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TAO_LF_Event Class Reference

Use the Leader/Follower loop to wait for one specific event. More...

#include <LF_Event.h>

Inheritance diagram for TAO_LF_Event:

[legend]Collaboration diagram for TAO_LF_Event:

[legend]List of all members.

State management
A Leader/Followers event goes through several states during its lifetime. We use an enum to represent those states and state changes are validated according to the rules below.
enum	{   LFS_IDLE, LFS_ACTIVE, LFS_CONNECTION_WAIT, LFS_SUCCESS,   LFS_FAILURE, LFS_TIMEOUT, LFS_CONNECTION_CLOSED }
void	state_changed (int new_state)
	Change the state. More...
int	successful (void) const
	Return 1 if the condition was satisfied successfully, 0 if it has not. More...
int	error_detected (void) const
	Return 1 if an error was detected while waiting for the event. More...
Public Types
Public Methods
	TAO_LF_Event (void)
	Constructor. More...
virtual	~TAO_LF_Event (void)
	Destructor. More...
int	bind (TAO_LF_Follower *follower)
	An event can be waited on by at most one follower thread, this method is used to bind the waiting thread to the event, in order to let the event signal any important state changes. More...
int	unbind (void)
	Unbind the follower. More...
int	keep_waiting (void)
	Check if we should keep waiting. More...
void	reset_state (int new_state)
	Reset the state, irrespective of the previous states. More...
Protected Methods
void	state_changed_i (int new_state)
	Validate the state change. More...
Private Methods
int	is_state_final (void)
	Check whether we have reached the final state.. More...
void	set_state (int new_state)
	Set the state. More...
Private Attributes
int	state_
	The current state. More...
TAO_LF_Follower *	follower_
	The bound follower thread. More...
Friends
class	TAO_Leader_Follower

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Detailed Description

Use the Leader/Follower loop to wait for one specific event.

The Leader/Follower event loop is used to wait for incoming responses, as well as to wait for all the data to be flushed. This class encapsulates this event loop. It uses Template Method to parametrize the 'waited for' predicate (i.e. reply received or message sent.)

Todo:

Implementing the Leader/Followers loop in this class, as well as the callbacks to communicate that an event has completed leads to excessive coupling. A better design would use a separate class to signal the events, that would allow us to remove the Leader/Followers logic from the ORB. However, that requires other major changes and it somewhat complicates the design.

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Member Enumeration Documentation

anonymous enum

Enumeration values: LFS_IDLE  The event is created, initial state can only move to LFS_ACTIVE or LFS_CONNECTION_WAIT. LFS_ACTIVE  The event is active, can change to any of the following states, each of them is a final state. LFS_CONNECTION_WAIT  The event is waiting for connection completion. It can change to the any of the following states, each of them being a final state. LFS_SUCCESS  The event has completed successfully. LFS_FAILURE  A failure has been detected while the event was active. LFS_TIMEOUT  The event has timed out. LFS_CONNECTION_CLOSED  The connection was closed while the state was active.

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Constructor & Destructor Documentation

TAO_LF_Event::TAO_LF_Event (  void    )

Constructor.

TAO_LF_Event::~TAO_LF_Event (  void    )  [virtual]

Destructor.

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Member Function Documentation

ACE_INLINE int TAO_LF_Event::bind (  TAO_LF_Follower *    follower )

An event can be waited on by at most one follower thread, this method is used to bind the waiting thread to the event, in order to let the event signal any important state changes. Returns: -1 if the LF_Event is already bound, 0 otherwise

int TAO_LF_Event::error_detected (  void    )  const

Return 1 if an error was detected while waiting for the event.

ACE_INLINE int TAO_LF_Event::is_state_final (  void    )  [private]

Check whether we have reached the final state..

ACE_INLINE int TAO_LF_Event::keep_waiting (  void    )

Check if we should keep waiting.

ACE_INLINE void TAO_LF_Event::reset_state (  int    new_state )

Reset the state, irrespective of the previous states.

ACE_INLINE void TAO_LF_Event::set_state (  int    new_state )  [private]

Set the state.

void TAO_LF_Event::state_changed (  int    new_state )

Change the state.

void TAO_LF_Event::state_changed_i (  int    new_state )  [protected]

Validate the state change.

int TAO_LF_Event::successful (  void    )  const

Return 1 if the condition was satisfied successfully, 0 if it has not.

ACE_INLINE int TAO_LF_Event::unbind (  void    )

Unbind the follower.

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Friends And Related Function Documentation

friend class TAO_Leader_Follower [friend]

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Member Data Documentation

TAO_LF_Follower* TAO_LF_Event::follower_ [private]

The bound follower thread.

int TAO_LF_Event::state_ [private]

The current state.

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

• LF_Event.h
• LF_Event.cpp
• LF_Event.inl

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