TAO_Synch_Queued_Message Class Reference

Specialize TAO_Queued_Message for synchronous requests, i.e. twoways and oneways sent with reliability better than SYNC_NONE. More...

#include <Synch_Queued_Message.h>

Inheritance diagram for TAO_Synch_Queued_Message:

Collaboration diagram for TAO_Synch_Queued_Message:

List of all members.

Public Member Functions
	TAO_Synch_Queued_Message (const ACE_Message_Block *contents, TAO_ORB_Core *oc, ACE_Allocator *alloc=0, bool is_heap_allocated=false)
	Constructor.
virtual	~TAO_Synch_Queued_Message (void)
	Destructor.
const ACE_Message_Block *	current_block (void) const
Implement the Template Methods from TAO_Queued_Message
virtual size_t	message_length (void) const
	Return the length of the message.
virtual int	all_data_sent (void) const
	Return 1 if all the data has been sent.
virtual void	fill_iov (int iovcnt_max, int &iovcnt, iovec iov[]) const
	Fill up an io vector using the connects of the message.
virtual void	bytes_transferred (size_t &byte_count)
	Update the internal state, data has been sent.
virtual TAO_Queued_Message *	clone (ACE_Allocator *alloc)
	Clone this element.
virtual void	destroy (void)
	Reclaim resources.
virtual void	copy_if_necessary (const ACE_Message_Block *chain)
	Provide a hook for copying the underlying data.
Private Attributes
ACE_Message_Block *	contents_
	The contents of the message.
ACE_Message_Block *	current_block_
	The current message block.
bool	own_contents_
	Do we own the contents_ message block?

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Detailed Description

Specialize TAO_Queued_Message for synchronous requests, i.e. twoways and oneways sent with reliability better than SYNC_NONE.

Reliable requests block the sending thread until the message is sent, likewise, the sending thread must be informed if the connection is closed or the message times out.

In contrast oneway (and AMI) requests sent with the SYNC_NONE policy are simple discarded if the connection fails or they timeout.

Another important difference is the management of the data buffer: one SYNC_NONE messages the buffer is immediately copied into a newly allocated buffer, and must be deallocated. Other types of requests use the memory allocated by the sending thread.

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Constructor & Destructor Documentation

TAO_Synch_Queued_Message::TAO_Synch_Queued_Message	(	const ACE_Message_Block *	contents,
		TAO_ORB_Core *	oc,
		ACE_Allocator *	alloc = 0,
		bool	is_heap_allocated = false
	)

Constructor.

Parameters:

contents	The message block chain that must be sent.
alloc	The allocator that is used to allocate objects of this type.

TAO_Synch_Queued_Message::~TAO_Synch_Queued_Message

(

void

)

[virtual]

Destructor.

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Member Function Documentation

int TAO_Synch_Queued_Message::all_data_sent

(

void

)

const [virtual]

Return 1 if all the data has been sent.

Implements TAO_Queued_Message.

void TAO_Synch_Queued_Message::bytes_transferred

(

size_t &

byte_count

)

[virtual]

Update the internal state, data has been sent.

After the TAO_Transport class completes a successful (or partially successful) I/O operation it must update the state of all the messages queued. This callback method is used by each message to update its state and determine if all the data has been sent already.

Parameters:

byte_count

The number of bytes successfully sent. The TAO_Queued_Message should decrement this value by the number of bytes that must still be sent.

Returns:

Returns 1 if the TAO_Queued_Message has any more data to send.

Implements TAO_Queued_Message.

TAO_Queued_Message * TAO_Synch_Queued_Message::clone

(

ACE_Allocator *

allocator

)

[virtual]

Clone this element.

Implements TAO_Queued_Message.

void TAO_Synch_Queued_Message::copy_if_necessary

(

const ACE_Message_Block *

chain

)

[virtual]

Provide a hook for copying the underlying data.

Parameters:

chain

For use in determining origin of underlying data. This parameter must not be modified (through const_cast).

Implements TAO_Queued_Message.

const ACE_Message_Block * TAO_Synch_Queued_Message::current_block

(

void

)

const

void TAO_Synch_Queued_Message::destroy

(

void

)

[virtual]

Reclaim resources.

Reliable messages are allocated from the stack, thus they do not be deallocated. Asynchronous (SYNC_NONE) messages are allocated from the heap (or a pool), they need to be reclaimed explicitly.

Implements TAO_Queued_Message.

void TAO_Synch_Queued_Message::fill_iov	(	int	iovcnt_max,
		int &	iovcnt,
		iovec	iov[]
	)		const [virtual]

Fill up an io vector using the connects of the message.

Different versions of this class represent the message using either a single buffer, or a message block. This method allows a derived class to fill up the contents of an io vector, the TAO_Transport class uses this method to group as many messages as possible in an iovector before sending them to the OS I/O subsystem.

Parameters:

iovcnt_max	The number of elements in iov
iovcnt	The number of elements already used by iov, this method should update this counter
iov	The io vector

Implements TAO_Queued_Message.

size_t TAO_Synch_Queued_Message::message_length

(

void

)

const [virtual]

Return the length of the message.

If the message has been partially sent it returns the number of bytes that are still not sent.

Implements TAO_Queued_Message.

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Member Data Documentation

ACE_Message_Block* TAO_Synch_Queued_Message::contents_ [private]

The contents of the message.

The message is normally generated by a TAO_OutputCDR stream. The application marshals the payload, possibly generating a chain of message block connected via the 'cont()' field.

ACE_Message_Block* TAO_Synch_Queued_Message::current_block_ [private]

The current message block.

The message may be set in multiple writev() operations. This point keeps track of the next message to send out.

bool TAO_Synch_Queued_Message::own_contents_ [private]

Do we own the contents_ message block?

This flag differs from the is_heap_allocated_ flag in that it only applies to the contents_ message block and not the TAO_Synch_Queued_Message object itself.

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

• Synch_Queued_Message.h
• Synch_Queued_Message.cpp