line 61 of file block_prefetcher.h.

template<typename block_type , typename bid_iterator_type >

completion_handler stxxl::block_prefetcher< block_type, bid_iterator_type >::do_after_fetch [protected]

Definition at line 78 of file block_prefetcher.h.

template<typename block_type , typename bid_iterator_type >

unsigned_type stxxl::block_prefetcher< block_type, bid_iterator_type >::nextconsume [protected]

Definition at line 67 of file block_prefetcher.h.

template<typename block_type , typename bid_iterator_type >

unsigned_type stxxl::block_prefetcher< block_type, bid_iterator_type >::nextread [protected]

Definition at line 66 of file block_prefetcher.h.

template<typename block_type , typename bid_iterator_type >

const int_type stxxl::block_prefetcher< block_type, bid_iterator_type >::nreadblocks [protected]

Definition at line 69 of file block_prefetcher.h.

template<typename block_type , typename bid_iterator_type >

int_type* stxxl::block_prefetcher< block_type, bid_iterator_type >::pref_buffer [protected]

Definition at line 76 of file block_prefetcher.h.

template<typename block_type , typename bid_iterator_type >

int_type* stxxl::block_prefetcher< block_type, bid_iterator_type >::prefetch_seq [protected]

Definition at line 64 of file block_prefetcher.h.

template<typename block_type , typename bid_iterator_type >

bid_type* stxxl::block_prefetcher< block_type, bid_iterator_type >::read_bids [protected]

Definition at line 73 of file block_prefetcher.h.

template<typename block_type , typename bid_iterator_type >

block_type* stxxl::block_prefetcher< block_type, bid_iterator_type >::read_buffers [protected]

Definition at line 71 of file block_prefetcher.h.

template<typename block_type , typename bid_iterator_type >

request_ptr* stxxl::block_prefetcher< block_type, bid_iterator_type >::read_reqs [protected]

Definition at line 72 of file block_prefetcher.h.

template<typename block_type , typename bid_iterator_type >

unsigned_type stxxl::block_prefetcher< block_type, bid_iterator_type >::seq_length [protected]

Definition at line 62 of file block_prefetcher.h.

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

• include/stxxl/bits/mng/block_prefetcher.h