In the data flow implementation, a channel is created by chaining ChannelElementBase objects. More...

#include <rtt/base/ChannelElementBase.hpp>

Inheritance diagram for RTT::base::ChannelElementBase:

Public Types
typedef boost::intrusive_ptr < ChannelElementBase >	shared_ptr
Public Member Functions
	ChannelElementBase ()
	A default constructed ChannelElementBase has no input nor output configured.
void	removeInput ()
	Removes the input channel (if any).
ChannelElementBase::shared_ptr	getInput ()
	Returns the current input channel element.
ChannelElementBase::shared_ptr	getInputEndPoint ()
	Returns the first input channel element of this connection.
ChannelElementBase::shared_ptr	getOutput ()
	Returns the next channel element in the channel's propagation direction.
ChannelElementBase::shared_ptr	getOutputEndPoint ()
	Returns the last output channel element of this connection.
void	setOutput (shared_ptr output)
	Sets the output of this channel element to output and sets the input of output to this.
virtual bool	signal ()
	Signals that there is new data available on this channel By default, the channel element forwards the call to its output.
virtual bool	inputReady ()
	This is called by an input port when it is ready to receive data.
virtual void	clear ()
	Clears any data stored by the channel.
virtual void	disconnect (bool forward)
	Performs a disconnection of this channel's endpoints.
virtual PortInterface *	getPort () const
	Gets the port this channel element is connected to.
Protected Member Functions
void	ref ()
	Increases the reference count.
void	deref ()
	Decreases the reference count, and deletes the object if it is zero.
Friends
void RTT_API	intrusive_ptr_add_ref (ChannelElementBase *e)
void RTT_API	intrusive_ptr_release (ChannelElementBase *e)

Detailed Description

In the data flow implementation, a channel is created by chaining ChannelElementBase objects.

ChannelElementBase objects are refcounted. In the chain, an element maintains the refcount for its successor, and holds a simple pointer to its predecessor.

Definition at line 59 of file ChannelElementBase.hpp.

Constructor & Destructor Documentation

ChannelElementBase::ChannelElementBase ( )

A default constructed ChannelElementBase has no input nor output configured.

The only way to set an input or output is to use setOutput().

Definition at line 46 of file ChannelInterface.cpp.

References ORO_ATOMIC_SETUP().

Member Function Documentation

void ChannelElementBase::clear ( ) [virtual]

Clears any data stored by the channel.

It means that ChannelElement::read() will return false afterwards (provided that no new data has been written on the meantime of course)

By default, the channel element forwards the calls to its input

Reimplemented in RTT::internal::ChannelBufferElement< T >, and RTT::internal::ChannelDataElement< T >.

Definition at line 116 of file ChannelInterface.cpp.

References getInput().

void ChannelElementBase::disconnect ( bool forward ) [virtual]

Performs a disconnection of this channel's endpoints.

If forward is true, then the disconnection is initiated by the input endpoint. Otherwise, it has been initiated by the output endpoint.

Reimplemented in RTT::corba::RemoteChannelElement< T >, RTT::internal::ConnOutputEndpoint< T >, and RTT::internal::ConnInputEndpoint< T >.

Definition at line 75 of file ChannelInterface.cpp.

References getInput(), and getOutput().

ChannelElementBase::shared_ptr ChannelElementBase::getInput ( )

Returns the current input channel element.

This will only return a valid channel element if another element has received this object as an argument to setOutput().

Returns:

Reimplemented in RTT::base::ChannelElement< T >.

Definition at line 58 of file ChannelInterface.cpp.

Referenced by clear(), disconnect(), getInputEndPoint(), and inputReady().

ChannelElementBase::shared_ptr ChannelElementBase::getInputEndPoint ( )

Returns the first input channel element of this connection.

Will return the channel element the furthest away from the input port, or this if none.

Returns:: getInput() ? getInput()->getInputEndPoint() : this

Definition at line 96 of file ChannelInterface.cpp.

References getInput().

ChannelElementBase::shared_ptr ChannelElementBase::getOutputEndPoint ( )

Returns the last output channel element of this connection.

Will return the channel element the furthest away from the output port, or this if none.

Returns:: getOutput() ? getOutput()->getInputEndPoint() : this

Definition at line 101 of file ChannelInterface.cpp.

References getOutput().

PortInterface * ChannelElementBase::getPort ( ) const [virtual]

Gets the port this channel element is connected to.

Returns:: null if no port is connected to this element, the port (or a proxy representing the port) otherwise.

Reimplemented in RTT::internal::ConnOutputEndpoint< T >, and RTT::internal::ConnInputEndpoint< T >.

Definition at line 131 of file ChannelInterface.cpp.

bool ChannelElementBase::inputReady ( ) [virtual]

This is called by an input port when it is ready to receive data.

Each channel element has the responsibility to pass this notification on to the next, in the direction of the output.

Returns:: false if a fatal connection failure was encountered and the channel needs to be destroyed.

Reimplemented in RTT::corba::RemoteChannelElement< T >, RTT::mqueue::MQChannelElement< T >, RTT::internal::ConnOutputEndpoint< T >, and RTT::internal::ConnInputEndpoint< T >.

Definition at line 107 of file ChannelInterface.cpp.

References getInput().

void RTT::base::ChannelElementBase::removeInput ( )

Removes the input channel (if any).

This call may delete channels from memory.

void ChannelElementBase::setOutput ( shared_ptr output )

Sets the output of this channel element to output and sets the input of output to this.

This implies that this channel element becomes the input of output. There is no setInput function since this function does both setting input and output of this and output.

Parameters:

output the next element in chain.

Definition at line 68 of file ChannelInterface.cpp.

Referenced by RTT::internal::ConnFactory::buildBufferedChannelInput(), RTT::internal::ConnFactory::buildBufferedChannelOutput(), and RTT::internal::ConnFactory::buildChannelInput().

bool ChannelElementBase::signal ( ) [virtual]

Signals that there is new data available on this channel By default, the channel element forwards the call to its output.

Returns:: false if an error occured that requires the channel to be invalidated. In no ways it indicates that the sample has been received by the other side of the channel.

Reimplemented in RTT::mqueue::MQChannelElement< T >, RTT::corba::RemoteChannelElement< T >, and RTT::internal::ConnOutputEndpoint< T >.

Definition at line 123 of file ChannelInterface.cpp.

References getOutput().

Referenced by RTT::internal::ChannelDataElement< T >::write(), and RTT::internal::ChannelBufferElement< T >::write().

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

rtt/base/ChannelElementBase.hpp
rtt/base/ChannelInterface.cpp

Public Types

Public Member Functions

Protected Member Functions

Friends

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation