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ACE_Asynch_Read_File Class Reference

This class is a factory for starting off asynchronous reads on a file. This class forwards all methods to its implementation class. More...

#include <Asynch_IO.h>

Inheritance diagram for ACE_Asynch_Read_File:

[legend]Collaboration diagram for ACE_Asynch_Read_File:

[legend]List of all members.

Public Methods
	ACE_Asynch_Read_File (void)
	A do nothing constructor.
virtual	~ACE_Asynch_Read_File (void)
	Destructor.
int	open (ACE_Handler &handler, ACE_HANDLE handle=ACE_INVALID_HANDLE, const void *completion_key=0, ACE_Proactor *proactor=0)
int	read (ACE_Message_Block &message_block, size_t bytes_to_read, u_long offset=0, u_long offset_high=0, const void *act=0, int priority=0, int signal_number=ACE_SIGRTMIN)
int	readv (ACE_Message_Block &message_block, size_t bytes_to_read, u_long offset=0, u_long offset_high=0, const void *act=0, int priority=0, int signal_number=ACE_SIGRTMIN)
ACE_Asynch_Read_File_Impl *	implementation (void) const
	Return the underlying implementation class.
Protected Methods
void	implementation (ACE_Asynch_Read_File_Impl *implementation)
	Set the implementation class.
Protected Attributes
ACE_Asynch_Read_File_Impl *	implementation_

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Detailed Description

This class is a factory for starting off asynchronous reads on a file. This class forwards all methods to its implementation class.

Once <open> is called, multiple asynchronous <read>s can started using this class. An ACE_Asynch_Read_File::Result will be passed back to the <handler> when the asynchronous reads completes through the <ACE_Handler::handle_read_file> callback. This class differs slightly from ACE_Asynch_Read_Stream as it allows the user to specify an offset for the read.

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Constructor & Destructor Documentation

ACE_Asynch_Read_File::ACE_Asynch_Read_File (  void    )

A do nothing constructor.

ACE_Asynch_Read_File::~ACE_Asynch_Read_File (  void    )  [virtual]

Destructor.

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Member Function Documentation

void ACE_Asynch_Read_File::implementation (  ACE_Asynch_Read_File_Impl *    implementation )  [protected]

Set the implementation class.

ACE_Asynch_Read_File_Impl * ACE_Asynch_Read_File::implementation (  void    )  const

Return the underlying implementation class. Reimplemented from ACE_Asynch_Read_Stream.

int ACE_Asynch_Read_File::open (  ACE_Handler &    handler, ACE_HANDLE    handle = ACE_INVALID_HANDLE, const void *    completion_key = 0, ACE_Proactor *    proactor = 0 )

Initializes the factory with information which will be used with each asynchronous call. If (<handle> == ACE_INVALID_HANDLE), <ACE_Handler::handle> will be called on the <handler> to get the correct handle. Reimplemented from ACE_Asynch_Read_Stream.

int ACE_Asynch_Read_File::read (  ACE_Message_Block &    message_block, size_t    bytes_to_read, u_long    offset = 0, u_long    offset_high = 0, const void *    act = 0, int    priority = 0, int    signal_number = ACE_SIGRTMIN )

This starts off an asynchronous read. Upto <bytes_to_read> will be read and stored in the <message_block>. The read will start at <offset> from the beginning of the file. Priority of the operation is specified by <priority>. On POSIX4-Unix, this is supported. Works like <nice> in Unix. Negative values are not allowed. 0 means priority of the operation same as the process priority. 1 means priority of the operation is one less than process. And so forth. On Win32, this argument is a no-op. <signal_number> is the POSIX4 real-time signal number to be used for the operation. <signal_number> ranges from ACE_SIGRTMIN to ACE_SIGRTMAX. This argument is a no-op on non-POSIX4 systems.

int ACE_Asynch_Read_File::readv (  ACE_Message_Block &    message_block, size_t    bytes_to_read, u_long    offset = 0, u_long    offset_high = 0, const void *    act = 0, int    priority = 0, int    signal_number = ACE_SIGRTMIN )

Same as above but with scatter support, through chaining of composite message blocks using the continuation field. NOTE: In win32 Each data block payload must be at least the size of a system memory page and must be aligned on a system memory page size boundary

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Member Data Documentation

ACE_Asynch_Read_File_Impl* ACE_Asynch_Read_File::implementation_ [protected]

Delegation/implementation class that all methods will be forwarded to. Reimplemented from ACE_Asynch_Read_Stream.

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

• /export2/deucetmp/bala/release_try/ACE_wrappers/ace/Asynch_IO.h
• /export2/deucetmp/bala/release_try/ACE_wrappers/ace/Asynch_IO.cpp

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