AsyncIOTask Class Reference

An object representing an asynchronous I/O operation. More...

#include <AsyncIOTask.h++>

List of all members.

Public Member Functions
	AsyncIOTask ()
	Construct a new AsyncIOTask.
	~AsyncIOTask ()
	Destructor.
bool	isCompleted () throw (IOException, InterruptedException)
	Determine if the asynchronous I/O task has completed (either successfully or with an error); and, if so, determine the result of the operation.
void	cancel () throw (IOException)
	Attempt to cancel the asynchronous I/O task.
void	waitFor (timespan_ms_t timeout) throw (IOException, InterruptedException)
	Wait for an asynchronous I/O task to complete.
size_t	getBytesTransferred () throw ()
	Get the number of bytes transferred by the I/O task.
Friends
class	Stream
class	AsyncIOPoller

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Detailed Description

An object representing an asynchronous I/O operation.

Author:

Mark Lindner

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Constructor & Destructor Documentation

AsyncIOTask

(

)

Construct a new AsyncIOTask.

The to collect the results of the task, either:

• Periodically call isCompleted() until that method returns true, or
• Call waitFor() to block until the operation completes.

~AsyncIOTask

(

)

Destructor.

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Member Function Documentation

void cancel

(

)

throw (IOException)

Attempt to cancel the asynchronous I/O task.

Whether a given I/O task is actually cancellable is implementation-defined. Note that due to limitations in the Win32 API, on Windows versions prior to Vista this call will cancel all pending asynchronous I/O operations for the stream associated with this task.

Exceptions:

IOException

If the task could not be cancelled.

size_t getBytesTransferred

(

)

throw ()

Get the number of bytes transferred by the I/O task.

This method should only be called after it has been determined that the task has completed via a call to isCompleted().

Returns:

The number of bytes that were transferred. Returns 0 if the operation is still in progress, or if its result has not yet been collected via a call to isCompleted().

bool isCompleted

(

)

throw (IOException, InterruptedException)

Determine if the asynchronous I/O task has completed (either successfully or with an error); and, if so, determine the result of the operation.

If the I/O task involved a ByteBuffer, that buffer's position is bumped by the number of bytes that were transferred.

Returns:

true if the task has completed; false if it is still in progress.

Exceptions:

	IOException	If an I/O error occurred during the operation.
	InterruptedException	If the I/O task was cancelled via a call to cancel().

void waitFor

(

timespan_ms_t

timeout

)

throw (IOException, InterruptedException)

Wait for an asynchronous I/O task to complete.

Parameters:

timeout

The maximum amount of time to wait, in milliseconds.

Exceptions:

	TimeoutException	If the operation times out.
	IOException	If an I/O error occurred during the operation.
	InterruptedException	If the I/O task was cancelled via a call to cancel().

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Friends And Related Function Documentation

friend class AsyncIOPoller [friend]

friend class Stream [friend]

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

• AsyncIOTask.h++
• AsyncIOTask.c++