request_interface Class Reference

Functional interface of a request. More...

#include <request_interface.h>

Inheritance diagram for request_interface:

Public Types
enum	request_type { READ, WRITE }
typedef stxxl::external_size_type	offset_type
typedef stxxl::internal_size_type	size_type

Public Member Functions
virtual bool	add_waiter (onoff_switch *sw)=0
virtual void	delete_waiter (onoff_switch *sw)=0
virtual void	serve ()=0
virtual void	wait (bool measure_time=true)=0
	Suspends calling thread until completion of the request. More...
virtual bool	cancel ()=0
	Cancel a request. More...
virtual bool	poll ()=0
	Polls the status of the request. More...
virtual const char *	io_type () const =0
	Identifies the type of I/O implementation. More...
virtual std::ostream &	print (std::ostream &out) const =0
	Dumps properties of a request. More...

Protected Member Functions
virtual void	notify_waiters ()=0
virtual void	completed ()=0

Detailed Description

Functional interface of a request.

Since all library I/O operations are asynchronous, one needs to keep track of their status: e.g. whether an I/O operation completed or not.

Member Function Documentation

virtual bool request_interface::cancel ( )

pure virtual

Cancel a request.

The request is canceled unless already being processed. However, cancelation cannot be guaranteed. Canceled requests must still be waited for in order to ensure correct operation. If the request was canceled successfully, the completion handler will not be called.

Returns

true iff the request was canceled successfully

Implemented in request_with_state.

virtual const char* request_interface::io_type ( ) const

pure virtual

Identifies the type of I/O implementation.

Returns

pointer to null terminated string of characters, containing the name of I/O implementation

Implemented in serving_request.

virtual bool request_interface::poll ( )

pure virtual

Polls the status of the request.

Returns

true if request is completed, otherwise false

Implemented in request_with_state.

Referenced by buffered_writer< typed_block >::get_free_block().

virtual std::ostream& request_interface::print ( std::ostream &  out ) const

pure virtual

Dumps properties of a request.

Implemented in request.

virtual void request_interface::wait ( bool  measure_time = true )

pure virtual

Suspends calling thread until completion of the request.

Implemented in request_with_state.

Referenced by block_prefetcher< block_type, bid_iterator_type >::block_consumed(), buffered_writer< typed_block >::flush(), ksort(), fileperblock_file< base_file_type >::lock(), stream::runs_creator< use_push< ValueType_ >, Cmp_, BlockSize_, AllocStr_ >::push(), sort(), stable_ksort(), buffered_writer< typed_block >::write(), block_prefetcher< block_type, bid_iterator_type >::~block_prefetcher(), and buffered_writer< typed_block >::~buffered_writer().

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

• request_interface.h